Evaluation of Low-Cost Carbon Sources for the Production of Bacterial Cellulose by Gluconacetobacter xylinus (PTCC ۱۷۳۴)

Commercial production of bacterial cellulose (BC) faces economic challenges due to the high cost of glucose-based media and yeast extract. Using affordable carbon sources like agricultural and industrial wastes can reduce production costs. In this study, ۵% w/v extracts of wheat straw, barley straw, rice husk, and pistachio husk were utilized as carbon sources for BC production with Gluconacetobacter xylinus (PTCC ۱۷۳۴) in HS medium, alongside vinasse and whey powder as industrial by-products. To improve BC production from low-yield sources like vinasse and pistachio hulls, acid treatment with a ۲ M mixture of nitric and sulfuric acids was applied. Reducing sugar and protein levels in the samples were measured using DNS and Bradford assays. Results indicated the highest protein concentration in diluted vinasse (۱۰۲۱.۱۱ µg/ml) and the highest reducing sugar content in whey powder (۵۴۹۶.۷ mg/l). Among the agricultural waste extracts, barley straw showed the highest yield, producing approximately ۰.۱۳ g of dry BC per ۱۰۰ ml of culture medium. While pistachio hulls extract initially failed to produce BC, acid treatment significantly enhanced its yield, reaching about ۰.۰۳۴ g/۱۰۰ ml. Despite this relatively low yield, pistachio hulls, being abundant and low-cost, hold potential as a carbon source for BC production. The produced BC samples exhibited a highly porous structure with exceptional water retention, able to retain ۸۰ to ۱۲۰ times their dry weight in water, making them ideal for biohydrogel applications.

کلیدواژه ها:

Gluconacetobacter xylinus ، Cellulose ، low-cost carbon sources ، acid treatment