紫外线诱变木醋杆菌及优良突变菌种的选育

UV-mutagenesis of Acetobacter xylinum and Screening Good Mutant Strains

为了提高细菌纤维素(简称BC)量和续代发酵的稳定性,该研究利用紫外线照射木醋杆菌Acetobacter xylinum CGMCC 5173菌株诱变,还对3种不同培养基培养得到BC进行了对比。研究表明,紫外线分别照射3 min、4 min和5 min,经筛选得到UV31、UV32、UV33、UV42、UV44五株产量较高的突变菌株,其产量高达26.96 g/L～35.48 g/L;菌株UV31、UV32、UV33、UV42连续发酵四代产量仍比较稳定,分别稳定在23 g/L～39 g/L、25 g/L～36 g/L、24 g/L～39 g/L;菌株UV32、UV42和野生菌在CMMF中的BC产量高约为19.94 g/L～39.97 g/L,但结构松散,在MMF中BC的产量低为10.17 g/L～22.28 g/L,均匀紧密,在CO-MMF-CMMF中BC产量中等为16.24 g/L～31.09 g/L,较均匀紧密。结果表明,紫外诱变3 min菌株的BC产量高且3代～4代发酵产量保持稳定,CO-MMF-CMMF是最适于发酵的培养基。

In order to improve the yield of Bacterial Cellulose（BC） and the stability of the strain,the strain Acetobacter xylinum CGMCC 5173 was irradiated by ultraviolet and the BCs fermented by 3 different kinds of medium were compared with each other.After the strain was exposed to UV-irradiation for 3 min,4 min and 5 min respectively,five mutant strains UV31,UV32,UV33,UV42,UV44 were screened.The BCs of these mutants were from 26.96 to 35.48 g/L,higher than the wild type＇s.When these mutants were sub-cultured for 4 generations,the BCs yield of UV31,UV32,UV33 and UV42 were stable followed as 23 g/L-39 g/L,25 g/L36 g/L and 24 g/L-39 g/L,respectively;The stain UV32,UV42 and the wild type can fermented the loose BCs in the CMMF medium with a yield of 19.94 g/L-39.97 g/L,the uniformly firm BC with a lower yield of 10.17 g/L22.28 g/L in the MMF medium and the considerable uniformly firm BCs with a moderate yield in 16.24 g/L 31.09 g/L in the CO-MMF-CMMF medium.These results show that UV irradiating for 3 min can improve the yield of BC and the stability of the strain,CO-MMF-CMMF was the optimum medium for BC fermentation.