LACHNOSPIRA-PECTINOSCHIZA SP-NOV AN ANAEROBIC PECTINOPHILE FROM THE PIG INTESTINE

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 th e rumina of cattle. We isolated three strains of pectinophilic bacteri a from colonic contents of pigs but were unable to isolate pectinophil es from the rumen contents of four sheep, even when the animals were f ed a high-pectin diet. The pectinophiles isolated from pigs were stric tly anaerobic, motile, gram-positive rods (0.36 to 0.56 by 2.4 to 3.1 mum). Pectin, polygalacturonic acid, and gluconate were the only subst rates that supported rapid growth. All three strains grew slowly on ei ther lactose or cellobiose and fermented fructose after a lag of sever al days. Pectin was degraded by means of an extracellular pectin methy lesterase and a Ca2+-dependent exopectate lyase. A comparison of the 1 6S rRNA sequences of these isolates with the 16S rRNA sequences of oth er gram-positive bacteria revealed a specific relationship with Lachno spira multipara (level of similarity, 94%). The Gram reaction, formati on of spore-like structures, and the utilization of lactose and cellob iose differentiated the pig isolates from previously described pectino philes. The pig isolates represent a previously undescribed species of the genus Lachnospira, for which we propose the name Lachnospira pect inoschiza.