TABLE 2.
Biogenically synthesized conjugated nanomaterials.
| Type of nanomaterials | Microbial cell associated with the synthesis | Conditions required for synthesis | Characterization of the nanomaterials | Biosynthetic pathways | Reference |
|---|---|---|---|---|---|
| PbS NPs | Aspergillus flavus | 0.5 mM of lead acetate with 6.4 mM of sodium sulfide along with the growth in potato dextrose agar at a temperature of 30°C for a period of 120 h and 150 rpm | Cubic crystalline structure, 35–100 nm | Extracellular synthesis | Priyanka et al. (2017) |
| ZnS: Gd NPs and ZnS | Aspergillus flavus | Fungal cells were grown in potato dextrose agar at 28°C for a period of 115 rpm. Along with the biomass, 3 mM of ZnSO4 was added at 27°C and 200 rpm. For the synthesis of ZnS:Gd NPs, 0.3 mM Gd(NO3)3 was added for a period of 96 h | Nanocrystalline structure, spherical structure, and 12–24 nm. ZnS: Gd NPs—10–18 nm | Extracellular synthesis | Uddandarao et al. (2019) |
| ZnS:Gd nanoparticle 0.3 m | |||||
| Chitosan NPs | Trichoderma harzianum | Filtered biomass of the fungi that was grown in potato dextrose agar for a period of 72 h at 28°C at 180 rpm, followed by the addition | Spherical and amorphous, 98.8 nm | Synthesized extracellularly by enzymes | Saravanakumar et al. (2018) |
| AuNPs | Penicillium brevicompactum | Fungi were grown for a period of 72 h within potato dextrose broth at 30°C at 200 rpm. The filtered biomass was mixed in Milli Q sterile water and agitated at 30°C for a period of 72 h at 200 rpm. The supernatant was then mixed with HAuCl4 at a concentration of 1 mm at a temperature of 30°C in the dark | Hexagonal and triangular in shape. 25–60 nm | The NPs are synthesized extracellularly. Electrostatic interactions are responsible for the entrapment of ions with the fungal cell wall. The organic reagents that are present within the media are specifically used as reducing agents | Mishra et al. (2011) |
| AgNPs | Fusarium oxysporum | The fungi was grown in potato dextrose agar for a period of 5 days, followed by mixing the filtered biomass with 1 mm silver nitrate at 28°C for a period of 120 h in the dark | Face-centered cubic crystal, 5–13 nm | The reductase enzyme helps in the synthesis of the NPs | Husseiny et al. (2015) |
| AgNPs | Humicola sp. | The fungi were cultured in MGYP media at pH 9 and shaken at 200 rpm for a period of 50°C. This was followed by the addition of the mycelial mass with 1 mM AgNO3, which was shaken at 200 rpm, at a temperature of 50°C for a period of 96 h | Face-centered cubic crystal, spherical, and 5–13 nm | The biomolecules produced by the fungi helps in the extracellular synthesis of NPs | Syed et al. (2013) |
| TeNPs | Aspergillus welwitschiae | The fungi was grown in Czapek’s medium within a pH range of 7.3 at 30°C for a period of 5 days to which 2 mmol of K2TeO3 was added | Oval and spherical in shape, 60–80 nm | Abo Elsoud et al. (2018) | |
| CdTe QDs | Saccharomyces cerevisiae | The fungi were grown under anaerobic conditions within Czapek’s medium for a period of 2 days. The cell aliquot stored at 5°C was added with 3 mM CdCl2 along with 0.8 mm Na2TeO3, 1.5 mm CH3SO3H, and 2.6 mm NaBH4, followed by rotation at 500 rpm | Cubic crystal, 2.6–3.0 nm | Extracellular synthesis of NPs | Luo et al. (2014) |
| Magnetosome chains | Magnetospirillum gryphiswaldense | Organisms that were grown micro-anaerobically were mixed with 50 µM of Fe(III)citrate | — | Genetic modification resulting in the enhancement of click beetle luciferase (CBR), thereby increasing the production of NPs | Roda et al. (2013) |
| γ-Fe2O3 magnetosome chains and individual γ-Fe2O3 magnetosomes | Magnetospirillum magneticum | The organism was grown micro-anaerobically | 150–300 nm | The synthesis of the NPs occurs by the venous proteins that occur by genetic modifications and expression of RGD | Alphandéry et al. (2011) |
