In this present research, acetic acid bacteria were isolated from local vinegar samples produced from fermented apple, date and grape; from all (26) vinegar samples; twenty-one isolates of the bacteria were obtained as a dense and smooth colonies with creamy colour on the surface of HS-agar medium, four isolates were identified as Acetobacter xylinum by followed many physiological and biochemical tests, the isolates were gram negative, oxidase negative and catalase positive, the isolates showed positive growth at (25, 30 and 40)°C and furthermore at pH 7.0 and 4.5, but there was no growth at (45°C), pH (2.5 and 8.5). All isolated bacteria were unable to liquefy gelatin. Four isolates were capable to ferment glucose, xylose, galactose, mannose and unable to ferment lactose, mannitol and maltose.The isolates BS2, BS3, BS8 and BS20 had ability for bacterial cellulose production. The percentage of dry weight of cellulose ranged between (2.163 – 7.234)%. Since BS2 showed the best productivity, which had the maximum cellulose production (7.234g/L) was obtained after incubation time of 7 days with Hestrin and Hchramm (HS) media in static fermentation. The isolates (BS2, BS3, BS8 and BS20) were examined for bacterial cellulose production in HS broth medium. The dry weight of crude cellulose produced by each isolates was measured and ranged from (0.36-0.42) gm. and the pH value of bacterial cellulose were (6.2-6.9), approximately equal and nearly to the neutral values with comparison with plant cellulose. The thickness of bacterial cellulose membrane is a key parameter in preparing film, the initial thickness of the wet BC membrane was measured as 32 micrometers and after drying the computed thickness of BC membrane decreased to 0.4 µm. The average tensile strength value and the average elongation at break value of the dried BC films were 34.5 MPa and 5.2% respectively.
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