Sustainable and cost-effective production of bacterial cellulose by using rice straw hydrolysate: a response surface approach.

Abstract

Despite having many exceptional qualities, bacterial cellulose's (BC) commercialization and applications are restricted by high production cost and low productivity. Therefore, the enzymatic hydrolysate of rice (RSH- rice straw hydrolysate) was employed in this study as an alternative low-cost carbon source. Rice straw has been pretreated with 2% NaOH prior to enzymatic hydrolysis and 29.35 ± 0.4 g/l of reducing sugar was detected in the RSH. Further, the production of BC by using RSH medium was optimised by using Box- Behnken design (BBD). After two weeks of cultivation on the optimized RSH medium (RSH dilution 1 and pH 6) at 32.5 °C, the BC yield was 7.17 ± 0.05 g/L, which is fairly higher than many other previously reported BC yield, by utilizing various lignocellulosic waste. The physico-chemical analysis of BC films so obtained was done by SEM, XRD, and FT-IR and compared with the BC produced in standard HS (Hestrin-schramm) medium. The typical nanocellulose fibrillar network morphology has been confirmed by SEM; the peaks associated with cellulose I, has been shown by XRD; and the FTIR spectra displayed the absorption bands associated with BC specific functional groups. Overall, RSH medium didn't alter the basic properties of BC, except slight variations. Therefore, rice straw hydrolysate could be a potential low-cost carbon source for large scale production of BC.