109 research outputs found
Demo-scale production of protein-rich fungal biomass from potato protein liquor for use as innovative food and feed products
Innovative food and feed products have recently attracted the attention of both producers and consumers. Filamentous fungi are important biomass producers with their high protein contents. In this study, fungal biomass production from edible potato protein liquor (PPL), generated during starch production processes, was investigated through different fungal strains (Rhizopus oryzae, R. oligosporus, R. delemar, Aspergillus oryzae and Neurospora intermedia). The effects of PPL concentration, incubation time, initial pH, and cultivation conditions (in shake flaks and different scale reactors) were examined to determine the amount of biomass and its crude protein level. It was determined that the fungal biomass produced by R. delemar in industrial scale contained 53% crude protein. For this strain, the amino acid and fatty acid profiles as well as metals (iron, manganese, copper, and zinc) of the produced biomass were also investigated to assess possible use as a food or feed source. The R. delemar fungal biomass can be a promising raw material for feed and food production, for example, considering its protein and fatty acid profiles with 41% essential amino acids and 33% polyunsaturated fatty acids
Production of fungal biomass from oat flour for the use as a nutritious food source
Fermentation can be a powerful tool for developing new sustainable foods with increased nutritional value and fermented microbial biomass derived from filamentous fungi is a promising example. This study investigates the nutritional profile of edible Aspergillus oryzae biomass produced under submerged fermentation (SmF) using oat flour as a substrate. The fermentation occurred in a 1m3 airlift bioreactor during 48 h at 35 \ub0C and the nutritional profile of the produced fungal biomass in terms of amino acids, fatty acids, minerals (Fe, Zn, Cu, Mn), vitamins (E, D2), and dietary fiber was compared to oat flour as well as pure fungal biomass grown on semi-synthetic medium. The total amount of amino acids increased from 11% per dry weight (dw) in oat flour to 23.5% dw in oat fungal biomass with an improved relative ratio of essential amino acids (0.37 to 0.42). An increase in dietary fibers, minerals (Fe, Zn, Cu), vitamin E, as well as vitamin D2 were also obtained in the oat fungal biomass compared to oat flour. Moreover, the short chain omega-3 α-linolenic acid (ALA) and omega-6 linoleic acid (LA) values increased from 0.6 to 8.4 and 21.7 to 68.4 (mg/g dry weight sample), respectively, in oat fungal biomass. The results indicate that fungal biomass grown on oat flour could have a potential application in the food industry as a nutritious source for a wide variety of products
Enhanced volatile fatty acid production from oil palm empty fruit bunch through acidogenic fermentation - A novel resource recovery strategy for oil palm empty fruit bunch
The glucan-rich fraction, hemicellulosic compounds-rich fraction, and a mixture of both fractions obtained from organosolv pretreatment of oil palm empty fruit bunch (OPEFB) were used as substrates to produce volatile fatty acids (VFAs) in acidogenic fermentation. In this study, the effects of medium adjustment (carbon to nitrogen ratio and trace elements supplementation) and methanogenesis inhibition (through the addition of 2-bromoethanesulfonate or by heat shock) to enhance VFAs yield were investigated. The highest VFA yield was 0.50 \ub1 0.00 g VFAs/g volatile solid (VS), which was obtained when methanogens were inhibited by heat shock and cultivated in a mixture of glucan-rich and hemicellulosic compounds-rich fractions. Under these conditions, the fermentation produced acetic acid as the only VFA. Based on the results, the mass balance of the whole process (from pretreatment and fermentation) showed the possibility to obtain 30.4 kg acetic acid and 20.3 kg lignin with a 70% purity from 100 kg OPEFB
Ethanol from Lignocellulose: Physiological Effects of Inhibitors and Fermentation Strategies
