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Showing papers on "Solid-state fermentation published in 2002"


Journal ArticleDOI
TL;DR: The Aspergillus niger NCIM 1207 organism, being GRAS cleared, can be used for large-scale production of enzyme for commercial purpose.

305 citations


Journal ArticleDOI
Poluri Ellaiah1, K. Adinarayana1, Y Bhavani1, P Padmaja1, B Srinivasulu1 
TL;DR: In this article, Aspergillus sp. A3 under solid state fermentation was optimized for the production of glucoamylase employing a laboratory isolate, which showed that wheat bran showed the highest enzyme activity.

225 citations


Journal ArticleDOI
Yun-Jin Park1, Su-Yeon Kang1, Jinwon Lee, Sung-Yong Hong1, Seung Wook Kim1 
TL;DR: Under the optimized conditions, the activity and productivity of xylanase obtained after 5 days of fermentation were 5,071 IU/g of rice straw and 14,790 IU l–1 h–1, respectively.
Abstract: The initial moisture content, cultivation time, inoculum size and concentration of basal medium were optimized in solid state fermentation (SSF) for the production of xylanase by an Aspergillus niger mutant using statistical experimental designs. The cultivation time and concentration of basal medium were the most important factors affecting xylanase activity. An inoculum size of 5 x 10(5) spores/g, initial moisture content of 65%, cultivation time of 5 days and 10 times concentration of basal medium containing 50 times concentration of corn steep liquor were optimum for xylanase production in SSF. Under the optimized conditions, the activity and productivity of xylanase obtained after 5 days of fermentation were 5,071 IU/g of rice straw and 14,790 IU l(-1) h(-1), respectively. The xylanase activity predicted by a polynomial model was 5,484 IU/g of rice straw.

222 citations


Journal ArticleDOI
TL;DR: Pectin lyase and polygalacturonase production by newly isolated Penicillium viridicatum strain Rfc3 was carried out by means of solid state fermentation using orange bagasse, corn tegument, wheat bran and mango and banana peels as carbon sources as mentioned in this paper.

161 citations


Journal ArticleDOI
TL;DR: Results showed better efficiency of NaCl medium for wheat bran and seawater for sesamum oil cake and external supplementation of fermentation medium with various organic and inorganic nitrogen sources was of no benefit for enzyme production.

153 citations


Journal ArticleDOI
TL;DR: The bioconversion of vineyard pruning and grape pomace by Pleurotus spp.
Abstract: The bioconversion of vineyard pruning and grape pomace by Pleurotus spp. using a solid state fermentation (SSF) was evaluated. Fruiting body production and chemical changes in the substrates after harvesting were measured. Biological efficiency and bioconversion ranged from 37.2 to 78.7% and from 16.7 to 38.8%, respectively. The best substrates for mycelial growth and mushroom yield were the mixtures with higher vineyard pruning content. Inclusion of pruning content had higher phenolic components and total sugars, better C/N ratio, and lower crude fat and total nitrogen than pomace. On the contrary, mycelium grew more slowly and scarcely in all treatments with 100% grape pomace. Moisture, protein, fat, and lignin contents were generally higher in mixtures with higher pomace proportion, whereas neutral detergent fiber, hemicellulose, and cellulose contents were higher with pruning content. Pleurotus strains may act depending on the availability of fiber fractions of substrate, and dynamic changes in digest...

132 citations


Journal ArticleDOI
TL;DR: The present investigation describes the production of lipase by solid-state fermentation of Rhizopus oligosporous GCBR-3 under optimum environmental and cultural conditions and finds the lipase value supported by the organism and calculated as units per gram substrate per hour was greater than the values reported by other workers.

