【摘要】 从27份深海沉积物中筛选到30株产淀粉酶细菌,并对其中的W7菌株的产酶条件及酶学性质进行了研究。对W7菌株进行16SrDNA序列分析表明该菌株属于盐单胞菌属(Halomonas)。其最适生长温度为25℃,能适应pH值7～13和盐度0～100的环境条件。该菌株可利用多种碳源,但只在淀粉存在的条件下产酶,可利用有机氮源和无机氮源,但有机氮源更能促进淀粉酶的产生。产酶的最适条件为:25℃,pH10,接种量2%,盐度50,150r/min摇床培养36～48h。粗酶液的最适作用温度为40℃,最适pH值为10。该菌具有反硝化和氨化活性。更多还原

【Abstract】 30 isolates producing extracellular amylase were screened from 27 deep-sea sediments. Phylogenetic analysis indicates that the strain W7 belongs to genus of Halomonas sp. It can grow at the range of pH 7～13 and salinity 0～10%. Its optimal growth temperature is 25 ℃. The strain can utilize many types of carbon sources but produce amylase only in the presence of starch. It can utilize both inorganic nitrogen sources and organic nitrogen sources but the use of organic nitrogen sources increases amylase yield. The optimal fermentation conditions were as follows:2 % inoculation volume,5 % salinity and initial pH10 with cultivating at 25 ℃ for 36～48 h on a shaker at a speed of 150 r/min.The optimal pH and temperature for the amylase activity are pH10 and 40 ℃ respectively. This strain also showes the activity of denitrification and ammoniation.更多还原