Comparison of phytase production on wheat bran and oilcakes in solid-state fermentation by Mucor racemosus

Comparisons were made for phytase production using wheat bran (WB) and oilcakes as substrates in solid-state fermentation (SSF) by Mucor racemosus NRRL 1994. WB was also used as mixed substrate with oil cakes. Sesame oil cake (SOC) served as the best carbon source for phytase synthesis by the fungal strain as it gave the highest enzyme titres (30.6 U/gds). Groundnut oil cake (GOC) also produced a reasonably good quantity of enzyme (24.3 U/gds). Enzyme production on WB was surprisingly much less (almost 3.5 times less in comparison to SOC). Mixing WB with SOC (1:1 ratio) resulted in better phytase activity (32.2 U/gds). Optimization of various process parameters such as incubation time, initial moisture content and inoculum concentration was carried out using the single variable mode optimization technique. Under optimized conditions, the production of phytase reached 44.5 U/gds, which was almost 1.5-fold higher than the highest yield obtained with any individual substrate used in this study and was more than 4-fold higher than that obtained from WB.     

Alpha-galactosidase production by Aspergillus oryzae in solid-state fermentation

Comparisons were made for alpha-galactosidase production using red gram plant waste (RGPW) with wheat bran (WB) and other locally available substrates using the fungus Aspergillus oryzae under solid-state fermentation (SSF). RGPW proved to be potential substrate for alpha-galactosidase production as it gave higher enzyme titers (3.4 U/g) compared to WB (2.7 U/g) and other substrates tested. Mixing WB with RGPW (1:1, w/w) resulted enhanced alpha-galactosidase yield. The volume of moistening agent in the ratio of 1:2 (w/v), pH 5.5 and 1 ml (1 x 10(6) spores) of inoculum volume and four days incubation were optimum for alpha-galactosidase production. Increase in substrate concentration (RGPW+WB) did not decrease enzyme yield in trays.     

Ellagic acid production by <Emphasis Type="Italic">Aspergillus niger</Emphasis> in solid state fermentation of pomegranate residues

Two Aspergillus niger strains (GH1 and PSH) previously isolated from a semiarid region of Mexico were characterized for their effectiveness in converting pomegranate ellagitannins (ET) into ellagic acid (EA) in a solid state fermentation (SSF). Pomegranate seeds and husk were used as support for the SSF. Released EA was evaluated by liquid chromatography. Yields of 6.3 and 4.6 mg of EA per gram of dried pomegranate husk were obtained with A. niger GH1 and PSH, respectively. Total hydrolyzable polyphenols of pomegranate husk were degraded during the first 72 h of culture (71 and 61%, by GH1 and PSH strains, respectively). Tannin acyl hydrolase activity was not clearly associated with EA production. EA that accumulated in cultures of A. niger GH1 was remarkably pure after a simple extraction process. Pomegranate husk is a good support, and at the same time an excellent substrate in the production of high commercial interest metabolites like EA due the degradation of its ET content.     

Solid state fermentation for the production of α-amylase from Penicillium chrysogenum using mixed agricultural by-products as substrate

Production of α-amylase from local isolate, Penicillium chrysogenum, under solid-state fermentation (SSF) was carried out in this study. Different agricultural by-products, such as wheat bran (WB), sunflower oil meal (SOM), and sugar beet oil cake (SBOC), were used as individual substrate for the enzyme production. WB showed the highest enzyme activity (750 U/gds). Combination of WB, SOM, and SBOC (1:3:1 w/w/w) resulted in a higher enzyme yield (845 U/gds) in comparison with the use of the individual substrate. This combination was used as mixed solid substrate for the production of α-amylase from P. chrysogenum by SSF. Fermentation conditions were optimized. Maximum enzyme yield (891 U/gds) was obtained when SSF was carried out using WB + SOM + SBOC (1:3:1 w/w/w), having initial moisture of 75%, inoculum level of 20%, incubation period of 7 days at 30°C. Galactose (1% w/w), urea and peptone (1% w/w), as additives, caused increase in the enzyme activity.     

