Modulibacteria

Modulibacteria is a bacterial phylum formerly known as KS3B3 or GN06. It is a candidate phylum, meaning there are no cultured representatives of this group. Members of the Modulibacteria phylum are known to cause fatal filament overgrowth (bulking) in high-rate industrial anaerobic wastewater treatment bioreactors^[1]^[2].

The Modulibacteria phylum was first proposed in 2006 by two independent research groups based on analyses of 16S rRNA gene sequences. One group recovered Modulibacteria sequences from the a hypersaline microbial mat from Guerrero Negro (Baja California Sur, Mexico) and used the provisional name GN06 for the novel phylum^[3], while the other recovered sequences from sulfur-rich black mud marine sediments and used the provisional name KSB3^[4].

The first genomic insights into the phylum were achieved in 2015, at which time the name "Modulibacteria" was proposed^[5]. Two genomes were recovered from methanogenic sludge samples of a full-scale upflow anaerobic sludge blanket (UASB) reactor treating a high-strength organic wastewater discharged from a food-processing factory. Through a combination of genome-based metabolic reconstruction and microscopic observation, it was determined that that the two studied Modulibacteria species (Moduliflexus flocculans and Vecturithrix granuli) produce filamentous structures and are Gram-negative, strictly anaerobic fermenters capable of non-flagellar based gliding motility. Both have an unusually large number of sensory and response regulator genes compared to other bacteria^[5].

Taxonomy

The following taxonomy was proposed by Sekiguchi et al (2015)^[5].

Class Moduliflexia
- Order Moduliflexales
  - Family Moduliflexaceae
    - Genus Moduliflexus
      - Species Moduliflexus flocculans

Class Vecturitrichia
- Order Vecturatrichales
  - Family Vecturatrichaceae
    - Genus Vecturithrix
      - Species Vecturithrix granuli

References

^ Yamada, Takeshi; Yamauchi, Toshihiro; Shiraishi, Koji; Hugenholtz, Philip; Ohashi, Akiyoshi; Harada, Hideki; Kamagata, Yoichi; Nakamura, Kazunori; Sekiguchi, Yuji (2007-05-31). "Characterization of filamentous bacteria, belonging to candidate phylum KSB3, that are associated with bulking in methanogenic granular sludges". The ISME Journal. 1 (3): 246–255. doi:10.1038/ismej.2007.28. ISSN 1751-7362.
^ Yamada, Takeshi; Kikuchi, Kae; Yamauchi, Toshihiro; Shiraishi, Koji; Ito, Tsukasa; Okabe, Satoshi; Hiraishi, Akira; Ohashi, Akiyoshi; Harada, Hideki; Kamagata, Yoichi; Nakamura, Kazunori (2011-01-21). "Ecophysiology of Uncultured Filamentous Anaerobes Belonging to the Phylum KSB3 That Cause Bulking in Methanogenic Granular Sludge". Applied and Environmental Microbiology. 77 (6): 2081–2087. doi:10.1128/aem.02475-10. ISSN 0099-2240.
^ Ley, Ruth E.; Harris, J. Kirk; Wilcox, Joshua; Spear, John R.; Miller, Scott R.; Bebout, Brad M.; Maresca, Julia A.; Bryant, Donald A.; Sogin, Mitchell L.; Pace, Norman R. (2006-05-01). "Unexpected Diversity and Complexity of the Guerrero Negro Hypersaline Microbial Mat". Applied and Environmental Microbiology. 72 (5): 3685–3695. doi:10.1128/AEM.72.5.3685-3695.2006. ISSN 0099-2240. PMID 16672518.
^ Tanner, Michael (2006). "Complex Microbial Communities Inhabiting Sulfide-rich Black Mud from Marine Coastal Environments" (PDF). Biotechnology et alia. 8: 1–16.
^ ^a ^b ^c Sekiguchi, Yuji; Ohashi, Akiko; Parks, Donovan H.; Yamauchi, Toshihiro; Tyson, Gene W.; Hugenholtz, Philip (2015-01-27). "First genomic insights into members of a candidate bacterial phylum responsible for wastewater bulking". PeerJ. 3. doi:10.7717/peerj.740. ISSN 2167-8359. PMC 4312070. PMID 25650158.{{cite journal}}: CS1 maint: unflagged free DOI (link)

[1] Yamada, Takeshi; Yamauchi, Toshihiro; Shiraishi, Koji; Hugenholtz, Philip; Ohashi, Akiyoshi; Harada, Hideki; Kamagata, Yoichi; Nakamura, Kazunori; Sekiguchi, Yuji (2007-05-31). "Characterization of filamentous bacteria, belonging to candidate phylum KSB3, that are associated with bulking in methanogenic granular sludges". The ISME Journal. 1 (3): 246–255. doi:10.1038/ismej.2007.28. ISSN 1751-7362.

[2] Yamada, Takeshi; Kikuchi, Kae; Yamauchi, Toshihiro; Shiraishi, Koji; Ito, Tsukasa; Okabe, Satoshi; Hiraishi, Akira; Ohashi, Akiyoshi; Harada, Hideki; Kamagata, Yoichi; Nakamura, Kazunori (2011-01-21). "Ecophysiology of Uncultured Filamentous Anaerobes Belonging to the Phylum KSB3 That Cause Bulking in Methanogenic Granular Sludge". Applied and Environmental Microbiology. 77 (6): 2081–2087. doi:10.1128/aem.02475-10. ISSN 0099-2240.

[3] Ley, Ruth E.; Harris, J. Kirk; Wilcox, Joshua; Spear, John R.; Miller, Scott R.; Bebout, Brad M.; Maresca, Julia A.; Bryant, Donald A.; Sogin, Mitchell L.; Pace, Norman R. (2006-05-01). "Unexpected Diversity and Complexity of the Guerrero Negro Hypersaline Microbial Mat". Applied and Environmental Microbiology. 72 (5): 3685–3695. doi:10.1128/AEM.72.5.3685-3695.2006. ISSN 0099-2240. PMID 16672518.

[4] Tanner, Michael (2006). "Complex Microbial Communities Inhabiting Sulfide-rich Black Mud from Marine Coastal Environments" (PDF). Biotechnology et alia. 8: 1–16.

[:0-5] Sekiguchi, Yuji; Ohashi, Akiko; Parks, Donovan H.; Yamauchi, Toshihiro; Tyson, Gene W.; Hugenholtz, Philip (2015-01-27). "First genomic insights into members of a candidate bacterial phylum responsible for wastewater bulking". PeerJ. 3. doi:10.7717/peerj.740. ISSN 2167-8359. PMC 4312070. PMID 25650158.{{cite journal}}: CS1 maint: unflagged free DOI (link)

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