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Fermentation Media (fermentation + media)
Selected AbstractsApplying Near-Infrared Spectroscopy in Downstream Processing: One Calibration for Multiple Clarification Processes of Fermentation MediaBIOTECHNOLOGY PROGRESS, Issue 2 2008Licínia O. Rodrigues The use of near-infrared spectroscopy (NIRS) is demonstrated in the first downstream processing (DSP) steps of an active pharmaceutical ingredient (API) manufacturing process. The first method developed was designed to assess the API content in the filtrate stream (aqueous) of a rotary drum vacuum filter. The PLS method, built after spectral preprocessing and variable selection, had an accuracy of 0.01% (w/w) for an API operational range between 0.20 and 0.45% (w/w). The robustness and extrapolation ability of the calibration was proved when samples from ultrafiltration and nanofiltration processes, ranging from 0 to 2% (w/w), were linearly predicted ( R2=0.99). The development of a robust calibration model is generally a very time-consuming task, and once established it is imperative that it can be useful for a long period of time. This work demonstrates that NIR procedures, when carefully developed, can be used in different process conditions and even in different process steps of similar unit operations. [source] Effect of acetic acid and pH on the cofermentation of glucose and xylose to ethanol by a genetically engineered strain of Saccharomyces cerevisiaeFEMS YEAST RESEARCH, Issue 4 2010Elizabeth Casey Abstract A current challenge of the cellulosic ethanol industry is the effect of inhibitors present in biomass hydrolysates. Acetic acid is an example of one such inhibitor that is released during the pretreatment of hemicellulose. This study examined the effect of acetic acid on the cofermentation of glucose and xylose under controlled pH conditions by Saccharomyces cerevisiae 424A(LNH-ST), a genetically engineered industrial yeast strain. Acetic acid concentrations of 7.5 and 15 g L,1, representing the range of concentrations expected in actual biomass hydrolysates, were tested under controlled pH conditions of 5, 5.5, and 6. The presence of acetic acid in the fermentation media led to a significant decrease in the observed maximum cell biomass concentration. Glucose- and xylose-specific consumption rates decreased as the acetic acid concentration increased, with the inhibitory effect being more severe for xylose consumption. The ethanol production rates also decreased when acetic acid was present, but ethanol metabolic yields increased under the same conditions. The results also revealed that the inhibitory effect of acetic acid could be reduced by increasing media pH, thus confirming that the undissociated form of acetic acid is the inhibitory form of the molecule. [source] Evaluation of the fermentability of oat fractions obtained by debranning using lactic acid bacteriaJOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2008G. Kedia Abstract Aims:, The overall kinetics of the fermentation of four oat fractions obtained by debranning using three potentially probiotic lactic acid bacteria were investigated. The main objective was to study the suitability of these fractions as fermentation media for the growth and the metabolic production of bacteria isolated from human intestine. Methods and Results:, The cell growth, lactic acid production and substrate uptakes of the three lactobacilli was monitored for 30 h. An unstructured mathematical model was used to describe and fit the experimental data. In the medium from fraction B (1,3% pearlings or ,-glucan-rich fraction) all strains reached the highest cell populations, maximum growth rates and maximum lactic acid productions. This could be because of the high levels of total fibre and ,-glucan of this fraction. Limited growth and lactic acid formation was found in medium A (0,1% pearlings or bran-rich fraction). Conclusions:, Medium B (1,3% pearling fraction) is the most suitable for fermentation and produces considerably higher probiotic cell concentrations. Significance and Impact of the Study:, Debranning technology could be used to separate fractions from cereal grains for the production of functional formulations with higher probiotic levels than the ones that were obtained with the whole grain. [source] Enhancement of antibiotic and secondary metabolite detection from filamentous fungi by growth on nutritional arraysJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2008G.F. Bills Abstract Aims:, We asked to what extent does the application of the OSMAC (one strain, many compounds) approach lead to enhanced detection of antibiotics and secondary metabolites in fungi? Protocols for bacterial microfermentations were adapted to grow fungi in nutritional arrays. Methods and Results:, Protocols for microfermentations of non-sporulating fungi were validated using known antifungal-producing fungi. Detection of antifungal activity was often medium dependent. The effects of medium arrays and numbers of strains on detection of antifungal signals were modelled by interpolation of rarefaction curves derived from matrices of positive and negative extracts. Increasing the number of fermentation media for any given strain increased the probability of detection of growth inhibition of Candida albicans. Increasing biodiversity increased detection of antifungal phenotypes, however, nutritional arrays could partly compensate for lost antibiotic phenotypes when biodiversity was limiting. Conclusions:, Growth and extraction in microtiter plates can enable a discovery strategy emphasizing low-cost medium arrays that can better exploit the metabolic potential of strains. Significance and Impact of the Study:, Increasing fermentation parameters raise the probability of detecting bioactive metabolites from strains. The protocols can be used to pre-select strains and their growth conditions for scale up that will most likely yield antibiotics and secondary metabolites. [source] Green biorefinery demonstration plant in Havelland (Germany),BIOFUELS, BIOPRODUCTS AND BIOREFINING, Issue 3 2010Birgit Kamm Abstract The Green Biorefinery (GBR) is a complex and full-integrated system of environment- and resource-protecting technologies for comprehensive material and energetic use of green biomasses. GBR's are multiproduct systems and perform and produce in accordance with the physiology of the corresponding plant material preserving and using the diversity of the synthesis generated by nature. In addition to the general biorefinery concept, GBR's are based strongly on sustainable principles (sustainable land use, sustainable raw materials, gentle technologies, autarkic energy supply, etc.). Existing agricultural structures of the green crop processing industry, such as green crop drying plants, offer good opportunities for the implementation of biorefinery technologies that will help overcoming energy-intensive and partially obsolete technologies, such as the thermal drying of feedstock. Accordingly, the primary fractionation of green biomasses and the integrated production of proteins, fermentation media, animal feed, and biogas was projected and will be realized in a demonstration facility directly linked to the existing green crop drying plant, Selbelang, in Havelland (Germany, state Brandenburg, 50 km west of Berlin). The primary refinery will have an annual capacity of 20 000 tons alfalfa and grass biomass and can be diversified in modules for the production of platform chemicals and synthesis gas. We discuss the processes, products, operating costs and climate protection effects through examination of the basic engineering of the primary refinery. The production site and planned demonstration facility are also presented. Copyright © 2010 Society of Chemical Industry and John Wiley & Sons, Ltd [source] A new approach to design and optimize fermentation mediaBIOTECHNOLOGY & BIOENGINEERING, Issue 1 2008Article first published online: 26 NOV 200 No abstract is available for this article. [source] | ||||||||||