Showing papers on "Solid-state fermentation published in 1999"
Journal Article•
TL;DR: This review focuses on the production of various industrial enzymes by SSF processes, and an illustrative survey is presented on various individual groups of enzymes such as cellulolytic, pectinolytics, ligninolytic, amylolytic and lipolytic enzymes.
Abstract: Enzymes are among the most important products. obtained for human needs through microbial sources. A large number of industrial processes in the areas of industrial, environmental and food biotechnology utilize enzymes at some stage or the other. Current developments in biotechnology are yielding new applications for enzymes. Solid state fermentation (SSF) holds tremendous potential for the production of enzymes. Tt can be of special interest in those processes where the crude fermented products may be used directly as enzyme sources. This review focuses on the production of various industrial enzymes by SSF processes. Following a brief discussion of the micro-organisms and the substrates used in SSF systems, and aspects of the design of fermenter and the factors affecting production of enzymes, an illustrative survey is presented on various individual groups of enzymes such as cellulolytic, pectinolytic, ligninolytic, amylolytic and lipolytic enzymes, etc.
912 citations
TL;DR: Growth and enzyme production in SSF by a Brazilian strain of Penicillium restrictum was studied in this article, where solid waste from the babassu oil industry was used as the basic nutrient source and was supplemented with peptone, olive oil or starch at different C/N ratios.
238 citations
TL;DR: In this paper, the effects of pre-treatment of the substrate, moisture content, particle size, pH of the medium, incubation temperature, enrichment with nitrogen and carbon sources, inoculum size and the incubation period were observed for optimal production of these enzymes by the bacterial strain Bacillus subtilis (CBTK 106), isolated from banana waste.
201 citations
TL;DR: In this article, the effects of water content, dosage of wheat bran and initial pH value in solid substrate on cellulase synthesis were studied in shallow tray fermentors and the highest cellulase activity (158 IFPU/g koji) was obtained in the second fermentation batch.
176 citations
TL;DR: Strains of Aspergillus terreus and A. niger, known to produce xylanase with undetectable amounts of cellulase, were studied for xylan enzyme production on various lignocellulosic substrates using solid state fermentation.
Abstract: Strains of Aspergillus terreus and A. niger, known to produce xylanase with undetectable amounts of cellulase, were studied for xylanase (EC 3.2.1.8) production on various lignocellulosic substrates using solid state fermentation. Of the lignocellulosic substrates used, wheat bran was the best for xylanase production. The effects of various parameters, such as moistening agent, level of initial moisture content, temperature of incubation, inoculum size and incubation time, on xylanase production were studied. The best medium for A. terreus was wheat bran moistened with 1:5 Mandels and Strenberg mineral solution containing 0·1% tryptone, at 35 °C, and at inoculum concentration 2×107−2×108 spores 5 g−1 substrate; forA. niger, the best medium was wheat bran moistened with 1:5 Mandels and Strenberg mineral solution containing 0·1% yeast extract, at 35 °C, and at an inoculum concentration of 2×107−2×108 spores 5 g−1 substrate. Under these conditions, A. terreus produced 68·9 IU ml−1 of xylanase, and A. niger, 74·5 IU ml−1, after 4 d of incubation. A crude culture filtrate of the two Aspergillus strains was used for the hydrolysis of various lignocellulosic materials. Xylanase preparations from the two strains selectively removed the hemicellulose fraction from all lignocellulosic materials tested.
167 citations
TL;DR: It is concluded that at least partial extracellular mineralization of lignin may have occurred during solid-state fermentation of wheat straw using Nematoloma frowardiiproduced manganese peroxidase (MnP) as the predominant ligninolytic enzyme during SSF.
Abstract: The basidiomycetous fungus Nematoloma frowardii produced manganese peroxidase (MnP) as the predominant ligninolytic enzyme during solid-state fermentation (SSF) of wheat straw. The purified enzyme had a molecular mass of 50 kDa and an isoelectric point of 3.2. In addition to MnP, low levels of laccase and lignin peroxidase were detected. Synthetic 14C-ring-labelled lignin (14C-DHP) was efficiently degraded during SSF. Approximately 75% of the initial radioactivity was released as 14CO2, while only 6% was associated with the residual straw material, including the well-developed fungal biomass. On the basis of this finding we concluded that at least partial extracellular mineralization of lignin may have occurred. This conclusion was supported by the fact that we detected high levels of organic acids in the fermented straw (the maximum concentrations in the water phases of the straw cultures were 45 mM malate, 3.5 mM fumarate, and 10 mM oxalate), which rendered MnP effective and therefore made partial direct mineralization of lignin possible. Experiments performed in a cell-free system, which simulated the conditions in the straw cultures, revealed that MnP in fact converted part of the 14C-DHP to 14CO2 (which accounted for up to 8% of the initial radioactivity added) and 14C-labelled water-soluble products (which accounted for 43% of the initial radioactivity) in the presence of natural levels of organic acids (30 mM malate, 5 mM fumarate).
