Niamsup Piyanuch, Sujaya I Nengah, Tanaka Michiko, Sone Teruo, Hanada Satoshi, Kamagata Yoichi, Lumyong Saisamorn, Assavanig Apinya, Asano Kozo, Tomita Fusao, Yokota Atsushi
Laboratory of Microbial Resources and Ecology, Graduate School of Agriculture, Hokkaido University, Kita-9 Nishi-9, Kita-ku, Sapporo 060-8589, Japan.
Laboratory of Applied Microbiology, Graduate School of Agriculture, Hokkaido University, Kita-9 Nishi-9, Kita-ku, Sapporo 060-8589, Japan.
Int J Syst Evol Microbiol. 2003 Jan;53(Pt 1):263-268. doi: 10.1099/ijs.0.02347-0.
Five strains of thermotolerant lactic acid bacteria (G 12, G 22, G 35T, G 43 and G 44) isolated from chicken faeces were characterized taxonomically. The strains were facultatively anaerobic, Gram-positive, catalase-negative, non-motile, non-spore-forming rods. They were heterofermentative lactobacilli that produced DL-lactic acid. Growth of the strains occurred at 45 degrees C but not at 15 degrees C. The optimum temperature for growth was 42 degrees C, as determined from the specific growth rate. The highest permissive temperatures for growth were 50 degrees C for strain G35T and 48 degrees C for the other four strains. DNA G+C content of the strains was between 49 and 51 mol%. Complex fatty acid patterns of the strains showed the presence of C14:0, C16:0, sometimes C18:0, C18:1 and C19:0 cyclo in the cell walls. Phylogenetic analysis of the 16S rRNA gene sequences of the five strains placed them in the Lactobacillus caseil Pediococcus group, with Lactobacillus fermentum as their closest relative (about 95% sequence similarity). DNA-DNA hybridization data indicated that the thermotolerant strains were not L. fermentum. Taken together, the findings of this study show that the five strains isolated from chicken faeces represent a novel species within the genus Lactobacillus, for which the name Lactobacillus thermotolerans is proposed (G 35T = DSM 14792T =JCM 11425T).
对从鸡粪中分离出的5株耐热乳酸菌（G 12、G 22、G 35T、G 43和G 44）进行了分类学鉴定。这些菌株为兼性厌氧菌，革兰氏阳性，过氧化氢酶阴性，无运动性，不产芽孢，呈杆状。它们是产生DL-乳酸的异型发酵乳酸菌。这些菌株在45℃可生长，但在15℃不能生长。根据比生长速率确定，其生长的最适温度为42℃。菌株生长的最高允许温度，G35T为50℃，其他4株为48℃。这些菌株的DNA G+C含量在49至51mol%之间。菌株复杂的脂肪酸模式表明，其细胞壁中存在C14:0、C16:0，有时还有C18:0、C18:1和C19:0环丙烷脂肪酸。对这5株菌株的16S rRNA基因序列进行系统发育分析，结果表明它们属于干酪乳杆菌-片球菌群，与发酵乳杆菌亲缘关系最近（序列相似性约为95%）。DNA-DNA杂交数据表明，这些耐热菌株不是发酵乳杆菌。综上所述，本研究结果表明，从鸡粪中分离出的这5株菌株代表了乳杆菌属内的一个新物种，为此提出了“耐热乳杆菌”这一名称（G 35T = DSM 14792T =JCM 11425T）。