Coconut oil cake--a potential raw material for the production of alpha-amylase

Solid-state fermentation (SSF) was carried out using coconut oil cake (COC) as substrate for the production of alpha-amylase using a fungal culture of Aspergillus oryzae. Raw COC supported the growth of the culture, resulting in the production of 1372 U/gds alpha-amylase in 24 h. Process optimization using a single parameter mode showed enhanced enzyme titre, which was maximum (1827 U/gds) when SSF was carried out at 30 degrees C for 72 h using a substrate with 68% initial moisture. Supplementation with glucose and starch further enhanced enzyme titre, which was maximum (1911 U/gds) with 0.5% starch. However, maltose inhibited the enzyme production. Studies on the effect of addition of external organic and inorganic nitrogenous compounds further showed a positive impact on enzyme synthesis by the culture. Increase of 1.7-fold in the enzyme activity (3388 U/gds) was obtained when peptone at 1% concentration was added to the fermentation medium. The enzyme production was growth-related, the activity being the maximum when the fungal biomass was at its peak at 72 h. Use of COC as raw material for enzyme synthesis could be of great commercial significance. To the best of our knowledge this is the first report on alpha-amylase production using COC in SSF.     

Effect of fermentation system on the production and properties of tannase of Aspergillus niger van Tieghem MTCC 2425

The tannase-producing efficiency of liquid-surface fermentation (LSF) and solid-state fermentation (SSF) vis-à-vis submerged fermentation (SmF) was investigated in a strain of Aspergillus niger, besides finding out if there was a change in the activity pattern of tannase in these fermentation processes. The studies on the physicochemical properties were confined to intracellular tannase as only this form of enzyme was produced by A. niger in all three fermentation processes. In LSF and SmF, the maximum production of tannase was observed by 120 h, whereas in SSF its activity peaked at 96 h of growth. SSF had the maximum efficiency of enzyme production. Tannase produced by the SmF, LSF and SSF processes had similar properties except that the one produced during SSF had a broader pH stability of 4.5-6.5 and thermostability of 20 degrees-60 degrees C.     

Production of protease and lipase by solvent tolerant Pseudomonas aeruginosa PseA in solid-state fermentation using Jatropha curcas seed cake as substrate

Deoiled Jatropha seed cake was assessed for its suitability as substrate for enzyme production by solid-state fermentation (SSF). Solvent tolerant Pseudomonas aeruginosa PseA strain previously reported by us was used for fermentation. The seed cake supported good bacterial growth and enzyme production (protease, 1818 U/g of substrate and lipase, 625 U/g of substrate) as evident by its chemical composition. Maximum protease and lipase production was observed at 50% substrate moisture, a growth period of 72 and 120 h, and a substrate pH of 6.0 and 7.0, respectively. Enrichment with maltose as carbon source increased protease and lipase production by 6.3- and 1.6-fold, respectively. Nitrogen supplementation with peptone for protease and NaNO(3) for lipase production also enhanced the enzyme yield reaching 11,376 U protease activity and 1084 U lipase activity per gram of Jatropha seed cake. These results demonstrated viable approach for utilization of this huge biomass by solid-state fermentation for the production of industrial enzymes. This offers significant benefit due to low cost and abundant availability of cake during biodiesel production.     

Production and extraction of pectinases obtained by solid state fermentation of agroindustrial residues with Aspergillus niger

In this work soy and wheat bran were employed as raw materials for the production of pectinases by Aspergillus niger through solid-state fermentation. Several fermentation and recovery parameters were studied. The kinetics of enzyme synthesis was investigated in the range from 13 to 96 h with moisture contents varying from 25% to 70% (w/w). A medium moisture content of 40% and a fermentation time of 22 h were selected, as these conditions resulted in high pectolytic activity and enhanced polygalacturonase productivity. In order to optimise the recovery step, the best combination of temperature of extraction, contact time and solvent type was investigated. Acetate buffer (pH 4.4), 35°C and 30 min provided the best recovery. The present results show that optimising the extraction conditions is a simple way of obtaining more concentrated enzyme extracts and could be a useful instrument to extract more selectively a desired biomolecule from fermented solids.     

Tannase production by Aspergillus aculeatus DBF9 through solid-state fermentation

Tannase an industrially important enzyme was produced by Aspergillus aculeatus DBF9 through a solid-state fermentation (SSF). The organism produced good amount of enzyme and gallic acid in wheat bran among the solid substrate used in SSF. Maximum enzyme and gallic acid production occurred in 5% tannic acid after 72 h. Eighty percent initial substrate moisture and 30 degrees C temperature was found suitable for tannase production.     