| Nanocomposites formed by bacterial nanocellulose with AgNPs AuNPs and CdSe and ZnS quantum dots that remain functionalized in the presence of biotinylated antibodies | Acetobacter xylinum | The synthesis of the NPs was performed within the static | 45 ± 10 nm | Various types of extracellular and intracellular enzymes like glucokinase, phosphoglucomutase, pyrophosphgorylase, UDPG, and cellulose synthase | Morales-Narváez et al. (2015) |
| Bacterial nanocellulose fibrils | Acetobacter xylinum | Static culture enriched with polysaccharides | 2–100 nms | Various types of extracellular and intracellular enzymes like glucokinase, phosphoglucomutase, pyrophosphorylase, UDPG, and cellulose synthase | Shao et al. (2015) |
| CdTe QDs | Escherichia coli | The bacterial cells were grown in Luria Bertani broth along with 3 mM CdCl2, 0.8 mm Na2TeO3, 6 mM Na3C6H5O7, 26 mM NaBH4, and 8 mM C4H6O4S at 37°C for 24 h at 200 rpm | Cubic structure, size 2–3 nm | Produced extracellularly. Specifically, it is a protein-associated nuclear process | Bao et al. (2010) |
| Ag NPs | Bacillus licheniformis | Bacterial biomass was mixed with 1 mm AgNO3 at a temperature of 37°C | 40–50 nm | Kalishwaralal et al. (2009) | |
| Ag NPs | Shewanella oneidensis | Bacterial biomass was mixed with 1 mm AgNO3 at a temperature of 37°C | Spherical and crystalline in shape, 2–11 nm | Extracellular synthesis associated with NADH-dependent reductases | Suresh et al. (2010) |
| AuNPs and AgNPs | Brevibacterium casei | Bacterial biomass was mixed with 0.001 M AgNO3 and 0.001 HAuCl4 at a temperature of 37°C | 10–50 nm whereas AuNPs are 0–50 nm | It allows intracellular synthesis of NPs which is an NADH-dependent nitrate reductase for AgNPs and α-NADPH–dependent sulfite reductase for AuNPs | Kalishwaralal et al. (2010) |
| Au NPs | Nocardiopsis sp. | Cell-free supernatant was added with 1 mm HAuCl4 | Spherical in shape, 12 ± 5 nm | It is an extracellular mechanism of synthesis where enzyme-based shuttle-based enzymatic reduction of ionic Au3+ to Au0 occurs | Suresh et al. (2011) |
| Se NPs | Pantoea agglomerans | Overnight-grown culture within trypic soy broth added to 1 mm Na2SeO3 at a temperature of 25°C for a period of 24 h | Amorphous and spherical shaped, 100 nm | Se (III) is reduced to Se(0) by the mechanism of intracellular reduction | Torres et al. (2012) |
| Se NPs | Streptomyces minutiscleroticus | The bacterial biomass was grown for a period of 120 h. To that, 1 mm Na2SeO3 was added, followed by stirring at 200 rpm | Spherical and crystalline in shape, 10–250 nm | Extracellular synthesis of NPs | Ramya et al. (2015) |
| Polycrystalline AgNPs | Amphora | The growth is achieved within F/2 media within filtered sterile brackish water maintained at pH 8.2 at a temperature of 30°C for a period of 16.8 h at a rotation of 120 rpm followed by addition of 2 mm Silver nitrate | 20–25 nm | This involves the process of extracellular synthesis of NPs where fucoxanthin is involved | Jena et al. (2015) |
| Au NPs with biogenic silica | Fossil diatoms | NA | 10–30 µm | NA | Panwar and Dutta (2019) |
| Biogenic silica | Thalassiosira weissflogii | The growth of the organism was achieved in silicate-rich sea water media at a temperature of 18–20°C for a period of 12:12 light and dark cycles | NA | Natural process of biomineralization | Lo Presti et al. (2018) |
| Streptomycin loaded within biogenic silica | Coscinodiscus concinnus | NA | 220 µm | Natural process of biomineralization | Gnanamoorthy et al. (2014) |
| AuNPs | Tetraselmis kochinensis | The organism was grown within Guillard’s Marine Enrichment media at a temperature of 28°C for a period of 15 days under light conditions, followed by the addition of the supernatant with 1 mM HAuCl4 at a rotation of 200 rpm and a temperature of 28–29°C | 5–35 nm | Intracellular synthesis of NPs by means of active compounds that are associated with the cell wall and the cytoplasm | Senapati et al. (2012) |