Isolation and characterization of Acetobacter and Gluconobacter spp from sugarcane and rotten fruits

Author(s): Md.Arifuzzaman, Md.Zahid Hasan, S.M.Badier Rahman, Md.Kamruzzaman Pramanik

Potential acetic acid bacteria were investigated from different readily available sources. Seven different samples (sugarcane bagasse, sugarcane juice, sugarcane juice processing water, soil, rotten apples, rotten red grapes and rotten white grapes) were collected from local market. After processing and enrichment, samples were inoculated on Glucose Yeast Calciumcarbonate (GYC) agar plates and incubated at 30C for four days. Nineteen different bacterial colonies were selected and isolated on the basis of clear zone formation onGYCmedium. The bacterial isolates were identified on the basis of their morphological, biochemical and physiological characterization.Among nineteen isolates, onewas identified as Acetobacter aceti, one as Acetobacter pasteurianus, one as Acetobacter orleansis, two were identified as Acetobacter cibinongensis, and the remaining fourteen isolates were identified as Gluconobacter spp. As potential acetic acid producers, only the Acetobacter isolates were further assessed for their acid production capability under different temperature and pH using ‘Potency Index’ as a potency determining parameter. Temperature 30C and pH 5.5 were found to be the optimum temperature and pH respectively for maximum acetic acid production by most of the species. Acetobacter pasteurianus with the highest P.I. value of 3.78 was the most potent acetic acid producer among these isolates.

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