Fermentative ethanol production from dilute-acid hydrolyzates of wood using the yeast Saccharomyces cerevisiae was investigated. Of known inhibitors in hydrolyzates, acetic acid, furfural and hydroxymethyl furfural (HMF) were found in the highest concentrations (up to about 10 g/l). Physiological effects of these inhibitors were studied in synthetic media. Based on these studies, on-line control of fed-batch cultivation for in-situ detoxification of the hydrolyzates was subsequently developed. The effect of acetic acid on yeast was found to strongly depend on pH. At concentration of undissociated acetic acid higher than 5 g/l, growth stopped. However, presence of the acid in the medium at low concentration (e.g. 1 g/l) increased ethanol yield and decreased the formation of fermentation by-products. Furfural (4 g/l) severely decreases the specific growth rate of S. cerevisiae in pulse addition experiments. However, the yeast was able to convert furfural to less inhibiting products, mainly by reduction to furfuryl alcohol, with a specific conversion rate of 0.6 g/g.sigma.h. A previously unidentified metabolite was also found and was characterized by mass spectrometry. Presumably, the metabolite was formed from pyruvate and furfural. HMF is less inhibiting to yeast than furfural, but remains in the medium for about 4 times longer than furfural due to a lower conversion rate. The yeast converts HMF mainly to hydroxymethyl-furfuryl alcohol and a newly identified compound probably formed from HMF and acetaldehyde. Fed-batch fermentation was suggested as a suitable mode of operation for fermenting dilute-acid hydrolyzates from the physiological studies of the inhibitors. With a suitable feed rate, it was possible to ferment also severely inhibiting spruce and birch hydrolyzates using fed-batch operation without any pretreatment of the hydrolyzates. However, the feed rate was critical in order to obtain a successful operation. A simple feedback control strategy was therefore developed, allowing the feed rate to be determined on-line, without any other input variable than the measured carbon dioxide evolution rate
Ethanol from Lignocellulose: Physiological Effects of Inhibitors and Fermentation Strategies
Fermentative ethanol production from dilute-acid hydrolyzates of wood using the yeast Saccharomyces cerevisiae was investigated. Of known inhibitors in hydrolyzates, acetic acid, furfural and hydroxymethyl furfural (HMF) were found in the highest concentrations (up to about 10 g/l). Physiological effects of these inhibitors were studied in synthetic media. Based on these studies, on-line control of fed-batch cultivation for in-situ detoxification of the hydrolyzates was subsequently developed. The effect of acetic acid on yeast was found to strongly depend on pH. At concentration of undissociated acetic acid higher than 5 g/l, growth stopped. However, presence of the acid in the medium at low concentration (e.g. 1 g/l) increased ethanol yield and decreased the formation of fermentation by-products. Furfural (4 g/l) severely decreases the specific growth rate of S. cerevisiae in pulse addition experiments. However, the yeast was able to convert furfural to less inhibiting products, mainly by reduction to furfuryl alcohol, with a specific conversion rate of 0.6 g/g.sigma.h. A previously unidentified metabolite was also found and was characterized by mass spectrometry. Presumably, the metabolite was formed from pyruvate and furfural. HMF is less inhibiting to yeast than furfural, but remains in the medium for about 4 times longer than furfural due to a lower conversion rate. The yeast converts HMF mainly to hydroxymethyl-furfuryl alcohol and a newly identified compound probably formed from HMF and acetaldehyde. Fed-batch fermentation was suggested as a suitable mode of operation for fermenting dilute-acid hydrolyzates from the physiological studies of the inhibitors. With a suitable feed rate, it was possible to ferment also severely inhibiting spruce and birch hydrolyzates using fed-batch operation without any pretreatment of the hydrolyzates. However, the feed rate was critical in order to obtain a successful operation. A simple feedback control strategy was therefore developed, allowing the feed rate to be determined on-line, without any other input variable than the measured carbon dioxide evolution rate
BULK HYDROPHILIC FUNTIONALIZATION OF POLYAMIDE 46
A modified polymer as result of a bulk functionalization of polyamide 46 (PA 46) is presented, as well as methods for synthesizing the modified polymer. This functionalization of PA 46 is performed to provide a homogenous semi-permeable polyamide 46 capable of different charges and different porosities with particles of nanoscale size in order to replace or improve other polyamide fibers used in the textile industry, filtering processes, selective sorption, controlled release devices, phase transfer catalysts, chromatography media, biocompatible capsules, artificial skins, organs, bone void repair as well as in cell bioreactors and incubators, dental impliments, medical devices, clothing, detectors, perfusion devices, in regenerative medicine, and fuel cells
