Production of xylitol and ethanol from acid and enzymatic hydrolysates of Typha latifolia by Candida tropicalis JFH5 and Saccharomyces cerevisiae VS3

Currently, there is an increased usage of lignocellulosic biomass for production of various renewable bioproducts. In the present study, an aquatic weed Typha latifolia (commonly known as cattail) was used as substrate for xylitol and bioethanol production. Initially, dilute alkali pretreatment with sodium bisulfite (2% w/v NaHSO₃; at room temperature for 18 h) led to maximum of 75.30 ± 1.45% delignification with 1.11 ± 0.32% sugar loss, while dilute acid hydrolysis (at 121 °C for 60 min with2% H₂SO₄) of alkali-pretreated T. latifolia released 13.30 ± 0.30% g/L xylose sugars with 0.83 ± 0.08 g/L phenolics and 0.50 ± 0.08 g/L furfurals. After chemical detoxification (overliming and activated charcoal treatment) of acid hydrolysate, the phenolics and furfurals concentration reduced to 72.95% and 80.38%, respectively. Furthermore, enzymatic saccharification of cellulosic-rich residue of alkali acid–treated T. latifolia showed maximum 658.40 ± 10.14 mg/g sugar yield with 79.70 ± 1.42% saccharification efficiency. Subsequently, fermentation of detoxified acid hydrolysate with pentose utilizing yeast Candid tropicalis JFH5 produced 6.15 ± 0.17 g/L xylitol with 0.65 g/g yield. Furthermore, enzymatic saccharification of cellulosic-rich biomass released 11.20 ± 0.92 g/L sugars; which on subsequent fermentation with Saccharomyces cerevisiae VS3 produced 6.90 ± 0.30 g/L ethanol with 0.43 g/g yield.