The design of biocatalytic processes for industrial synthetic chemistry is determined in large part by the choice of isolated enzyme or whole-cell catalyst form. In the present paper, the considerations for choice are identified and some important classes of bioconversion are discussed in relation to the choice to be made. Recent developments in cell and protein engineering as well as reactor a...

This report describes the bioconversion of 19-hydroxy-androsta-4, 7-diene-3, 17-dione into equilin with Nocardia rubra. Through mutation and improvement of medium and of conditions, the bioconversion could be improved to yield 40% equilin for a substrate concentration of 1 g/liter. Aromatization of several other 19-hydroxy and 19-nor substrates of the androstene series is reported, and the infl...

The potential bioconversion of synthesis gas (syngas) to fuels and chemicals by microbial cell has attracted considerable attention in past decade. The feasibility of enhancing syngas bioconversion to ethanol and acetate using Clostridium ljungdahlii in a continuous tank bioreactor (CSTBR), kinetics and mass transfer coefficient of carbon monoxide (CO) utilization were evaluated. Two different ...

An extractive bioconversion with Bacillus cereus cyclodextrin glycosyltransferase (CGTase, EC 2.4.1.19) in aqueous two-phase system (ATPS) was investigated for the synthesis and recovery of cyclodextrins (CDs). Optimum condition for the extractive bioconversion of CDs was achieved in ATPS consisted of 7.7% (w/w) polyethylene glycol (PEG) 20,000 and 10.3% (w/w) dextran T500 with volume ratio (VR...

In this work the possibility of producing vanillin through microbial bioconversion from ferulic acid obtained from the enzymatic hydrolysis of wheat bran has been explored. The biocatalyst employed was Escherichia coli JM109/pBB1, a recombinant strain containing the genes from Pseudomonas fluorescens BF13 for the transformation of ferulic acid into vanillin. The substrate of the bioconversion, ...

vanillin is undoubtedly one of the most popular and widely used flavoring agents in the world. natural vanillin is extracted from vanilla beans and is relatively expensive. moreover, the consumer demand for natural vanillin highly exceeds the amount of vanillin extracted by plant sources. this had led to the investigation of alternative routes for its production such as microbial bioconversion....

Modern approach to utilization of non-edible biomass is its conversion to glucose, and the following fermentation of the sugar into final bioproducts. Among various biomass types, the waste of office paper is distinguished by increased content of cellulose and negligible content of lignin; therefore it can be a suitable feedstock for bioconversion into valuable bioproduct, e.g. ethanol. An adva...

a model describing the main processes occurring in the uasb reactor was developed; in orderto maintain simplicity and applicability of the model, only the fundamental aspects were considered. in themodel, the reactor is divided in several well-stirred reactors coupled in series and it comprises substratedegradation, biomass growth and the reactions that take place within the granules. the impor...

Rice straw hemicellulosic hydrolysate was used as fermentation medium for ethanol production by Pichia stipitis NRRL Y-7124. Shaking bath experiments were initially performed aiming to establish the best initial xylose concentration to be used in this bioconversion process. In the sequence, assays were carried out under different agitation (100 to 200 rpm) and aeration (V(flask)/V(medium) ratio...

Bioethanol from cellulosic raw material has proved to be the best alternative renewable energy source. Cellulase is a multienzyme complex catalyses the bioconversion of cellulose to glucose, which can be used for ethanol production. The objective of this research is to reduce the cost of cellulase production by optimization of fermentation conditions and modeling of the fermentation process. Re...