Cold-Adapted Bacterial Diversity in Mingyong Glacier based on Combination Analysis of Fatty Acids and 16S rRNA Gene Sequence

Abstract

The Mingyong Glacier is located in the northwest of Yunnan Province, China. The area, including the cold temperate zone, the middle temperate zone, and the warm temperate zone, is a typical vertical climate zone. To explore new classification and identification methods for cold-adapted bacteria in this area, the Sherlock automated microbial identification system (MIDI, Inc., Newark, DE, United States) and 16S rRNA gene sequencing was used. Phylogenetic analysis showed that for cold-adapted bacteria the analysis by unsaturated fatty acids in membranes provided more precise taxonomic information than 16S rRNA gene analysis, which is sensitive enough to distinguish cold-adapted bacteria at the same genus level. The results also demonstrated that the proportion of unsaturated fatty acids in those cold-adapted bacterial cell membranes was inversely proportional to temperature. Although most of the unsaturated fatty acid composition was similar to other reported cold-adapted bacteria, the fatty acid composition of some of the cold-adapted bacteria was not the same, which warrants further study.