黑曲霉固态发酵苹果渣产β-甘露聚糖酶的工艺优化

目的:对黑曲霉SL-08固态发酵苹果渣生产β-甘露聚糖酶的生产工艺进行优化,旨在探寻苹果渣的综合利用方式,降低β-甘露聚糖酶的生产成本。方法:采用Plackett-Burman试验设计和响应面法进行优化。结果:最佳培养基组成为苹果渣与棉粕1∶1(w/w)、尿素2%(w/w)、KH2PO40.1%(w/w)、初始含水率59%(w/w)、CaCl20.2%(w/w)、MgCl20.1%(w/w),30℃恒温培养48h,β-甘露聚糖酶酶活力可达539U/g干曲,比基础培养基提高了28.3%,达到了以豆粕与麸皮为生产原料时的产酶水平。结论:采用黑曲霉SL-08对苹果渣进行固态发酵是一种有效的生物转化方式,既可用于β-甘露聚糖酶的生产,取代豆粕与麸皮等常规原料,降低生产成本;也可以对苹果渣进行综合利用。     

Coconut cake – a potent substrate for the production of lipase by Candida rugosa in solid-state fermentation

Investigations were conducted with the aim of producing extracellular lipase from Candida rugosa by solid-state fermentation (SSF), using coconut oil cake (COC) as a solid substrate. To optimize production, various modifications were made to enrich the substrate by supplementing it with mineral solution, different carbon sources and several inorganic as well as organic nitrogen sources. Among them, urea (1%), peptone (3%) and maltose (5%) were found to be most suitable. Addition of olive oil (10%) encouraged lipase synthesis. The maximum lipase activity in the enriched substrate was 87.76 units per gram of dry fermented substrate [U/gds] compared to 25.81 U/gds in the raw cake at 96 h of fermentation, and growth was as high as 14.44 mg/gds of glucosamine. This was reached at 72 h in the enriched substrate. C. rugosa growth was calculated indirectly by estimating the glucosamine content in the cell wall after its hydrolysis. The enzyme yield was far better than any values reported as yet.     

The enzymatic hydrolysis and fermentation of pretreated wheat straw to ethanol

Autohydrolysis and ethanol-alkali pulping were used as pretreatment methods of wheat straw for its subsequent saccharification by Trichoderma reesei cellulase. The basic hydrolysis parameters, i.e., reaction time, pH, temperature, and enzyme and substrate concentration, were optimized to maximize sugar yields from ethanol-alkali modified straw. Thus, a 93% conversion of 2.5% straw material to sugar syrup containing 73% glucose was reached in 48 h using 40 filter paper units/g hydrolyzed substrate. The pretreated wheat straw was then fermented to ethanol at 43 degrees C in the simultaneous saccharification and fermentation (SSF) process using T. reesei cellulase and Kluyveromyces fragilis cells. From 10% (w/v) of chemically treated straw (dry matter), 2.4% (w/v) ethanol was obtained after 48 h. When the T. reesei cellulase system was supplemented with beta-glucosidase from Aspergillus niger, the ethanol yield in the SSF process increased to 3% (w/v) and the reaction time was shortened to 24 h.     

Tamarind seed powder and palm kernel cake: two novel agro residues for the production of tannase under solid state fermentation by Aspergillus niger ATCC 16620

Palm kernel cake (PKC), the residue obtained after extraction of palm oil from oil palm seeds and tamarind seed powder (TSP) obtained after removing the fruit pulp from tamarind fruit pod were tested for the production of tannase under solid-state fermentation (SSF) using Aspergillus niger ATCC 16620. The fungal strain was grown on the substrates without any pretreatment. In PKC medium, a maximum enzyme yield of 13.03 IU/g dry substrate (gds) was obtained when SSF was carried out at 30 degrees C, 53.5% initial substrate moisture, 33 x 10(9) spores/5 g substrate inoculum size and 5% tannic acid as additional carbon source after 96 h of fermentation. In TSP medium, maximum tannase yield of 6.44 IU/gds was obtained at 30 degrees C, 65.75% initial substrate moisture, 11 x 10(9) spores/5 g substrate inoculum, 1% glycerol as additional carbon source and 1% potassium nitrate as additional nitrogen source after 120 h of fermentation. Results from the study are promising for the economic utilization and value addition of these important agro residues, which are abundantly available in many tropical and subtropical countries.     

Production and optimization of thermophilic alkaline protease in solid-state fermentation by <Emphasis Type="Italic">Streptomyces</Emphasis> sp. CN902

The purpose of the present research is to study the production of thermophilic alkaline protease by a local isolate, Streptomyces sp. CN902, under solid state fermentation (SSF). Optimum SSF parameters for enzyme production have been determined. Various locally available agro-industrial residues have been screened individually or as mixtures for alkaline protease production in SSF. The combination of wheat bran (WB) with chopped date stones (CDS) (5:5) proved to be an efficient mixture for protease production as it gave the highest enzyme activity (90.50 U g⁻¹) when compared to individual WB (74.50 U g⁻¹) or CDS (69.50 U g⁻¹) substrates. This mixed solid substrate was used for the production of protease from Streptomyces sp. CN902 under SSF. Maximal protease production (220.50 U g⁻¹) was obtained with an initial moisture content of 60%, an inoculum level of 1 × 10⁸ (spore g⁻¹ substrate) when incubated at 45°C for 5 days. Supplementation of WB and CDS mixtures with yeast extract as a nitrogen source further increased protease production to 245.50 U g⁻¹ under SSF. Our data demonstrated the usefulness of solid-state fermentation in the production of alkaline protease using WB and CDS mixtures as substrate. Moreover, this approach offered significant benefits due to abundant agro-industrial substrate availability and cheaper cost.     