115 citations


Journal ArticleDOI
TL;DR: Among the various substrate combinations examined, neem hull and wheat bran wastes gave the highest ligninolytic activity.
Abstract: Lignocellulosic wastes such as neem hull, wheat bran, and sugarcane bagasse, available in abundance, are excellent substrates for the production of ligninolytic enzymes under solid-state fermentation by white-rot fungi. A ligninolytic enzyme system with high activity showing enhanced decomposition was obtained by cocultivation of Pleurotus ostreatus and Phanerochaete chrysosporium on combinations of lignocellulosic waste. Among the various substrate combinations examined, neem hull and wheat bran wastes gave the highest ligninolytic activity. A maximum production of laccase of 772 U/g and manganese peroxidase of 982 U/g was obtained on d 20 and lignin peroxidase of 656 U/g on d 25 at 28 +/- 1 degrees C under solid-state fermentation. All three enzymes thus obtained were partially purified by acetone fractionation and were exploited for decolorizing different types of acid and reactive dyes.

111 citations


Journal ArticleDOI
TL;DR: The results indicate the scope for production of phytase using coconut oil cake as solid substrate without additional nutrients, and demonstrate improved feed yield ratios and reduction in the environmental costs associated with the disposal of animal wastes.
Abstract: Solid-state fermentation of coconut oil cake has been carried out with Rhizopus oligosporus for the production of phytase. Phytase is used commercially in the animal feed industry to improve animal performance because there is a substantial and growing interest among swine and poultry producers in the application of phytase to improve the nutritional quality in animal feeds. Demonstrated benefits include improved feed yield ratios and reduction in the environmental costs associated with the disposal of animal wastes. We report the production of extracellular phytase by R. oligosporus under solid-state fermentation using coconut oil cake as substrate. Maximal enzyme production (14.29 U/g of dry substrate) occurred at pH 5.3, 30°C, and 54.5% moisture content after 96 h of incubation. The addition of extra nutrients to the substrate resulted in inhibition of product formation. The results indicate the scope for production of phytase using coconut oil cake as solid substrate without additional nutrients.

99 citations


Journal ArticleDOI
TL;DR: The molecular and physiological aspects of the fungus in submerged fermentation (SmF) and SSF are compared and a number of differences correlated with the different growth conditions are observed.
Abstract: We report the progress of a multi-disciplinary research project on solid-state fermentation (SSF) of the filamentous fungus Aspergillus oryzae. The molecular and physiological aspects of the fungus in submerged fermentation (SmF) and SSF are compared and we observe a number of differences correlated with the different growth conditions. First, the aerial hyphae which occur only in SSFs are mainly responsible for oxygen uptake. Second, SSF is characterised by gradients in temperature, water activity and nutrient concentration, and inside the hyphae different polyols are accumulating. Third, pelleted growth in SmF and mycelial growth in SSF show different gene expression and protein secretion patterns. With this approach we aim to expand our knowledge of mechanisms of fungal growth on solid substrates and to exploit the biotechnological applications.

89 citations


Journal ArticleDOI
TL;DR: Diverse food wastes, apple, orange and potato, were screened for laccase production, under solid-state fermentation conditions, by the white-rot fungus Trametes hirsuta, giving the highest activity, reaching about 5000 U l−1 within 8 days.
Abstract: Diverse food wastes, apple, orange and potato, were screened for laccase production, under solid-state fermentation conditions, by the white-rot fungus Trametes hirsuta. Potato peelings gave the highest activity, reaching about 5000 U l−1 within 8 days. These values are higher than those reported to date.

Journal ArticleDOI
TL;DR: In this article, solid state fermentation (SSF) culture conditions were investigated for the production of feruloyl esterase by Aspergillus niger I-1472 and compared with submerged culture conditions.

Journal ArticleDOI
TL;DR: In this article, the growth of Gongronella butleri USDB 0201 was compared in solid state fermentation (SSF) and submerged fermentation (SMF) using various nitrogen sources.

