Showing papers on "Solid-state fermentation published in 2010"

Lignocellulose as raw material in fermentation processes

Abstract: Lignocellulose in the form of forestry, agricultural, and agro%industrial wastes is accumulated in large quantities every year. These materials are mainly composed of three groups of polymers, namely cellulose, hemicellulose, and lignin. Cellulose and hemicellulose are sugar rich fractions of interest for use in fermentation processes, since microorganisms may use the sugars for growth and production of value added compounds such as ethanol, food additives, organic acids, enzymes, and others. Submerged and solid%state fermentation systems have been used to produce compounds of industrial interest from lignocellulose, as an alternative for valorization of these wastes and also to solve environmental problems caused by their disposal. When submerged fermentation systems are used, a previous stage of hydrolysis for separation of the lignocellulose constituents is required. This work is an overview about the potential uses of lignocellulosic materials in fermentation processes. Aspects related to submerged and solid%state fermentation systems will be described focusing on the raw materials, hydrolysis processes, fermentation conditions, microorganisms, and products that can be obtained.

Acid protease production by solid-state fermentation using Aspergillus oryzae MTCC 5341: optimization of process parameters.

Abstract: Aspergillus oryzae MTCC 5341, when grown on wheat bran as substrate, produces several extracellular acid proteases. Production of the major acid protease (constituting 34% of the total) by solid-state fermentation is optimized. Optimum operating conditions obtained are determined as pH 5, temperature of incubation of 30 degrees C, defatted soy flour addition of 4%, and fermentation time of 120 h, resulting in acid protease production of 8.64 x 10(5) U/g bran. Response-surface methodology is used to generate a predictive model of the combined effects of independent variables such as, pH, temperature, defatted soy flour addition, and fermentation time. The statistical design indicates that all four independent variables have significant effects on acid protease production. Optimum factor levels are pH 5.4, incubation temperature of 31 degrees C, 4.4% defatted soy flour addition, and fermentation time of 123 h to yield a maximum activity of 8.93 x 10(5) U/g bran. Evaluation experiments, carried out to verify the predictions, reveal that A. oryzae produces 8.47 x 10(5) U/g bran, which corresponds to 94.8% of the predicted value. This is the highest acid protease activity reported so far, wherein the fungus produces four times higher activity than previously reported [J Bacteriol 130(1): 48-56, 1977].

Production of Xylanase From an Alkalitolerant Streptomyces sp. 7b Under Solid-State Fermentation, Its Purification, and Characterization

Abstract: Streptomyces sp. 7b showed highest xylanase activity among 41 bacterial isolates screened under submerged fermentation. The organism grew over broad pH (5-11) and temperatures range (25-55 degrees C) and displayed maximum xylanase production on wheat bran (1230 U/g) under solid-state fermentation. Xylanase production was enhanced substantially (76%-77%) by inclusion of trypton (2180 U/g) or beef extract (2170 U/g) and moderately (36%-46%) by yeast extract (1800 U/g) or soybean meal (1670 U/g). Inclusion of readily utilizable sugars such as glucose, maltose, fructose, lactose or xylose in the substrate repressed the xylanase production. The optimum initial pH of the medium for maximum enzyme production was 7 to 8; however, appreciable level of activity was obtained at pH 6 (1,680 U/g) and 9 (1,900 U/g). Most appropriate solid to liquid ratio for maximum xylanase production in solid-state fermentation was found to be 1:2.5. The organism produced a single xylanase of molecular weight of approximately 30 kDa as analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis after purification with ammonium sulfate precipitation, and carboxy methyl sephadex chromatography. The enzyme was purified to the extent of 5.68-fold by salt precipitation and ion-exchange chromatography. Optimum temperature and pH for maximum xylanase activity were 50 degrees C and 6, respectively.

Horticultural waste as the substrate for cellulase and hemicellulase production by Trichoderma reesei under solid-state fermentation.

Abstract: Horticultural waste in wood chips form collected from a landscape company in Singapore was utilized as the substrate for the production of cellulase and hemicellulase under solid-state fermentation by Trichoderma reesei RUT-C30. The effects of substrate pretreatment methods, substrate particle size, incubation temperature and time, initial medium pH value, and moisture content on cellulase and hemicellulase production were investigated. Enzyme complex was obtained at the optimal conditions. This enzyme mixture contained FPase (15.0 U/g substrate dry matter, SDM), CMCase (90.5 U/g SDM), β-glucosidase (61.6 U/g SDM), xylanase (52.1 U/g SDM), and β-xylosidase (10.4 U/g SDM). The soluble protein concentration in the enzyme complex was 26.1 mg/g SDM. The potential of the crude enzyme complex produced was demonstrated by the hydrolysis of wood chips, wood dust, palm oil fiber, and waste newspaper. The performance of the crude enzyme complex was better than the commercial enzyme blend.

Cellulase production by Trichoderma sp. on apple pomace under solid state fermentation

Abstract: The feasibility of using apple pomace for cellulase production by Trichoderma sp. under solid state fermentation was evaluated in this study. Our results indicated that initial moisture level of the medium, incubation temperature and inoculum size influenced the cellulase production greatly. The optimum initial moisture level, incubation temperature and inoculum size were 70%, 32 and 2×108 spores/flask, respectively. The supplement of lactose and corn-steep solid to the apple pomace favored the enzyme formation markedly.

