Study On Physiology, Biochemistry And Metabolites Of Enterobacter Xiangfangensis Strain M2017152

In this paper,the physiological and biochemical characteristics of a strain of Enterobacter xiangfangensis strain(deposit number CCTCC NO: M2017152)isolated from the epidermis of vitis dividii were studied.The growth and reproduction of the two strains under different fermentation conditions and the differences of aroma components in fermented bean sprout juice,apple and pear were compared with Saccharomyces cerevisiae.Finally,ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS)was used to comparatively study the differences between the non-volatile metabolites of E.xiangfangensis strain M2017152 and S.cerevisiae.The results showed that E.xiangfangensis strain M2017152 is a gram-negative non-spore bacillus,aerobic or facultative anaerobic,non-motile,its suitable growth pH 2.0-8.0,temperature ? 404,can tolerate 12% of the salt concentration and more than 0.5 g/L sodium metabisulfite,a wide range of utilization of carbon source nitrogen source.E.xiangfangensis strain M2017152 grew and propagated most vigorously at an initial sugar concentration of 12% and sufficient oxygen,and had the most abundant aroma component species;it grew and propagated most vigorously at an initial pH 6.5,but had the least aroma component species;it grew and propagated most vigorously 4 d before fermentation.Through the study of the aroma components of E.xiangfangensis strain M2017152,it was found that the aroma components produced by fermentation of E.xiangfangensis strain M2017152 were very different from those of S.cerevisiae in terms of species and content.The main aroma components detected in the fermented fruit wine by E.xiangfangensis strain M2017152 were 3-methyl-1-butanol,2-methylbutanol,3-methylbutyl acetate,2-methylbutyl acetate,n-propyl acetate,phenylethyl acetate,phenylethyl alcohol,ethyl decanoate,and isobutyric acid,which presented aroma characteristics such as wine aroma,floral aroma,fruit aroma,sweet aroma,and grass aroma.By UPLC-Q-TOF-MS analysis,no significant toxic and harmful components were found to be produced in the metabolites of soybean sprout juice fermented by E.xiangfangensis strain M2017152.N-acetyl-D-galactosamine,albuterol,tetrahydrobiopterin,succinic anhydride,hypoxanthine,phenylpyruvic acid and ethyl erythorbate among the unique metabolites produced from fermented bean sprout juice by E.xiangfangensis strain M2017152 have some application value and can be further studied.