Showing papers on "Solid-state fermentation published in 1998"

Production of pectinesterase and polygalacturonase by Aspergillus niger in submerged and solid state systems

Abstract: Production of pectinesterase and polygalacturonase by Aspergillus niger was studied in submerged and solid-state fermentation systems With pectin as a sole carbon source, pectinesterase and polygalacturonase production were four and six times higher respectively in a solid state system than in a submerged fermentation system and required a shorter time for enzyme production The addition of glucose increased pectinesterase and polygalacturonase production in the solid state system but in submerged fermentation the production was markedly inhibited A comparison of enzyme productivities showed that those determined for pectinesterase and polygalacturonase with pectin as a carbon source were three and five times higher by using the solid state rather than the submerged fermentation system The productivities of the two enzymes were affected by glucose in both fermentation systems The membranes of cells from the solid state fermentation showed increased levels of C18:1, C16:0 and C18:0 fatty acids Differences in the regulation of enzyme synthesis by Aspergillus niger depended on the fermentation system, favoring the solid state over the submerged fermentation for pectinase production

Lipase production by solid state fermentation of olive cake and sugar cane bagasse

Abstract: Olive oil cake (OOC) from Morocco and sugar cane bagasse (SCB) were used for lipase production using thermostable fungal cultures of Rhizomucor pusillus and Rhizopus rhizopodiformis. The maximum production of lipase by Rhizomucor pusillus and Rhizopus rhizopodiformis in solid state fermentation (SSF) using SCB, was 4.99 U/g DM equivalent to 1.73 U/ml and 2.67 U/g DM equivalent to 0.97 U/ml, respectively. However, the mixture of OOC and SCB, 50% each, increased the lipase activity as high as 79.6 U/g DM equivalent to 43.04 U/ml and 20.24 U/g DM equivalent to 10.83 U/ml obtained by Rhizopus rhizopodiformis and Rhizomucor pusillus, respectively. These data compare favourably with most of the activities reported for other lipase hyperproducing microorganisms.

Bioconversion of biomass: a case study of ligno-cellulosics bioconversions in solid state fermentation

Abstract: Lignocellulosic residues obtained from crops cultivation form useful sources to be used as substrate for bioconversion processes. Sugarcane bagasse, which is a complex substrate obtained from the processing of sugar cane, is an important biomass among such sources. Due to its abundant availability, it can serve as an ideal substrate for microbial processes for the production of value added products. This paper reviews recent developments on biological processes developed on production of various products in solid state fermentation using sugarcane bagasse as the substrate and describes production of protein enriched feed, enzymes, amino acid, organic acids and compounds of pharmaceutical importance, etc. through microbial means.

Selection of a strain of Aspergillus for the production of citric acid from pineapple waste in solid-state fermentation

Abstract: Aspergillus foetidus ACR I 3996 (=FRR 3558) and three strains of Aspergillus niger ACM 4992 (=ATCC 9142), ACM 4993 (=ATCC 10577), ACM 4994 (=ATCC 12846) were compared for the production of citric acid from pineapple peel in solid-state fermentation. A. niger ACM 4992 produced the highest amount of citric acid, with a yield of 19.4 g of citric acid per 100 g of dry fermented pineapple waste under optimum conditions, representing a yield of 0.74 g citric acid/g sugar consumed. Optimal conditions were 65% (w/w) initial moisture content, 3% (v/w) methanol, 30 degrees C, an unadjusted initial pH of 3.4, a particle size of 2 mm and 5 ppm Fe2+. Citric acid production was best in flasks, with lower yields being obtained in tray and rotating drum bioreactors.

Utilization of prawn waste for chitinase production by the marine fungus Beauveria bassiana by solid state fermentation.

