Culturable psychrotolerant methanotrophic bacteria in landfill cover soil

• Published in: Microbiology (New York) 2013-11, Vol.82 (6), p.847-855
• Main Authors: Kallistova, A. Yu, Montonen, L., Jurgens, G., Münster, U., Kevbrina, M. V., Nozhevnikova, A. N.
• Format: Article
• Language: English
• Subjects: Biomedical and Life Sciences; Experimental Articles; Life Sciences; Medical Microbiology; Methylobacter; Methylocaldum; Methylosinus; Microbiology; Pseudomonas; Verrucomicrobium
• ISSN: 0026-2617; 1608-3237
• DOI: 10.1134/S0026261714010044

Methanotrophs closely related to psychrotolerant members of the genera Methylobacter and Methylocella were identified in cultures enriched at 10°C from landfill cover soil samples collected in the period from April to November. Mesophilic methanotrophs of the genera Methylobacter and Methylosinus were found in cultures enriched at 20°C from the same cover soil samples. A thermotolerant methanotroph related to Methylocaldum gracile was identified in the culture enriched at 40°C from a sample collected in May (the temperature of the cover soil was 11.5–12.5°C). In addition to methanotrophs, methylobacteria of the genera Methylotenera and Methylovorus and members of the genera Verrucomicrobium, Pseudomonas , Pseudoxanthomonas, Dokdonella , Candidatus Protochlamydia, and Thiorhodospira were also identified in the enrichment cultures. A methanotroph closely related to the psychrotolerant species Methylobacter tundripaludum (98% sequence identity of 16S rRNA genes with the type strain SV96 T ) was isolated in pure culture. The introduction of a mixture of the methanotrophic enrichments, grown at 15°C, into the landfill cover soil resulted in a decrease in methane emission from the landfill surface in autumn (October, November). The inoculum used was demonstrated to contain methanotrophs closely related to Methylobacter tundripaludum SV96.