Zou Yang, Robbens Johan, Heyndrickx Marc, Debode Jane, Raes Katleen
Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University Campus Kortrijk, Graaf Karel de Goedelaan 5, 8500, Kortrijk, Belgium.
Flanders Research Institute for Agriculture, Fisheries and Food, Burgemeester Van Gansberghelaan 92 bus 1, 9820, Merelbeke, Belgium.
Curr Microbiol. 2020 Dec;77(12):3927-3936. doi: 10.1007/s00284-020-02216-8. Epub 2020 Sep 28.
A total of 92 marine bacteria belonging to Pseudomonas, Pseudoalteromonas, Psychrobacter, and Shewanella were first screened for their proteolytic activity. In total, four Pseudomonas strains belonging to Ps. fluorescens, Ps. fragi, Ps. gessardii, and Ps. marginalis; 14 Pseudoalteromonas strains belonging to Psa. arctica, Psa. carrageenovora, Psa. elyakovii, Psa. issachenkonii, Psa. rubra, Psa. translucida, and Psa. tunicata; and two Shewanella strains belonging to S. baltica and S. putrefaciens were identified to have a weak to high proteolytic activity (from 478 to 4445 mU/mg trypsin equivalent) against skim milk casein as protein source. Further chitinolytic activity screening based on these 20 proteolytic strains using colloidal chitin yielded five positive strains which were tested against three different chitin substrates in order to determine the various types of chitinases. Among the strains that can produce both proteases and chitinases, Psa. rubra DSM 6842 expressed not only the highest proteolytic activity (2558 mU/mg trypsin equivalent) but also the highest activity of exochitinases, specifically, β-N-acetylglucosaminidase (6.33 mU/10 cfu) as well. We anticipate that this strain can be innovatively applied to the valorization of marine crustaceans side streams.
总共对92株属于假单胞菌属、假交替单胞菌属、嗜冷杆菌属和希瓦氏菌属的海洋细菌进行了蛋白水解活性筛选。其中，共有4株假单胞菌菌株，分别属于荧光假单胞菌、脆弱假单胞菌、杰氏假单胞菌和边缘假单胞菌；14株假交替单胞菌菌株，分别属于北极假交替单胞菌、卡拉胶假交替单胞菌、叶卡氏假交替单胞菌、伊氏假交替单胞菌、红色假交替单胞菌、透明假交替单胞菌和被膜假交替单胞菌；以及2株希瓦氏菌菌株，分别属于波罗的海希瓦氏菌和腐败希瓦氏菌，被鉴定对脱脂奶粉酪蛋白作为蛋白质来源具有弱到高的蛋白水解活性（478至4445 mU/mg胰蛋白酶当量）。基于这20株蛋白水解菌株，使用胶体几丁质进行进一步的几丁质酶活性筛选，得到5株阳性菌株，为了确定不同类型的几丁质酶，对这5株菌株在三种不同的几丁质底物上进行了测试。在能够同时产生蛋白酶和几丁质酶的菌株中，红色假交替单胞菌DSM 6842不仅表现出最高的蛋白水解活性（2558 mU/mg胰蛋白酶当量），还表现出最高的外几丁质酶活性，具体而言，β-N-乙酰氨基葡萄糖苷酶活性也最高（6.33 mU/10 cfu）。我们预计该菌株可创新性地应用于海洋甲壳类动物副产物的增值利用。
