Free and cell-bound cellulase activity of Cellulomonas flavigena.

Free beta-1, 4-glucanase activity was measured in the supernatant of cultures of Cellulomonas flavigena grown on carboxymethylcellulose or filter paper as the main carbon source. Filtration through a series of filter papers resulted in quantitative removal of the enzyme from the supernatant. The glucanase was found to be tightly bound to the paper. Cellobiose was produced from the filters containing the enzyme, when incubated at 40 degrees C. After removal of the bacterial cells the paper remnants of a C. flavigena culture also formed cellobiose. Apparently beta-1, 4-glucanase is freed into solution after the paper has been partially degraded. This release is a consequence of the decreasing ratio of cellulose to enzyme. Some glucosidase activity could be detected in the supernatant of stationary phase cultures. This was probably the result of some cell lysis. However, high activities could be measured in ultrasonic cell debris. This suggests that the beta-glucosidase of C. flavigena, contrary to beta-1, 4-glucanase, is cell-bound.

Survival of microorganisms after drying and storage.

Bacteria, yeasts and fungi suspended in a dextran solution were added to ampoules containing strips of filter paper which were dried without vacuum conditions. The ampoules were sealed and stored in the dark at room temperature. Viability counts were made of the original suspension immediately after drying and after storage periods of 3-48 months. Although bacterial cultures of many general did not show much resistance against dry conditions, bacteria of 13 other general had survived well or moderately after 4 years of storage. Most of the dried yeast cultures had survived after this period. Of the 16 fungal genera tested, species of 6 genera exhibited growth after 4 years. Results of this study were compared with those of two other preservation methods by which the same microorganisms were used.

Rate of drying and the survival of microorganisms.

The survival rate of cells of the genera Arthrobacter, Pseudomonas, Mycobacterium, Escherichia, Micrococcus and Saccharomyces when counted immediately after fast or slow drying (20 minutes and 24 hours, respectively) was rather similar. However, after prolonged periods of dry storage, the number of viable cells after slow drying was much higher as compared with the rapidly dried cells. Investigations with Escherichia coli demonstrated this phenomenon only when more than about 8 mg of water per 10(8) cells was available on a filter paper disc. In order to obtain optimum resistance to water loss the dessication period of 0.025 ml of suspension of E. coli must be longer than 13 hours.

Identification and flagellation of coryneform bacteria from poultry litter.

Thirth coryneform isolates from poultry litter were identified and checked for motility and flagellation. Twenty-seven formed a yellow pigment and 3 were orange. Twenty-three yellow strains were found to be Arthrobacter citreus, although starch was hydrolyzed by these strains. Four strains, including the three mainly pale yellow isolates, grew on citrate plus an ammonium salt and were classified as A. aurescens. Three orange strains were found to be Brevibacterium linens. Only six strains of A. citreus were motile. These strains displayed flagellated rods after 1 day and flagellated cocci after 5 days incubation. The flagellar shape and arrangement were studied. Non-motile strains never showed flagella after staining.