Solid-state fermentation of co-products from palm oil processing: Production of lipase and xylanase and effects on chemical composition

The palm oil industry generates large amounts of lignocellulosic co-products. Palm kernel cake (PKC) and palm pressed fibre (PPF) have nutritional limitations as ingredients in animal feed, and are therefore little used. Solid-state fermentation (SSF) is one alternative treatment to improve the nutritional value of these co-products and to increase their possible use, through the production of enzymes such as lipases and xylanases. These enzymes can reduce the contents of undesirable compounds, such as lipids, and degrade some components of the fibres to improve the digestibility of these co-products. The fungi Aspergillus niger, Aspergillus oryzae and Aspergillus awamori were able to grow in PKC/PPF (40/60 w/w) culture medium by SSF, and to produce xylanase and lipase. A. niger showed the highest lipase activity (20.7?U g^?1) at 72?h. A. awamori higher xylanase activity than the other fungi at all culture periods, reaching a maximum activity of 134.2?U g^?1 at 72?h. The unfermented co-products contained 7.49% lipids and 7.38% non-fibrous carbohydrates (NFC). Lipase produced by these fungi during SSF reduced the lipid content by 36%, 40% and 45% for A. oryzae, A. awamori and A. niger, respectively. The production of xylanases by SSF probably increased the NFC contents by up to 64%. Fermented solids with A. oryzae and A. awamori had the highest levels of NFC, 20.3% and 13.94%, respectively, which improved the nutritional value of these co-products.     

Process parameters study of α-amylase production in a packed-bed bioreactor under solid-state fermentation with possibility of temperature monitoring

Production of α-amylase in a laboratory-scale packed-bed bioreactor by Bacillus sp. KR-8104 under solid-state fermentation (SSF) with possibility of temperature control and monitoring was studied using wheat bran (WB) as a solid substrate. The simultaneous effects of aeration rate, initial substrate moisture, and incubation temperature on α-amylase production were evaluated using response surface methodology (RSM) based on a Box-Behnken design. The optimum conditions for attaining the maximum production of α-amylase were 37°C, 72% (w/w) initial substrate moisture, and 0.15 L/min aeration. The average enzyme activity obtained under the optimized conditions was 473.8 U/g dry fermented substrate. In addition, it was observed that the production of enzyme decreased from the bottom of the bioreactor to the top.     

Production of multiple extracellular enzyme activities by novel submerged culture of <Emphasis Type="Italic">Aspergillus kawachii</Emphasis> for ethanol production from raw cassava flour

Cassava is a starch-containing root crop that is widely used as a raw material in a variety of industrial applications, most recently in the production of fuel ethanol. In the present study, ethanol production from raw (uncooked) cassava flour by simultaneous saccharification and fermentation (SSF) using a preparation consisting of multiple enzyme activities from Aspergillus kawachii FS005 was investigated. The multi-activity preparation was obtained from a novel submerged fermentation broth of A. kawachii FS005 grown on unmilled crude barley as a carbon source. The preparation was found to consist of glucoamylase, acid-stable α-amylase, acid carboxypeptidase, acid protease, cellulase and xylanase activities, and exhibited glucose and free amino nitrogen (FAN) production rates of 37.7 and 118.7 mg/l/h, respectively, during A. kawachii FS005-mediated saccharification of uncooked raw cassava flour. Ethanol production from 18.2% (w/v) dry uncooked solids of raw cassava flour by SSF with the multi-activity enzyme preparation yielded 9.0% (v/v) of ethanol and 92.3% fermentation efficiency. A feasibility study for ethanol production by SSF with a two-step mash using raw cassava flour and the multi-activity enzyme preparation manufactured on-site was verified on a pilot plant scale. The enzyme preparation obtained from the A. kawachii FS005 culture broth exhibited glucose and FAN production rates of 41.1 and 135.5 mg/l/h, respectively. SSF performed in a mash volume of about 1,612 l containing 20.6% (w/v) dry raw cassava solids and 106 l of on-site manufactured A. kawachii FS005 culture broth yielded 10.3% (v/v) ethanol and a fermentation efficiency of 92.7%.     

