一株产几丁质脱乙酰酶海洋细菌的筛选、鉴定及发酵优化

目的:从海洋样品中筛选产几丁质脱乙酰酶细菌,对菌株进行鉴定和发酵条件优化。方法:利用显色平板从黄海海州湾燕尾港海域的海泥中筛选几丁质脱乙酰酶产生细菌。利用形态学、生理生化特性以及16S r DNA序列分析对菌株进行鉴定。利用单因素实验和正交实验优化菌株发酵条件。结果:筛选获得几丁质脱乙酰酶产生菌MCDA01,经形态学特征、生理生化特性以及16S r DNA序列分析将菌株鉴定为天目不动杆菌(Acinetobacter schindleri)。菌株最佳生长条件为30℃,p H8.0,Na Cl 4%。最佳产酶发酵条件为:发酵时间60 h,发酵温度20℃,培养基起始p H7,装液量20%,诱导剂几丁质浓度1%。在此条件下,产酶量达到201.37 U/m L,比优化前提高了4.14倍。结论:几丁质脱乙酰酶产生菌MCDA01产酶量达到201.37 U/m L,有工业应用潜力。 

Screening and identification of a marine bacteria producing chitin deacetylase and optimization of its fermentation conditions

Objective: Screen chitin-deacetylase-producing strains from marine samples, identify the strain and optimize its fermentation conditions.Methods: Chitin-deacetylase-producing strains were screened by color culture medium from the marine mud of Yanwei Harbor. The strains were identified by morphological, physiological and biochemical characteristics and16 S r DNA sequence analysis. The single factor and orthogonal experimental design were used to optimize the fermentation conditions.Results: Strain MCDA01 producing chitin deacetylase was screened, and it was identified as Acinetobacter schindleri through morphological, biochemical characteristics, and 16 S r DNA sequence analysis. The optimal culture conditions of strain MCDA01 was obtained as follows: 30 ℃, p H8.0, and Na Cl 4%.The optimal fermentation conditions was obtained as follows: the fermentation time was 60 h, the fermentation temperature was 20 ℃, the culture medium starts p H was 7, the liquid loading amount was 20%, and the inducer chitin concentration was 1%. Under this condition, production of enzyme was up to201.37 U/m L, which was increased by 4.14 times. Conclusion: The maximum of enzyme production were optimized to201.37 U/m L, and have industrial application potential.