Breeding and characteristics of the high efficient biodemulsifier-producing bacteria by mutagenesis.

To improve demulsifying property, the original biodemulsifier-producing bacterium, Bacillus mojavensis XH1, was mutated and bred by the combined treatment method using UV irradiation and niitrosoguanidine (NTG). A high efficient biodemulsifier-producing mutant XN5 with the better stability was obtained after continuous passages. The optimal cultural conditions were as follows: the mixture of 10 g/L glucose and 4 % liquid paraffin is the carbon source, the mixture of 4.0 g/L NH₄Cl and 1.0 g/L yeast extract is nitrogen source, pH =6. 5 , the rotating rate is 140 r/min and the incubated time is 24 h. The 12 h and 24 h demulsification ratios of the mutant XN5 were 94. 17% and 98. 67% , which were 64. 81% and 15. 12% higher than that of the original strain XH1, respectively. [ABSTRACT FROM AUTHOR]