一株产纤维素酶的枯草芽孢杆菌部分生物学特性研究

为了解藏绵羊源产纤维素酶的芽孢杆菌分离株(SWUN 6407)作为微生物添加剂候选菌株的潜力,用PCR扩增16S r DNA序列对其进行鉴定,刚果红染色法测定其产纤维素酶能力,以比浊法测定其对酸和牛胆盐的耐受力,用纸片法测定其对庆大霉素、链霉素、青霉素G、万古霉素、乙酰螺旋霉素、克林霉素、林可霉素、环丙沙星、红霉素、四环素、卡那霉素、磷霉素、替考拉宁、头孢噻肟、利福平、氨苄西林、呋喃妥因、阿莫西林等18种抗菌药物的敏感性.结果显示,SWUN 6407为枯草芽孢杆菌,水解圈与菌落直径的比值为5.8,在p H 2.0环境中存活率为30.5%,在0.7%牛胆盐环境中存活率为64.1%,对18种抗菌药物均敏感.综上可见,SWUN 6407是纤维素酶高产酶菌株,其耐酸、耐胆盐的能力符合微生物添加剂的要求,且不具有耐药性,是一株良好的高产纤维素酶微生物添加剂候选菌株.

Study on biological characteristics of Bacillus subtilis producing cellulase

In order to understand the potential of a cellulase producing Bacillus subtilis SWUN6407 which was islolated from Tibetan sheep as a candidate strain of micro ecological preparation.the 16SrDNA gene of the SWUN6407 strains was amplified by PCR-sequencing.The production of cellulase was determined by Congo red staining method. The tolerance to acid and bile salt was determined by turbidity method. The disc diffusion method was used to determine susceptibility of strain to 18 antimicrobial agents including gentamicin, streptomycin, penicillin G, vancomycin, acetylspiramycin, lincomycin, clindamycin, ciprofloxacin, erythromycin, tetracycline, kanamycin, fosfomycin, teicoplanin, cefotaxime, ampicillin, rifampicin, nitrofurantoin, and amoxicillin. The results showed that the Bacillus SWUN 6407 was Bacillus subtilis. Its survival rate was 30.5% under the environment of pH 2.0 and 64.1% under the environment of 0.7% bile salt. It was sensitive to 18 kinds of antimicrobial agents. In conclusion, SWUN6407 has good enzyme production, acid and bile salt stability to meet the requirements of microbial additives. Furthermore, this strain shows high susceptibility to 18 agents tested. SWUN6407 has biological characteristics to meet a micro ecological additice.