Showing papers on "Solid-state fermentation published in 2004"

Biotechnological advantages of laboratory-scale solid-state fermentation with fungi.

Abstract: Despite the increasing number of publications dealing with solid-state (substrate) fermentation (SSF) it is very difficult to draw general conclusion from the data presented This is due to the lack of proper standardisation that would allow objective comparison with other processes Research work has so far focused on the general applicability of SSF for the production of enzymes, metabolites and spores, in that many different solid substrates (agricultural waste) have been combined with many different fungi and the productivity of each fermentation reported On a gram bench-scale SSF appears to be superior to submerged fermentation technology (SmF) in several aspects However, SSF up-scaling, necessary for use on an industrial scale, raises severe engineering problems due to the build-up of temperature, pH, O2, substrate and moisture gradients Hence, most published reviews also focus on progress towards industrial engineering The role of the physiological and genetic properties of the microorganisms used during growth on solid substrates compared with aqueous solutions has so far been all but neglected, despite the fact that it may be the microbiology that makes SSF advantageous against the SmF biotechnology This review will focus on research work allowing comparison of the specific biological particulars of enzyme, metabolite and/or spore production in SSF and in SmF In these respects, SSF appears to possess several biotechnological advantages, though at present on a laboratory scale only, such as higher fermentation productivity, higher end-concentration of products, higher product stability, lower catabolic repression, cultivation of microorganisms specialized for water-insoluble substrates or mixed cultivation of various fungi, and last but not least, lower demand on sterility due to the low water activity used in SSF

Production, isolation, and purification of L-asparaginase from Pseudomonas aeruginosa 50071 using solid-state fermentation.

Abstract: The L-asparaginase (E. C. 3. 5. 1. 1) enzyme was purified to homogeneity from Pseudomonas aeruginosa 50071 cells that were grown on solid-state fermentation. Different purification steps (including ammonium sulfate fractionation followed by separation on Sephadex G-100 gel filtration and CM-Sephadex C50) were applied to the crude culture filtrate to obtain a pure enzyme preparation. The enzyme was purified 106-fold and showed a final specific activity of 1900 IU/mg with a 43% yield. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of the purified enzyme revealed it was one peptide chain with M(r) of 160 kDa. A Lineweaver-Burk analysis showed a K(m) value of 0.147 mM and V(max) of 35.7 IU. The enzyme showed maximum activity at pH 9 when incubated at 37 degrees C for 30 min. The amino acid composition of the purified enzyme was also determined.

Pectinase production by fungal strains in solid-state fermentation using agro-industrial bioproduct

Abstract: Pectin lyase and polygalacturonase production by newly isolated fungal strains was carried out in solid-state fermentation. Moniliella SB9 and Penicillium sp EGC5 produced polygalcturonase (PG) and pectin lyase (PL) on mixture of orange bagasse, sugar cane bagasse and wheat bran as substrate. PG and PL produced by Moniliella presented optimum activity at pH 4.5 and 10.0 and at 55 and 45°C, respectively, while these enzymes from Penicillium sp presented optimum activity at pH 4.5-5.0 and 9.0 and 40°C, respectively.

Production of fructosyl transferase by Aspergillus oryzae CFR 202 in solid-state fermentation using agricultural by-products

Abstract: Fructosyl transferase (FTase) production by Aspergillus oryzae CFR 202 was carried out by solid-state fermentation (SSF), using various agricultural by-products like cereal bran, corn products, sugarcane bagasse,cassava bagasse (tippi) and by-products of coffee and tea processing. The FTase produced was used for the production of fructo-oligosaccharides (FOS), using 60% sucrose as substrate. Among the cereal bran used, rice bran and wheat bran were good substrates for FTase production by A. oryzae CFR 202. Among the various corn products used, corn germ supported maximum FTase production, whereas among the by-products of coffee and tea processing used, spent coffee and spent tea were good substrates, with supplementation of yeast extract and complete synthetic media. FTase had maximum activity at 60°C and pH 6.0. FTase was stable up to 40°C and in the pH range 5.0–7.0. Maximum FOS production was obtained with FTase after 8 h of reaction with 60% sucrose. FTase produced by SSF using wheat bran was purified 107-fold by ammonium sulphate precipitation (30–80%), DEAE cellulose chromatography and Sephadex G-200 chromatography. The molecular mass of the purified FTase was 116.3 kDa by SDS-PAGE. This study indicates the potential for the use of agricultural by-products for the efficient production of FTase enzyme by A. oryzae CFR 202 in SSF, thereby resulting in value addition of those by-products.

