Exiguobacterium is a genus of
bacilli and a member of the
low GC phyla of
Bacillota. Collins et al. first described the genus Exiguobacterium with the characterization of E. aurantiacum strain DSM6208T from an alkaline potato processing plant.[2] It has been found in areas covering a wide range of temperatures (-12 °C—55 °C) including glaciers in
Greenland and hot springs in
Yellowstone, and has been isolated from ancient
permafrost in Siberia.[3] This ability to survive in varying temperature extremes makes them an important area of study. Some strains in addition to dynamic thermal adaption are also halotolerant (up to 13% added NaCl added to the medium), can grow within a wide range of pH values (5-11), tolerate high levels of UV radiation, and heavy metal stress (including arsenic).[4]
Seven
genomes from the genus have been completed as either complete (one circular
chromosome, with
plasmids) or in a draft format (containing multiple unassembled
contigs).
A new species of Exiguobacterium chiriqhucha has been found to have global distribution in cold lakes from Greenland, Pavilion Lake BC, and Laguna Negra, Argentina.[15] The 'Chiri qhucha' in Quechua means 'cold lake.'
The study of Gutiérrez-Preciado et al. was confirmed by the completion of genomes two strains of Exiguobacterium chiriqhucha RW2 and GIC31.[16]
Phospholipid fatty acid analysis (PLFA) of varying temperatures in Exiguobacterium chiriqhucha strain RW2 results in major rearrangements of cellular membrane function which may allow for its temperature, pH and salinity adaptation.[17]
Biodegradation of plastic
According to an article in the Stanford News Service,[18] senior research engineer Wei-Min Wu reported in his article "Biodegradation and Mineralization of Polystyrene by Plastic-Eating Mealworms. 2. Role of Gut Microorganisms."[19] that
mealworms can survive on a diet of
polystyrene when aided by strain YT2 of Exiguobacterium living in their gut.
^Raichand R, Pareek S, Singh NK, Mayilraj S (2012). "Exiguobacterium aquaticum sp. nov., a new member of the genus Exiguobacterium". Int. J. Syst. Evol. Microbiol. 62 (Pt 9): 2150–2155.
doi:
10.1099/ijs.0.035790-0.
PMID22058319.
^Singh NK, Raichand R, Kaur I, Kaur C, Pareek S, Mayilraj S (2013). "Exiguobacterium himgiriensis sp. nov., a novel member of the genus Exiguobacterium, isolated from the Indian Himalayas". Antonie van Leeuwenhoek. 103 (4): 789–796.
doi:
10.1007/s10482-012-9861-5.
PMID23229437.
S2CID2499061.
^Yang Y, Yang J, Wu WM, Zhao J, Song Y, Gao L, Yang R, Jiang L (2015). "Biodegradation and Mineralization of Polystyrene by Plastic-Eating Mealworms: Part 2. Role of Gut Microorganisms". Environ. Sci. Technol. 49 (20): 12087–93.
Bibcode:
2015EnST...4912087Y.
doi:
10.1021/acs.est.5b02663.
PMID26390390.