Skip to main content
NCBI home page
Springer logoLink to Springer
. 2024 Jun 18;31(30):43066–43079. doi: 10.1007/s11356-024-33926-2

Mycological air contamination level and biodiversity of airborne fungi isolated from the zoological garden air — preliminary research

Kinga Plewa-Tutaj 1,✉, Paweł Krzyściak 2, Aleksandra Dobrzycka 1
PMCID: PMC11222260  PMID: 38890249

Abstract  

The aim of this paper was to evaluate the degree of mycological air contamination and determine the taxonomic diversity of airborne fungi residing in the air of 20 different animal facilities in a zoological garden. The concentrations of fungi in the zoological garden were measured using a MAS-100 air sampler. The collected microorganisms were identified using the combination of molecular and morphological methods. The fungal concentration ranged from 50 to 3.65 × 104 CFU/m3 during the whole study. The quantitative analysis of the fungal aerosol showed that the obtained concentration values were lower than the recommended permissible limits (5 × 104 CFU/m3 for fungi). Environmental factors, including temperature and relative humidity, exerted a varying effect on the presence and concentration of isolated fungi. Relative humidity was shown to correlate positively with the concentration of fungal spores in the air of the facilities studied (rho = 0.57, p < 0.0021). In parallel, no significant correlation was established between temperature and total fungal concentration (rho =  − 0.1, p < 0.2263). A total of 112 fungal strains belonging to 50 species and 10 genera were isolated. Penicillium was the dominant genera, including 58.9% of total fungal strains, followed by Aspergillus 25.89%, Cladosporium 3.57%, Talaromyces 3.57%, Mucor 1.78%, Schizophyllum 1.78%, Syncephalastrum 0.89%, Alternaria 0.89%, Absidia 0.89%, and Cunninghamella 0.89%. Our preliminary studies provide basic information about the fungal concentrations, as well as their biodiversity in zoological garden. Further studies are needed to generate additional data from long-term sampling in order to increase our understanding of airborne fungal composition in the zoological garden.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11356-024-33926-2.

Keywords: Fungi, Microbial air contamination, Molecular identification, Aspergillus, Penicillium, Zoological garden

Introduction

Zoological gardens are one of the most popular attractions visited by tourists worldwide. We should perceive them not only as places where a large diversity of animals is kept, but also as places where people can admire both native and exotic species (Nekolný and Fialová 2018). Both visitors and zoo workers are potentially exposed to bioaerosols which contain bacteria, viruses, pollens, fungi, and mycotoxins (Michalska et al. 2021; Nageen et al. 2023). Among the microorganisms in bioaerosols, fungi are the most numerous group of biological particles (Szulc et al. 2020). Those microorganisms are abundant in the environment and play important roles as symbionts, saprotrophs, or parasites. It is estimated that airborne fungi constitute nearly 25% of the global biomass and, therefore, play a significant role in air pollution affecting human health (almost 150 fungal taxa are associated with allergies) (Nageen et al. 2023).

National and global research about the contamination and the biological diversity of fungi in breeding facilities was carried out mainly in the large-scale poultry houses, barns, and piggeries (Plewa and Lonc 2011; Pusz et al. 2015; Douglas et al. 2018; Seifi et al. 2018; Lee and Kim 2021). Against this background, research on fungal biodiversity and the degree of air and environmental pollution in zoological gardens are scarce (Rivas et al. 2018; Cateau et al. 2022; Álvarez-Pérez et al. 2023; Debergh et al. 2023). The majority of these cited works primarily concentrate on fungi of the genus Aspergillus, with a particular focus on Aspergillus fumigatus, its sensitivity to azole drugs, and the detection of fungi solely in the environment of a single animal group (penguins). They do not usually consider the presence of fungi in other animal habitats and another group of molds. Moreover, the only national study on microbial air contamination was carried out in Krakow’s Zoo (Grzyb and Lenart-Boroń 2019, 2020). The research focused entirely on the determining occurrence of individual bioaerosol (bacterial and fungal) fractions, without taking into account the biodiversity of fungi and their potential toxicity. The studies conducted in animal breeding places other than zoos often showed high concentrations of this group of microorganisms that can be harmful to human and animal health. Among the isolated fungi, the most frequently identified were fungi belonging to the genera Aspergillus (A. fumigatus, A. niger, A. flavus), Penicillium (P. citrinum, P. viridicatum), Cladosporium spp., Alternaria spp., and Scopulariopsis spp. (Plewa and Lonc 2011; Pusz et al. 2015; Seifi et al. 2018). The presence of these poses a risk of disease in people with bronchial asthma, EAA (extrinsic allergic alveolitis), allergic rhinitis, and ODTS (dust-induced toxic syndrome organic), while in animals, it causes pulmonary aspergillosis and mycotoxicosis (Szulc et al. 2020).

Therefore, research in zoological gardens is important because these facilities are not only places for breeding animals but may be a source of dangerous fungi. This is important information, taking into account the specificity of zoos, which are not only a working environment, but also one of the most frequently visited tourist places. Thus, the aim of this paper was to evaluate the degree of mycological air contamination and determine the taxonomic diversity of airborne fungi residing in the air of different animal facilities using the combination of microscopic and genetic analyses.

Materials and methods

Study area

The study was conducted at the Zoological Garden in Wroclaw. This zoo has the largest collection of animals in Poland, with almost 1100 different species in an area covering 33 hectares (https://zoo.wroclaw.pl).

The measurements were carried out inside twenty facilities: two sites of Monkey House, four sites of Apes Pavilion (Pan troglodytes), Papio Pavilion (Papio anubis), three cages with maggots (Macaca sylvanus), five sites in Kongo Pavilion (with crocodiles, manatees, and numerous species of birds), and five sites in East Africa (with the Hippopotamus amphibious, Orycteropus afer, Heterocephalus glaber). The choice of study sites was guided by their convenient accessibility.

