This is a report of a method to estimate the three parameters of Monod's bacterial growth model, μ0KS and Y, by linearization and integration of data from batch culture experiments. This method can be used with either substrate or biomass data. The technique is tested on three sets of data, from the literature or from our laboratory. The accuracy of the values obtained for the parameters is appreciated by using them as initial estimates of a non linear fitting procedure. It is shown that in some cases the method can provide fairly precise estimates for the three parameters.
A perfectly defined minimal medium for strain Es 5 of Bifidobacteriumbifidum was established. It consists of 3.5% D-(+)-lactose, 2.5% sodium acetate, 0.2% ammonium acetate, 0.25% dipotassium phosphate, 50μg/ ml riboflavin, 50μg/ml D-pantethine, 50ng/ml biotin, 0.3% potassium pyruvate, 0.1% L-cysteine-HCl, 0.5mM MgCl+2, 1mM FeCl2, 0.5μM MnCl2 and 50μM CaCl2 (pH 6.6). Many auxotrophic mutants were isolated from the strain using this minimal medium.
The patterns produced by nine enzymes of ballistosporogenous yeasts and supposedly related yeasts were studied by electrophoresis on polyacrylamide gel. Forty-two strains belonged to the genera Sporobolomyces, Sporidiobolus, Aessosporon and Bullera and twenty-four strains to Rhodotorula, Rhodosporidium, Cryptococcus, unidentified ballistosporogenous yeasts, and Candida edax. Four Sporobolomyces salmonicolor strains, two Sporobolomyces holsaticus strains, two Sporobolomyces odorus strains, five Sporidiobolus salmonicolor strains, two Aessosporon salmonicolor strains, and one strain of Aessosporon dendrophilum produced similar electrophoretic patterns. Moreover, mating was observed between some of these strains. Sporobolomycesroseus and Sporobolomyces shibatanus differed from Sporobolomycessalmonicolor in their glucose-6-phosphate dehydrogenase (EC 188.8.131.52.), but the patterns of the other enzymes were similar; all three species differed clearly from Sporobolomyces singularis, Sporobolomycesgracilis, Sporobolomyces puniceus, and Sporobolomyces antarcticus. Sporobolomyces albo-rubescens showed a peculiar 6-phosphogluconate dehydrogenase (EC 184.108.40.206.) pattern and was similar to two Rhodotorularubra strains in the pattern of their enzymes. Close relationships were also seen between Sporidiobolus ruinenii and Rhodotorula graminis, and between Bullera alba and a strain in Cryptococcus albidus var. albidus in the electrophoretic patterns of their enzymes. Four unidentified strains which had lost the ability to produce ballistospores had patterns similar to those of Bullera alba, Rhodotorula glutinis, Cryptococcus laurentii var. flavescens, and Cryptococcus macerans. Three colorless strains, putatively derived from a strain of Sporobolomyces roseus, showed the same electrophoretic patterns as the strains from which they originated.
Twelve bacterial strains which decompose carrageenan were isolated and purified from sea water and algae on modified ZoBell 2216 E carrageenan and agar media. The isolates were examined for morphological, physiological and biochemical characteristics. They were gram negative, facultative anaerobic, non-flagellate, long rods, formed spreading colonies and contained carotenoid pigments. The isolates produced phosphatase and were resistant to polymyxin B. The GC content ranged between 39.3 and 41.8mol (%). These characteristics indicate that the strains belong to the genus Cytophaga. The carrageenan decomposing bacteria were classified into four groups according to their behaviour in decomposing other high molecular weight compounds such as agar, casein, gelatin and starch.
A type II restriction endonuclease was purified from "Acetobacter liquefaciens" IAM 1834 by consecutive column chromatography on heparin- Sepharose CL-6B, DEAE-Sepharose CL-6B and Sephacryl S-400 superfine. The purified enzyme was homogeneous on polyacrylamide gel disc electrophoresis. The enzyme preparation was essentially free from other nuclease activity, as judged by constancy of a lambda DNA-digest electrophoretic pattern after prolonged incubation for 24hr. The enzyme was optimally active at 37° at pH 7.5, and did not require NaCl, which rather inhibited its activity. The recognition sequence for the enzyme was determined to be 5′-G-G-A-T-C-C-3′, and the enzyme was found to cut between G and G in the sequence, being an isoschizomer of the endonuclease from "Bacillus amyloliquefaciens" H (Bam HI).
Edited and published by : Applied Microbiology, Molecular and Cellular Biosciences Research Foundation/Center for Academic Publications Japan Produced and listed by : TERRAPUB, Center for Academic Publications Japan/Shobi Printing Co., Ltd. (-Vol.60,No12), Center for Academic Publications Japan/InternationalAcademic Printing Co., Ltd.(-Vol.54,No1)