Bioethanol production from corn stalk juice using Saccharomyces cerevisiae TISTR 5020

This study aimed to use sweet corn hybrid hi-brix53 stalk juice for bioethanol production, to give a solution to the growing problem of food vs. fuel and to utilize waste for cheaper production. Hi-brix 53 stalk juice contained 112.07 ± 2.99 g L^?1 of total sugars and 21.83 ± 1.09 g L^?1 of reducing sugars. Through fermentation (24–120 h) using yeast (Saccharomyces cerevisiae), it produced 6.01% (v/v) bioethanol. The final ethanol produce (g L^?1) yield efficiency and volumetric ethanol productivity were at the highest at 24 h with 47.87 L^?1, 87.62% and 1.97 ± 0.06 (g L^?1 h^?1). These results suggest that hi-brix 53 stalk juice is an ideal substrate for bioethanol production.     

Effects of substrate concentration and hydraulic retention time on hydrogen production from common reed by enriched mixed culture in continuous anaerobic bioreactor

This study aims to investigate the effect of substrate concentration and hydraulic retention time (HRT) on hydrogen production in a continuous anaerobic bioreactor from unhydrolyzed common reed (Phragmites australis) an invasive wetland and perennial grass. The bioreactor has capacity of 1 L and working volume of 600 mL. It was operated at pH 5.5, temperature at 37 °C, hydraulic retention time (HRT) 12 h, and variation of substrate concentration from 40, 50, and 60 g COD/L, respectively. Afterward, the HRT was then varied from 12, 8, to 4 h for checking the optimal biohydrogen production. Each condition was run until reach steady state on hydrogen production rate (HPR) which based on hydrogen percentage and daily volume. The results were obtained the peak of substrate concentration was at the 50 g COD/L with HRT 12 h, average HPR and H₂ concentration were 28.71 mL/L/h and 36.29%, respectively. The hydrogen yield was achieved at 106.23 mL H₂/g CODre. The substrate concentration was controlled at 50 g COD/L for the optimal HRT experiments. It was found that the maximum of average HPR and H₂ concentration were 43.28 mL/L/h and 36.96%, respectively peak at HRT 8 h with the corresponding hydrogen yield of 144.35 mL H₂/g CODre. Finally, this study successful produce hydrogen from unhydrolyzed common reed by enriched mixed culture in continuous anaerobic bioreactor.     

Raffinose family oligosaccharides in seed of Glycine max cv. Chiang Mai60 and potential source of prebiotic substances

Raffinose family oligosaccharides (RFOs) content in Glycine max seed of cultivar Chiang Mai60, a local soybean of Thailand, was investigated. RFOs and other low molecular weight sugars were extracted by 50% (v/v) ethanol and quantified by high‐performance liquid chromatography (HPLC). The prebiotic property of this extract was subsequently studied by in vitro method. The results showed that the concentrations of raffinose, stachyose and verbascose were 6.74 ± 1.62, 145.32 ± 18.74 and 1.60 ± 0.52 mg g^?1 dry seed, respectively, while glucose and sucrose were detected at 10.73 ± 1.35 and 13.28 ± 2.16 mg g^?1 dry seed, respectively. The growth of four Lactobacilli probiotics were increased significantly in a basal liquid medium supplemented with this ethanolic extract as carbon source compared to glucose supplementation. Subsequently, defined mixed culture was studied and it was found that growth stimulation of total Lactobacilli by extracted sugars resulted in the suppression of Escherichia coli and Salmonella enterica serovar Typhimurium growth. It could be concluded that this cultivar showed the RFOs‐rich content and a potential to be a source of an effective prebiotic substance for food application.