Complete Genome and Calcium Carbonate Precipitation of Alkaliphilic Bacillus sp. AK13 for Self-Healing Concrete

• Published in: Journal of Microbiology and Biotechnology Vol. 30; no. 3; pp. 404 - 416
• Main Authors: Jung, Yoonhee, Kim, Wonjae, Kim, Wook, Park, Woojun
• Format: Journal Article
• Language: English
• Published: Korea (South) Korean Society for Microbiology and Biotechnology 28.03.2020; 한국미생물·생명공학회
• Subjects: Alkalies - chemistry; Bacillus - drug effects; Bacillus - genetics; Calcium Carbonate - pharmacology; Chemical Precipitation; Genome, Bacterial; Phylogeny; Research article; 생물학; microbially-induced calcium carbonate precipitation; X-ray diffraction; calcium acetate; Bacillus species; crack healing; isotope ratio mass spectrometer
• ISSN: 1017-7825; 1738-8872
• DOI: 10.4014/jmb.1908.08044

Bacteria that are resistant to high temperatures and alkaline environments are essential for the biological repair of damaged concrete. Alkaliphilic and halotolerant sp. AK13 was isolated from the rhizosphere of . Unlike other tested species, the AK13 strain grows at pH 13 and withstands 11% (w/v) NaCl. Growth of the AK13 strain at elevated pH without urea promoted calcium carbonate (CaCO ) formation. Irregular vateritelike CaCO minerals that were tightly attached to cells were observed using field-emission scanning electron microscopy. Energy-dispersive X-ray spectrometry, confocal laser scanning microscopy, and X-ray diffraction analyses confirmed the presence of CaCO around the cell. Isotope ration mass spectrometry analysis confirmed that the majority of CO ions in the CaCO were produced by cellular respiration rather than being derived from atmospheric carbon dioxide. The minerals produced from calcium acetate-added growth medium formed smaller crystals than those formed in calcium lactate-added medium. Strain AK13 appears to heal cracks on mortar specimens when applied as a pelletized spore powder. Alkaliphilic sp. AK13 is a promising candidate for self-healing agents in concrete.