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An optimization process with a cheap and abundant substrate is considered one of the factors affecting the price of the production of economical 2,3-Butanediol (2,3-BD). A combination of the conventional method and response surface methodology (RSM) was applied in this study. The optimized levels of pH, aeration rate, agitation speed, and substrate concentration (maltodextrin) were investigated to determine the cost-effectiveness of fermentative 2,3-BD production by metabolically-engineered Klebsiella oxytoca KMS005. Results revealed that pH, aeration rate, agitation speed, and maltodextrin concentration at levels of 6.0, 0.8 vvm, 400 rpm, and 150 g/L respectively were the optimal conditions. RSM also indicated that the agitation speed was the most influential parameter when either agitation and aeration interaction or agitation and substrate concentration interaction played important roles for 2,3-BD production by the strain from maltodextrin. Under interim fed-batch fermentation, 2,3-BD concentration, yield, and productivity were obtained at 88.1±0.2 g/L, 0.412±0.001 g/g, and 1.13±0.01 g/L/h respectively within 78 h.

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The viability and functionality of probiotics may be influenced by industrial production processes resulting in a decrease in probiotic efficiency that benefit the health of humans. This study aimed to investigate the probiotic characteristics of Bifidobacterium strains isolated from fecal samples of healthy Thai infants. In the present work, three local strains (BF014, BF052, and BH053) belonging to Bifidobacterium animalis showed a great resistance against conditions simulating the gastrointestinal tract. Among these, B. animalis BF052 possessed considerable probiotic properties, including high acid and bile tolerance, strong adhesion capability to Caco-2 cells, and inhibitory activity against pathogens including Salmonella typhimurium and Vibrio cholerae. This strain also exhibited a high survival rate compared to commercial strains during storage in a wide variety of products, including pasteurized milk, soy milk, drinking yogurt, and orange juice. The impact of food processing processes as well as the freeze-drying process, storage of freeze-dried powders, and incorporation of freeze-dried cells in food matrix on probiotic properties was also determined. The stability of the probiotic properties of the BF052 strain was not affected by food processing chain, especially its resistance in the simulated gastrointestinal conditions and its adherence ability to Caco-2 cells. It indicates that it satisfies the criteria as a potential probiotic and may be used as an effective probiotic starter in food applications.

A metabolically engineered Escherichia coli KJ122 was efficiently utilized for succinate production from cassava pulp during batch separate hydrolysis and fermentation (SHF) under simple anaerobic conditions. Succinate concentration of 41.46 ± 0.05 g/L with yield and productivity of 82.33 ± 0.14 g/100 g dry pulp and 0.84 ± 0.02 g/L/h was obtained. In batch simultaneous saccharification and fermentation (SSF), hydrolysis of 12 % (w/v) cassava pulp with an enzyme loading of 2 % AMG + 3 % Cel (v/w) at pH 6.5 was optimized at 39 °C. Succinate concentration of 80.86 ± 0.49 g/L with a yield of 70.34 ± 0.37 g/100 g dry pulp and a productivity of 0.84 ± 0.01 g/L/h was attained using E. coli KJ122. Fed-batch SSF significantly enhanced succinate concentration to 98.63 ± 0.12 g/L at yield and productivity of 71.64 ± 0.97 g/100 g dry pulp and 1.03 ± 0.01 g/L/h. This result indicated an efficient and economical succinate production from cassava pulp using SHF and SSF by the use of E. coli KJ122.