Sampling methods

Air samples were taken in October 2022 and in January, April, and June 2023 using a MAS-100 air sampler (Merck KgaA, Darmstadt, Germany). Three parallel samples (two incubated at 27 °C degree, one at 37 °C) were collected at the center point of each location at a height of 1.5 m above the ground and directly struck on the surface of Sabouraud agar. The plates were incubated for about 7 days at 25 °C (two samples) and 37 °C (one sample). The number of fungal colonies was expressed as a total colony-forming units (CFU/m3) and revised by the equation: Pr = N[1/N + 1/N − 1 + 1/N − 2 + 1/N − r + 1] where Pr, r, and N stand for revised colonies, number of viable colonies, and the number of sieve pores, respectively (Feller 1968). The concentration of airborne microorganisms (CFU/m3) was calculated according to the following formula: X = (a × 1000)/V, where “a” is the number of fungal colonies, and “V” is the air volume sampled (m3) (Michalska et al. 2021).

Characterization of meteorological conditions

The air temperature and relative humidity were measured during each sampling session using a thermo-hygrometer (HI9565 HANNA, Poland). The air temperature ranged from 11.2 to 22.7 °C (autumn season), 17.1 to 24 °C (winter season), 18.1 to 24.6 °C (spring season), and 19.4 to 25.6 °C (summer season), respectively. Relative humidity in the autumn season was between 27.9 and 89.4%, in the winter season from 30.8 to 95.5%, in the spring season from 35.5 to 90.8, and in the summer season from 54.7 to 80.1%.

Identification of fungi

Airborne fungi were identified based on their macro- and microscopic features using diagnostic keys (Samson et al. 2014, 2019; Yilmaz et al. 2014; Visagie et al. 2014). Then, the cultured fungi were subjected to molecular identification to confirm species identity. DNA extraction from the selected and dominant fungi was performed using the Tissue DNA Purification Kit (EURx, Gdańsk, Poland) according to the manufacturer’s instructions. For the diagnostic of the airborne fungi, we used both morphological criteria and molecular analyses based mainly on the sequence of the internal transcribed spacer ITS. In the case of several closely related strains, we sequenced b-tubulin and calmodulin fragment. Amplification parts of the ITS were amplified according to the methods described by White et al. (1990). The ITS was amplified using a pair of primers: ITS1 (5′-TCCGTAGGTGAACCTGCGG-3′) and ITS4 (5′-TCCTCCGCTTATTGATATGC-3′). PCR reactions were performed in a T100 Thermal Cycler (Bio-Rad, Warsaw, Poland) in a total volume of 12.5 µL. Each PCR reaction contains 6.25 μL of 2 × PCR Mix Plus (A&A Biotechnology, Gdansk, Poland), 0.625 μL of each primer (10 mM), 4 μL of DNA template, and 1 μL of ddH2O. PCR conditions included an initial denaturation step of 95 °C (30 s); 34 cycles of 95 °C (45 s), 55 °C (60 s), and 72 °C (60 s); and the final elongation of 72 °C (3 min).

Calmodulin gene amplification was performed using the set of primers Cmd5 and Cmd6, and amplification of b-tubulin was performed using the primer pairs Bt2a (5-GGT AAC ATC CAA GCT GCT GGT TTC-3) and Bt2b (5-CTC AGT GTA ACC GTG ACC CTT GGC-3) Glass and Donaldson (1995). For both regions, the conditions were as follows: denaturation step of 95 °C (3 min); 40 cycles of 95 °C (45 s), 55 °C (60 s), and 72 °C (60 s); and the final elongation of 72 °C (7 min). The PCR products were visualized in 1% agarose gel staining with SimplySafe (EURx).

All positive samples obtained in the PCR reaction were purified and sequenced (Macrogen, Amsterdam, the Netherlands) using the same primer pairs as in the PCR reaction. The obtained sequences were manually edited using DNA Baser Sequence Assembly software (Heracle BioSoft SRL Romania), and consensus sequences were aligned and compared with sequences deposited in the National Center for Biotechnology Information’s GenBank (NCBI, Bethesda, MD, USA) using the BLAST algorithm (http://www.ncbi.nlm.nih.gov/). The most representative sequences that form the basis of the phylogenetic tree have been included in the GenBank database (Table 1). Phylogenetic analysis was performed using the Maximum Likelihood method with the MEGA 7.0 software, bootstrapping was performed using 1000 replicates.

Table 1.

Molecular identification (using ITS region) of fungi isolated from the air in the zoological garden

Fungal species Isolate Accession no Identity
Aspergillus niger (1) 7fj OR807891.1 100%
Aspergillus niger (2) 15cj OR807968.1 100%
Aspergillus ostianus 17cj OR801711.1 100%
Aspergillus ostianus 11bl OR802129.1 100%
Aspergillus westerdijkiae (1) 1dz OR816133.1 99.55%
Aspergillus westerdijkiae (2) 4dz OR816127.1 99.55%
Aspergillus elegans (1) 1bz OR802130.1 99%
Aspergillus elegans (2) 2cz OR802142.1 100%
Aspergillus steynii 16cw OR806947.1 100%
Aspergillus flavus (1) 2gw OR806964.1 100%
Aspergillus flavus (2) 18aw OR806964.1 100%
Aspergillus fumigatus (1) 3fw OR8069661.1 100%
Aspergillus giganteus 19cz OR808008.1 100%
Aspergillus sydowii 4bl OR807981.1 100%
Aspergillus versicolor 13cz OR807986.1 100%
Penicillium chrysogenum 12aj OR810003.1 99.82%
Penicillium solitum 15aj OR810004.1 99,63%
Penicillium commune 6dj OR810005.1 100%
Penicillium raistrickii 9bw OR810006.1 100%
Penicillium bialowieziense 9bj OR810007.1 100%
Penicillium brevicompactum (1) 9cj OR810008.1 100%
Penicillium olsonii 13bz PP494186.1 100%
Penicillium glandicola 6aw OR810010.1 100%
Penicillium citreosulfuratum 1az OR810011.1 100%
Penicillium glabrum 8aj PP494188.1 100%
Penicillium citrinum (1) 15az OR810014.1 100%
Penicllium citrinum (2) 15bl OR810013.1 100%
Penicilllium steckii 18cw OR810015.1 100%
Penicillium steckii (2) 20cz OR810016.1 100%
Penicillium sumatraense 15bz PP494184.1 100%
Penicillium copticola (1) 17bz PP494185.1 100%
Penicillium copticola (2) 18az OR810019.1 100%
Open in a new tab

Statistical analysis

The data underwent statistical analysis using R version 4.3.1 in RStudia 2023.09.0. Linear regression models and Spearman correlations were computed to evaluate the correlation between fungal abundance and meteorological parameters (humidity and temperature). The Kruskal–Wallis test and Dunn’s post hoc test for multiple comparisons were utilized to investigate the influence of qualitative factors, such as location and season, on fungal abundance. For statistical significance, results with p < 0.05 were considered. Margalef’s Index and Jaccard’s Similarity Index were employed to assess the diversity of fungal species at specific research sites. The Jaccard Index was calculated pairwise, and then the average value for each site was obtained.