Journal ArticleDOI
TL;DR: When milled grains were used, the particle-size distribution and the chemical composition of the medium influenced the rate of micro-organism growth and therefore the trend followed by endo- and ex-PG production, but these two parameters did not affect the maximum production of exo-PG and enda-PG.
Abstract: The production of exo-polygalacturonase (exo-PG) and endo-PG by Aspergillus awamori grown on wheat in solid-state fermentation was studied. Endo- and exo-PG activities were detected after 24 h of inoculation. Glucose released from starch hydrolysis acted as a catabolite repressor for the exo-PG enzyme. In contrast, endo-PG production was not affected by glucose repression. When milled grains were used, the particle-size distribution and the chemical composition of the medium influenced the rate of micro-organism growth and therefore the trend followed by endo- and exo-PG production. However, these two parameters did not affect the maximum production of exo-PG and endo-PG. For one of the milled samples, three different moisture contents were used (50, 55, 60%). Moisture contents of 60% provide a higher yield of pectinases by A. awamori.

Journal ArticleDOI
TL;DR: In cultures of A. oryzae on a wheat-flour model substrate, aerial hyphae contributed up to 75% of the oxygen uptake rate by the fungus, which means that diffusion limitation in the densely packed mycelium layer that is formed closer to the substrate surface and that has liquid-filled pores is much less important for A.oryzae.
Abstract: Oxygen transfer is for two reasons a major concern in scale-up and process control in industrial application of aerobic fungal solid-state fermentation (SSF): 1) heat production is proportional to oxygen uptake and it is well known that heat removal is one of the main problems in scaled-up fermenters, and 2) oxygen supply to the mycelium on the surface of or inside the substrate particles may be hampered by diffusion limitation. This article gives the first experimental evidence that aerial hyphae are important for fungal respiration in SSF. In cultures of A. oryzae on a wheat-flour model substrate, aerial hyphae contributed up to 75% of the oxygen uptake rate by the fungus. This is due to the fact that A. oryzae forms very abundant aerial mycelium and diffusion of oxygen in the gas-filled pores of the aerial hyphae layer is rapid. It means that diffusion limitation in the densely packed mycelium layer that is formed closer to the substrate surface and that has liquid-filled pores is much less important for A. oryzae than was previously reported for R. oligosporus and C. minitans. It also means that the overall oxygen uptake rate for A. oryzae is much higher than the oxygen uptake rate that can be predicted in the densely packed mycelium layer for R. oligosporus and C. minitans. This would imply that cooling problems become more pronounced. Therefore, it is very important to clarify the physiological role of aerial hyphae in SSF.

Journal ArticleDOI
TL;DR: In this article, the authors compared the performance of a static and a dynamic solid-state fermentation with a filter paper enzyme activity (FPA) of 20.4 and 10.8 IU/g at a bed height of 9.0 cm, respectively.

Journal ArticleDOI
TL;DR: The comparative production of GA3 by solid-state fermentation and submerged fermentation indicated better productivity with the former technique, mainly with pretreated substrate, and higher yields ofGA3 were achieved using a mixed substrate comprising coffee husk and cassava bagasse, increasing the results twice.
Abstract: Five strains of Gibberella fujikuroi and one of Fusarium moniliforme were screened for the production of gibberellic acid (GA3) in coffee husk, and based on the results, one strain, G. fujikuroi LPB-06, was selected. The comparative production of GA3 by solid-state fermentation and submerged fermentation indicated better productivity with the former technique, mainly with pretreated substrate. The GA3 accumulation was 6.1 times higher in the case of solid-state fermentation. Considering the C:N relation, higher yields of GA3 were achieved using a mixed substrate comprising coffee husk and cassava bagasse (7:3, dry wt), increasing the results twice. Supplementation of an optimized saline solution containing 0.03% FeSO4 and 0.01% (NH4)2SO4 enhanced the accumulation of GA3 1.7 times in the fermented substrate. Under the finally optimized condition, the culture gave a maximum of 492.5 mg of GA3/kg of dry substrate, with a pH of 5.3, moisture of 75%, and incubation temperature of 29 degrees C. GA3 yield was almost 13 times more than the initial results.

