南海岛礁鱼源产蛋白酶菌株热带芽孢杆菌BTZB2的特性研究  

Characterization of proteinase-producing strain Bacillus tropicalis BTZB2 from source of fish in reef of South China Sea

作　　者：胡晓娟[1,2,3] 文国樑 徐煜[1,2,3] 苏浩昌 徐武杰[1,2] 陈作志 张殿昌[1,2] 王晶晶 曹煜成[1,2] HU Xiaojuan;WEN Guoliang;XU Yu;SU Haochang;XU Wujie;CHEN Zuozhi;ZHANG Dianchang;WANG Jingjing;CAO Yucheng(South China Sea Fisheries Research Institute,Chinese Academy of Fishery Sciences/Southern Marine Science and Engineering Guang-dong Laboratory(Zhuhai),Guangzhou 510300,China;Key Laboratory of South China Sea Fishery Resources Exploitation&Utilization,Ministry of Agriculture and Rural Affairs/Guang-dong Provincial Key Laboratory of Fishery Ecology and Environment,Guangzhou 510300,China;Sanya Tropical Fisheries Research Institute,Sanya 572018,China)

机构地区：[1]中国水产科学研究院南海水产研究所/南方海洋科学与工程广东省实验室(珠海),广东广州510300 [2]农业农村部南海渔业资源开发利用重点实验室/广东省渔业生态环境重点实验室,广东广州510300 [3]三亚热带水产研究院,海南三亚572018

出　　处：《南方水产科学》2024年第6期1-9,共9页South China Fisheries Science

基　　金：南方海洋科学与工程广东省实验室(珠海)资助项目(SML2023SP236);广东省重点研发计划项目(2021B0202040001);农业农村部财政专项(NHZX2024);中国水产科学研究院基本科研业务费专项资金(2023TD57);国家虾蟹产业技术体系(CARS-48)。

摘　　要：深远海及南海岛礁海域较近海海域受人类活动的影响小,微生物资源丰富。金带齿颌鲷(Gnathodentex aurolineatus)是南海典型的珊瑚礁食肉鱼类之一,其肠道微生物群落具有较高的碳源代谢能力。为挖掘南海典型岛礁鱼类肠道微生物中可培养蛋白酶的菌株资源,从南海渚碧礁海域金带齿颌鲷肠道样品中富集筛选到产蛋白酶菌株BTZB2,其在酪蛋白平板上具有明显水解圈,水解圈直径与菌落直径的比值在第24小时达3.0。从分子水平结合细菌形态学特征及生理生化特性分析,确定该菌株为热带芽孢杆菌(Bacillus tropicus)。该菌株最优产蛋白酶条件为:pH 8、盐度15‰、温度30℃、培养时间48 h、初始菌量105 C F U·m L^(-1)。优化后该菌株发酵48 h后的蛋白酶活力可达319.48 U·mL^(-1),较筛选时菌株的酶活力(124.55 U·mL^(-1))提高了156.5%。在组合1(pH 7、盐度22‰、温度30℃、初始接种量105 CFU·mL^(-1))和组合2(pH 8、盐度15‰、温度30℃、初始接种量105 CFU·mL^(-1))2种优化条件下,发酵第24小时粗酶液的比活力分别达975.34和889.97 U·mg-1,第48小时粗酶液的比活力分别达1836.51和2400.83 U·mg-1。结果表明,热带芽孢杆菌BTZB2具有良好的产蛋白酶能力,可作为南海鱼源功能微生物菌剂资源的备选菌株。Deep sea and islands and reefs in the South China Sea with abundant microbial resources are less affected by human activities than the nearshore waters.As one of the typical coral reef carnivorous fish in the South China Sea,Gnathodentex aurolineatus'intestinal microbiota has a high ability to metabolize carbon sources.To explore cultivable proteinase-producing strains from the intestinal microbiota of typical reef fish in the South China Sea,we selected the proteinase-producing strains from the intestinal microbiota of G.aurolineatus in Zhubi Reef of the South China Sea,and isolated the strain BTZB2.It had a clear hy-drolysis circle on the casein plate,and the ratio of hydrolysis circle diameter to colony diameter reached 3.0 at 24th hour.The strain was identified as Bacillus tropicus on molecular level,combining with morphological and physiological characteristics of bacteria.The optimal conditions for the protease production of this strain were pH of 8.0,salinity of 15‰,temperature of 30℃,cultivation time of 48 h and initial bacterial count of 105 CFU·mL^(-1).After fermentation for 48 h,the protease production acti-vity of this strain reached 319.48 U·mL^(-1),156.5%higher than that of the screened strain(124.55 U·mL^(-1)).Under the two opti-mal conditions:Combination 1(pH of 7,salinity of 22‰,temperature of 30℃,initial inoculation volume of 105 CFU·mL^(-1))and Combination 2(pH of 8,salinity of 15‰,temperature of 30℃,initial inoculation volume of 105 CFU·mL^(-1)),the specific activi-ties of crude enzyme solution for 24 h were 975.34 and 889.97 U·mg-1,and those for 48 h were 1836.51 and 2400.83 U·mg-1,re-spectively.The results indicate that B.tropicus BTZB2 has a good proteinase production ability,and it can be used as a candidate strain of functional microbial resource from fish in the South China Sea.

关 键 词：热带芽孢杆菌 产蛋白酶菌株 酶活力 金带齿颌鲷 

分 类 号：S932.8[农业科学—渔业资源]