Table 1.
Microorganisms producing eDNA and their release mechanisms.
| Microorganism | Mechanism of eDNA release | Regulation of eDNA release | Function of eDNA | References |
|---|---|---|---|---|
| GRAM-NEGATIVE BACTERIA | ||||
| Acinetobacter calcoaceticus | Lysis | Unknown | Unknown | Palmen and Hellingwerf, 1995 |
| Campylobacter jejuni | Autolysis | Unknown | Biofilm matrix | Svensson et al., 2014 |
| Caulobacter crescentus | Lysis | Unknown | Biofilm dispersal | Berne et al., 2010 |
| Haemophilus influenzae | Unknown | Unknown | Biofilm matrix | Izano et al., 2009 |
| Helicobacter pylori | Vesicles | Unknown | Biofilm matrix | Grande et al., 2011, 2015 |
| Neisseria gonorrhoeae | Type IV secretion system | Unknown | HGT and biofilm | Hamilton et al., 2005; Steichen et al., 2011 |
| Neisseria meningitidis | Lysis | Unknown | Biofilm matrix | Lappann et al., 2010 |
| Pseudomonas aeruginosa | Vesicles/prophage | QS | Biofilm matrix and nutrient source | Kadurugamuwa and Beveridge, 1996; Allesen-Holm et al., 2006; Mulcahy et al., 2010 |
| Pseudomonas chlororaphis | Autolysis | Unknown | Biofilm matrix | Wang et al., 2016 |
| Pseudomonas fluorescens | Unknown | Unknown | Unknown | Catlin and Cunningham, 1958 |
| Pseudomonas stuzeri | Lysis | Unknown | HGT | Stewart et al., 1983 |
| Rhodovulum sulfidophilum | Unknown | QS | Biofilm matrix (flocculation) | Watanabe et al., 1998 Suzuki et al., 2009 |
| Shewanella oneidensis | Autolysis | Phage-induced upon iron-mediated oxidative stress | Biofilm matrix and nutrient source | Gödeke et al., 2011a,b; Binnenkade et al., 2014 |
| Vibrio costicolus | Unknown | Unknown | Unknown | Smithies and Gibbons, 1955 |
| Xanthomonas citri | Unknown | Unknown | Biofilm matrix | Sena-Vélez et al., 2016 |
| GRAM-POSITIVE BACTERIA | ||||
| Bacillus cereus | Unknown | Unknown | Biofilm matrix | Vilain et al., 2009 |
| Bacillus subtilis | Lytic-independent mechanism | QS (early competence) | HGT, nutrient source? | Takahashi, 1962 Zafra et al., 2012 |
| Deinococcus radiodurans | Unknown | Unknown | DNA repair | Boling and Setlow, 1966 |
| Enterococcus faecalis | Fratricidal-mechanism of autolysis | Unknown | Biofilm matrix | Thomas et al., 2008, 2009 |
| Lysteria monocytogenes | Unknown | Unknown | Biofilm matrix | Harmsen et al., 2010 |
| Micrococcus halodenitrificans | Unknown | Unknown | Unknown | Smithies and Gibbons, 1955 |
| Micrococcus sodonensis | Unknown | Unknown | Unknown | Campbell et al., 1961 |
| Mycobacterium avium | Unknown | Unknown | Biofilm matrix | Rose et al., 2015 |
| Staphylococcus aureus | Autolysis | QS | Biofilm matrix | Rice et al., 2007 Brackman et al., 2016 |
| Staphylococcus epidermidis | Autolysis | Unknown | Biofilm matrix | Qin et al., 2007 |
| Staphylococcus lugdunensis | Lytic-independent mechanism | Competence (comEB) | Biofilm matrix | Rajendran et al., 2015 |
| Streptococcus gordonii | Lytic-independent mechanism | QS (competence) | Biofilm matrix | Kreth et al., 2009; Jack et al., 2015 |
| Streptococcus intermedius | Unknown | Unknown | Biofilm matrix | Petersen et al., 2004; Nur et al., 2013 |
| Streptococcus mutans | Vesicles | Unknown | Biofilm matrix | Liao et al., 2014 |
| Streptococcus pneumoniae | Competence-induced lysis | QS (CSP) (competence) | Biofilm matrix, HGT, nutrient source? | Steinmoen et al., 2002; Moscoso et al., 2006 |
| Streptococcus sanguinis | Lytic-independent mechanism | Unknown | Biofilm matrix (aggregation) | Kreth et al., 2009 |
| ARCHAEA | ||||
| Halorubrum lacusprofundi | Unknown | Unknown | Biofilm matrix | Fröls et al., 2012 |
| Haloferax volcanii | Unknown | Unknown | Biofilm matrix, HGT, nutrient source | Chimileski et al., 2014a,b |
| Thermococcus spp. | Vesicles/unknown | Unknown | Unknown | Soler et al., 2008 |
| Thermococcus onnurineus | Vesicles | Unknown | Unknown | Choi et al., 2015 |
| EUKARYOTES | ||||
| Aspergillus fumigatus | Autolysis | Unknown | Biofilm matrix (antifungal resistance) | Rajendran et al., 2013 |
| Candida albicans | Unknown | Unknown | Biofilm matrix (antifungal resistance) | Kasai et al., 2006; Martins et al., 2010; Mathé and Van Dijck, 2013 |
We have listed all the microorganisms that have been described to date that release eDNA. However, it is important to note that only a small proportion of the microbial species present on Earth can be grown under laboratory conditions. Therefore, if we take into account the widespread distribution of eDNA in the environment it is very likely that the list is small compared to the real number of living microorganisms able to produce eDNA.