Results and discussion

Fungal concentrations in air samples

A total of 240 air samples were collected from 20 locations in the zoological garden. Fungi were detected in 234 (97.5%) samples. The concentrations of countable fungal aerosol are presented in Table 2 and ranged from 5.0 × 101 to 3.65 × 104 CFU/m3 (for a temperature of 27 °C). The lowest concentration of fungi was recorded in Papio Pavilion 5 × 101 CFU/m3 (range 5 × 101 –2.5 × 102 CFU/m3). It is worth noticing that this concentration was lower than the recorded at another site, because the air sampling was done just before the morning cleaning of the room. The highest concentration of fungi was recorded in the Apes Pavilion and ranged between 2.02 × 104 and 3.65 × 104 CFU/m3. Similar concentrations were found in the Papio Pavilion (range 1.31 × 104–1.32 × 102 CFU/m3) and the Kongo Pavilion (1.38 × 104–2.61 × 104 CFU/m3). Statistical analysis performed using the Kruskal-Walis test showed statistically significant differences between the sampling location and the CFU/m3 fungi values (Fig. 1).

Table 2.

Air fungal concentration (CFU/m3) during seasonal samplings

Fungal count (CFU/m3)
Location Autumn Winter Spring Summer
1 250 250 100 750 900 150 1650 2500 750 1000 1350 900
2 300 400 400 250 450 0 550 650 200 850 800 350
3 1500 1300 0 Z Z 350 2900 3600 350 7500 5950 5500
4 1600 1000 50 Z Z 1650 3650 4700 150 3400 2700 3900
5 2050 Z 300 Z Z 800 1000 1700 300 1450 1750 1850
6 20250 36500 150 3250 4650 250 1700 2450 100 650 900 200
7 1400 Z 0 2400 2550 350 1150 1100 100 950 1000 400
8 8150 2550 600 6500 7100 150 1650 800 150 1900 1500 350
9 4150 3200 4000 6400 5850 700 2500 2250 150 850 650 250
10 Z Z 900 150 250 50 1150 1100 50 13150 13250 250
11 11150 8900 50 5150 5850 1000 12700 15050 1100 2500 3150 2600
12 5950 7550 0 5200 3550 650 9850 7700 3000 3000 2150 850
13 4700 5600 0 2600 3600 250 11950 12300 3200 2700 1750 1650
14 4450 5600 0 3000 4550 600 6500 6000 2900 1150 3050 2100
15 4450 4200 50 5600 4700 1000 8900 4700 3600 1700 1300 250
16 6200 4000 500 3600 4100 750 5350 4950 1750 2500 2800 650
17 13950 7200 350 3500 3600 1700 7700 6850 1500 1900 2350 850
18 13800 26100 400 2400 2900 1350 7000 7400 1450 1100 3350 350
19 13450 3250 250 2550 2250 750 6300 7250 1300 3000 2150 400
20 4750 8700 250 3050 3800 400 9850 10550 1750 2900 2700 450
Open in a new tab

1–2 (Monkey House), 3–5 (cages with maggots 1), 6–9 (Apes Pavilion), 10 (Papio Pavilion), 11–15 (Kongo Pavilion), 16–20 (East Africa pavilion); Z, overgrown Petri dish

The first two columns in each season concern strains grown at a temperature of 27 °C; the last one is for strains grown at 37 °C

Fig. 1.

Fig. 1

Open in a new tab

Fungal conidia concentration in the air across locations group

There have been a lot of studies about microbial and mycological air contamination in animal production premises (Plewa and Lonc 2011; Pusz et al. 2015; Matković et al. 2009) or in the farming environment (Radon et al. 2002; Almatawah et al. 2023), but there are only several publications relating to non-production facilities, such as zoos. In Poland, the first study carried out in the zoological garden was initiated by Grzyb and Lenart-Boroń (2019) and focused mainly on bacterial bioaerosol in the selected animal premises in the Krakow’s Zoological Garden. Another study conducted by Grzyb and Lenart-Boroń (2020) inside the premises where animals are kept demonstrated similar “to our work” total concentration of fungi (range 8.4 × 102–2.84 × 104). The highest median concentration of fungi was recorded in the exotarium (range 9.79 × 103–2.84 × 104 CFU/m3), and the lowest was recorded in rooms for pygmy hippopotamus 966 CFU/m3 (range 8.4 × 102–1.3 × 103 CFU/m3) (Grzyb and Lenart-Boroń 2020). Because of the lack of other studies on the mycological quality of air in zoos, the results of our own research can be compared to other breeding facilities, e.g., poultry houses and cowshed. Matković et al. (2007) observed in the barn the average concentration of fungi ranged from 5.23 × 104 CFU/m3 (at noon) to 8.35 × 104 CFU/m3 (in the morning). The air quality in some farming objects has been described by Radon et al. (2002). According to that author, the total number of fungi in poultry houses and in pig farms was higher than the concentrations of airborne fungi noticed in our research and ranged from 8.3 × 104 to 1.1 × 109 (Radon et al. 2002). Such large differences in the level of microbial contamination between the zoological garden and other breeding premises are most likely due to different methods of air sampling. The sampler used in our investigation has some limitations. This device is characterized by sampling efficiency described by the cuttoff size parameter D50, at the level of 1.7 μm (Górny et al. 2023). All particles above the size would be collected and almost all particles smaller than that size may not be captured by this impactor. Airborne fungal spores typically have an aerodynamic diameter (dae) of 2 to 4 μm, and some species release fragments of 0.3 to 1.3 μm (Madsen et al. 2016). That is why the number of airborne fungi in our research may have been underestimated in relation to the actual concentration in the air. The results of the present study suggest that it is necessary to use the same instruments and methods to assess microbial contamination. The lack of standardization of air sampling methods may lead to incorrect conclusions.