Chinese Vinegar and its Solid-State Fermentation Process

Abstract: China uses solid-state fermentation (SSF) processes on a large scale for products such as vinegar, Chinese distilled spirit, soy sauce, Furu, and other national foods that are consumed around the world. In this article, the typical SSF process is discussed, with a focus on Chinese vinegars, especially those that are prepared through solid-state fermentation. Six well-known types are discussed in detail. Finally, possible ways to improve the traditional vinegar production process are discussed. The article discloses Chinese information about solid-state vinegar fermentation that otherwise would be inaccessible to Western scientists due to language barriers.

Enzyme production and profile by Aspergillus niger during solid substrate fermentation using palm kernel cake as substrate.

Abstract: The oil palm sector is one of the major plantation industries in Malaysia. Palm kernel cake is a byproduct of extracted palm kernel oil. Mostly palm kernel cake is wasted or is mixed with other nutrients and used as animal feed, especially for ruminant animals. Recently, palm kernel cake has been identified as an important ingredient for the formulation of animal feed, and it is also exported especially to Europe, South Korea, and Japan. It can barely be consumed by nonruminant (monogastric) animals owing to the high percentages of hemicellulose and cellulose contents. Palm kernel cake must undergo suitable pretreatment in order to decrease the percentage of hemicellulose and cellulose. One of the methods employed in this study is fermentation with microorganisms, particularly fungi, to partially degrade the hemicellulose and cellulose content. This work focused on the production of enzymes by Aspergillus niger and profiling using palm kernel cake as carbon source.

Effect of temperature, moisture, and carbon supplementation on lipase production by solid-state fermentation of soy cake by Penicillium simplicissimum.

Abstract: The production of lipases by Penicillium simplicissimum using solid-state fermentation and soy cake as substrate was investigated. The effects of temperature, cake moisture, and carbon supplementation on lipase production were studied using a two-level experimental plan. Moisture, pH, and lipase activity were followed during fermentation. Statistical analysis of the results was performed to evaluate the effect of the studied variables on the maximum lipase activity. Incubation temperature was the variable that most affected enzyme activity, showing a negative effect. Moisture and carbon supplementation presented a positive effect on activity. It was possible to obtain lipase activity as high as 21 U/g of dry cake in the studied range of process variables.

Polyol accumulation by Aspergillus oryzae at low water activity in solid-state fermentation

Abstract: Polyol accumulation and metabolism were examined in Aspergillus oryzae cultured on whole wheat grains or on wheat dough as a model for solid-state culture. In solid-state fermentation (SSF), water activity (a w) is typically low resulting in osmotic stress. In addition to a high level of mannitol, which is always present in the cells, A. oryzae accumulated high concentrations of glycerol, erythritol and arabitol at relatively low a w (0·96–0·97) in SSF. Accumulation of such a mixture of polyols is rather unusual and might be typical for SSF. A. oryzae mycelium accumulating various polyols at low a w contained at least four distinct polyol dehydrogenases with highest activities toward glycerol, erythritol, d-arabitol and mannitol. NADP+-dependent glycerol dehydrogenase activity correlated very well with glycerol accumulation. A similar correlation was observed for erythritol and NADP+–erythritol dehydrogenase suggesting that NADP+-dependent glycerol and erythritol dehydrogenases are involved in biosynthesis of glycerol and erythritol, respectively, and that these enzymes are induced by osmotic stress.

Production of poly(3-hydroxybutyrate) by solid-state fermentation with Ralstonia eutropha.

Abstract: The use of solid-state fermentation is examined as a low-cost technology for the production of poly(hydroxyalkanoates) (PHAs) by Ralstonia eutropha. Two agroindustrial residues (babassu and soy cake) were evaluated as culture media. The maximum poly(hydroxybutyrate) (PHB) yield was 1.2 mg g(-1) medium on soy cake in 36 h, and 0.7 mg g(-1) medium on babassu cake in 84 h. Addition of 2.5% (w/w) sugar cane molasses to soy cake increased PHB production to 4.9 mg g(-1) medium in 60 h. Under these conditions, the PHB content of the dry biomass was 39% (w/w). The present results indicate that solid-state fermentation could be a promising alternative for producing biodegradable polymers at low cost.

