Baisuo Zhao
Chinese Academy of Agricultural Sciences, China
Title: Complete genome sequence of Alkalitalea saponilacus, an anaerobic haloalkaliphilic bacterium capable of secreting halostable xylanase
Biography
Biography: Baisuo Zhao
Abstract
The anaerobic haloalkaliphile Alkalitalea saponilacus SC/BZ-SP2T could utilize xylan as sole carbon source and produce propionate as the main fermentation product. The xylanase activity from A. using the combined substrates of 0.4% (w/v) sucrose + 0.1% (w/v) birch xylan was 3.2-fold than that of 0.5% (w/v) sucrose or 0.5% (w/v) birch xylan. The xylanse is halo-stable as it exhibited optimal activity at a broad range of 2-6% NaCl. Its activity was inhibited by Cu2+, Fe3+, Ni2+, Al3+, Mn2+, Co2+, Zn2+ and Ca2+ while increased 1.16-fold with the addition of Tween 20. In order to get a deep understanding of the potential genetic mechanisms of xylanase secretion and adaptive saline-alkali tolerance, the complete genome sequence of strain SC/BZ-SP2T was performed with the Pacbio SMRT and Illumina Misseq platforms. The genome contained one chromosome, with the total size of 4,775,573 bps, and the G+C content of this strain was 39.27%. A number of genes related to xylan degradation and its complete xylan degradation pathway, xyn A gene of xylanase belonging to a glycoside hydrolase (GH) family 10 and its neighborhood genes were systematically identified. Furthermore, various genes involved in biosynthesis and transportation of osmolytes, as well as genes encoding monovalent cation/proton antiporters, multi-subunit sodium/ proton antiporters, F0F1-ATP synthases, H+-transporting ATPases, Na+/solute symporters and K+ transport systems were predicted. This genome sequence provides molecular information and elucidation for halo-stable xylanase production, and will be used in the biotechnology.