RT Journal Article SR Electronic(1) A1 Kupriyanova, Elena A1 Villarejo, Arsenio A1 Markelova, Alexandra A1 Gerasimenko, Lyudmila A1 Zavarzin, Georgy A1 Samuelsson, Göran A1 Los, Dmitry A A1 Pronina, NataliaYR 2007 T1 Extracellular carbonic anhydrases of the stromatolite-forming cyanobacterium Microcoleus chthonoplastes JF Microbiology, VO 153 IS 4 SP 1149 OP 1156 DO https://doi.org/10.1099/mic.0.2006/003905-0 PB Microbiology Society, SN 1465-2080, AB Active extracellular carbonic anhydrases (CAs) were found in the alkaliphilic stromatolite-forming cyanobacterium Microcoleus chthonoplastes. Enzyme activity was detected in intact cells and in the cell envelope fraction. Western blot analysis of polypeptides from the cell envelope suggested the presence of at least two polypeptides cross-reacting with antibodies against both α and β classes of CA. Immunocytochemical analysis revealed putative α-CA localized in the glycocalyx. This α-CA has a molecular mass of about 34 kDa and a pI of 3.5. External CAs showed two peaks of activity at around pH 10 and 7.5. The possible involvement of extracellular CAs of M. chthonoplastes in photosynthetic assimilation of inorganic carbon and its relationship to CaCO3 deposition during mineralization of cyanobacterial cells are discussed., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.2006/003905-0