The integration of batch fermentation and membrane-based pervaporation process in a membrane bioreactor (MBR) was studied to enhance bioethanol production compared to conventional batch fermentation operated at optimum condition. For this purpose, a laboratory-scale MBR system was designed and fabricated. Dense hydrophobic Polydimethylsiloxane (PDMS) membrane was used for pervaporation. For fer...

A marked enhancement in the production of cell-bound phytase in Pichia anomala was achieved in cyclic fed batch fermentation (47333 UL -1 ) in comparison with that in batch (11569 UL -1 ) and fixed volume fed batch (36911 UL -1 ) fermentations in cane molasses medium. Phytase productivity was sustainable in cyclic fed batch fermentation over seven days, and therefore, this mode of fed batch fer...

Astaxanthin is a main carotenoid pigment. Fed-batch fermentation bioprocesses of astaxanthin in 2.0 M fermentor have been investigated. Moreover, pH shift control was employed in fed-batch fermentation at 2.0 M scale. The results of astaxanthin fermentation showed that the fed-batch fermentation with pH shift strategy was the best among all the experiments, and the maximum astaxanthin concentra...

the batch fermentation production of human growth hormone (hgh) was studied in a newrecombinant escherichia coli. the effect of different levels of dissolved oxygen and glucoseconcentration on cell density and substrate utilization were evaluated. the results indicated that theoptimum level of dissolved oxygen was 25% of air saturation. the specific growth rate reached amaximum for an optimal g...

D-lactic acid was produced by Sporolactobacillus sp. strain CASD in repeated batch fermentation with one- and two-reactor systems. The strain showed relatively high energy consumption in its growth-related metabolism in comparison with other lactic acid producers. When the fermentation was repeated with 10% (v/v) of previous culture to start a new batch, D-lactic acid production shifted from be...

Alkali-pretreated sugarcane bagasse fiber was subjected to fed-batch simultaneous saccharification and fermentation (SSF) with a prehydrolysis process to increase the solids loading and produce a high concentration of ethanol. The hydrolysis medium and yeast feeding modes were investigated to determine suitable conditions for high sugar yield and ethanol production. Batch addition resulted in a...

Rhamnolipids find broad applications as natural surfactants, emulsifiers, and antibiotics because of their low toxicity, high biodegradability and environmental soundness. In this study, a pH stage-controlled process of fermentation of rhamnolipids by Pseudomonas aeruginosa O-2-2 was established. A yield of 24.06 g/L in batch fermentation was achieved in a 5-L fermentor via the optimization of ...

modeling of fermentation processes is so complicated and uncertain; therefore it is necessary to provide a robust and appropriate dynamic optimization method. in order to obtain the maximum amount of yeast (saccharomyces cerevisiae), the bioreactor must be operated under optimal conditions. to determine substrate feeding in a fed-batch bioreactor, a simulated annealing (sa) approach was examine...

There are three variations of the fermentation process. In batch fermentation, a sterilized nutrient solution in the fermentor is inoculated with micro-organisms and incubation is allowed to proceed. During the course of the fermentation, oxygen is added (as in the case of aerobic microorganisms) and an acid or base to control the pH. The composition of the culture medium, the biomass concentra...

To intensify the brewing process and increase the fermenter productivity, many breweries throughout the world have been embracing high-gravity brewing. However, increasing original wort concentration can cause a negative effect on yeast fermentation performance. This study focused on the application of fed-batch fermentation in high-gravity brewing. High gravity worts of 24oBx (using 30% high m...