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. 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.

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.
^ 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.

[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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