一株产脂肪酶芽胞杆菌菌株SJXYZ的鉴定

摘要

[Objective]To identify strain SJXYZ,which was isolated from commercial sterilized milk.[Method]Strain SJXYZ was character-ized by morphological, biochemical and physiological tests,16S rRNA gene sequence determination and phylogenetic analyses.[Result]16S rRNA gene analysis indicated that strain SJXYZ belonged to the genus Bacillus and had small higher than 97% similarity to B.altitudinis 41KF2bT, B.xiamenensis HYC-10T, B.safensis FO-36bT, B.zhangzhouensis DW5-4T, B.australimaris NH7I_1T and B.pumilus ATCC 7061T.The phylogenetic analysis showed that strain SJXYZ was closest to B.altitudinis 41KF2bT,but formed an independent branch separa-ted from all the reference strains.Cells were gram-stain-positive,straight rod,motile.Growth occurred at pH 5-9,at 0%-5% NaCl,and with optimum temperature at 30 -35 ℃.Lipase was passive.Proteinase, cellulase and amylase were negative.Sensitive to ampicillin (10 μg), gentamycin(10 μg), norxacin(10 μg), cefazolin(30 μg), tetracycline(30 μg), cephalothin(30 μg)and streptomycin (10 μg).Genomic and phenotypic data of strain SJXYZ shew a big difference from B.altitudinis 41KF2bT.[Conclusion]On the basis of these findings, we propose that strain SJXYZ represents a new species of Bacillus for which we propose the name Bacillus sp.SJXYZ.%[目的]对分离自市售高温灭菌牛奶的产脂肪酶菌株SJXYZ进行鉴定.[方法]通过16S rRNA基因序列及系统发育树分析、形态观察和生理生化特性分析,对菌株SJXYZ生物学特性进行初步鉴定.[结果]16S rRNA基因序列分析显示该菌株属于芽胞杆菌属(Ba-cillus),与B.altitudinis 41KF2bT(高地芽胞杆菌)、B.xiamenensis HYC -10T(厦门芽胞杆菌)、B.safensis FO-36bT(沙福芽胞杆菌)、B. zhangzhouensis DW5-4T(漳州芽胞杆菌)、B.australimaris NH7I_1T(南海芽胞杆菌)和B.pumilus ATCC 7061T(短小芽胞杆菌)相似度皆为97%以上.系统发育分析显示,该菌株与B.altitudinis 41KF2bT亲缘关系最近,但形成独立的进化分支,无法归入已知物种.菌株SJXYZ为革兰氏阳性,直杆状,运动性,最适温度为30~35 ℃,适宜pH为5~9,适宜盐度(NaCl)为0%~5%;产脂肪酶,不产纤维素酶、淀粉酶、蛋白酶;对氨苄西林(10 μg)、庆大霉素(10 μg)、氟哌酸(10 μg)、头孢唑啉(30 μg)、四环素(30 μg)、头孢噻吩(30 μg)、链霉素(10 μg)敏感.所测特性与B.altitudinis 41KF2bT有较大的差异.[结论]菌株SJXYZ可能为新的物种,暂命名为Bacillus sp.SJXYZ.