The concentration of airborne fungi varies across different seasons and is dependent on environmental factors such as temperature or relative humidity (Yuan et al. 2022). The important factors that increase the spread of fungi in the air and sustain their growth are temperature and humidity (Pflieger et al. 2020). Therefore, our studies were conducted in a seasonal cycle (spring, summer, autumn, winter), and the environmental conditions (temperature and relative air humidity) were measured during each sampling season using a thermo-hygrometer (Table 3). The lowest recorded temperature (11 °C) was noted in autumn in the room for Papio Pavilion, while the highest temperatures were noted in summer in the Kongo Pavilion (25.5–25.9 °C). Similarly, the highest humidity was observed in winter in East Africa (95.5%) and in the Kongo Pavilion. In general, the relative humidity during the studies varied from 29.3% (in the Apes Pavilion) to 95.5% in the Kongo Pavilion. Environmental parameters (temperature and relative humidity) were correlated with the total number of CFU/m3 noted in all locations, based on Spearman correlation analysis. The relative humidity correlated positively with the total fungal concentration (rho = 0.57, p < 0.0021), while temperature showed no significant correlation with the total fungal concentration at all locations (rho =  − 0.1, p < 0.2263) (Figs. 2 and 3).

Table 3.

Results of air temperature and relative humidity measurements inside 20 locations in the zoologic garden in autumn, winter, spring, and summer sampling seasons

No Autumn Winter Spring Summer
Temp (°C) RH (%) Temp (°C) RH (%) Temp (°C) RH (%) T (°C) RH (%)
1 22.7 29.3 23.3 32.1 23.4 41.8 25.1 54.7
M2 22.7 27.9 21.6 38.0 23.5 35.7 25.5 52.6
3 12 55.8 20.6 30.8 18.1 58.7 19.5 75.2
4 11.3 54,7 17.9 52.0 16.6 75.7 19.4 76.7
5 11.2 57 24.0 30.8 17.9 47.7 19.4 73.3
6 20 57.5 16.8 86.8 19.4 56.5 22.8 67.8
7 20.8 41,4 15.1 56.0 19.8 463 22.4 64.2
8 20.6 42 19.7 62.0 21.4 48.3 21.9 62.3
9 54.8 17.8 19.3 53.4 22.7 46.5 21.1 61.5
10 11 57.7 17.1 61.0 17.6 90.8 20 80.1
11 20.4 72.8 19.1 95.5 21.9 76.2 24.4 70.4
12 20.3 71.2 18.9 90.3 21.8 79 24.4 68.4
13 19.9 74.2 18.7 87.5 22.3 74.8 24.5 70.2
14 19.8 71 18.7 86.5 22.1 72.7 24.9 69.2
15 19.8 62.4 18.9 91.4 22 72.4 24.5 69.6
16 22 89.4 21.6 91.4 23.9 88.8 25.9 79.2
17 20.7 86.8 23.5 85.5 21.6 87.5 25.8 74.3
18 21.5 85.1 24.0 83.0 24.4 85.1 25.7 75.5
19 21.7 80.3 24.0 78.8 25.1 85.7 25.6 75.4
20 22 77.1 23.8 75.3 24.6 82.9 25.5 75.1
Open in a new tab

Fig. 2.

Fig. 2

Open in a new tab

The correlation between temperature and fungal conidia concentration in the air

Fig. 3.

Fig. 3

Open in a new tab

The correlation between relative humidity and fungal conidia concentration in the air

The concentration of airborne fungi observed at each location varied significantly across the seasons. The highest concentration was recorded in the autumn, reaching a level of 3.65 × 105 CFU/m3 while the lowest levels were observed in the spring and summer, with values of 1.5 × 104 and 1.32 × 104 CFU/m3, respectively. The lowest concentration of fungi (2.5 × 102 CFU/m3) was observed in the winter season. It has been demonstrated that optimal temperature and high relative humidity can contribute to a sudden increase in the concentration of airborne fungi. The medium fungal concentrations varied considerably by season, with the greatest variation noted between summer and autumn (p < 0.0018). A strong variety of airborne fungal concentrations was also noticed between spring and summer (p < 0.0056), while no statistically significant differences were observed between other seasons (Fig. 4).

Fig. 4.

Fig. 4

Open in a new tab

Fungal conidia concentration in the air across different seasons

Interpretation of the results of microbiological air contamination is challenging because of the lack of acceptable limits for microbiological agents. The most commonly used measure of exposure to microbial air pollution is the degree of such pollution, expressed in terms of the number of colony-forming units (CFU) in 1 m3 of air (Górny et al. 2016). The threshold limit values (TLV) were used in the assessment of mycological air contamination. For microbiological agents in the air of occupational and non-occupational environments, TLV was proposed by the Expert Group on Biological Agents at the Polish Interdepartmental Commission for Maximum Admissible Concentrations and Intensities for Agents Harmful to Health in the Working Environment (Górny et al. 2016). These values (5 × 104 CFU/m3 for fungi) were developed as a result of volumetric measurements of environmental bioaerosols. Based on the TLV proposed by the mentioned Expert Group, we can conclude that the quantitative analysis of the fungal aerosol showed lower concentration values than the recommended permissible limits. Nevertheless, this is not equivalent to the absence of microbial contamination in the facilities that were studied. Particularly as some of the values were close to TLV values. The US government agency, Occupational Safety and Health Administration (OSHA), suggests that a value higher than 1.0 × 103 CFU/m3 indoor may be an indicator of microbial contamination. However, a determination of bioaerosol biodiversity is needed to confirm a health hazard, as certain species may pose a greater health concern than others (OSHA 2015; Rivas et al. 2018).

Biodiversity of airborne fungi

The total number of airborne fungi varied by location (Table 4) and seasons (Table 5). The Margalef’s Index was used to analyze the biodiversity of airborne fungi throughout the study period and in different locations. The highest value of Margalef’s Index (0.93) was recorded at Kongo Pavilion in location no 18 and the lowest (0.00) was observed at East Africa Pavilion in location no 12. Concerning seasons, the highest diversity of airborne fungi was recorded in the winter (34), followed by the autumn (29), and spring (27), whereas the lowest number of strains were noted in the summer (21). The average Jaccard Index for all sites was quite low, at 0.135. The lowest average Jaccard Index, calculated pairwise for each research site, was for the Kongo Pavilion (0.12). This indicates that the Kongo Pavilion had the highest number of unique isolated species compared to other research sites. Direct comparison showed the lowest species similarity between the Kongo Pavilion and the Apes Pavilion (Jaccard Index = 0.06) and between the Kongo Pavilion and the Papio Pavilion (0.08). The highest similarity was found between the Kongo Pavilion and the East Africa Pavilion (0.22).

