Bacterial Diversities In Vinegar Pei And Properties Of Gluconacetobacter Xylinus Cellulose

Microbes involved in the fermentation process vary in different vinegar,which leads to distinctive tastes.In this paper,we sampled vinegar pei of Duliu aged vinegar from Tianjin and persimmon vinegar from Shanxi.The methodology of metagenomics was applied to to reveal bacterial diversities.Moreover,Gluconacetobacter xylinus(G.xylinus)isolated from persimmon vinegar pei was used to produce bacterial cellulose,whose structure?properties and application were further studied.Totally,19 AAB strains were isolated through observation of transparent circles and qualitative test of yielding acetic acid.Combining their morphological features with physiological and biochemical characteristics,6 strains from Duliu aged vinegar were identified as Acetobacter pasteurianus(A.pasteurianus)and the other 4 strains were Acetobacter pomorum,while 6 strains from persimmon vinegar were G.xylinus and the other 3 strains were A.pasteurianus.Furthermore,4 high-yield strains belonging to different genera from a certain sample were selected according to the quantitative test result of yielding acetic acid.The genetic analysis of these 4 strains gained the same result as above.As traditional culture method is only suitable for culturable bacteria,it is limited to reveal bacterial communities during the fermentation of vinegar to some extent.We hence used high-throughput sequencing to analyze bacterial diversities during AAF of Duliu aged vinegar.Those bacteria detected from sample D3 belonged to 17 genera;those from D18 belonged to 37 genera;those from D24 belonged to 13 genera.There were three genera with high abundances-Lactobacillus?Acetobacter and Serratia.G.xylinus s8 isolated from persimmon vinegar pei was capable of synthesizing jelly-like substance,which was identified as bacterial cellulose with cellulose?crystal structure by the qualitative test of cellulose?analyzing its patterns of FTIR spectra and X-ray diffraction.Property analysis showed the dried cellulose film by vacuum freeze-drying was better than that by heat-drying process.Antibacterial agents were used to make antibacterial composite films with bacterial cellulose.Results of antibacterial effect tests showed that the composite film prepared with a low concentration of chitosan gained inhibition zone.However,carboxymethyl chitosan composite film did not show any antibacterial effect.Taken together,the composite film prepared with chitosan and bacterial cellulose was feasible as a wound dressing.