Journal ArticleDOI
TL;DR: Spent Brewing Grains was evaluated for its efficacy to be used as sole carbon source for the synthesis of α‐amylase in solid‐state fermentation using a fungal strain of Aspergillus oryzae NRRL 6270 to cause repression in enzyme synthesis by the fungal culture.
Abstract: Spent Brewing Grains (SBG) was evaluated for its efficacy to be used as sole carbon source for the synthesis of alpha-amylase in solid-state fermentation using a fungal strain of Aspergillus oryzae NRRL 6270. Enzyme production was superior when the culture grew on mesophilic temperatures and best yields were at 25 degrees C. At 30 degrees C, yields were almost comparable. Maximum production of alpha-amylase [6870 U/g dry substrate (gds)] was obtained when SSF was carried out at 30 degrees C for 96 h using SBG medium, which had initial moisture of 70% and was inoculated using a spore suspension containing 1 x 10(7) spores/ml. Supplementation of SBG with external carbon sources such as mono-, di and polysaccharides caused repression in enzyme synthesis by the fungal culture.

Journal ArticleDOI
TL;DR: The production of laccase by a Brazilian strain of Pleurotus pulmonarius was studied in solid state fermentation using wheat bran as substrate and the enzyme was greatly stable at alkaline pH, but not at acidic pH.
Abstract: The production of laccase by a Brazilian strain of Pleurotus pulmonarius was studied in solid state fermentation using wheat bran as substrate. Among oxidative and hydrolytic enzymes tested (laccase, aryl alcohol oxidase, lignin peroxidase, Mn peroxidase, xylanase and cellulase), laccase was the main enzyme produced by P. pulmonarius. The most suitable condition for maximum production of laccase (8,600 U/g substrate) was initial moisture content of 75% and 5 days of cultivation at 30 degrees C. The optimum pH and temperature for laccase activity were found to be 6.5 and 50 degrees C, respectively. P. pulmonarius laccase was stable at 50 degrees C for more than 6 hours, and it retained about 73% and 18% of its activity when heated for 1 h at 55 and 60 degrees C, respectively. The enzyme was greatly stable at alkaline pH, but not at acidic pH. The laccase activity appear to be correlated with the ability of crude extract to decolourize several industrial dyes.

Journal ArticleDOI
TL;DR: To investigate the effect of amino acids, vitamins and surfactants on polygalacturonase production from Bacillus sp.
Abstract: Aims: To investigate the effect of amino acids, vitamins and surfactants on polygalacturonase production from Bacillus sp. MG-cp-2 under submerged (SmF) and solid state fermentation (SSF). Methods and Results: Bacillus sp. MG-cp-2 was isolated from the outer covering of the seeds of Celastrus paniculatus. Out of the various surfactants, amino acids and vitamins, Tween-60, DL-serine and folic acid maximally enhanced polygalacturonase production by 2·7-fold (240·0 U ml−1), 4·0-fold (360·0 U ml−1) and 3·8-fold (342·0 U ml−1) respectively, under submerged fermentation (SmF). In solid state fermentation (SSF), Tween-80, pyridoxine and DL-ornithine monohydrochloride induced highest enzyme production up to 1·73-fold (6956·5 U g−1), 5·3-fold (21224·4 U g−1) and 5·74-fold (23076·9 U g−1), respectively. Conclusion: Amino acids and their analogues, vitamins and surfactants effect significantly polygalacturonase production by Bacillus sp. MG-cp-2 when grown under submerged (SmF) and solid state fermentation (SSF) conditions. Significance and Impact of the Study: The study provides useful information about regulation of polygalacturonase biosynthesis in Bacillus sp. MG-cp-2, which appears to be an interplay of nutritional and physical factors. Alkaline polygalacturonase from Bacillus sp. MG-cp-2 will be extremely useful in the treatment of alkaline pectic waste waters from vegetable and fruit processing industries and in degumming of bast fibres.