Table 4.

Number of fungi species isolated from the air in the 20 locations in the zoological garden

No Species Zoological garden Total
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
1 Aspergillus niger 1 1 1 3
2 Aspergillus ostianus 1 1 2
3 Aspergillus tubigensis 1 1
4 Aspergillus elegans 2 1 1 4
5 Aspergillus giganteus 1 1 2
6 Aspergillus ochraceus 1 1 1 1 1 5
7 Aspergillus steynii 1 1
8 Aspergillus puulaauensis 1 1
9 Aspergillus westerdijkiae 1 1 1 3
10 Aspergillus versicolor 1 1
11 Aspergillus fumigatus 1 1 2 4
12 Aspergillus flavus 1 1 2
13 Penicillium brevicompactum 1 1 1 1 4
14 Penicillium chrysogenum 1 1 1 3
15 Penicillium commune 1 1 1 1 4
16 Penicillium glabrum 1 1 1 1 1 5
17 Penicillium lanosocoeruleum 1 1 2
18 Penicillium solitum 1 1 2
19 Penicillium steckii 1 2 2 5
20 Penicillium brasilianum 1 1
21 Penicillium allii 2 2
22 Penicillium citrinum 2 1 3
23 Penicillium bialowieziense 1 1
24 Penicillium copticola 1 2 3
25 Penicillium griseofulvum 2 1 1 4
26 Penicillium olsonii 1 1
27 Penicillium sumatreanse 1 1 2
28 Penicillium citreosulfuratum 2 2
29 Penicillium hetheringtoini 1 1
30 Penicillium raistrickii 1 1
31 Penicillium rubens 1 1
32 Penicillium glandicola 1 1 2
33 Penicillium sarajorii 1 1
34 Penicillium griseoroseum 1 1
35 Penicillium toxicarium 1 1
36 Penicillium vanlyukii 1 1
37 Penicillium spp. 1 2 2 1 1 1 1 3 1 13
38 Talaromyces aspriconidius 1 1
39 Talaromyces minioluteus 1 1
40 Talaromyces divercus 1 1
41 Talaromyces piceae 1 1
42 Cladosporium cladosporoides 1 1 2
43 Cladosporium halotolerans 1 1
44 Cladosporium spp. 1 1 2
45 Syncephalastrum racemosum 1 1
46 Mucor plumbeus 2 2
47 Absidia spp. 1 1
48 Schizophyllumcommune 1 1 2
49 Cuninghamella clavata 1 1
50 Alternaria alternata 1 1
Total 9 9 5 7 3 8 3 5 5 4 2 1 2 4 9 3 8 10 10 5 112
Open in a new tab

1–2 (Monkey House), 3–5 (cages with maggots 1), 6–9 (Apes Pavilion), 10 (Papio Pavilion), 11–15 (Kongo Pavilion), 16–20 (East Africa pavilion)

Table 5.

Number of fungi species isolated from the air in the seasons

No Species Zoological Garden Total
Autumn Winter Spring Summer
1 Aspergillus niger 3 3
2 Aspergillus ostianus 1 1 2
3 Aspergillus tubigensis 1 1
4 Aspergillus elegans 2 2 4
5 Aspergillus giganteus 2 2
6 Aspergillus ochraceus 2 2 1 5
7 Aspergillus steynii 1 1
8 Aspergillus puulaauensis 1 1
9 Aspergillus westerdijkiae 2 1 3
10 Aspergillus versicolor 1 1
11 Aspergillus fumigatus 2 2 4
12 Aspergillus flavus 2 2
13 Penicillium brevicompactum 4 4
14 Penicillium chrysogenum 1 1 1 3
15 Penicillium commune 1 2 1 4
16 Penicillium glabrum 1 4 5
17 Penicillium lanosocoeruleum 2 2
18 Penicillium solitum 2 2
19 Penicillium steckii 2 2 1 5
20 Penicillium brasilianum 1 1
21 Penicillium allii 1 1 2
22 Penicillium citrinum 2 1 3
23 Penicillium bialowieziense 1 1
24 Penicillium copticola 2 1 3
25 Penicillium griseofulvum 4 4
26 Penicillium olsonii 1 1
27 Penicillium sumatreanse 1 1 2
28 Penicillium citreosulfuratum 2 2
29 Penicillium hetheringtoini 1 1
30 Penicillium raistrickii 1 1
31 Penicillium rubens 1 1
32 Penicillium glandicola 2 2
33 Penicillium sarajorii 1 1
34 Penicillium griseoroseum 1 1
35 Penicillium toxicarium 1 1
36 Penicillium vanlyukii 1 1
37 Penicillium spp. 7 3 2 1 13
38 Talaromyces aspriconidius 1 1
39 Talaromyces minioluteus 1 1
40 Talaromyces divercus 1 1
41 Talaromyces piceae 1 1
42 Cladosporium cladosporoides 2 2
43 Cladosporium halotolerans 1 1
44 Cladosporium sp. 1 1 2
45 Syncephalastrum racemosum 1 1
46 Mucor plumbeus 1 1 2
47 Absidia spp. 1 1
48 Schizophyllum commune 2 2
49 Cuninghamella clavata 1 1
50 Alternaria alternata 1
Total 29 34 27 21 112
Open in a new tab

We used both morphological and molecular identity methods based on sequencing regions of the ITS, b-tubulin, and calmodulin. Using these methods, a total of 112 fungal strains belonging to 10 genera and 50 species were isolated during the whole 1-year-long study. The molecular identification corresponded well with the morphological diagnosis and proved to be a good tool for diagnostic strains that were not identified microscopically. By comparing the partial sequences of the ITS region of the own isolates with the sequences of other isolates available in GenBank, the results showed that the similarity percentage of nucleotide sequences ranged between 95 and 100% (Supplement 1). In most cases, (87%) the sequence data allowed the identification at the species level. The study based on the molecular analysis allowed us to identify 97 out of 112 species of fungi. Diagnosis of thirteen strains belonged to Penicillium genera, and one strain each of the Cladosporium and Absidia genera failed. Analysis of ITS region revealed that they belong to closely related species. Even the sequencing of the less conservative region (b-tubulin) and calmodulin did not allow for the identification of these fungi at the species level.