Abstract: Prawn waste, a chitinous solid waste of the shellfish processing industry, was used as a substrate for chitinase production by the marine fungus Beauveria bassiana BTMF S10, in a solid state fermentation (SSF) culture. The␣process parameters influencing SSF were optimized. A maximum chitinase yield of 248.0 units/g initial dry substrate (U/gIDS) was obtained in a medium containing a 5:1 ratio (w/v) of prawn waste/sea water, 1% (w/w) NaCl,␣2.5% (w/w) KH2PO4, 425–600μm substrate particle size at 27°C, initial pH 9.5, and after 5 days of incubation. The presence of yeast extract reduced chitinase yield. The results indicate scope for the utilization of shellfish processing (prawn) waste for the industrial production of chitinase by using solid state fermentation.

Optimizing some factors affecting protease production under solid state fermentation

Abstract: Production of extracellular alkaline protease by a locally isolated fungal species, Rhizopus oryzae, under solid state fermentation was optimized. The maximum enzyme activity under the optimum conditions of temperature (32 °C), relative humidity (90%–95%), spore count (∼2 × 105/g wheat bran), moisture content of solid substrate (140%) adjusted suitably with salt solution (M-9) of pH 5.5 was 341 unit/g wheat bran.

Optimization studies on the production of cyclosporin A by solid state fermentation

Abstract: Several parameters including (a) tray fermentation with and without perforation (b) thickness of solid substrate bed (c) type of inoculum (d) size of inoculum (e)␣effect of relative humidity were studied for the optimum production of Cyclosporin A by solid state fermentation using Tolypocladium sp. The results indicate that while perforations in the trays had no significance on the yield of Cyc A, the other parameters had an influence on the production of Cyc A. The results indicate that under the optimized conditions, Cyc A can be produced in bulk quantities economically.

Solid-state fermentation - A mini review

Abstract: The increasing interests in biotechnology for the application of fungi on the one hand, and for cheap agricultural products on the other, can be combined in so-called solid-state fermentation (SSF). SSF resembles a close to natural habitat for filamentous microorganisms and can be applied to insoluble substrates. Many applications are described in the literature, ranking from animal feed to production of fine chemicals. The substrates used are, with the exception of synthetic media, cheap agricultural end- and by-products. The fermentation itself can be executed very simply. Several static and dynamic fermenters are described in the literature. Despite the wide applicability and apparent simplicity, fungal SSFs contain complex intrinsic difficulties. Therefore, biological and physical processes in SSF are difficult to control. This report gives an overview of the applications and intrinsic difficulties of SSF.

Solid-state fermentation plus extrusion to make biopesticide granules

Abstract: Five fungal biocontrol agents useful in agriculture were grown on rice flour in plastic bags. The flour, infested with Colletotrichum truncatum, an Alternaria sp., Paecilomyces fumosoroseus, or atoxigenic Aspergillus flavus and A. parasiticus, was mixed with wheat flour, kaolin, and water and extruded into granules. The inoculum survived extrusion and fluid bed drying at 50°C 3–92 times better than inoculum produced in liquid fermentation. Depending on the agent, the high level of flour infestation permitted a 1:9 to 1:1600 dilution to yield the 1×106 cfu/g in the final product which is usually needed for biocontrol efficacy. © Rapid Science Ltd. 1998

Heat transfer simulation of solid state fermentation in a packed-bed bioreactor

Abstract: A dynamic two-dimensional mathematical model was developed to simulate the heat transfer in solid state fermentation of rice bran inoculated with Aspergillus niger. Two bioreactors of 47 mm diameter and 300 mm height were used. Forced aeration conditions were simulated and saturated air with 60 ml/g h flow at 30°C and a bed porosity equal to 0.3 were determined as being the optimum operating conditions for the used packed-bed bioreactor. © Rapid Science Ltd. 1998

Oxygen uptake kinetics during solid state fermentation with Rhizopus oligosporus

Abstract: Membrane filter culture was used to relate O2 uptake with direct biomass measurement of Rhizopus oligosporus in solid-state fermentation (SSF). Overall values of YX/O and mO were 0.782 mg biomass mg O2−1 and 0.0413 mg O2 mg biomass−1 h−1, respectively. However, these values were not constant during the fermentation, which makes the use of O2 uptake to estimate biomass during SSF problematic. Despite these problems, measuring bioreactor off-gases is the only practical method which allows on-line monitoring of bioreactor performance.

