Analysis of the alginate metabolic pathways in the marine Vibrio X511 based on comparative transcriptome

Abstract:

[Objective] A marine Vibrio X511 with strong ability to use alginate was isolated from the rotten Sargassum in the Weizhou Island of the North Sea. The metabolic pathway of using alginate by Vibrio X511 was studied by transcriptome sequencing.[Methods] Transcriptions sequencing was done by Illumina HiSeq2500 sequencing platform and the transcriptome of the strains cultured in alginate and glucose were sequenced. Differential transcripts were compared and analyzed, and the sequencing results were confirmed by fluorescence quantitative PCR. The fluorescence quantitative PCR was applied to verify the sequencing results. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes were used to annotate the function and pathway in differential transcripts.[Results] There were 2024 differentially expressed genes in the culture of alginate compared to those in glucose, with 1066 genes up-regulated and 958 genes down-regulated. Some genes in the ubiquitous metabolic pathway were also differentially expressed in different cultures. The transcriptions of all the genes involved in alginate utilization and the key genes of synthetic ethanol in Vibrio X511 were up-regulated. In addition, the strain had a unique way to utilize alginate and one of the metabolic processes has not been reported in Vibrio.[Conclusion] Our findings enrich the research of biological method for degradation of alginate, and provide valuable data for the research of large seaweed biomass-based energy.

Key words:transcriptome;fluorescence quantification;gene function;alginate;metabolic pathway