Showing papers on "Solid-state fermentation published in 1996"

Banana waste as substrate for α-amylase production by Bacillus subtilis (CBTK 106) under solid-state fermentation

Abstract: Bacillus subtilis CBTK 106, isolated from banana wastes, produced high titres of α-amylase when banana fruit stalk was used as substrate in a solid-state fermentation system. The effects of initial moisture content, particle size, cooking time and temperature, pH, incubation temperature, additional nutrients, inoculum size and incubation period on the production of α-amylase were characterised. A maximum yield of 5 345 000 U mg-1 min-1 was recorded when pretreated banana fruit stalk (autoclaved at 121 °C for 60 min) was used as substrate with 70% initial moisture content, 400 μm particle size, an initial pH of 7.0, a temperature of 35 °C, and additional nutrients (ammonium sulphate/sodium nitrate at 1.0%, beef extract/peptone at 0.5%, glucose/sucrose/starch/maltose at 0.1% and potassium chloride/sodium chloride at 1.0%) in the medium, with an inoculum-to-substrate ratio of 10% (v/w) for 24 h. The enzyme yield was 2.65-fold higher with banana fruit stalk medium compared to wheat bran.

Solid-state fermentation of wheat bran by Trichoderma reesei QM9414: substrate composition changes, C balance, enzyme production, growth and kinetics.

Abstract: A description is given of the solid-state fermentation of wheat bran by Trichoderma reesei QM9414 at constant temperature and relative humidity. Glucosamine, the oxygen consumption rate (OCR), the carbon dioxide production rate (CPR), changes in wheat bran composition and the production of four enzymes were measured during 125 h of fermentation. A C balance was set up between CO2 production, based on CPR measurements, CO2 production as expected on the basis of substrate composition changes and substrate elemental composition in combination with dry-matter weight loss. Glucosamine was used as the measure of biomass. The results indicate that the glucosamine content of fungi in liquid culture cannot be used to estimate the biomass content in solid-state fermentations. Using glucosamine, correlations between fungal growth and respiration kinetics could only partly be described with the linear-growth model of Pirt. A decline in OCR and CPR started the moment the glucosamine level was 50% of its maximum value. After the glucosamine level had reached its maximum OCR and CPR continued to decline. The activities of xylanase and protease are linearly related to the glucosamine level. No clear correlations between glucosamine and carboxylmethylcellulose-hydrolysing enzyme activity and amylase activity were found.

Production and isolation of chitosan by submerged and solid‐state fermentation from Lentinus edodes

Abstract: A method for the laboratory-scale production and isolation of chitosan (polyglucosamine) by liquid and solidstate fermentation from Lentinus edodes was developed. The yields of isolated chitosan were 120 mg/L of fermentation medium under liquid fermentation conditions and 6.18 g/kg of fermentation medium under solid-state fermentation conditions. The latter method, which gives up to 50 times yields than other chitosan production methods from fungi, provides a new flexible and easily scaledup procedure for the production of low acetylation degree chitosan.

Solid state fermentation for L-glutamic acid production using Brevibacterium sp.

Abstract: Solid state fermentation system was used to cultivate Brevibacterium sp. on sugar cane bagasse impregnated with a medium containing glucose, urea, mineral salts and vitamins for producing L-glutamic acid. Maximum yields (80 mg glutamic acid per g dry bagasse with biomass and substrate - mg/gds) were obtained when bagasse of mixed particle size was moistened at 85–90 % mositure level with the medium containing 10 % glucose. This is the first report on the cultivation of Brevibacterium sp. in solid cultures for production of glutamic acid.

Production of Secondary Metabolites by Solid-State Fermentation

Abstract: Microbial secondary metabolites are useful high value products that are normally produced by liquid culture; but could be advantageously produced by solid-state fermentation (SSF). Particularly if SSF could benefit from a deeper understanding of microbial physiology in a solid environment. Recent research indicates that different kind of secondary metabolites can be produced by SSF: antibiotics, phytohormones, food grade pigments, alkaloids, etc. Physiology in SSF shows several similarities with physiology in liquid medium, so similar strategies must be adapted for efficient processes. However, there are certain particularities of idiophase in solid medium which dictate the need for special strains.

Production of Cellulase in Solid-State Fermentation with Trichoderma reesei MCG 80 on Wheat Straw

Abstract: It is an accepted fact that ethanol production from lignocellulosic materials is not economical as yet because of the high cost of cellulase production. To reduce the cost of cellulase production, lignocellulosic material (wheat straw EWS]), a comparatively much cheaper substrate, was used instead of costly substrates (pure cellulose or lactose). A pan bioreactor was developed for solid-state fermentation (SSF) that required a small capital investment. High yields of complete cellulase system were obtained compared to that in the liquid-state fermentation (LSF) from WS, when treated with 4.25% NaOH at 121°C for 1 h and mixed with Mandels’ medium. A complete cellulase system is defined as one in which the ratio of sglucosidase activity to filter paper activity in the enzyme solution is close to 1.0. The cellulase system derived from SSF using the pan bioreactor gave more than 85% hydrolysis of delignified WS. The prototype pan bioreactor requires further improvements so that optimum quantity of substrate can be fermented to obtain high yields of complete cellulase system per unit space. The SSF process provides a means for the production of complete cellulase system for the economical bioconversion of renewable biomass into ethanol.

Purification and characterization of glucoamylase produced by Aspergillus niger in solid state fermentation.

