Methanobacteria Explained

Methanobacteria is a class of archaeans in the kingdom Euryarchaeota.^[1] Several of the classes of the Euryarchaeota are methanogens and the Methanobacteria are one of these classes.

Applications

Methanobacteria can be used in biomass conversion as well as energy production through Anaerobic digestion (AD) process. Microbial community is used in Anaerobic digestion (AD) to convert organic wastes into clean energy by reducing chemical and biological oxygen demand in the wastes.^[2] Solid-state anaerobic digestion, which contains six genera of methanogens including Methanobacteria, can ferment rice straw and then produce methane. Since conventional treatment is burning rice straw in field, applying Methanobacteria to waste disposal process can reduce the air pollution caused by straw burning and also alleviate energy shortage problem, especially in rural areas.^[3] During biomethanation process, insoluble organic material and higher molecular mass compounds will first be transformed into simple carbon compounds. These break-down products will then be fermented to acetic acid, hydrogen and carbon dioxide. Eventually, the acetic acids can be fermented by different methanogenic bacteria to produce methane.^[4]

The product of Methanobacteria in human body can be used to test diseases. Methane in breath is produced by anaerobic methanobacteria in human colon as a metabolic end product.^[5] The status of Methanobacteria product detected in breath tests can be used to evaluate patients' particular gastrointestinal disorders. It is shown that the proportion of breath methane excreters among patients with colorectal cancer is much higher than that of normal people. However, methane breath status might be influenced by variable factors existing in diagnostic procedures, limiting the usage of breath methane test in cancer diagnosis.^[6]

See also

• List of Archaea genera

Further reading

Brusa. T.. Conca. R.. Ferrara. A.. Ferrari. A.. Pecchioni. A.. The presence of methanobacteria in human subgingivai piaque. Journal of Clinical Periodontology . December 14, 2005. 14. 8. 470–471. 10.1111/j.1600-051X.1987.tb02254.x. 3308971.

Scientific journals

• Cavalier-Smith . T . 2002 . The neomuran origin of archaebacteria, the negibacterial root of the universal tree and bacterial megaclassification . Int. J. Syst. Evol. Microbiol. . 52 . 7 - 76 . 11837318 . Pt 1 . 10.1099/00207713-52-1-7. free .
• Woese . CR . Kandler O . Wheelis ML . 1990 . Towards a natural system of organisms: proposal for the domains Archaea, Bacteria, and Eucarya . Proc. Natl. Acad. Sci. USA . 87 . 4576 - 4579 . 2112744 . 10.1073/pnas.87.12.4576 . 12 . 54159 . 1990PNAS...87.4576W. free .

Scientific books

• Book: Boone, DR . 2001 . Class I. Methanobacteria class. nov. . Bergey's Manual of Systematic Bacteriology Volume 1: The Archaea and the deeply branching and phototrophic Bacteria . 2nd . DR Boone . RW Castenholz . 169 . . New York . 978-0-387-98771-2 . https://archive.org/details/bergeysmanualofs00boon/page/169 .
• Book: Garrity GM . Holt JG . 2001 . Phylum AII. Euryarchaeota phy. nov. . Bergey's Manual of Systematic Bacteriology Volume 1: The Archaea and the deeply branching and phototrophic Bacteria . 2nd . DR Boone . RW Castenholz . 169 . Springer Verlag . New York . 978-0-387-98771-2 . https://archive.org/details/bergeysmanualofs00boon/page/169 .
• Book: Murray, RGE . 1983 . The higher taxa, or, a place for everything... . Bergey's Manual of Systematic Bacteriology, Volume 1 . 1st . NR Krieg . JG Holt . 169 . The Williams & Wilkins Co. . Baltimore .

Notes and References

1. See the NCBI webpage on Methanobacteria. Data extracted from the Web site: NCBI taxonomy resources . . 2007-03-19.
2. Chen. Ye. Cheng. Jay J.. Creamer. Kurt S.. July 2008. Inhibition of anaerobic digestion process: A review. Bioresource Technology. 99. 10. 4044–4064. 10.1016/j.biortech.2007.01.057. 17399981.
3. Yan. Zhiying. Song. Zilin. February 2015. The effects of initial substrate concentration, C/N ratio, and temperature on solid-state anaerobic digestion from composting rice straw. Bioresource Technology. 177. 266–273. 10.1016/j.biortech.2014.11.089. 25496947.
4. Santosg. Yadvika. Sreekrishnan. T.R.. Kohli. Sangeeta. Rana. Vineet. October 2004. Enhancement of biogas production from solid substrates using different techniques–a review. Bioresource Technology. 95. 1. 1–10. 10.1016/j.biortech.2004.02.010. 15207286.
5. GA. Weaver. JA. Krause. TL. Miller. MJ. Wolin. 1986. Incidence of methanogenic bacteria in a sigmoidoscopy population: an association of methanogenic bacteria and diverticulosis.. Gut. 27. 6. 698–704. 10.1136/gut.27.6.698. 3721294. 1433329.
6. Abdelshaheed. NN. 1997. Biochemical tests in diseases of the intestinal tract: their contributions to diagnosis, management, and understanding the pathophysiology of specific disease states.. Critical Reviews in Clinical Laboratory Sciences. 152. 2. 137–141. 10.3109/10408369709049587. 9143817.