利用细胞融合技术获得高产乳酸菌的研究

Rearch on Protoplast Fusant of Bacillus Licheniformis and Lactobacillus Bulgaricus

利用细胞融合技术将有芽孢的整肠生菌株(Bacillus licheniformis)与无芽孢的保加利亚乳酸杆菌(Lactobacil- lus bulgaricus)作为亲本,进行细胞融合,并对融合子产乳酸、丁二醇能力以及酸奶发酵能力进行了研究。结果表明,在MM培养基内。融合子乳酸产量为10．104μg/mL、丁二醇产量为46．13μg/mL,乳酸和丁二醇产量高于两亲本菌株。在CM培养基内,融合子乳酸产量为12．85μg/mL,其产量高于两亲本；丁二醇产量为69．19μg/mL．其产量高于保加利亚乳酸杆菌。在细胞形态上,融合子也与亲本存在一定的差异。在酸奶发酵的过程中,乳酸产量和pH值与亲本保加利亚乳酸杆菌发酵的结果一致。经过10次传代培养后,其遗传稳定性保持在99%以上。

This paper reports the study on protoplast fusant of Bacillus licheniformis and Lactobacillus bulgaricus. The study showed, in MM substrate, fusant yielded lactic acid 10.104μg/mL and butanediol 46.13μg/mL. The yield was higher than both its parents. In CM substrate, fusant yielded lactic acid 12.85μg/mL, it was higher than both its parents and yielded butanediol 69.19μg/mL higher than Lactobacillus bulgaricus. In fermented of acidophilus milk, the new bacillus has the same yield of lactic acid and the same pH value with Lactobacillus bulgaricus. And the fusant＇s genetic stability was maintained over 99%.