Cornick N A, Jensen N S, Stahl D A, Hartman P A, Allison M J
U.S. Department of Agriculture, Iowa State University, Ames 50010.
Int J Syst Bacteriol. 1994 Jan;44(1):87-93. doi: 10.1099/00207713-44-1-87.
Pectinophiles are bacteria that utilize pectin and only a few related compounds as substrates. Obligately anaerobic pectinophiles have been isolated from the intestinal tracts and gingivae of humans and from the rumina of cattle. We isolated three strains of pectinophilic bacteria from colonic contents of pigs but were unable to isolate pectinophiles from the rumen contents of four sheep, even when the animals were fed a high-pectin diet. The pectinophiles isolated from pigs were strictly anaerobic, motile, gram-positive rods (0.36 to 0.56 by 2.4 to 3.1 microns). Pectin, polygalacturonic acid, and gluconate were the only substrates that supported rapid growth. All three strains grew slowly on either lactose or cellobiose and fermented fructose after a lag of several days. Pectin was degraded by means of an extracellular pectin methylesterase and a Ca(2+)-dependent exopectate lyase. A comparison of the 16S rRNA sequences of these isolates with the 16S rRNA sequences of other gram-positive bacteria revealed a specific relationship with Lachnospira multipara (level of similarity, 94%). The Gram reaction, formation of spore-like structures, and the utilization of lactose and cellobiose differentiated the pig isolates from previously described pectinophiles. The pig isolates represent a previously undescribed species of the genus Lachnospira, for which we propose the name Lachnospira pectinoschiza.
嗜果胶菌是一类利用果胶及少数几种相关化合物作为底物的细菌。专性厌氧的嗜果胶菌已从人类肠道和牙龈以及牛的瘤胃中分离出来。我们从猪的结肠内容物中分离出三株嗜果胶菌，但即使给四只绵羊喂食高果胶日粮，也未能从它们的瘤胃内容物中分离出嗜果胶菌。从猪身上分离出的嗜果胶菌为严格厌氧菌，具运动性，革兰氏阳性杆菌（0.36至0.56×2.4至3.1微米）。果胶、聚半乳糖醛酸和葡萄糖酸盐是仅有的能支持其快速生长的底物。所有三株菌在乳糖或纤维二糖上生长缓慢，且在数天的延迟期后能发酵果糖。果胶通过一种胞外果胶甲基酯酶和一种依赖Ca(2+)的外切果胶裂解酶降解。将这些分离株的16S rRNA序列与其他革兰氏阳性菌的16S rRNA序列进行比较，发现它们与多枝瘤胃球菌有特定关系（相似性水平为94%）。革兰氏反应、类芽孢结构的形成以及乳糖和纤维二糖的利用情况使猪分离株与先前描述的嗜果胶菌有所不同。猪分离株代表了瘤胃球菌属中一个先前未描述的物种，我们为此提议将其命名为多枝嗜果胶瘤胃球菌。
