奶酪中高产β-半乳糖苷酶菌株的筛选及发酵条件的优化-《中国调味品》

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Title:: Screening of high-yield -galactosidase strains in cheese and optimization of fermentation conditions HUANG Qian, Z HENG Xiao -chun, W ANG Bin, S HI Xue-wei*

摘要:: 以新疆哈萨克族奶酪样品为原料，通过蓝白斑筛选找到9株产β-半乳糖苷酶的菌株。经过摇瓶发酵测定β-半乳糖苷酶的水解活性，筛选出一株酶活力较高的菌株y-2经鉴定为马克思克鲁维酵母。通过研究温度、pH、破壁时间，乳糖浓度，金属离子和接种量等6个参数对这株菌酶活的影响，以优化合成培养基中β-半乳糖苷酶的产生。通过单因素实验进行响应面法回归统计分析。结果表明，酶活最高的最佳条件是：温度37℃、pH为7、破壁时间为5min，K+是促生长因子且浓度为0.001g/L，乳糖浓度为10％，接种量为4%。

Abstract:: Using Xinjiang Kazakh cheese samples as the raw materials, 9 strains producing β-galactosidase are found through blue - white screening. The hydrolytic activity of β-galactosidase is measured by shake - flask fermentation, and a strain y-2 with high enzyme activity i s selected and identified as Kluyveromyces marxianus. By studying the influence of temperature, pH, wall breaking time, lactose concentration, metal ions and inoculation amount on the enzyme activity of the strain, the production of β-galactosidase in the synthetic medium is optimized. The regression statistical analysis of response surface method is conducted through single factor experiment. The results show that the activity of β-galactosylase produced by Kluyveromyces marxianus is the highest at 37 ℃, pH 7, wall breaking time 5 min, K⁺as a growth factor at the concentration of 0.001 g/L, 10% lactose and 4% inoculation amount.