Chitosan degradation potential of a newly isolated Mitsuaria sp. C4 and its whole genome sequencing

An endo-chitosanase (COSE) with a molecular weight of 34 kDa was purified and characterized from a newly isolated Mitsuaria sp. C4 (C4), reaching a 38.46% recovery rate and 4.79 fold purification. The purified C4 COSE exhibited optimum activity at 40 ℃ and pH 7.2, and significantly inhibited in the presence of Cu2+ and Fe3+. Km and Vmin of the COSE towards chitosan (COS) were calculated to be 2.449 g/L and 0.042 g/min/L. The highest COSE activity was statistically optimized to reach 8.344 U/mL by 1.34 fold of increase. Additionally, chitooligosaccharides were obtained by COSE hydrolysis of COS by TLC and HPLC analysis. Whole-genome sequencing demonstrated that the C4 strain contains 211 carbohydrate enzymes of which, COSE belongs to GHs-46 involved in the carbohydrate degradation. This work indicates that C4 strain could be a good resource used to enhance carbohydrate degradation, providing a new useful tool for chitooligosaccharides production.