一株高产δ-ALA的酿酒酵母菌株的固态发酵条件优化及其代谢产物检测方法

Optimization of solid-state fermentation conditions and detection of metabolites of a strain with high-yield of δ-ALA Saccharomyces cerevisiae

通过发酵底物、发酵培养基、发酵时长的优化,确定高产δ-氨基乙酰丙酸(δ-ALA)的菌株PRS-416固态发酵的最佳工艺条件,并对分光光度法、高效液相色谱法及液相色谱-质谱法3种方法测定δ-ALA的结果进行比较,建立测定饲料中δ-ALA的检测方法。结果表明,发酵底物玉米∶玉米蛋白粉∶豆粕∶大米粉的最佳比例为4∶1∶0∶0,发酵培养基的最佳比例为葡萄糖0.25%、丁二酸0.5%、甘氨酸0.5%,最佳发酵时长为48 h。在最佳发酵条件下,烘干后的发酵产物中δ-ALA含量可达到338.87 mg/kg;利用分光光度法测定δ-ALA含量,会存在一定的偏差,需要与高效液相色谱法进行结合测定,并用液相色谱-质谱法进行定性,才能保证结果的准确性。

The purpose of this paper is to optimize the fermentation substrate,fermentation medium and fermentation time to determine the best conditions for solid-state fermentation of strain PRS-416 with high yield ofδ-aminolevulinic acid(δ-ALA),and to compare the results of determination ofδ-ALA by spectrophotometry,high performance liquid chromatography and liquid mass spectrometry,so as to establish the detection method ofδ-ALA in feed.The results showed that:the best proportion of fermentation substrate corn∶corn protein meal∶soybean meal∶rice meal was 4∶1∶0∶0,the best proportion of fermentation medium was glucose 0.25%,succinic acid 0.5%,glycine 0.5%,and the best fermentation time was 48 h.Under the optimum fermentation conditions,the content ofδ-ALA in the dried fermentation product was up to 338.87 mg/kg.There will be a certain deviation in the determination ofδ-ALA by spectrophotometry,which needs to be combined with HPLC and qualitative analysis by liquid mass spectrometry to ensure the accuracy of the results.