【Title】A PRIMARY STUDY ON EXTRACELLULAR ENZYME PRODUCTION OF ARCTIC SEA-ICE BACTERIA AND THE EFFECT OF LEADING ENVIRONMENT FACTORS
【摘要】覆盖在北极海洋上的广阔海冰为其内部生存的微生物群落提供了一个独特的生境。研究表明 ,大量海冰细菌能够分泌产生胞外酶 ,其中产蛋白或脂质水解酶细菌的比例远高于产多糖水解酶的细菌。温度、盐度是直接影响海冰细菌生存与活力的 2个主要环境因子。 76%的产酪蛋白酶海冰细菌为低温菌 ,菌株只能在 <35°C条件下生长 ;而 98%的酪蛋白酶最适作用温度≥ 35°C ,其中 62 %的酶最适作用温度≥ 45°C。几乎所有的产酪蛋白酶海冰细菌都耐盐或嗜盐
【Abstract】Sea ice covering Arctic sea provides a unique habitat with lower temperature and higher salinity, containing a complex microbial community. Numerous sea ice bacteria could produce extracellular enzymes, and the property of enzymes hydrolyzing proteins or lipids was much higher than that hydrolyzing polysaccharids. Temperature and salinity were two leading environment factors directly affecting the survival and activity of sea ice bacteria. This paper showed, with a high growth temperature limit at 35 °C , 76% of sea ice bacteria producing protease was cold adapted. However, 98% of those proteases had an optimum temperature higher than 35°C , and 62% of them even higher than 45 °C . Nearly all sea ice bacteria producing protease were halophilous or salt adapted.