Influence of cultivating conditions on the α-galactosidase biosynthesis from a novel strain of Penicillium sp. in solid-state fermentation

Abstract: Aims: The work is intended to achieve optimum culture conditions of α-galactosidase production by a mutant strain Penicillium sp. in solid-state fermentation (SSF). Methods and Results: Certain fermentation parameters involving incubation temperature, moisture content, initial pH value, inoculum and load size of medium, and incubation time were investigated separately. The optimal temperature and moisture level for α-galactosidase biosynthesis was found to be 30°C and 50%, respectively. The range of pH 5·5–6·5 was favourable. About 40–50 g of medium in 250-ml flask and inoculum over 1·0 × 106 spores were suitable for enzyme production. Seventy-five hours of incubation was enough for maximum α-galactosidase production. Substrate as wheat bran supplemented with soyabean meal and beet pulp markedly improved the enzyme yield in trays. Conclusions: Under optimum culture conditions, the α-galactosidase activity from Penicillium sp. MAFIC-6 indicated 185·2 U g−1 in tray of SSF. Significant and Impact of the Study: The process on α-galactosidase production in laboratory scale may have a potentiality of scaling-up.

Xylanase production by the thermophilic mold Humicola lanuginosa in solid-state fermentation.

Abstract: Among the lignocellulosic substrates tested, wheat bran supported a high xylanase (EC 3.2.1.8) secretion by Humicola lanuginosa in solid-state fermentation (SSF). Enzyme production reached a peak in 72 h followed by a decline thereafter. Enzyme production was very high (7832 U/g of dry moldy bran) when wheat bran was moistened with tap water at a substrate-to-moistening agent ratio of 1:2.5 (w/v) and an inoculum level of 3 × 106 spores/10 g of wheat bran at a water activity (a w ) of 0.95. Cultivation of the mold in large enamel trays yielded a xylanase titer comparable with that in flasks. Parametric optimization resulted in a 31% increase in enzyme production in SSF. Xylanase production was approx 23-fold higher in SSF than in submerged fermentation (SmF). A threshold constitutive level of xylanase was secreted by H. lanuginosa in a medium containing glucose as the sole carbon source. The enzyme was induced by xylose and xylan. Enzyme synthesis was repressed beyond 1.0% (w/v) xylose in SmF, whereas it was unaffected up to 3.0% (w/w) in SSF, suggesting a minimization of catabolite repression in SSF.

Optimization of process parameters for production of lipase in solid-state fermentation by newly isolated Aspergillus species

Abstract: Of the 34 fungal species, isolated from a number of oily substrates, 9 exhibited lipase activity. AU 15, identified as Aspergillus sp., was found to be excellent lipase producer in submerged fermentation and was selected for solid-state fermentation (SSF). Among substrates like oil cakes of coconut, groundnut and sesame, wheat rawa, bombay rawa and soya beans (crushed), wheat rawa showed the highest lipase activity. The maximum enzyme yield (1934 U/g) was obtained with basal medium containing wheat rawa, olive oil and corn steep liquor, at 80% moisture content, pH 7.0 and 96 hrs incubation.

Kinetics of Gibberella fujikuroi growth and gibberellic acid production by solid-state fermentation in a packed-bed column bioreactor.

Abstract: In this work the growth of Gibberella fujikuroi and gibberellic acid (GA3) production were studied using coffee husk and cassava bagasse as substrates in a packed-bed column bioreactor connected to a gas chromatograph for exit gas analysis With the respirometric data, a logarithmic correlation between accumulated CO2 and biomass production was determined, and the kinetics of the fungal growth was compared for estimated and experimental data The solid medium consisted of coffee husk (pretreated with alkali solution), mixed with cassava bagasse (7:3 dry weight basis), with a substrate initial pH of 52 and moisture of 77% Cultivation was carried out in glass columns, which were packed with preinoculated substrate and with forced aeration of 024 L of air/[h (g of substrate)] for the first 3 days, and 072 L of air/[h (g of substrate)] for the remaining period The maximum specific growth rate (microm) obtained was 0052 h(-1) (between 24 and 48 h of fermentation) A production of 0925 g of GA3/kg of substrate was achieved after 6 days of fermentation

Statistical optimization of a thermostable and neutral glucoamylase production by a thermophilic mold Thermomucor indicae-seudaticae in solid-state fermentation

Abstract: Glucoamylase production by a thermophilic mold Thermomucor indicae-seudaticae was optimized in solid-state fermentation (SSF) by conventional ‘one variable at a time approach’ and further statistically using response surface methodology (RSM). Glucoamylase secretion was strongly affected by three variables (moisture ratio, inoculum level and incubation time), and therefore, these three factors were further optimized using response surface methodology. The glucoamylase production in flasks containing wheat bran, under the conditions optimized by RSM, was 455 ± 23 U/g of dry moldy bran (DMB), while the predicted value by a polynomial model was 433.30 U/g DMB. The enzyme titre (455 ± 23 U/g DMB) attained in the validation experiment of this investigation is higher than those reported in the literature. When the large-scale production was attempted in enamel trays, a marginally lower enzyme titres were attained. An overall 1.8-fold increase in glucoamylase production was achieved in SSF due to statistical optimization in comparison with that of ‘one variable at a time’ approach (250 ± 13 U/g DMB). A 10-fold enhancement in glucoamylase production was recorded in SSF as compared to that in submerged fermentation.