Phytase production by solid-state fermentation of groundnut oil cake by Aspergillus niger: A bioprocess optimization study for animal feedstock applications

This investigation deals with the use of agro-industrial waste, namely groundnut oil cake (GOC), for phytase production by the fungi Aspergillus niger NCIM 563. Plackett–Burman design (PBD) was used to evaluate the effect of 11 process variables and studies here showed that phytase production was significantly influenced by glucose, dextrin, distilled water, and MgSO₄ · 7H₂O. The use of response surface methodology (RSM) by Box–Behnken design (BBD) of experiments further enhanced the production by a remarkable 36.67-fold from the original finding of 15 IU/gds (grams of dry substrate) to 550 IU/gds. This is the highest solid-state fermentation (SSF) phytase production reported when compared to other microorganisms and in fact betters the best known by a factor of 2. Experiments carried out using dried fermented koji for phosphorus and mineral release and also thermal stability have shown the phytase to be as efficient as the liquid enzyme extract. Also, the enzyme, while exhibiting optimal activity under acidic conditions, was found to have significant activity in a broad range of pH values (1.5–6.5). The studies suggest the suitability of the koji supplemented with phytase produced in an SSF process by the “generally regarded as safe” (GRAS) microorganism A. niger as a cost-effective value-added livestock feed when compared to that obtained by submerged fermentation (SmF).     

Streptomyces sp. TEM 33 possesses high lipolytic activity in solid-state fermentation in comparison with submerged fermentation

Solid-state fermentation (SSF) is a bioprocess that doesn’t need an excess of free water, and it offers potential benefits for microbial cultivation for bioprocesses and product development. In comparing the antibiotic production, few detailed reports could be found with lipolytic enzyme production by Streptomycetes in SSF. Taking this knowledge into consideration, we prefer to purify Actinomycetes species as a new source for lipase production. The lipase-producing strain Streptomyces sp. TEM 33 was isolated from soil and lipase production was managed by solid-state fermentation (SSF) in comparison with submerged fermentation (SmF). Bioprocess-affecting factors like initial moisture content, incubation time, and various carbon and nitrogen additives and the other enzymes secreted into the media were optimized. Lipase activity was measured as 1.74 ± 0.0005 U/g dry substrate (gds) by the p-nitrophenylpalmitate (pNPP) method on day 6 of fermentation with 71.43% final substrate moisture content. In order to understand the metabolic priority in SSF, cellulase and xylanase activity of Streptomyces sp. TEM33 was also measured. The microorganism degrades the wheat bran to its usable form by excreting cellulases and xylanases; then it secretes the lipase that is necessary for degrading the oil in the medium.     

Bioconversion of grape must into modulated gluconic acid production by Aspergillus niger ORS-4.410

AIMS: Analysis of regulators for modulated gluconic acid production under surface fermentation (SF) condition using grape must as the cheap carbohydrate source, by mutant Aspergillus niger ORS-4.410. Replacement of conventional fermentation condition by solid-state surface fermentation (SSF) for semi-continuous production of gluconic acid by pseudo-immobilization of A. niger ORS-4.410. METHODS AND RESULTS: Grape must after rectification was utilized for gluconic acid production in batch fermentation in SF and SSF processes using mutant strain of A. niger ORS-4.410. Use of rectified grape must led to the improved levels of gluconic acid production (80-85 g l(-1)) in the fermentation medium containing 0.075% (NH4)2HPO4; 0.1% KH2PO4 and 0.015% MgSO4.7H2O at an initial pH 6.6 (+/-0.1) under surface fermentation. Gluconic acid production was modulated by incorporating the 2% soybean oil, 2% starch and 1% H2O2 in fermentation medium at continuously high aeration rate (2.0 l min(-1)). Interestingly, 95.8% yield of gluconic acid was obtained when A. niger ORS-4.410 was pseudo-immobilized on cellulose fibres (bagasse) under SSF. Four consecutive fermentation cycles were achieved with a conversion rate of 0.752-0.804 g g(-1) of substrate into gluconic acid under SSF. CONCLUSIONS: Use of additives modulated the gluconic acid production under SF condition. Semi-continuous production of gluconic acid was achieved with pseudo-immobilized mycelia of A. niger ORS-4.410 having a promising yield (95.8%) under SSF condition. SIGNIFICANCE AND IMPACT OF THE STUDY: The bioconversion of grape must into modulated gluconic acid production under SSF conditions can further be employed in fermentation industries by replacing the conventional carbohydrate sources and expensive, energy consuming fermentation processes.