摘要
从新疆不同地区采集到的哈萨克族手工奶酪中分离得到100株菌种,通过分离(RB)培养基和罗丹明B培养基筛选出4株产脂肪酶酵母菌,分别为Y-2、Z-5、S-6、N-5。结合菌种生理生化及26SrDNA基因序列分析确定4株菌的系统进化地位,在系统发育上Y-2、Z-5隶属于马克斯克鲁维酵母(Kluyveromyces marxianus),S-6和N-5分别隶属于毕赤酵母(Pichia kudriavzevii)、乳酸克鲁维酵母(Kluyveromyces lactis)。利用对硝基苯酚法对4株菌种产酶酶活进行测定,发现K.marxianus Z-5产脂肪酶酶活最高,达23.00 U/mL;对K.marxianus Z-5产酶条件进行优化,确定最优发酵条件为:温度30℃、pH 7.5、接种量2.5mL/100mL左右时,其酶学活性最强,为25.99U/mL。
100 strains were isolated from traditional Kazak cheese in different parts of Xinjiang Uygur Autonomous Region.Four yeast strains Y-2,Z-5,S-6 and N-5 of producing lipase were screened by RB and Rhodamine B medium and they were identified by 26 SrRNA gene D1/D2 and internal transcribed spacers.The results showed that strains Y-2 and Z-5 were belonged to Kluyveromyces marxianus,while S-6 and N-5 belonged to Pichia kudriavzevii and Kluyveromyces lactis,respectively.The lipase producing activities of the 4 strains were determined by p-nitrophenol method,and the K.marxianus Z-5 was the highest,up to 23.00 U/mL.The optimum lipase production conditions of K.marxianus Z-5 were determined as follows：fermentation temperature 30 ℃,pH 7.5,inoculum 2.5 mL/100 mL.The obtained enzymatic activity was 25.99 U/mL.
作者
刘飞
郑晓吉
李宝坤
史学伟
董娟
李开雄
诸葛斌
LIU Fei;ZHENG Xiao-ji;LI Bao-kun;SHI Xue-wei;DONG Juan;LI Kai-xiong;ZHU-GE Bin(College of Food Science, Shihezi University, Shihezi, Xinjiang 832000, China;College of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China)
出处
《食品与机械》
CSCD
北大核心
2018年第3期54-58,共5页
Food and Machinery
基金
国家自然科学基金青年基金项目(编号:31660453)
石河子大学应用基础研究项目(编号:2015ZRKXYQ11)
关键词
脂肪酶
酵母菌
筛选
条件优化
Lipase
yeast
screening
condition optimization