Journal ArticleDOI
TL;DR: The study of production of Aspergillus terreus CECT 2663 α‐L‐rhamnosidase in solid state fermentation using wheat bran, washed sugar cane bagasse and polyurethane foam as substrates or supports for the enzyme production is studied.
Abstract: Aims: The study of production of Aspergillus terreus CECT 2663 α-L-rhamnosidase in solid state fermentation using wheat bran, washed sugar cane bagasse and polyurethane foam as substrates or supports for the enzyme production. Methods and Results: Cultures were carried out in Petri dishes under controlled temperature and humidity. Naringin or rhamnose were the enzyme inducers and carbon sources. The enzyme activity to inducer ratio was appreciably greater when using sugar cane bagasse or polyurethane foam than wheat bran. The influence of inoculum size, inducer, airflow, humidity and temperature were determined. Under optimum conditions, about four units of enzyme per ml nutrient solution were obtained after 4–6 d. Conclusions: The activity to inducer ratio was higher, and the cultivation time was shorter in solid state fermentation than those observed in submerged cultures. Significance and Impact of the Study: Solid cultures, using naringin as inducer, can be appropriate α-L-rhamnosidase production.

Journal ArticleDOI
TL;DR: Undesirable protease production by Aspergillus niger Aa-20 in submerged culture and solid-state culture was evaluated using different concentrations of tannic acid as sole carbon source in a model system designed for tannase production.
Abstract: Undesirable protease production by Aspergillus niger Aa-20 in submerged culture and solid-state culture was evaluated using different concentrations of tannic acid as sole carbon source in a model system designed for tannase production. Protease production was found to be dependent on the culture system used (submerged culture or solid-state culture) and on the initial tannic acid concentration. Expression of protease activity in submerged culture was higher (up to 10 times) than activity obtained in solid-state culture, using identical culture medium composition. In submerged culture, the lowest final protease activity (0.13 IU) was obtained with the highest tannic acid concentration, while in solid-state culture protease activity was not affected by changes in initial substrate concentration. Absence of detectable proteolytic activity in solid-state culture is related to high production of tannase enzyme. Hence, the use of solid-state culture for fungal enzyme production may allow for higher and more stable enzyme titers present in culture extracts.

Journal ArticleDOI
TL;DR: The results demonstrate that NMR can play an important role in quantitative analysis of water and glucose gradients at the particle level during solid-state fermentation, which is needed to improve the understanding of the response of fungi to this nonconventional fermentation environment.
Abstract: Gradients inside substrate particles cannot be prevented in solid-state fermentation. These gradients can have a strong effect on the physiology of the microorganisms but have hitherto received little attention in experimental studies. We report gradients in moisture and glucose content during cultivation of Aspergillus oryzae on membrane-covered wheat-dough slices that were calculated from 1H-NMR images. We found that moisture gradients in the solid substrate remain small when evaporation is minimized. This is corroborated by predictions of a diffusion model. In contrast, strong glucose gradients developed. Glucose concentrations just below the fungal mat remained low due to high glucose uptake rates, but deeper in the matrix glucose accumulated to very high levels. Integration of the glucose profile gave an average concentration close to the measured average content. On the basis of published data, we expect that the glucose levels in the matrix cause a strong decrease in water activity. The results demonstrate that NMR can play an important role in quantitative analysis of water and glucose gradients at the particle level during solid-state fermentation, which is needed to improve our understanding of the response of fungi to this nonconventional fermentation environment

Journal ArticleDOI
TL;DR: It is concluded that Mn2+ plays a key role in lignin degradation under different nutritional and growth conditions, since it is required for the production of MnP in P. ostreatus.
Abstract: The white-rot fungus Pleurotus ostreatus produces two types of extracellular peroxidases: manganese-dependent peroxidase (MnP) and versatile peroxidase (VP). The effect of Mn2+ on fungal growth, peroxidase activity profiles, and lignin degradation by P. ostreatus was studied in liquid culture and under solid-state fermentation conditions on perlite, the latter resembling the natural growth conditions of this fungus. The fungus was grown in either a defined asparagine-containing basidiomycete selective medium (BSM) or in a rich peptone medium (PM). Biomass production, as determined by respiration experiments in solid-state fermentation and liquid cultures and fungal growth on Petri dishes, was higher in the PM than in the BSM. Mn2+ affected biomass production only in the PM on Petri dishes. In the nonamended PM, high levels of MnP and VP activity were detected relative to the nonamended BSM. Nevertheless, a higher rate of 14C-lignin mineralization was measured in the Mn2+-amended BSM, as determined during the course of 47 d of fermentation. Mn2+ amendment of the PM increased mineralization rate to that obtained in the Mn2+-amended BSM. The enzyme activity profiles of MnP and VP were studied in the BSM using anion-exchange chromatography. In the nonamended BSM, only minute levels of MnP and VP were detected. On Mn2+ amendment, two MnP isoenzymes (B1 and B2) appeared. Isoenzyme B2 was purified and showed 100% identity with the MnP isoenzyme purified in our previous study from PM-solid-state fermentation (P6). P6 was found to be the dominant isoenzyme in terms of activity level and gene expression compared with the VP isoenzymes. Based on these results, we concluded that Mn2+ plays a key role in lignin degradation under different nutritional and growth conditions, since it is required for the production of MnP in P. ostreatus.

