一株高产丁酸的丁酸梭菌分离鉴定及其生物学性质研究

从健康成人新鲜粪便中筛选得到一株高产丁酸的丁酸梭菌C1-6,分析其生长特性和部分生物学性质。从形态学特征、生理生化试验、16S rDNA基因序列同源性以及多位点序列分型(Multi-site sequence typing,MLST)等方面对菌株进行鉴定;分析了该菌的部分生物学性质,包括发酵液中丁酸含量,对酸、胆盐、模拟消化道的耐受性以及抗生素抗性。结果表明,丁酸梭菌C1-6的24 h发酵液中丁酸含量达到2.1 g/L左右;对酸、胆盐以及模拟消化道环境具有较强的耐受性,其在pH2和pH3的酸性条件下孵育3 h后的存活率分别为72.5%和91.8%,对胆盐的耐受性随胆盐浓度的提高略有上升,当胆盐浓度为1%时,其存活率为104.63%,经过模拟消化道环境后其存活率仍高达93%以上;除对氯霉素、卡那霉素等氨基糖苷类抗生素和青霉素具有抗性外,对氨苄西林、四环素、万古霉素、头孢呋辛均比较敏感,有必要进一步评价其耐药基因的转移风险。由以上结果发现,丁酸梭菌C1-6有一定的潜在应用价值。

Isolation and Identification of a Strain of Clostridium butyricum with High Yield of Butyric Acid and Its Biological Characteristics

A strain of Clostridium butyricum C1-6 with high butyric acid production was isolated from faeces of healthy adults and its growth and biological characteristics were analyzed. The strain was identified in the aspects of morphological features,physiological and biochemical tests,16S rDNA gene sequence homology and multi-site sequence typing(MLST). The biological properties of the strains were evaluated by measuring the content of butyric acid in the fermentation broth,the tolerance to acid,bile salts,simulated digestive tract and antibiotic resistance. The results showed that the butyric acid content of the 24 h fermentation broth of this strain reached about 2.1 g/L. It was highly resistant to acid,bile salts and simulated digestive tract environment. The survival rate after incubation for 3 h under acidic conditions of pH2 and pH3 was 72.5% and 91.8%. The tolerance to bile salts was promoted with the increase of bile salt concentration. Its tolerance was 104.63% when the bile salt concentration was 1%. And its survival rate was still above 93% after undergoing simulated the digestive tract environment. This strain was sensitive to ampicillin,tetracycline,vancomycin,and cefuroxime except certain aminoglycoside antibiotics such as chloramphenicol and kanamycin,and penicillin. It was necessary to further evaluate the risk of antibiotic resistance genes transfer. From the above results,C. butyricum C1-6 has application potential.