Optimization of Fermentation Parameters for Higher Lovastatin Production in Red Mold Rice through Co-culture of Monascus purpureus and Monascus ruber

Abstract: Monascus, fermented rice (red mold rice), has been found to reduce the serum total cholesterol and triglyceride due to presence of lovastatin. Lovastatin acts as an inhibitor of 3-hydroxy-3-methyl glutaryl coenzyme A reductase. Coculture of Monascus purpureus MTCC 369 and Monascus ruber MTCC 1880 was used to produce red mold rice by solid-state fermentation. Optimization of different fermentation process parameters such as temperature, fermentation time, inoculum volume, and pH of the solid medium was carried out by Box–Behnken’s factorial design of response surface methodology to maximize lovastatin concentration in red mold rice. Maximum lovastatin production of 2.83 mg/g was predicted at 14th day in solid medium under optimized process condition.

Lipase production by solid fermentation of soybean meal with different supplements

Abstract: The aim of this work was to study the production of extracellular lipases by solid state fermentation in soybean meal with different supplements. Lipase production by two microorganisms, screened by their potential for lipase production, was followed in terms of hydrolytic activity at different pH values(4, 7 and 9). The supplementation of the medium with urea and soybean oil significantly increased the enzyme production for all studied pH and microorganisms. Microorganism Penicillium P58 and P74 showed the possibility of production of different lipases with alkaline and acidic characteristics. In soybean meal supplemented with urea and soybean oil, this microorganism yielded 139.2 and 140.7U lipase/g of dry substrate in 48 h of fermentation, in alkaline and acidic conditions, respectively. Different behavior was observed when the enzyme extract was evaluated in neutral conditions, which yielded 180.0U lipase/g in 72 h. A new promising lipase producer strain was testedon soybean meal with different supplements. The strain produced a lipase with high activities by solid state fermentation of soybean meal supplemented with urea and soybean oil.

Cellulase production by Aspergillus niger in biofilm, solid-state, and submerged fermentations

Abstract: Cellulase production by Aspergillus niger was compared in three different culture systems: biofilm, solid-state, and submerged fermentation. Biofilm and solid-state fermentations were carried out on perlite as inert support, and lactose was used as a carbon source in the three culture systems. In cryo-scanning electron microscopy, biofilm and solid-state cultures gave similar morphological patterns and confirmed that both spore first attachment and hyphal adhered growth are helped by the production of an adhesive extracellular matrix. Biofilm cultures produced higher cellulase activities than those in submerged and solid-state cultures (1,768, 1,165, and 1,174 U l−1, respectively). Although biofilm cultures grew less than the other cultures, they produced significantly higher cellulase yields (370, 212, and 217 U g−1 lactose, respectively) and volumetric productivities (24, 16, and 16 U l−1 h−1, respectively). Likewise, endoglucanase and xylanase activities were higher in biofilm cultures. Under the conditions tested, it seems that fungal attached growth on perlite may favor better enzyme production. Biofilms are efficient systems for cellulase production and may replace solid-state fermentation. Biofilm fermentation holds promise for further optimization and development. The results of this work reveal that fungal biofilms may be used for the commercial production of cellulase employing the technology developed for submerged fermentation at high cell densities.

Solid State Fermentation of Aspergillus oryzae for Glucoamylase Production on Agro residues

Abstract: Glucoamylase is a well recognized amylolytic enzyme used in food industry, which is generally produced by Aspergillus genus under solid-state fermentation (SSF). This study presents production of glucoamylase by Aspergillus oryzae on the solid surface of rice husk, wheat bran, rice bran, cotton seed powder, corn steep solids, bagasse powder, coconut oil cake, and groundnut oil cake as substrates. Optimization of the SSF media and parameters resulted in a 24% increase in the glucoamylase activity. Optimum glucoamylase production (1986 μmoles of glucose produced per minute per gram of dry fermented substrate) was observed on wheat bran supplemented with 1%, (w/w) starch, 0.25%, (w/w) urea at pH 6, 100%, (v/w) initial moisture and 30°C after incubation 120 hrs. Therefore, A. oryzae can be useful in bioprocessing application for saccharification of agro-residues. Keywords : Glucoamylase, Aspergillus oryzae, solid state fermentation, agro residues DOI: 10.3126/ijls.v4i0.2892 International Journal of Life Sciences Vol.4 2010 pp.16-25

Cellulases and Xylanases Production by Penicillium echinulatum Grown on Sugar Cane Bagasse in Solid-State Fermentation

Abstract: To investigate the production of cellulases and xylanases from Penicillium echinulatum 9A02S1, solid-state fermentation (SSF) was performed by using different ratios of sugar cane bagasse (SCB) and wheat bran (WB). The greatest filter paper activity obtained was 45.82 ± 1.88 U gdm−1 in a culture containing 6SCB/4WB on the third day. The greatest β-glucosidase activities were 40.13 ± 5.10 U gdm−1 obtained on the third day for the 0SCB/10WB culture and 29.17 ± 1.06 U gdm−1 for the 2SCB/8WB culture. For endoglucanase, the greatest activities were 290.47 ± 43.57 and 276.84 ± 15.47 U gdm−1, for the culture 6SCB/4WB on the fourth and fifth days of cultivation, respectively. The greatest xylanase activities were found on the third day for the cultures 6SCB/4WB (36.38 ± 5.38 U gdm−1) and 4SCB/6WB (37.87 ± 2.26 U gdm−1). In conclusion, the results presented in this article showed that it was possible to obtain large amounts of cellulases and xylanases enzymes using low-cost substrates, such as SCB and WB.