摘要
从海洋环境中筛选得到了1株高产角蛋白酶的菌株,经鉴定命名为弯曲假单胞菌(Pseudomonas geniculata)Gxun-15。经过单因素试验和正交优化,得到该菌最佳培养基组成及产酶条件为:初始pH 7.5,羽毛含量2.5%(m/V),酪蛋白1 g/L,蔗糖40 g/L。优化后酶活力可达674.39 U/mL,较优化前(202.35 U/mL)提高了3.3倍。酶学性质分析表明,该角蛋白酶最适作用温度和pH分别为60℃和6.5~8.0。化学试剂β-巯基乙醇可使酶活提高5倍,十二烷基磺酸钠(SDS)和苯甲基磺酰氟(PMSF)能抑制该酶酶活。羽毛降解产物中共检测到16种氨基酸,其中7种为必需氨基酸,总的游离氨基酸含量为221.24 mg/L,其中苯丙氨酸含量最高为118.36 mg/L。综上,海洋来源的P.geniculata Gxun-15具有高效分泌角蛋白酶的能力,所产角蛋白酶为丝氨酸蛋白酶,具有较强的化学试剂稳定性。该菌的羽毛降解产物中富含多种氨基酸,在饲料方面具有较好的应用潜力。
A strain with high keratinase production was screened from marine environment and identified as Pseudomonas geniculata Gxun-15.The optimal enzyme producing medium and culture conditions were obtained as follows:initial pH 7.5,feather content 2.5%(m/V),casein 1 g/L and sucrose 40 g/L.After optimization the enzyme activity reached 674.39 U/mL,a 3.3-fold increase compared to the pre-optimization(202.35 U/mL).The enzymatic properties of the keratinase showed that the optimum temperature and pH were 60℃and 6.5~8.0 respectively.The chemicalβ-mercaptoethanol increases the enzyme activity 5-fold and sodium dodecyl sulfonate(SDS)and phenyImethylsulfonyl fluoride(PMSF)inhibit the enzyme activity.A total of 16 amino acids were detected in the feather degradation products,of which 7 were essential amino acids,and the total free amino acid content was 221.24 mg/L,with the highest content of phenylalanine at 118.36 mg/L.To sum up,the marine origin P.geniculata Gxun-15 had the ability to secrete keratinase efficiently and the keratinase it produced was a serine proteinase with a strong chemical reagent stability.The feather degradation products of this bacterium were rich in various amino acids and had good application potential in feed.
作者
谢晨杰
宋超东
谭柄福
杨登峰
申乃坤
姜明国
张红岩
XIE Chenjie;SONG Chaodong;TAN Bingfu;YANG Dengfeng;SHEN Naikun;JIANG Mingguo;ZHANG Hongyan(Guangxi Marine Microbial Resources Industrialization Engineering Technology Research Center,Guangxi Key Laboratory for Polysaccharide Materials and Modifications,School of Marine Sciences and Biotechnology,Guangxi Minzu University,Nanning,Guangxi 530008,China;Guangxi Academy of Sciences,Guangxi Beibu Gulf Marine Research Center,Guangxi Key Laboratory of Marine Natural Products and Combinatorial Biosynthesis Chemistry,Nanning,Guangxi 530007,China)
出处
《中国饲料》
北大核心
2023年第23期26-35,共10页
China Feed
基金
广西民族大学引进人才项目(2018KJQD17)
广西科技重点研发计划项目(AA18242026,AB21196019,AB21220020)
国家自然科学基金项目(31660022,32060020)
广西研究生教育创新计划课题(YCSW2022256)
大学生创新创业训练计划课题(202110608014,S2022106008164,S202210608156)
广西民族大学实验技术创新与实验室管理研究课题(2019MDSY010,2020MDSY006)。
关键词
羽毛降解菌
角蛋白酶
弯曲假单胞菌
条件优化
酶学性质
feather-degrading bacteria
keratinase
Pseudomonas geniculata
condition optimization
enzymatic properties
