小麦基质下枯草芽孢杆菌与酵母共发酵代谢特征

以小麦粉为基质，采用枯草芽孢杆菌（Bacillus subtilis）分别与汉逊酵母（Hansenula sp.）、弗比恩毕赤酵母（Pichia fabianii）、酿酒酵母（Saccharomyces cerevisiae）和鲁氏酵母（Zygosaccharomyces rouxii）共发酵，通过对还原糖、乙醇及氨基酸的检测分析其代谢特征。结果表明，汉逊酵母和枯草芽孢杆菌共发酵最利于乙醇的合成，乙醇最高含量为（740.00±28.28） mg/L。枯草芽孢杆菌分别与汉逊酵母、弗比恩毕赤酵母、酿酒酵母、鲁氏酵母共发酵时氨基酸合成代谢存在差异，分别合成10、10、12、12种氨基酸，最高总氨基酸含量分别为（210.41±18.75）μg/mL、（160.92±9.11）μg/mL、（3 957.35±261.47）μg/mL、（956.71±56.64）μg/mL，酿酒酵母与枯草芽孢杆菌共发酵时更有利于氨基酸的合成。四种发酵体系中共有氨基酸为缬氨酸、亮氨酸、异亮氨酸、脯氨酸、苯丙氨酸、组氨酸和酪氨酸，非共有氨基酸为丝氨酸、甘氨酸、丙氨酸、半胱氨酸、苏氨酸、色氨酸、谷氨酸以及谷氨酰胺。

Metabolic characteristics of Bacillus subtilis and yeast co-fermentation in wheat flour

Using wheat flour as substrate, Bacillus subtilis was co-fermented with Hansenula sp., Pichia fabianii, Saccharomyces cerevisiae and Zygosaccharomyces rouxii, respectively. The metabolic characteristics of the co-fermentation of yeast and B. subtilis were analyzed by the detection of reducing sugar, ethanol and amino acid. The results showed that the co-fermentation of Hansenula sp. and B. subtilis was most beneficial to the synthesis of ethanol, and the highest ethanol content was (740.00±28.28) mg/L. When B. subtilis was co-fermented with Hansenula sp., P. fabianii, S. cerevisiae and Z. rouxii, respectively, there were differences in amino acid metabolism, which produced 10, 10, 12, 12 amino acids, respectively, with the highest total amino acid content of (210.41±18.75) μg/ml, (160.92±9.11) μg/ml, (3 957.35±261.47) μg/ml, (956.71±56.64) μg/ml, respectively, indicating that the co-fermentation of S. cerevisiae and B. subtilis was more beneficial to the synthesis of amino acids. The common amino acids in the four systems were valine, leucine, isoleucine, proline, phenylalanine, histidine and tyrosine. The non-common amino acids were serine, glycine, alanine, cysteine, threonine, tryptophan, glutamate and glutamine.