With a new enrichment protocol, pentachlorophenol (PCP)-degrading bacteria were isolated from soil, water, and sewage. When characterized, all isolates were related and shared characteristics of the genus Arthrobacter. Growth rates for strain NC were determined for a number of substrates, including PCP and 2,4,6trichlorophenol. Changes in PCP concentration affected growth rate and length of the lag phase but not cell yield. Increasing the pH from 6.8 to 7.8 decreased the length of the lag phase for growth on PCP. Cessation of growth, upon incremental addition of PCP, was found to be related to a decrease in pH rather than to a buildup of a toxic metabolite. Degradation of PCP by strain NC was shown to be complete.

Motility in Arthrobacter atrocyaneus, A. citreus, and A. simplex was found to correlate with the morphogenic cycle of these organisms. The percentage of the A. atrocyaneus and A. simplex populations that were flagellated at a given time during the growth cycle differed significantly from that of the nonmorphogenic Pseudomonas aeruginosa population. Flagellation inA. atrocyaneus was shown to be dependent upon the morphogenic cycle rather than upon growth. The commitment to flagellar synthesis in A. atrocyaneus was found to occur only after induction to the rod morphology. Flagellar synthesis in A. atrocyaneus was shown to be restricted to only a small segment of the morphogenic cycle.

Hot-water extracts of mesquite (Prosopis glandulosa) wood were assayed for their total carbohydrate, reducing sugar, and glucose content. These hydrolysates were then used as complete media for yeast growth. A total of 10 strains of yeasts were evaluated for their biomass production in the mesquite wood hydrolysates. Levels of utilizable carbohydrate proved to be the limiting factor for yeast growth in the hydrolysates.

The potential for modifying proteins in a rational manner warrants more extensive studies and the development of practical sources of transglutaminase.

No abstract