Acidobacteria

phylum of bacteria

The phylum acidobacteria is distributed across nearly all ecosystems. Acidobacteria are particularly abundant in acidic soils, peatlands and environments with rich iron minerals.[1][2]  Most acidobacteria prefer acidic conditions (pH3.0-6.5) for growth,[1] but multiple members also live in alkaline soils.[3]

Acidobacterium

The characteristics of acidobacteria are gram-negative (gram staining negative), non-spore-forming and with multiple shapes. In most cases, they reproduce through binary fission (separate a body into two new parts). Most acidobacteria get energy from chemical substances (chemoheterotrophs), but some get it from light.[2]

Due to the most acidobacteria's capacity to live with a low level of nutrients, acidobacteria are hard to culture on the conventional growth media in the laboratory. Hence, they were underrepresented until gene analysis in recent decades.[1] Currently, acidobacteria have 26 subdivisions based on the results of DNA analysis.[4]

Acidobacteria has a large proportion of the genes encoding proteins that can transport nutrients from the environment into cells, which facilitates acidobacteria to acquire a wide range of nutrients, helping them to survive in nutrient-poor environments.[1]

Ecological roles

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Modulation of biogeochemical cycles

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Acidobacteria contains genes that help them in degrading sugar polymers. They can act as decomposers in soil and recycle organic matters produced by plants, fungi and insects.[5] Acidobacteria is likely to supplement their energy intake with carbon monoxide(CO), but this remains to be confirmed.[3] They significantly contribute to the carbon cycle in these two major parts: degradations of sugars and CO oxidation.[3]

Acidobacteria can process nitrogen in many different forms and they play a central role in the nitrogen cycle in plant-soil ecosystems.[1]

Some members of acidobacteria can do anaerobic respiration (respiration without oxygen) and promote the global sulfur cycle.[1]

Some acidobacteria can breathe oxygen at atmospheric and at very low oxygen concentrations. They have survival advantages in soils with a low level of oxygen.[1]

Some strains can consume hydrogen (H2) at the atmospheric level and this contributes to the global hydrogen cycle.[6]

Production of complex sugars

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Acidobacteria species can produce and send complex sugars to the outside of their cells , which could help plant roots uptake nutrients and water from soils by modifying the properties of soils around roots.[1] These sugars also support bacteria to adhere to the root surfaces.[7]

Influencing plant growth

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Acidobacteria species could actively produce important compounds that stimulate plant growth.[7]

References

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  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Kalam, Sadaf; Basu, Anirban; Ahmad, Iqbal; Sayyed, R. Z.; El-Enshasy, Hesham Ali; Dailin, Daniel Joe; Suriani, Ni Luh (2020). "Recent Understanding of Soil Acidobacteria and Their Ecological Significance: A Critical Review". Frontiers in Microbiology. 11: 580024. doi:10.3389/fmicb.2020.580024. ISSN 1664-302X. PMC 7661733. PMID 33193209.
  2. 2.0 2.1 Dedysh, Svetlana N.; Sinninghe Damsté, Jaap S. (22 January 2018). [10.1002/9780470015902.a0027685 "Acidobacteria"]. eLS: 1–10. doi:10.1002/9780470015902.a0027685. ISBN 9780470016176. {{cite journal}}: Check |url= value (help)
  3. 3.0 3.1 3.2 Ward, Naomi L.; Challacombe, Jean F.; Janssen, Peter H.; Henrissat, Bernard; Coutinho, Pedro M.; Wu, Martin; Xie, Gary; Haft, Daniel H.; Sait, Michelle; Badger, Jonathan; Barabote, Ravi D. (April 2009). "Three Genomes from the Phylum Acidobacteria Provide Insight into the Lifestyles of These Microorganisms in Soils". Applied and Environmental Microbiology. 75 (7): 2046–2056. doi:10.1128/AEM.02294-08. ISSN 0099-2240. PMC 2663196. PMID 19201974.
  4. Barns, Susan M.; Cain, Elizabeth C.; Sommerville, Leslie; Kuske, Cheryl R. (May 2007). "Acidobacteria Phylum Sequences in Uranium-Contaminated Subsurface Sediments Greatly Expand the Known Diversity within the Phylum". Applied and Environmental Microbiology. 73 (9): 3113–3116. doi:10.1128/AEM.02012-06. ISSN 0099-2240. PMC 1892891. PMID 17337544.
  5. John Wiley & Sons, Ltd, ed. (2001-05-30). eLS (1 ed.). Wiley. doi:10.1002/9780470015902.a0027685. ISBN 978-0-470-01617-6.
  6. Eichorst, Stephanie A.; Trojan, Daniela; Roux, Simon; Herbold, Craig; Rattei, Thomas; Woebken, Dagmar (March 2018). "Genomic insights into the Acidobacteria reveal strategies for their success in terrestrial environments". Environmental Microbiology. 20 (3): 1041–1063. doi:10.1111/1462-2920.14043. ISSN 1462-2912. PMC 5900883. PMID 29327410.
  7. 7.0 7.1 Kielak, Anna M.; Cipriano, Matheus A. P.; Kuramae, Eiko E. (December 2016). "Acidobacteria strains from subdivision 1 act as plant growth-promoting bacteria". Archives of Microbiology. 198 (10): 987–993. doi:10.1007/s00203-016-1260-2. ISSN 0302-8933. PMC 5080364. PMID 27339258.