Production of amylases from rice by solid-state fermentation in a gas-solid spouted-bed bioreactor

Abstract: A gas−solid spouted-bed bioreactor was developed to produce amylases from rice in solid-state fermentation by Aspergillusoryzae. The spouted-bed bioreactor was developed to overcome many of the problems inherent to large-scale solid-state fermentation, including mass- and heat-transfer limitations in the conventional tray reactors and solids-handling difficulties seen in packed-bed bioreactors. The solid-state fermentation results from the tray-type reactor with surface aeration were poor because of mass- and heat-transfer problems. A packed-bed bioreactor with continuous aeration through the rice bed produced high protein and enzymes, but the fermented rice was difficult to remove and process due to the formation of large chunks of rice aggregates knitted together with fungal mycelia. Also, the fermentation was not uniform in the packed bed. The spouted-bed bioreactor with intermittent spouting with air achieved high production levels in both total protein and enzymes (α-amylase, β-amylase, and glucoamylase) that were comparable to those found in the packed-bed bioreactor, but without the nonuniformity and solids-handling problems. However, continual spouting was found to be detrimental to this solid-state fermentation, possibly because of shear or impact damage to fungal mycelia during spouting. Increasing spouting frequency from 4-h intervals to 1-h intervals decreased protein and enzyme production. Other operating conditions critical to the fermentation include proper humidification to prevent drying of the substrate and control of reactor wall temperature to prevent excessive condensation, which would interfere with proper spouting.

Comparison of fermentation profiles between lupine and soybean by Aspergillus oryzae and Aspergillus sojae in solid-state culture systems

Abstract: To explore the possibilities of using lupine as a soybean replacement in fermented foods, fermentation profiles of lupine and soybean by Aspergillus oryzae and A. sojae, respectively, in a solid-state culture were compared. Biomass, spore concentration, oxygen consumption rate, carbon dioxide production rate, water activity, and production of three enzymes, namely amylase, protease, and cellulase, were measured during a 7-day fermentation. The similarity of fermentation profiles and the reported nutritive value of lupine and soybean lead to the conclusion that lupine can be used as a potential replacement of soybean in certain fermented foods.

Packing density and thermal conductivity determination for rice bran solid-state fermentation

Abstract: The fermentation of rice bran by Aspergillus niger to produce glucoamylase was carried out in a packed-bed bioreactor. The optimum packing density of medium was between 586 and 858 g/l. Also, thermal conductivity (K) was determined and an experimental correlation with packing density (PD) and moisture (M) was obtained as K = 47.5080 0.0115PD 0.1295M − 6.0737ln(PD) − 5.5555ln(M). © Rapid Science Ltd. 1998

Peroxidase and aryl metabolite production by the white rot fungus Bjerkandera sp. strain BOS55 during solid state fermentation of lignocellulosic substrates.

Abstract: Ligninolytic enzymes and secondary metabolite production by Bjerkandera sp. strain BOS 55 were monitored during solid state fermentation (SSF) on two lignocellulosic substrates, beech wood and hemp stem wood (HSW). After 6 weeks of SSF, the fungus was responsible for removing 27 and 39% of the Klason lignin as well as 43 and 70% of the apolar extractives on beech and HSW, respectively. The lignin degradation during beech wood decay was very selective. On both substrates, high activities of lignin peroxidase (LiP) and manganese peroxidase (MnP) were detected. The peak activity of LiP was 660 nmol ml 1 min. -1 on HSW and that of MnP was 1320 nmol ml 1 min. 1 on beech wood. The presence of several LiP and MnP isoenzymes at different times during the SSF was demonstrated by FPLC profiles of these heme proteins. The production of the secondary aryl metabolites, veratryl alcohol and 3-chloro-p-anisaldenyde reached peak concentrations of 820 and 90μM, respectively. The enhanced production of these secondary metabolites compared to defined liquid cultures is suggested to be due to the release of lignin degradation products serving as alternative precursors for their biosynthesis. The high production of veratryl alcohol, which is a cofactor known to protect LiP from inactivation by physiological levels of H 2 O 2 , may account for the high production of active LiP on the lignocellulosic substrates.

