产腺苷蛋氨酸酵母菌株的选育

目的筛选产腺苷蛋氨酸(SAM)的酵母菌并进行诱变育种。方法以选择性培养基筛选酵母菌株并用高效液相色谱检测SAM。利用紫外线和γ-射线处理对菌株进行诱变。结果从34份土样中筛选到1株产SAM的酵母菌Q95菌株,经过5轮紫外线诱变和1轮γ-射线诱变,筛选到1株SAM产量显著提高的正突变株Q6-13。摇瓶发酵27 h后,其SAM产量达到1860μg/mL,与Q95相比提高了86.9%。在15 L外循环气升式生物反应器中补料发酵22 h后,Q6-13的SAM产量达到2540μg/mL。结论通过筛选和诱变,得到了1株高产SAM的酵母菌突变株,为SAM的微生物发酵法规模化生产奠定了基础。

Screening and breeding of S-adenosylmethionine producing yeast

Purpose To screen S-adenosylmethionine(SAM)-producing yeast strain and to improve its SAM production.MethodsYeast strains were isolated by a selective medium and SAM produced was assayed by HPLC.Strain improvement was carried out by UV and γ-ray mutagenesis.ResultsA baker′s yeast strain numbered Q95 wasisolated and consecutively improved by UV and γ-ray mutagenesis.After 5 cycles of UV mutagenesis and one cycle of γ-ray mutagenesis,Q6-13,a mutant with higher SAM production was selected.Its SAM yield reached 1 860 μg/mL after 27 h fermentation in shaking flasks,which is 86.9% higher than that of the original strain.The SAM yield of Q6-13 strain reached 2 540 μg/mL after 22 h fed-batchfermentation in an eternal loop airlift reactor.ConclusionA high SAM-producing yeast mutant was obtained by yeast screening and strain improving.The mutant may be useful for SAM-production on a large scale.