Abstract: Glucoamylases produced by Aspergillus niger grown on wheat brain in solid cultures were purified. Four different forms, GA I, GA I', GA II and GA III, were found having apparent molecular weights of 112,000, 104,000, and 74,000 and 61,000 Da respectively. The enzymes are glycoproteins with a carbohydrate content of 16%, and optimal activity at 60 degrees C and pH 4.4. Activity was strongly inhibited by Hg2+ while Mn2+ and Fe2+ were stimulatory. The Km values for the degradation of starch and maltose were 3.5 and 7.8 mg ml-1, respectively.

Production of tannase by solid-state fermentation

Abstract: An attempt has been made to optimize the production of enzyme tannase by solid state fermentation (SSF) using the organism Rhizopus oryzae. The best favourable conditions for enzyme production include initial pH 5 with 4 days of incubation period at 40°C and 72% humidity, and 10 g wheat bran soaked in 2.5% tannic acid.

L-Glutaminase production by marine Vibrio costicola under solid-state fermentation using different substrates

Abstract: Microbial Technology Unit, Department of Biotechnology, Cochin University of Science and Technology

Biomass estimation of Aspergillus niger growing on real and model supports in solid state fermentation

Abstract: Direct hydrolysis of Aspergillus niger mycelium growth on amberlite IRA-900 or sugar cane bagasse on solid state fermentation followed by the analysis of soluble protein by the dye binding method was carried out Hydrolysis with phosphoric acid 025M during 7 min allowed maxima protein extraction available to be measured Color interference of medium components was not observed, allowing the use of this method for biomass estimation when amberlite IRA-900 or sugar cane bagasse are used as support in solid state fermentation processes

Production of amyloglucosidase by Aspergillus niger under different cultivation regimens.

Abstract: Amyloglucosidase (AMG) was produced by Aspergillus niger in solid-state fermentation (SSF), submerged fermentation (SmF) and an aqueous, two-phase system of polyethyleneglycol (PEG) and salt. In SSF, a fed-batch mode of operation gave a yield of 64 U/ml compared with 44 U/ml in batch mode. Similar trends were observed for SmF, where fed-batch cultivation gave a yield of 102 U/ml compared with 66 U/ml in batch. Shorter cultivation times (66 h) were required for SmF than for SSF (96 h). In the aqueous, two-phase cultivation, the productivity and yield of AMG were both twice those in the control fermentation.

Processing of agricultural wastes in solid state fermentation for microbial protein production

Abstract: Newer aspects of microbial protein production and protein enrichment of various agricultural wastes and agroindustrial byproducts in solid state fermentation are described. It is pointed out that SSF is attractive due to its low level technology, reduced reactor volume per unit substrate converted and the direct applicability of the fermented product for feed production. SSF of lignocellulosic substrates, starchy material, citrus wastes, normal apple pomace and carob pods is also presented. Some typical SSF processes for protein enriched animal feed production have also been tabulated along with data on substrates and microorganisms.

Gluconate production by spores of Aspergillus niger

Abstract: Spores of Aspergillus niger obtained by solid state fermentation on buckwheat seeds produced gluconic acid from glucose with a high yield, near 1.06 g gluconic acid/g glucose, close to the stoichiometric value. The reaction itself could be carried out either with purified biocatalyst or with the whole buckwheat medium resulting from spore production process. 200 g gluconic acid/L were obtained in 200 h with sequential feedings of glucose up to 190 g/L.

Processing of agricultural wastes in solid state fermentation for cellulolytic enzymes production

Abstract: The state-of-the-art of cellulase production in solid state fermentation is presented. It is argued that with appropriate technology, improved bioreactors and operation controls, SSF may be a competitive method for the production of a lignocellulose hydrolysing enzyme - cellulase. Advantages of the cellulase production in SSF are enumerated along with the factors affecting cellulase production. Some typical SSF processes used for cellulolytic enzymes production are also tabulated along with details about substrates, microorganisms and enzymes.

Production of Cellulase Systems by Selected Mutants of Trichoderma reesei in Solid-State Fermentation and Their Hydrolytic Potentials

Abstract: Three mutants of Trichoderma reesei were grown in solid-state fermentation (SSF) in flasks and in a pan bioreactor. Mutant strain MCG 80 proved to be best at producing an optimal cellulase system using lignocellulosic material (wheat straw [WS]) as substrate. This preparation exhibited a β-glucosidase activity (βGA) to FPA (FPA) ratio of about 1.0, which is indicative of a high potential for hydrolysis of cellulose. The yields of cellulase systems and the ratio of PGA to FPA produced in flasks were comparable to that of the pan bioreactor. The cellulase system of T. reesei MCG 80 having a ratio of βGA to FPA close to 1.0 gave the most complete (88-95%) hydrolysis of 5% delignified wheat straw (DWS). On the other hand, the cellulase system of cocultures of T. reesei QMY-1 and Aspergillus phoenicis failed to produce high hydrolytic yields in spite of having a very high ratio of PGA to FPA (3.04). This failure was owing to the fact that coculture contained the relatively poor-quality cellulase system of the dominant organism, A. phoenicis. The resulting fermented WS can be used, as a source of enzyme (unextracted), for hydrolysis of wheat straw, and it gives increased yields of reducing sugars compared to analogous extracted enzyme preparations. The hydrolytic potential of two commercial enzymes tested were considerably lower than those of the cellulase systems produced on WS. It is evident that a complete cellulase system having a PGA-to-FPA ratio close to 1.0 and high hydrolytic potential can be produced on lignocellulosic feedstocks in SSF.