Most of the airborne fungi isolated in our studies were representatives of Ascomycota (93.75%), while Mucormycota constituted 4.46% of the mycobiota and Basidiomycota for 1.79%. Penicillium was the dominant genera, including 58.9% of total fungal strains, followed by Aspergillus 25.89%, Cladosporium 3.57%, Talaromyces 3.57%, Mucor 1.78%, Schizophyllum 1.78%, Syncephalastrum 0.89%, Alternaria 0.89%, Absidia 0.89%, and Cunninghamella 0.89%. Species belonging to the most representative Penicillium genera were grouped in the seven following sections such as the following: Fasciculata (P. solitum, P. commune, P. allii), Chrysogena (P. chrysogenum, P. lanosocoeruleum, P. rubens, P. vanlyukii), Penicillium (P. griseofulvum, P. glandicola), Ramosa (P. rastrickii), Brevicompacta (P. olsonii, P. brevicompactum, P. bialowieziense), Exilicaulis (P. citreosulfuratum), Aspergilloides (P. glabrum), Citrina (P. citrinum, P. copticola, P. sumataense, P. steckii, P. hetheringtonii) (Fig. 5). Aspergillus genera were represented by six dominant sections: Nigri (A. niger, A. tubigensis), Circumdati (A. ochraceus, A. westerdijkiae, A. ostianus, A. elegans, A. steynii), Flavi (A. flavus), Fumigatus (A. fumigatus), Versicolores (A. versicolor, A. sydowii, A. puulaauensis) (Fig. 6).

Fig. 5.

Fig. 5

Open in a new tab

Maximum likelihood (ML) phylogenetic tree (Tamura 3-parameter + G) for Penicillium sp. based on sequences of the ITS gene fragment. Bootstrap values are shown above the branches. Sequences from this study are marked with solid circles. The dendrogram was constructed with 1000 replications using MEGA software

Fig. 6.

Fig. 6

Open in a new tab

Maximum likelihood (ML) phylogenetic tree (Jukes-Cantor + G) for Aspergillus sp. based on sequences of the ITS gene fragment. Bootstrap values are shown above the branches. Sequences from this study are marked with solid circles. The dendrogram was constructed with 1000 replications using MEGA software

Diversity of identified fungi varied between different locations and seasons. Unfortunately, there is a lack of research about the biodiversity of airborne fungi in zoological gardens. Therefore, our results could be compared to the studies obtained for the livestock premises. For instance, in the China poultry houses, researchers observed a different genus composition than in our studies. They isolated mainly Trichosporon, Candida, Aspergillus, Cladosporium, and Alternaria genera (Chen et al. 2021). In other studies, Aspergillus, Scopulariopsis, Penicillium, and Cladosporium were detected in the air of the swine house (Kumari et al. 2016). Comparable results to ours have been reported by Matković et al. 2009. Croatian authors detected Aspergillus and Penicillium genera in dwellings for dairy cows and laying hens.

Some of the fungi isolated in our research may be associated with allergic respiratory diseases (especially in people with a weakened immune system). Filamentous fungi can be a source of polysaccharides such as the β(1 → 3)-glucans. This compound may cause inflammatory airway reactions and also affect the immune system. There is increasing evidence that β(1 → 3)-glucans cause non-specific inflammatory reactions and can be responsible for bioaerosol-induced respiratory symptoms observed in both indoor and occupational environments (Pflieger et al. 2020). The other fungi are important producers of mycotoxins, which have been suggested as one of the major possible causes of health problems. For example, several detected fungi belonging to Aspergilli in sections Circumdati (A. steynii and A. westerdijkiae), Flavi (A. flavus), and Nigri (A. carbonarius and A. niger) are well-known producers of ochratoxins, a mycotoxin teratogenic, carcinogenic, immunosuppressive, and nephrotoxic in animals (Kagot et al. 2019). The other species, such as A. versicolor and A. flavus, produce sterigmatocystin and aflatoxins, respectively. Aflatoxins are the most potent natural carcinogens (Lamoth 2016). What’s more, the identified in our study A. flavus is recognized as an opportunistic animal and human pathogen, while A. fumigatus is the main causative agent of pulmonary invasive aspergillosis (Al-Shaarani et al. 2023). The most abundant Penicillium genera isolated in our studies is listed among the most common allergenic fungal taxa and has been linked to asthma. Whereas, Schizophyllum commune, which accounted for 1.78%, may be the cause of ABPM (allergic bronchopulmonary mycosis) and allergy-related bronchopulmonary infections and sinusitis (Oguma et al. 2023).

Conclusion

This is the first research on culturable airborne fungi at the zoological garden in Poland. The quantitative analysis of the fungal aerosol showed that the obtained concentration values were lower than the recommended permissible limits. But a lot of detected fungi can be harmful to human and animal health. That is why, our study emphasizes the necessity of air quality monitoring.

Similar studies to ours are rarely conducted. Therefore, our preliminary research provides basic information about the fungal concentrations and their biodiversity in these touristic facilities. However, further long-term quantitative, as well as qualitative, and mycotoxicological research is needed to fully understand airborne fungal composition in the zoological garden and its potentially negative impact on human and animal health. Moreover, quantitative and qualitative assessment of mycotoxins in the air is of great importance from the occupational exposure point of view. In addition, our preliminary results along with planned long-term studies of mycological air contamination in the zoo may contribute in the future to the development of microbiological air quality standards by relevant institutions.

Supplementary Information

Below is the link to the electronic supplementary material.

Supplementary file1 (DOCX 30 KB) (29.6KB, docx)

Acknowledgements

The authors of this paper would like to express their appreciation to the Wroclaw Zoo Administration for allowing us to conduct our mycological research.

Author contribution

KPT: conceptualization, methodology, investigation, formal analysis, data curation, funding acquisition, and writing the original draft. PK: statistical analysis. AD: investigation. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded in whole by the National Science Centre, Poland, under the research project “MINIATURA 6,” grant 2022/06/X/NZ8/00430. For the purpose of Open Access, the author has applied a CC-BY public copyright license to any Author-Accepted Manuscript (AAM) version arising from this submission.