Strategies for the Selection of Mold Strains Geared to Produce Enzymes on Solid Substrates

Abstract: This paper deals with the problem of outlying a strategy for the selection of mold strains adapted to the production and excretion of enzymes by solid—substrate fermentation (SSF), as compared to the conventional technique of submerged fermentation (SmF). Such strategy is based on the analysis of the physiological differences between SSF and SmF in relation to repression-induction patterns, water activity requirements, excretion and enzyme productivity. The strategy used, so far, is based on the selection of Aspergillus niger mutants having a phenotype based on 2-deoxy glucose resistance together with adaptation to low levels of water activity. Recent work is reviewed in terms of the potential for developing industrial fermentation processes using those new strains together with some downstream considerations (water saving and solid waste recycling).

Optimization of solid-state fermentation parameters for the production of xylanase by trichoderma longibrachiatum on wheat bran

Abstract: Solid-state fermentation has the potential to produce inexpensive enzymes for use in high-volume industrial applications. Process parameters such as substrate moisture content and length of fermentation can have a significant effect on the amount and timing of enzyme production. This study was conducted in two stages, a screening stage and an optimization stage, to determine the effects of moisture content of the substrate, surfactant addition upon inoculation, depth of the substrate, and duration of fermentation on xylanase activity produced by Trichoderma longibrachiatum. Screening fermentations were conducted at 25°C, 50 and 75% wet basis moisture content (w.b.), 0.0 and 0.2% v/v surfactant addition, 0.5 and 1.5 cm depth of wheat bran, and 5 and 10 days of fermentation. Optimization fermentations were conducted at 25°C, 45, 55, and 65% moisture content (w.b.), 1.0, 1.5, and 2.0 cm depth of wheat bran, and three and five days of fermentation. Experiments were conducted as full factorial experiments with three replications of each treatment. The optimal values of the process variables were selected based on the units of xylanase activity produced per gram of wheat bran (U/g). Moisture content, depth of substrate, and duration of fermentation had significant main effects on the production of enzyme activity. Surfactant addition upon inoculation had interaction effects with moisture content, and the duration of fermentation by moisture content interaction also was significant. The treatment of 55% moisture content, 1.5 cm depth of substrate, and five days of fermentation resulted in the highest average xylanase activity (716 U/g wheat bran).

Sclerotia growth and carotenoid production of Penicillium sp PT95 during solid state fermentation of corn meal

Abstract: Using corn meal as fermentation substrate, the effect of some factors, fermentation time and supplementation of saccharide and nitrogen sources as well as vegetable oil, on the sclerotia growth and carotenoid production of Penicillium sp PT95 during solid state fermentation were studied. When PT95 strain was grown on the amended medium by supplementing of 3g NaNO3, 10g maltose and 2.5g soybean oil per liter of salt solution to basal medium for 20 days, the dry sclerotia weight and carotenoid yield reached 9.70 g and 5260 μg / 100 g of substrate, respectively. Without supplementation only 5.36g dry sclerotia and 2149μg carotenoid / 100 g of substrate was attained. © Rapid Science Ltd. 1998

An enzyme-linked immunosorbent assay for the estimation of fungal biomass during solid-state fermentation

Abstract: An enzyme-linked immunosorbent assay for sensitive, specific and quantitative estimation of fungal biomass during solid-state fermentation is described. Using this method, differential growth rates and colonization of the substrate can be studied. The assay has potential application for the efficient monitoring of solid-state fermentation involving specific fungus, for which available methods are not adequate.

Mimicking gas and temperature changes during enzyme production by Rhizopus oligosporus in solid-state fermentation

Abstract: Step changes in the gas environment and temperature during membrane culture of Rhizopus oligosporus were made to mimic those changes which arise during solid-state fermentation due to mass and heat transfer limitations. A decrease of O2 concentration from 21% to 0.5% did not alter protease production by R. oligosporus but retarded amyloglucosidase production. An upshift from 37°C to 50°C decreased the activities of both enzymes, with the effect on protease being due to enzyme deactivation rather than a decrease in production. © Rapid Science Ltd. 1998