Journal ArticleDOI
TL;DR: In this paper, the authors compared liquid and solid substrates for the production of 6-pentyl-α-pyrone (6-PP), an unsaturated D-lactone with a strong coconut-like aroma.
Abstract: The production of 6-pentyl-α-pyrone (6-PP), an unsaturated D-lactone with a strong coconut-like aroma was studied and compared with liquid and solid substrates. A fungi strain that produces coconut aroma compound was selected. The liquid medium of the submerged culture was used to impregnate a solid support of sugarcane bagasse in SSF (Solid State Fermentation). This substrate was adequate for growth and aroma production; the concentration obtained using SSF was higher than using liquid fermentation process. In the present work, it is demonstrated that, by solid-state-fermentation process, it is possible to produce 6-PP. The amount of 6-PP produced using a solid state substrate, following a 5 d culture, was 3 mg/g dry matter. Therefore, the amount of 6-PP produced during solid-state-fermentation process is higher than that reported in literature for submerged process.

Journal ArticleDOI
TL;DR: Five strains of filamentous fungi were compared for their capacity to produce endo-polygalacturonase (endo-PG) in solid state fermentation and maximum pectinolytic activity was reached, with the best two fungal strains being A. niger T0005007-2 and A. oryzae CCT 3940.
Abstract: Five strains of filamentous fungi (Aspergillus niger strains NRRL 3122 and T0005007-2, Aspergillus oryzae CCT 3940, Aspergillus awamori NRRL 3112 and a Trichoderma sp.) were compared for their capacity to produce endo-polygalacturonase (endo-PG) in solid state fermentation. Maximum pectinolytic activity was reached in 72 h of growth, the best two fungal strains being A. niger T0005007-2 and A. oryzae CCT 3940. Three types of commercial purified pectin and four of unprocessed pectin (tangerine, orange, Tahiti lime and sweet lime rind) were used to assess the effect of pectin on the production of endo-PG by A. niger T0005007-2. Maximum pectinolytic activity was achieved using 6 and 10% (w/w) of purified pectin as inducer. Depending on the origin of the commercial pectin used as inducer, maximum endo-PG levels varied from 223 to 876 units per gram of dry medium (one endo-PG unit (U) was defined as the quantity of enzyme which caused a reduction in viscosity of 50% in a 1% w/v solution of pectin in 30 min), indicating that care should be taken when choosing this component of the medium. When the crude pectins were used as inducers at the same concentration as purified pectin, maximum endo-PG activities were 250-300 units/g. However, by increasing the amount of Tahiti lime rind to 50% (w/w) maximum endo-PG was 919 U/g, thus opening up the possibility of a low cost medium for endo-PG production.

