EVALUATION OF CULTURE REQUIREMENTS FOR CELLULOSE PRODUCTION BY EGYPTIAN LOCAL ISOLATE ALONGSIDE REFERENCE STRAIN GLUCONACETO- BACTER HANSENII ATCC 23769

Abstract

Cellulose demonstrates unique properties and suitable for many different applications. In the present study an acetic acid bacterial strain has been isolated from rotten apple and investigated as cellulose producer. The strain was identified using morphological, biochemical characterization and 16s rRNA gene sequencing and named as Komagataeibacter hansenii (K. hansenii AS.5) under identity percentage 99%. Culture conditions for BC production by AS.5 were screened and compared with reference one Gluconacetobacter hansenii ATCC 23769 under static condition. Optimization of key production parameters has been carried out using OVAT (One Variable At Time) approach. Effect of media composition, inoculum size, pH, temperature, incubation time, different carbon and nitrogen sources were evaluated. The highest production of cellulose (3.75 g/l) was obtained after 10 days, 8% inoculum size, incubation 25◦C by K. hansenii AS.5 using Yamanaka medium with glucose and yeast extract as a sole carbon and nitrogen source, respectively. On contrast, G. hansenii ATCC 23769 exhibits the maximal BC production (2.18 g/l) under the modified GEM medium composed of mannitol and yeast extract as the optimum carbon and nitrogen source after 7 days at 25 ◦C and inoculum size 6%. It is clearly noticed the Cellulose production by the local isolate is higher than the reference one by 1.7- fold.