Characterization of genes involved in polysaccharide degradation by Microbulbifer sp. YPW1 and YPW16

Abstract:

[Background] Microbulbifer species isolated from the marine environments have the ability to degrade polysaccharides. They participate in the marine carbon cycle as an important player of carbohydrate metabolism in the environment. [Objective] To analyze the polysaccharide-degrading activities and genomics information of two Microbulbifer strains. [Methods] The 3,5-dinitrosalicylic acid colorimetry (DNS method) was employed to determine the polysaccharide-degrading activity. High-throughput sequencing was performed to sequence and assemble the genome sequence of the strains. [Results] Two strains of Microbulbifer species, namely YPW1 and YPW16, were isolated in this work, both of which were potential new species. YPW1 degraded 7 polysaccharides (agar, alginate, pectin, chitin, xylan, starch, and pullulan), while YPW16 only degraded starch and pullulan, with the activity lower than YPW1 under the experimental conditions. The genome comparison with other Microbulbifer strains showed that YPW1 had a wider polysaccharide degradation range due to its abundant genes for polysaccharide degradation. However, the polysaccharide degradation range of YPW16 was narrower. Moreover, the genes involved in polysaccharide degradation presented uneven distribution in the genomes of Microbulbifer species. [Conclusion] This study provided two potential new strain resources of Microbulbifer and a biological tool for polysaccharide degradation, laying a foundation for studying the distribution of polysaccharide degradation genes and the ecological functions of Microbulbifer.