Optimization of Saccharification Conditions of Acid-pretreated Sweet Sorghum Straw Using Response Surface Methodology

Abstract

This study focused on the cellulase production from C. versicolor TD17, white rot fungi. The maximum cellulase activity of 0.897 U/ml was obtained after 5 days of cultivation using 20 g/l cellobiose as a carbon source and 2 g/l ammonium sulfate supplemented with 0.3 g/l urea as nitrogen sources. Enzymatic saccharification of acid-pretreated sweet sorghum straw (SSS) using in house cellulase was optimized using Response Surface Methodology (RSM), variable five-code-level, four-factor; 1.0-7.0% w/v acid-pretreated SSS, 15-35 FPU/g dry substrate of cellulase enzyme, pH 3 to 7 and temperatures 30 to 70 °C. The optimal conditions were 1% w/v acid-pretreated SSS, 25 FPU/g dry substrate of cellulase, pH 5, 50 °C and 72 h cultivation. A maximal glucose yield of 0.440 g/g dry substrate was obtained.

Optimization of saccharification conditions of black rice (cv. Poireton) using microbial strains through response surface methodology

“…On the other hand the experimental values for the saccharification process were 3.27 mg/mL reducing sugars, 438.567 μg/mL TPC, 3.75 mg/mL FAN and 0.18% acidity which correlated with the predicted values ( Table 6). The experiments under the optimum conditions were in line with various model predictions (24,25) of the enzymatic saccharification process through RSM. Enzymatic saccharification through RSM in sugarcane top by microwave pretreatment was reported by Mauraya et al (26) and the optimal conditions obtained by RSM for sugarcane top were 50°C temperature and 72 h incubation time for maximum saccharification yield of reducing sugars (0.376 g/g glucose as a substrate).…”

Optimization of the Enzymatic Saccharification Process of Empty Fruit Bunch Pretreated with Laccase Enzyme

“…When the ratio was increased, the concentration of sugar was reduced. Phuengjayaem et al (2014) also studied the effect of substrate concentration of sorghum on its enzymatic saccharification using RSM and recorded a higher saccharification response (0.069 g/g of dry substrate) with a lower substrate concentration of 2.5% w/v, compared with 0.017 g/g obtained with a substrate concentration of 5.5% w/v. These results confirmed that increasing the substrate concentration of the enzymatic saccharification of biomass leads to slower saccharification because of an increased consistency and reduced surface contact between enzyme and substrate.…”

“…These authors achieved 83.27% saccharification efficiency at 50 °C and pH 5, which was higher than the 22.16% saccharification efficiency recorded at the temperature of 60 °C and pH 6. Phuengjayaem et al (2014) studied the effect of pH of the medium on the saccharification of sweet sorghum using RSM and found that at pH 5, 0.115 g/g of dried solid was obtained, compared with 0.00 g/g obtained at pH 7, even though the model predicted 0.026 g/g of dried solid.…”

“…These results indicated that the isoelectric point of the enzyme reaction was reached at pH 5 when the rate of saccharification was maximal. Phuengjayaem et al (2014) studied the effect of pH of the medium on the saccharification of sweet sorghum using RSM. They discovered that 0.115 g of glucose /g of dried solid were obtained at a pH of 5, compared with 0.00 g/g obtained when the pH was 7, despite the model prediction of 0.026 g/g of dried solid.…”

“…Phuengjayaem et al (2014) studied the saccharification of sweet sorghum with cellulase enzyme at different concentrations using RSM. A total of 0.058 g and 0.139 g of glucose/gram of dry substrate was recovered with an enzyme concentration of 20 FPU/g and 30 FPU/g of glucose/gram of dry substrate, respectively, showing an increase in the saccharification rate with increasing enzyme concentration.…”