Phage resistance and altered growth habit in a strain of Streptococcus bovis.

Bacteriophage (phi Sb01) of Streptococcus bovis, isolated from pooled rumen fluid of cattle, was a small siphovirus of morphotype B1. It contained double-stranded DNA of length 30.9 kb, which was digested by the restriction endonucleases, EcoRI, HindIII, and PvuII.

Morphology of three polycentric rumen fungi and description of a procedure for the induction of zoosporogenesis and release of zoospores in cultures.

Three polycentric rumen fungi, LL, LC2 and Ruminomyces elegans (C2), isolated from the rumen of cattle were grown in six culture media. LL and LC2 were morphologically similar. Their characteristics resembled those of Orpinomyces and Neocallimastix joyonii, and they grew well and produced sporangia after 3-4 d growth in all the media.

Inducible bacteriophages from ruminal bacteria.

The incidence of temperate bacteriophage in a wide range of ruminal bacteria was investigated by means of induction with mitomycin C. Supernatant liquid from treated cultures was examined for phagelike particles by using transmission electron microscopy. Of 38 ruminal bacteria studied, nine organisms (23.

The isolation and comparison of cellulase genes from two strains of Ruminococcus albus.

Endo-1,4-beta-glucanase genes have been cloned from two strains of Ruminococcus albus recently isolated in this laboratory. Although the strains were phenotypically similar, cross-hybridization studies between them showed significant genetic differences, with only 20% of the genome forming DNA heteroduplexes. Heteroduplexes displayed an average dissociation temperature 9 degrees C lower than that of the homoduplex.

Biology of gut anaerobic fungi.

The obligately anaerobic nature of the gut indigenous fungi distinguishes them from other fungi. They are distributed widely in large herbivores, both in the foregut of ruminant-like animals and in the hindgut of hindgut fermenters. Comparative studies indicate that a capacious organ of fermentative digestion is required for their development.