【摘要】 对一株分泌热稳定κ-卡拉胶酶印尼热泉菌进行了种属鉴定,并采用响应面法对该菌发酵产酶条件进行了优化。鉴定结果表明,该菌株属于芽孢杆菌属（Bacillus）,命名为Bacillus sp.Car19（Gene Bank:KT865196）。发酵条件优化结果显示,9个环境因子影响Bacillus sp.Car19产酶量。其中影响Bacillus sp.Car19产酶量的三个主要因素分别为培养温度、培养基中Cu²⁺浓度和培养基中Na Cl浓度。综合次要因素对Bacillus sp.Car19产酶影响,Bacillus sp.Car19最佳产酶发酵条件为:培养温度52.31℃、Cu²⁺浓度6.93 mmol/L、Na Cl浓度37.03 g/L,培养基p H为6,接种量1%,培养时间36 h,半乳糖浓度0.3 g/L,硝酸铵浓度7 g/L,卡拉胶浓度0.5 g/L。优化后发酵上清液酶活力达到15.21 U/m L,与优化前相比提高了1.5倍。更多还原

【Abstract】 In this study, we identified a high-yield κ-carrageenase bacteria strain by its 16 S r DNA sequence and optimized the fermentation conditions using a response surface methodology. The results show that the hot-spring bacterium was 99% identical to Bacillus sp. and therefore we assigned it to the Bacillus genus and named it Bacillus sp. Car19（Gen Bank accession number: KT865196）. The optimized fermentation conditions of Bacillus sp. Car19 involve nine factors that affect Bacillus sp. Car19 carrageenase production, and the three main factors are culture temperature, Cu²⁺ concentration, and Na Cl concentration. Combined with subordinate factors, the final optimized fermentation conditions for maximal activity, as determined by regression analysis are as follows: a culture temperature of 52.31℃, a Cu²⁺ concentration of 6.93 mmol/L, an Na Cl concentration of 37.03 g/L, medium p H = 6, 1% inoculation quantity, 36 h incubation time, a galactose concentration of 0.3 g/L, an ammonium nitrate concentration of 7 g/L, and a carrageenan concentration of 0.5 g/L. The supernatant carrageenase activity after optimized fermentation can reach 15.82 U/m L, which is 1.5 times that without optimization.更多还原