微波诱变选育产物耐受型地衣芽胞杆菌以提高杆菌肽发酵水平

摘要

Bacitracin is a kind of important microbial feed additive .Phenomenon of product feedback inhibition existed in process of bacitracin fermentation .It was necessary to screen product tolerance strain for improving baci-tracin fermentation.Bacillus licheniformis Y822, as the original strain, was mutagenized by microwave mutagene-sis.The mutagenized strains were spread on the plates containing bacitracin to screen product -tolerance clone . Then, high bacitracin-producing strains were rescreened by plates with indicator of Micrococcus luteus.A mutant strain, B.licheniformis Y8228X, with high ability of bacitracin tolerance was obtained .The bacitracin titer and productivity of the strain reached to 847.28 U/mL and 16.74 U/( mL · h ) , respectively .The fermentation per-formance of B.licheniformis Y8228X improved significantly compared with parent strain .Microwave mutagenesis following the product tolerance screening program was a simple and efficient method to breed and select high baci -tracin-producing strain .%杆菌肽是一种重要的饲料添加剂，其发酵生产过程中存在产物反馈抑制现象，选育产物耐受型生产菌可提高发酵水平。以Bacillus licheniformisY822为出发菌株，使用微波诱变技术选育产物耐受型菌株，进一步以敏感指示菌复筛，筛选杆菌肽高产菌株。选育得到产物耐受型生产菌Bacillus licheniformis Y8228X，杆菌肽产量和产率分别达到847.28 U／mL和16.74 U／（ mL· h），与出发菌株相比发酵水平显著提高。微波诱变结合产物耐受型菌株筛选是一种选育杆菌肽高产菌株的快速、有效方法。