Data availability

All data generated or analyzed during this study are included in this published article.

Declarations

Ethics approval and consent to participate

Not applicable.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.

Footnotes

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

References  

  1. Almatawah QA, Al-Khalaifah HS, Aldameer AS, Ali AK, Benhaji AH, Varghese JS. Microbiological indoor and outdoor air quality in chicken fattening houses. J Environ Public Health. 2023;29:3512328. doi: 10.1155/2023/3512328. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Al-Shaarani AAQA, Quach ZM, Wang X, Muafa MHM, Nafis MMH, Pecoraro L. Analysis of airborne fungal communities on pedestrian bridges in urban environments. Microorganisms. 2023;11(8):2097. doi: 10.3390/microorganisms11082097. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Álvarez-Pérez S, García ME, Martínez-Nevado E, Blanco JL. Presence of Aspergillus fumigatus with the TR34/L98H Cyp51A mutation and other azole-resistant aspergilli in the air of a zoological park. Res Vet Sci. 2023;164:104993. doi: 10.1016/j.rvsc.2023.104993. [DOI] [PubMed] [Google Scholar]
  4. Cateau E, Leclerc A, Cartier N, Valsecchi I, Bailly É, Le Senechal R, Becerra M, Le Gallou B, Lavergne RA, Chesnay A, Robin JP, Cray C, Goddard N, Thorel M, Guillot J, Mulot B, Desoubeaux G (2022) Aspergillosis in a colony of Humboldt penguins (Spheniscus humboldti) under managed care: a clinical and environmental investigation in a French zoological park. Med Mycol 60(7):myac046. 10.1093/mmy/myac046 [DOI] [PubMed]
  5. Chen G, Ma D, Huang Q, Tang W, Wei M, Li Y, Jiang L, Zhu W, Yu X, Zheng W, Zhang J, Zhang X. Aerosol concentrations and fungal communities within broiler houses in different broiler growth stages in summer. Front Vet Sc. 2021;13(8):775502. doi: 10.3389/fvets.2021.775502. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Debergh H, Becker P, Vercammen F, Lagrou K, Haesendonck R, Saegerman C, Packeu A. Pulmonary Aspergillosis in Humboldt penguins - susceptibility patterns and molecular epidemiology of clinical and environmental Aspergillus fumigatus isolates from a Belgian zoo, 2017–2022. Antibiotics. 2023;12(3):584. doi: 10.3390/antibiotics12030584. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Douglas P, Robertson S, Gay R, Hansel AL, Gant T. A systematic review of the public health risks of bioaerosols from intensive farming. Int J Hyg Environ Health. 2018;221(2):134–173. doi: 10.1016/j.ijheh.2017.10.019. [DOI] [PubMed] [Google Scholar]
  8. Feller W (1968) An introduction to probability theory and its application, Volume II, 3rd edn. John Wiley and Sons, Inc., New York, p 704
  9. Glass NL, Donaldson GC. Development of primer sets designed for use with the PCR to amplify conserved genes from filamentous ascomycetes. J Appl Environ Microbiol. 1995;61(4):1323–1330. doi: 10.1128/aem.61.4.1323-1330.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Górny RL, Harkawy AS, Ławniczek-Wałczyk A, Karbowska-Berent J, Wlazło A, Niesler A, Gołofit-Szymczak M, Cyprowski M. Exposure to culturable and total microbiota in cultural heritage conservation laboratories. Int J Occup Med Environ Health. 2016;29(2):255–75 . doi: 10.13075/ijomeh.1896.00630. [DOI] [PubMed] [Google Scholar]
  11. Górny RL, Gołofit-Szymczak M, Cyprowski M, Ławniczek-Wałczyk A, Stobnicka A, Wolska LA. Poultry house as point source of intense bioaerosol emission. Ann Agric Environ Med. 2023;30(3):432–454. doi: 10.26444/aaem/172770. [DOI] [PubMed] [Google Scholar]
  12. Grzyb J, Lenart-Boroń A. Bacterial bioaerosol concentration and size distribution in the selected animal premises in a zoological garden. Aerobiologia. 2019;35(2):253–268. doi: 10.1007/s10453-018-09557-9. [DOI] [Google Scholar]
  13. Grzyb J, Lenart-Boroń A. Size distribution and concentration of fungal aerosol in animal premises of a zoological garden. Aerobiologia. 2020;36:233–248. doi: 10.1007/s10453-020-09625-z(0123456789. [DOI] [Google Scholar]
  14. Kagot V, Okoth S, De Boevre M, De Saeger S. Biocontrol of Aspergillus and Fusarium mycotoxins in Africa: benefits and limitations. Toxins (basel) 2019;11(2):109. doi: 10.3390/toxins11020109. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Kumari P, Woo C, Yamamoto N, Choi HL. Variations in abundance, diversity and community composition of airborne fungi in swine houses across seasons. Sci Rep. 2016;6:37929. doi: 10.1038/srep37929. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Lamoth F (2016) Aspergillus fumigatus-related species in clinical practice. Front Microbiol 7:1–8. 10.3389/fmicb.2016.00683 [DOI] [PMC free article] [PubMed]
  17. Lee S-J, Kim K-Y. On-site investigation of airborne bacteria and fungi according to type of poultry houses in South Korea. Processes. 2021;9(9):1534. doi: 10.3390/pr9091534. [DOI] [Google Scholar]
  18. Madsen AM, Larsen ST, Koponen IK, Kling KI, Barooni A, Karottki DG, Tendal K, Wolkoff P. Generation and characterization of indoor fungal aerosols for inhalation studies. Appl Environ Microbiol. 2016;82(8):2479–93 . doi: 10.1128/AEM.04063-15. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Matković K, Vučemilo M, Vinković B, Šeol B, Pavičić Ž, Matković S. Qualitative structure of airborne bacteria and fungi in dairy barn and nearby environment. Czech J Anim Sci. 2007;52:249–253. doi: 10.17221/2280-CJAS. [DOI] [Google Scholar]
