| Abstract |
By the successive enrichment culture, more than 250 methanol-utilizing bacteria were isolated from various samples such as soil, waste water and sewage. Two strains of which were selected and tentatively identified as Acinetobacter sp. and Pseudomonas sp. experiments were carried out to determine the growth conditions for the higher biomass yield and to demonstrate the difference to protein composition dependent upon carbon sources of these two species. the results were as follows ; 1. The optimum pH was determined as 8 in the both species. The optimum temperature in Acinetobacter sp. was 25℃-30℃ and pseudomonas sp. was 30-35℃. The optimum initial concentration of methanol was determined as 1-2% in Acinetobacter sp. and 2-3% in pseudomonas sp. 2. The optimum concentrations of nitrogen source, micro-elements, and vitamins such as biotin and thiamine-HCl in Acnetobactar sp. were 1g (NH₄)₂SO₄, 1-3mg Mn^++, 4mg Fe^++, 10㎍ biotin, and 100㎍ thiamine-HCl per liter medium. In the Pseudomonas sp., 2g(NH₄)₂SO₄, 1mg Mn^++, trace amounts of Fe^++, 5㎍ biotin and 100.mu.g thiamine HCl per liter were effective. Maximum biomass yield was 2.5g/l in Acinetobacter sp. and 4.8g/l in Pseudomonas sp. 3. Protein composition of the two strains exhibited that alkali-labile protein was higher than alkali-stable protein. In Pseudomonas sp., the contents of acid soluble fraction and alkali-stable protein of the cells grown in the methanol medium were higher than in sucrose medium. On the other hand, in Acinetobacter sp., alkalilabile protein of the cells grown in sucrose medium was higher than in methanol medium. |