Ethanol production from cotton-based waste textiles
Ethanol production from cotton linter and waste of blue jeans textiles was investigated. In the best case, alkali pretreatment followed by enzymatic hydrolysis resulted in almost complete conversion of the cotton and jeans to glucose, which was then fermented by Saccharomyces cerevisiae to ethanol. If no pretreatment applied, hydrolyses of the textiles by cellulase and β-glucosidase for 24 h followed by simultaneous saccharification and fermentation (SSF) in 4 days, resulted in 0.140–0.145 g ethanol/g textiles, which was 25–26% of the corresponding theoretical yield. A pretreatment with concentrated phosphoric acid prior to the hydrolysis improved ethanol production from the textiles up to 66% of the theoretical yield. However, the best results obtained from alkali pretreatment of the materials by NaOH. The alkaline pretreatment of cotton fibers were carried out with 0–20% NaOH at 0 \ub0C, 23 \ub0C and 100 \ub0C, followed by enzymatic hydrolysis up to 4 days. In general, higher concentration of NaOH resulted in a better yield of the hydrolysis, whereas temperature had a reverse effect and better results were obtained at lower temperature. The best conditions for the alkali pretreatment of the cotton were obtained in this study at 12% NaOH and 0 \ub0C and 3 h. In this condition, the materials with 3% solid content were enzymatically hydrolyzed at 85.1% of the theoretical yield in 24 h and 99.1% in 4 days. The alkali pretreatment of the waste textiles at these conditions and subsequent SSF resulted in 0.48 g ethanol/g pretreated textiles used
BULK HYDROPHILIC FUNTIONALIZATION OF POLYAMIDE 46
A modified polymer as result of a bulk functionalization of polyamide 46 (PA 46) is presented, as well as methods for synthesizing the modified polymer. This functionalization of PA 46 is performed to provide a homogenous semi-permeable polyamide 46 capable of different charges and different porosities with particles of nanoscale size in order to replace or improve other polyamide fibers used in the textile industry, filtering processes, selective sorption, controlled release devices, phase transfer catalysts, chromatography media, biocompatible capsules, artificial skins, organs, bone void repair as well as in cell bioreactors and incubators, dental impliments, medical devices, clothing, detectors, perfusion devices, in regenerative medicine, and fuel cells
The performance of serial bioreactors in rapid continuous production of ethanol from dilute-acid hydrolyzates using immobilized cells
The performance of single, and series of, continuous stirred-tank (CSTBR) and fluidized-bed bioreactor (FBBR) in anaerobic continuous cultivation of glucose in defined media and dilute-acid hydrolyzates at dilution rates 0.22, 0.43, 0.65 and 0.86 h -1 using immobilized Saccharomyces cerevisiae CBS 8066, was investigated. While the single CSTBR and FBBR could not take up more than 77% and 92% of glucose in a defined medium at dilution rate 0.86 h -1 , addition of the second bioreactor decreased the residual glucose to less than 1.1% of the incoming sugar. A similar trend was obtained in cultivation of dilute-acid hydrolyzates. A CSTBR could take up 75% and 54% of the initial fermentable sugars at dilution rates 0.43 and 0.86 h -1 , while the addition of the FBBR improved the assimilation of the sugars to 100% and 86%, respectively. The ethanol yields from the hydrolyzate were between 0.41 and 0.48 g/g in all the experiments. The specific and volumetric ethanol productivities were 1.13 g/g h and 5.98 g/L h for the single bioreactor and 0.98 g/g h and 5.49 g/L h for the serial bioreactor at the highest dilution rate, respectively. Glycerol was the only important by-product in terms of concentration, and yielded 0.05-0.07 g/g from the hydrolyzate. From the initial 3.98 g/L acetic acid present in the hydrolyzate, 0.1-0.8 g/L was assimilated by the cells. The yeast cells were accumulated close to the surface of the beads. While the cells had a dry-weight concentration of 129 g/L close to the surface of the beads, the concentration in the core was only 13 g/L. \ua9 2007 Elsevier Ltd. All rights reserved
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