  20. Matković K, Vučemilo M, Vinković B. Airborne fungi in dwellings for dairy cows and laying hens. Arh Hig Rada Toksikol. 2009;60:395–399. doi: 10.2478/10004-1254-60-2009-1970. [DOI] [PubMed] [Google Scholar]
  21. Michalska M, Kurpas M, Zorena K, Wąż P, Marks R. Mold and yeast-like fungi in the seaside air of the Gulf of Gdańsk (Southern Baltic) after an emergency disposal of raw sewage. J Fungi (basel) 2021;7(3):219. doi: 10.3390/jof7030219. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Nageen Y, Wang X, Pecoraro L. Seasonal variation of airborne fungal diversity and community structure in urban outdoor environments in Tianjin, China. Front Microbiol. 2023;13:1–18. doi: 10.3389/fmicb.2022.1043224. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Nekolný L, Fialová D. Zoo tourism: what actually is a zoo? Czech J Tour. 2018;7(2):153–166. doi: 10.1515/cjot-2018-0008. [DOI] [Google Scholar]
  24. Occupational Health and Safety Administration (OSHA) (2015) Chapter 2 – indoor air quality investigation. In: OSHA technical manual, TED 1–0.15A. https://osha.gov. Accessed 8 Jun 2024
  25. Oguma T, Ishiguro T, Kamei K, Tanaka J, Suzuki J, Hebisawa A, Obase Y, Mukae H, Tanosaki T, Furusho S, Kurokawa K, Watai K, Matsuse H, Harada N, Nakamura A, Shibayama T, Baba R, Fukunaga K, Matsumoto H, Ohba H, Sakamoto S, Suzuki S, Tanaka S, Yamada T, Yamasaki A, Fukutomi Y, Shiraishi Y, Toyotome T, Fukunaga K, Shimoda T, Konno S, Taniguchi M, Tomomatsu K, Okada N, Asano K; Japan ABPM Research Program (2023) Clinical characteristics of allergic bronchopulmonary mycosis caused by Schizophyllum commune. Clin Transl Allergy 31:14(1). 10.1002/clt2.12327 [DOI] [PMC free article] [PubMed]
  26. Pfliegler W, Pócsi I, Győri Z, Pusztahelyi T (2020) The Aspergilli and their mycotoxins: metabolic interactions with plants and the soil biota. Front Microbiol 10:1–21. 10.3389/fmicb.2019.02921 [DOI] [PMC free article] [PubMed]
  27. Plewa K, Lonc E. Analysis of airborne contamination with bacteria and moulds in poultry farming: a case study. Pol J Environ Stud. 2011;20(3):725–731. [Google Scholar]
  28. Pusz W, Plaskowska E, Weber W, Kita W. Assessing the abundance of airborne fungi in a dairy cattle barn. Pol J Environ Stud. 2015;24(1):241–248 . doi: 10.15244/pjoes/29201. [DOI] [Google Scholar]
  29. Radon K, Danuser B, Iversen M, Monso E, Weber C, Hartung J, Donham K, Palmgren U, Nowak D. Air contaminants in different European farming environments. Ann Agric Environ Med. 2002;9:41–48. [PubMed] [Google Scholar]
  30. R Core Team (2023) R: a language and environment for statistical computing. R Foundation for Statistical Computing. Vienna, Austria. https://www.R-project.org
  31. Rivas AE, Dykstra MJ, Kranz K, Bronson E. Environmental fungal loads in an indoor-outdoor African penguin (Spheniscusdemersus) exhibit. J Zoo Wildl Med. 2018;49(3):542–555. doi: 10.1638/2017-0119.1. [DOI] [PubMed] [Google Scholar]
  32. Samson RA, Visagie CM, Houbraken J, Hong SB, Hubka V, Klaassen CH, Perrone G, Seifert KA, Susca A, Tanney JB, Varga J, Kocsubé S, Szigeti G, Yaguchi T, Frisvad JC. Phylogeny, identification and nomenclature of the genus Aspergillus. Stud Mycol. 2014;78:141–173. doi: 10.1016/j.simyco.2014.07.004. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Samson RA, Houbraken J, Thrane U, Frisvad JC, Anderen B (2019) Food and indoor fungi. Westerdijk Laboratory Manual series, 2nd edn. Westerdijk Fungal Biodiversity Institute, Utrecht
  34. Seifi S, Shokri H, KarimiMadab M. Isolation and characterization of mycoflora of chicken hatcheries in Mazandaran province, north of Iran. Vet Res Forum. 2018;9(4):373–378 . doi: 10.30466/vrf.2018.33106. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Szulc J, Okrasa M, Dybska-Stępień K, Sulyok M, Nowak A, Otlewska A, Szponar B, Majchrzycka K (2020) Assessment of microbiological indoor air quality in cattle breeding farms. Aerosol Air Qual Res 20(6):1353–1373. 10.4209/aaqr.2019.12.0641
  36. Visagie CM, Houbraken J, Frisvad JC, Hong SB, Klaassen CHW, Perrone G, Seifert KA, Varga J, Yaguchi T, Samson RA. Identification and nomenclature of the genus Penicillium. Stud Mycol. 2014;78:343–371. doi: 10.1016/j.simyco.2014.09.001. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. White TJ, Bruns T, Lee S, Taylor J. Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: Innis MA, Gelfand DH, Sninsky JJ, White TJ, editors. PCR Protocols: A Guide to Methods and Applications. New York, USA: Academic Press; 1990. pp. 315–322. [Google Scholar]
  38. Yilmaz N, Visagie CM, Houbraken J, Frisvad SRA. Polyphasic taxonomy of the genus Talaromyces. Stud Mycol. 2014;78:175–341. doi: 10.1016/j.simyco.2014.08.001. [DOI] [PMC free article] [PubMed] [Google Scholar]
  39. Yuan C, Wang X, Pecoraro L. Environmental factors shaping the diversity and spatial-temporal distribution of indoor and outdoor culturable airborne fungal communities in Tianjin University Campus, Tianjin. China Front Microbiol. 2022;14(13):928921. doi: 10.3389/fmicb.2022.928921. [DOI] [PMC free article] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

Supplementary file1 (DOCX 30 KB) (29.6KB, docx)

Data Availability Statement

All data generated or analyzed during this study are included in this published article.

Articles from Environmental Science and Pollution Research International are provided here courtesy of Springer

RESOURCES