Production of Phenolics from Corn Cobs by Coupling Enzymic Treatment and Solid State Fermentation

Abstract: A two-stage process that combined solid-state fermentation (SSF) and subsequent enzymic treatment was used in order to release p-coumaric (p-CA) and ferulic acid (FA) from corn cobs. Sporotrichum thermophile was grown on corn cobs under SSF conditions, and the production of cinnamoyl esterases and xylanases was studied over 7 days. The time course of enzyme production showed a maximum activity of 1483 nkat/g, 0.3 nkat/g and 0.067 nkat/g for xylanase, feruloyl esterase, and p-coumaroyl esterase, respectively. The importance of the moisture level of the growth substrate was discussed. After SSF, the fermented substrate was directly exposed to autohydrolysis and the in situ produced multienzyme system was successfully used for the partial degradation of cell wall components and the liberation of p-CA and FA. A yield of 0.85 g/kg and 0.38 g/kg FA and p-CA, respectively, of dry matter of corn cobs was obtained.

Production of extracellular pectinolytic, cellulolytic and xylanoytic enzymes by thermophilic mould Sporotrichum thermophile Apinis in solid state fermentation

Abstract: Among four thermophilic moulds, Sporotrichum thermophile produced high titres of xylanases, pectinases and cellulases after 4 days of incubation in solid-state fermentation (SSF). Of the 27 different combinations of agro-residues tried, wheat bran (WB) and citrus pectin (CP) in 1:1 ratio supported a very high production of enzymes. When the mixed substrate at pH 7.0 was moistened with tap water (1:2.5 ratio) to aw of 0.95 and inoculated with 60 × 10 conidiospores (from 5 day-old culture) 10 g of substrate, S. thermophile secreted maximum enzyme titres (xylanase 1900, pectinase 250 and cellulase 42 Ug dry mouldy bran in 4 days at 45°C. The mixture of enzymes has been found useful in the treatment of fruit pulps for enhanced juice recovery.

Comparison of citric acid production by solid-state fermentation in flask, column, tray, and drum bioreactors.

Abstract: Studies were conducted to evaluate citric acid production by solid-state fermentation (SSF) using cassava bagasse as substrate employing a fungal culture of Aspergillus niger LPB 21 at laboratory and semipilot scale. Optimization of the process parameters temperature, pH, initial humidity, aeration, and nutritive composition was conducted in flasks and column fermentors. The results showed that thermal treatment of cassava bagasse enhanced fungal fermentation efficacy, resulting in 220 g of citric acid/kg of dry cassava bagasse with only treated cassava bagasse as substrate. The results obtained from the factorial experimental design in a column bioreactor showed that an aeration rate of 60 mL/min (3 mL/[g.min]) and 60% initial humidity were optimum, resulting in 265.7 g/kg of dry cassava bagasse citric acid production. This was almost 1.6 times higher than the quantities produced under unoptimized conditions (167.4 g of citric acid/kg of dry cassava bagasse). The defined parameters were transferred to semipilot scale, which showed high promise for large-scale citric acid production by SSF with cassava bagasse. Respirometry assays were carried out in order to follow indirectly the biomass evolution of the process. Citric acid production reached 220, 309, 263, and 269 g/kg of dry cassava bagasse in Erlenmeyer flasks, column fermentors, a tray bioreactor, and a horizontal drum bioreactor, respectively.

Screening of laccase, manganese peroxidase, and versatile peroxidase activities of the genus Pleurotus in media with some raw plant materials as carbon sources

Abstract: Species of the genus Pleurotus are among the most efficient natural species in lignin degradation belonging to the subclass of ligninolytic organisms that produce laccase (Lac), Mn-dependent peroxidase (MnP), versatile peroxidase (VP), and the H2O2-generating enzyme aryl-alcohol oxidase, but not lignin peroxidases. Production of Lac and oxidation of 2,6-dimethoxyphenol (DMP) in the presence and absence of Mn2+ were detected both in submerged fermentation (SF) of dry ground mandarine peels and in solid-state fermentation (SSF) of grapevine sawdust in all investigated Pleurotus species and strains. Evidence of cultivation methods having a distinct influence on the level of enzyme activities has been demonstrated. Most of the species and strains had higher Lac activity under SSF conditions than under SF conditions. DMP oxidation in the presence and absence of Mn2+ was detected in all investigated species and strains, but was lower under SF conditions than under SSF conditions for most of them. However, relative activities of DMP oxidation in the absence of Mn2+, as percentages of activity against DMP in the presence of Mn2+, were higher under conditions of SF than in SSF cultures in most of the investigated species and strains. The obtained results showed that strains of different origins have different efficiently ligninolytic systems and that conditions of SSF are more favorable for ligninolytic activity than those in SF owing to their similarity to natural conditions on wood substrates.

