【摘要】 在汕头海域表层沉积物中分离得到69株高产几丁质酶的菌株,对其中6株形态特征差异比较明显、几丁质酶活力比较高的菌株SWCH-1、SWCH-2、SWCH-3、SWCH-5、SWCH-6和SWCH-9进行了16S rDNA序列鉴定,发现它们分别归属于5个属,即短芽孢杆菌属(Brevibacillus)、类芽孢杆菌属(Paenibacillus)、芽孢杆菌属(Bacillus)、气单胞菌属(Aeromonas)和寡养单胞菌属(Stenotrophomonas).采用兼并引物对6株菌几丁质酶编码基因的催化保守区片段进行了PCR扩增和序列分析,发现菌株均含有18家族几丁质酶编码基因;但是其编码的蛋白序列与NCBI收录的蛋白序列存在着差异,其中菌株SWCH-1和SWCH-3的蛋白序列与数据库中序列的相似性比较低,分别为85%和81%,菌株含有比较新的几丁质酶编码基因,其全基因序列的克隆和酶蛋白的纯化分析尚在进一步研究中.图6参18更多还原

【Abstract】 69 chitinolytic bacteria were isolated from the surface sediments of the Shantou Bay in Guangdong,China.According to their colony characteristics and chitinase activities,six strains(named SWCH-1,SWCH-2,SWCH-3,SWCH-5,SWCH-6 and SWCH-9)were chosen for further study.Based on their 16S rDNA sequences they belonged to five genera:Brevibacillus,Paenibacillus,Bacillus,Aeromonas and Stenotrophomonas.The catalytic conservative region of their chitinase genes were amplified by PCR.And the result from DNA sequencing revealed that all their coding protein sequences were related to the 18th chitinase family,but their protein sequences were different from the highest homologous NCBI records.Strains SWCH-1 and SWCH-3 had lower similarities,85% and 81%,respectively.Strains SWCH-1 and SWCH-3 might contain new chitinase coding genes.Fig 6,Ref 18更多还原