We studied the effects of administration of TOS , a new growth factor derived from lactose for Bifidobacterium, and Bifidobacterium breve 4006 on the fecal flora of normal subjects. All of the Bifidobacterium species tested , eight reference strains and B. breve 4006 were capable of fermenting TOS in vitro , while others, 2 Bacteroides strains and 4 Lactobacillus and Enterobacteriaceae strains , showed an appreciable growth among 55 cultures tested. It was evident that TOS is not intestinally absorbed by the recipient subjects, from hydrogen breath test . In vivo, TOS (3g or 10g/day) was observed to promote the growth of both administered B. breve 4006 and resident Bifidobacterium strains. Simultaneous administration of B. breve 4006 and TOS caused the suppression of gram negative anaerobes and aerobes, Bacteroidaceae and Enterobacteriaceae , and the reduction of fecal ammonia and urinary indican excretion . It is concluded that TOS is a typical bifidus factor.

Summary. Human faeces hydrolysed synthetic P-D-glucuronides of both p-nitrophenol and phenolphthalein. The origin of this activity in faeces was localised in the bacterial pellet fraction after centrifugation. Ninety-seven bacterial strains with P-glucuronidase activity isolated from fresh human faeces were identified as species of Bacteroides, Peptostreptococcus, Fusobacterium, Propionibacterium, Clostridium, Eubacteriurn and Bijidobacterium. They were classified into two groups according to their activity against two synthetic P-D-glucuronides. One group hydrolysed p-nitrophenyl glucuronide and phenolphthalein glucuronide to the same extent and the other hydrolysed p-nitrophenyl glucuronide much more strongly than phenolphthalein glucuronide. The bile of rats given benzo(a)pyrene by mouth was tested for mutagenicity in the presence and absence of cell-free extracts of human faeces and bacteria. Extracts of P-glucuronidase-positive bacteria increased the mutagenicity of metabolites of benzo(a)pyrene, as did faecal extracts, but extracts of P-glucuronidasenegative bacteria did not. D-Saccharic acid-1,4-1actone inhibited the increase in mutagenicity produced by the faecal extracts and extracts of P-glucuronidase-positive bacteria except for Peptostreptococcus strains 204 and 952. These results indicate that some intestinal bacteria have P-glucuronidases heterogenous in substrate specificity and that they may be involved in mutagenicity of benzo(a)pyrene in the intestinal tract.

Antigenic analyses of five species of the genus Pichia were carried out for taxonomic study by the slide agglutination method using monospecific and absorbed antisera and the agglutinin absorption technique. Comparative studies were also performed with a few strains of each of the same species and their classifications are discussed with respect to the antigenic structures and the patterns of proton magnetic resonance (PMR) spectra of their cell wall polysaccharides. Pichia delftensis and Pichia zaruensis possessed thermostable antigens 1, 2, 5 and 11, and the former had also thermolabile antigen m. Both species were closely related to Candida krusei. Pichia toletana possessed thermostable antigens 1, 2, 5, 11, 17 and 49. Pichia bovis contained thermostable antigens 1, 2, 14, 15, 16, 20 and 21, and it was related to most species of the genus Hansenula, although assimilation of potassium nitrate was negative. Finally, Pichia etchellsii possessed thermostable antigens 1, 2, 3, 4, 9 and 14, and was closely related to Pichia vini. Patterns of PMR spectra of mannans of these species also supported their serological relationships.Therefore, P. delftensis, P. zaruensis and P. etchellsii are considered to be the synonyms of Pichia fluxuum, Pichia dispora and P. vini respectively, although P. toletana and P. bovis are independent species.