Journal ArticleDOI
TL;DR: Genetic recombination, achieved through parasexual crosses in A. niger, results in improved strains with potential applications for solid-state fermentation processes, including invertase productivity levels 5–18 times higher than levels achieved by the corresponding haploid strains.
Abstract: Invertase production by Aspergillus niger grown by solid-state fermentation was found to be higher than by conventional submerged fermentation. The haploid mutant strains Aw96-3 and Aw96-4 showed better productivity of various enzymes, as compared to wild-type parental strain A. niger C28B25. Here we use parasexual crosses of those mutants to increase further the productivity of invertase in solid-state fermentation. We isolated both a diploid (DAR2) and an autodiploid (AD96-4) strain, which were able to grow in minimal medium after mutation complementation of previously isolated haploid auxotrophic strains. Invertase production was measured in solid-state fermentation cultures, using polyurethane foam as an inert support for fungal growth. Water activity value (Aw) was adjusted to 0.96, since low Aw values are characteristic in some solid-state fermentation processes. Such diploid strains showed invertase productivity levels 5-18 times higher than levels achieved by the corresponding haploid strains. For instance, values for C28B25, Aw96-3, Aw96-4, DAR2, and AD96-4 were 441, 254, 62, 1324, and 2677 IU/(L x h), respectively. These results showed that genetic recombination, achieved through parasexual crosses in A. niger, results in improved strains with potential applications for solid-state fermentation processes.

Journal ArticleDOI
TL;DR: In this article, exogenous addition of lipase resulted in an increase in flavour volatiles, which contribute to the aroma of tea, and therefore, it was considered worthwhile to amend tea leaves with microbial lipases and observe the changes in the flavour profile of the finished product.
Abstract: Lipases produced extracellularly by bacteria and fungi are being widely used in the food industry for flavour development. During tea processing, the possibility of enhancing the flavour of tea by the exogenous addition of lipase has not been reported. It was therefore considered worthwhile to amend tea leaves with microbial lipases and observe the changes in the flavour profile of the finished product. Among a few fungal lipases screened, the enzyme secreted by Rhizomucor miehei increased the formation of desired flavour compounds. Hence, studies were initiated to achieve enhanced production of this industrially useful enzyme. Under solid-state fermentation R.M. miehei produces an extracellular lipase in copious amounts on a simple solid substrate within 96 h, which is active at lower temperatures and at near-neutral pH. These attributes make this enzyme suitable for use during the manufacturing of tea, where reactions are carried out at temperatures of 15 to 20 ̊C and pH range of 5 to 7. In the present study, exogenous addition of lipase resulted in an increase in flavour volatiles, which contribute to the aroma of tea.

Journal ArticleDOI
TL;DR: The possibility of the re-use of agro-industrial orange peel and pulp wastes under solid state fermentation and natural environmental condition as a source of enzymes production and the possibility to use the fermented waste as a bio-fertilizer was done.
Abstract: Evaluation of the possibility of the re-use of agro-industrial orange peel and pulp wastes under solid state fermentation and natural environmental condition as a source of enzymes production [α & β amylase, cellulase, pectinase(s), lipase(s), esterase(s) and peroxidase(s)] the physiological enzymes of lysis and total protein. Different microorganisms such as fungi, bacteria and yeast which were charged of waste analyse and have ability to produce previous enzymes and protein. These microorganisms were isolated from the fermented waste and preliminarily identified to test each one of them for their enzymes production and also to test them for inducing the fermentation process under the natural conditions, or by using one of the present enzyme producer strain. The protein and physiological enzymes production were electro-phoretically patterned in different bands. And finally, the possibility to use the fermented waste as a bio-fertilizer was done and it stimulated the growth of wheat plant using water culture, especially after the toxicity of the fermented waste was investigated.

Journal ArticleDOI
TL;DR: The kinetic study showed that the caffeine degradation was related to the development of mold and its respiration and also with the consumption of reducing sugars present in coffee husk, and the maximum caffeine degradation achieved was 90%.
Abstract: Studies were carried out in a packed-bed column fermentor using coffee husk as substrate in order to verify a relationship between caffeine degradation and the respiration of Aspergillus sp. LPBx. Fermentation conditions were optimized by using factorial design experiments. The kinetic study showed that the caffeine degradation was related to the development of mold and its respiration and also with the consumption of reducing sugars present in coffee husk. From the values obtained experimentally for oxygen uptake rate and CO2 evolved, we determined a biomass yield of 3.811 g of biomass/g of consumed O2 and a maintenance coefficient of 0.0031 g of consumed O2/(g of biomass·h). The maximum caffeine degradation achieved was 90%.