BIO26) Selection and optimization of lipase production from Aspergillus flavus USM A10 via Solid State Fermentation (SSF) on rice husks and wood dusts as substrates

Abstract: Introduction Solid state fermentation (SSF) involves the growth of microorganisms on moist solid substrates in the absence of free flowing water. The necessary moisture in SSF exists in a complex form which is absorbed within the solid matrix, and this is considered advantageous for growth because of the possible efficient oxygen transfer process. In SSF, the water content is quite low and the microorganism is almost in contact with gaseous oxygen in the air, unlike in the case of submerged fermentation [1]. Many microorganisms are capable of growing on solid substrates, however, only filamentous fungi which are able to grow effectively in the absence of the free water. Bacteria and yeasts grow on solid substrates at 40-70% moisture level while filamentous fungi was reported to grow under a much lesser water content [1]. SSF has many advantages over submerged fermentation including economy of space needed for fermentation, simplicity of fermentation media, no requirement of complex machinery, equipment and control systems, compactness of fermentation vessel owing to lower water volume, superior yields, less energy demand, low capital and recurring expenditure [2, 3]. Thus, such a system finds greater applications in solid waste management, biomass energy conservation and in the production of secondary metabolites. Based on the low production cost coupled with other advantages, SSF is expected to have enormous potential for commercialization particularly for developing countries like Malaysia. A number of success stories have been documented in the commercialization of the SSF systems for the production of microbial metabolites mainly in countries like India, France and Eastern Europe. With the ultimate goal to commercialize the SSF system for enzyme production, the selection of a potential lipase producer via SSF was studied. The optimization of the SSF system based on the medium composition and cultural conditions was carried out. This paper described the findings of the selection of Aspergillus flavus USM A10 as the potential lipase producer and the enhancement of the enzyme production through the modification of the medium composition and cultural conditions.

Solid-state fermentation: a continuous process for fungal tannase production.

Abstract: Truly continuous solid-state fermentations with operating times of 2-3 weeks were conducted in a prototype bioreactor for the production of fungal (Penicillium glabrum) tannase from a tannin-containing model substrate. Substantial quantities of the enzyme were synthesized throughout the operating periods and (imperfect) steady-state conditions seemed to be achieved soon after start-up of the fermentations. This demonstrated for the first time the possibility of conducting solid-state fermentations in the continuous mode and with a constant noninoculated feed. The operating variables and fermentation conditions in the bioreactor were sufficiently well predicted for the basic reinoculation concept to succeed. However, an incomplete understanding of the microbial mechanisms, the experimental system, and their interaction indicated the need for more research in this novel area of solid-state fermentation.

Production of Chitinolytic Enzymes with Trichoderma Longibrachiatum IMI 92027 in Solid Substrate Fermentation

Abstract: Thirty Trichoderma strains representing 15 species within the genus were screened for extracellular production of chitinolytic enzymes in solid substrate fermentation. Trichoderma longibrachiatum IMI 92027 (ATCC 36838) gave the highest yield (5.0 IU/g of dry matter of substrate) after 3 d of fermentation on wheat bran-crude chitin (9:1 mixture) medium. The optimal moisture content (66.7%), chitin content (20%), initial pH of the medium (2.0-5.0), and time course (5 d) of solid substrate fermentation were determined for strain IMI 92027. Cellulase, xylanase, alpha-amylase, and beta-xylosidase activities were also detected. The pH and temperature optima of the chitinase complex of T. longibrachiatum IMI 92027 were 4.5 and 55 degrees C, respectively. The enzyme totally lost its activity at 70 degrees C in 5 min in the absence of the substrate but retained about 15% of its initial activity even at 70 degrees C after a 60-min incubation in the presence of solid substrate fermentation solids. Purification of protein extract from the solid substrate fermentation material revealed high chitinolytic activities between pI 5.9 and 4.8, where N-acetyl-beta-D-hexosaminidase and chitinase peaks have been found in the same pI range. Two chitinases of 43.5 and 30 kDa were purified at acidic pI.