Improved techniques for dissociating particle-associated mixed ruminal microorganisms from ruminal digesta solids.

Combinations of physical and chemical methods were evaluated for their ability to remove particle-associated microorganisms (PAM) from saline-washed ruminal digesta solids (SWRDS). Physical methods included chilling and storage, homogenization, multiple extraction, and agitation with marbles. Chemical methods included use of low pH, Tween 80, formaldehyde, methanol, tertiary butanol, and methylcellulose.

Electro-transformation of Clostridium beijerinckii NRRL B-592 with shuttle plasmid pHR106 and recombinant derivatives.

Conditions for transformation of the solventogenic anaerobe Clostridium beijerinckii NRRL B-592 with plasmid DNA via electroporation are described. Shuttle plasmid pHR106 and two derivatives constructed in this study were transferred and were expressed in this organism. One recombinant derivative of pHR106 was constructed by separately subcloning the clostridial tetracycline (tetP) resistance genes into pHR106.

The domains of slow bacterial growth.

Commonly used culture systems, e.g., batch culture and the chemostat, work poorly for defining the behavior of slowly growing bacteria, i.

Integration of the Vwa plasmid into the chromosome of Yersinia pestis strains harboring F' plasmids of Escherichia coli.

Conditional virulent strains of Yersinia pestis were used as recipients of an F-lac plasmid from either Escherichia coli 23.10S or E. coli CSH23.