Abstract:

To study the composition of the bacterial community and enzyme-producing activity of cultivable bacteria in the intertidal sediments of the Fildes Peninsula, Antarctica, sediment samples from 19 sites of the intertidal zone were collected, and the bacterial community composition of these sediments was sequenced by high-throughput sequencing using Illumina MiSeq technology. The absolute abundance of total bacteria in the sediments was measured by real-time PCR. The plate coating method was used to purify and isolate the culturable bacteria of sediment samples from 16 sites. Thirty-eight strains of bacteria were selected for the screening of enzyme activities. In total, 2 375 operational taxonomic units (OTUs) of the intertidal sediment samples were obtained, and these OTUs were assigned into 42 bacterial phyla, of which Proteobacteria, Bacteroidetes, and Actinobacteria were the dominant groups. The abundance of total bacteria ranged from 2.51 × 10⁷ to 6.65 × 10⁸ copies·g⁻¹. Among culturable bacteria, 129 strains were assigned to four phyla, 25 genera, and 50 species. Proteobacteria, Actinobacteria, and Bacteroides were the predominant groups, which were basically consistent with the results of high-throughput sequencing. Thirty-eight strains were selected for the screening of low-temperature enzyme activities (including lipase, amylase, gelatinase, alginate, and cellulase), and 17 strains were found to produce lipase, 24 strains produced amylase, 18 strains produced gelatin, four strains produced alginate, and four strains produced cellulase.