163 citations
TL;DR: The use of solid-state fermentation for the production of xylanase by Bacillus sp.
153 citations
TL;DR: Mixed culturing is beneficial for the economic production of cellulases on nutritionally poor agricultural residues, without the need for supplementation with expensive organic supplements.
138 citations
TL;DR: In this paper, Xanthomonas campestris strains were cultivated on a variety of solid substrates in order to evaluate their ability to produce the exopolysaccharide xanthan.
114 citations
TL;DR: In this article, the authors present a brief summary of the recent developments on citric acid production, describing micro-organisms, production techniques, and substrates, etc., and describe the most important organic acid produced in tonnage and extensively used in food and pharmaceutical industries.
Abstract: Citric acid is the most important organic acid produced in tonnage and is extensively used in food and pharmaceutical industries. It is produced mainly by submerged fermentation using Aspergillus niger or Candida sp. from different sources of carbohydrates, such as molasses and starch based media. However, other fermentation techniques, e.g. solid state fermentation and surface fermentation, and alternative sources of carbon such as agro-industrial residues have been intensively studied showing great perspective to its production. This paper reviews recent developments on citric acid production by presenting a brief summary of the subject, describing micro-organisms, production techniques, and substrates, etc.
111 citations
TL;DR: In this article, a bioreactor with a perforated float for carrying solid substrate and induced inoculum was used for the synthesis of tannase vis-a-vis gallic acid.
Abstract: Bioconversion of tannin to gallic acid from powder of teri pod (Caesalpinia digyna) cover was achieved by the locally isolated fungus, Rhizopus oryzae, in a bioreactor with a perforated float for carrying solid substrate and induced inoculum. Modified Czapek-Dox medium, put beneath the perforated float, with 2% tannic acid at pH 4.5, temperature 32°C, 93% relative humidity, incubated for 3 days with 3-day-old inoculum was optimum for the synthesis of tannase vis-a-vis gallic acid production. Conversion of tannin to gallic acid was 90.9%. Diethyl ether was used as the solvent for extraction of gallic acid from the fermented biomass.
TL;DR: This is the first report on inulinase production in SSF, and although the yeast culture produced relatively higher enzyme yields, the bacterial culture took a relatively shorter time to attain maximal yield.
TL;DR: The effects and control of operating conditions, such as temperature, water content and water activity, pH, aeration, and substrate, are presented and several suggestions are proposed which might further research and development of cellulase production by the solid-state fermentation process.
Abstract: The advances in the production of cellulase by solid-state fermentation are reviewed. In the process description of solid-state fermentation for cellulase production, the microorganisms, raw materials for solid-state fermentation, pretreatment of raw materials, sterilization and inoculation, and solid-state fermentation process are included. The effects and control of operating conditions, such as temperature, water content and water activity, pH, aeration, and substrate, are presented. A total of eight types of bioreactors with their advantages and disadvantages for solid-state fermentation are discussed. From the engineering aspect, mathematical models for the solid-state fermentation process are also discussed and several suggestions are proposed which might further research and development of cellulase production by the solid-state fermentation process.
TL;DR: A chitinolytic fungus, Beau6eria bassiana was isolated from marine sediment and significant process parameters influencing chitinase production in solid state fermentation using wheat bran were optimised and the maximum enzyme yield was 246·6 units g 1 initial dry substrate (U gIDS 1 ).
TL;DR: In this paper, the authors investigated xylanase production by Thermoascus aurantiacus using semisolid fermentation and multivariant statistical approaches were employed to evaluate the effects of several variables (initial moisture in the medium, cultivation time, inoculum level, and bagasse mass) on xylanases production.
Abstract: We investigated xylanase production by Thermoascus aurantiacus using semisolid fermentation. Multivariant statistical approaches were employed to evaluate the effects of several variables (initial moisture in the medium, cultivation time, inoculum level, and bagasse mass) on xylanase production. The initial moisture content and bagasse mass were the most important factors affecting xylanase activity. The xylanase activity produced by the fungus under the optimized conditions (81% moisture content and 17 g bagasse) was found to be 2700 U per gram of initial dry matter, whereas its value predicted by a polynomial model was 2400 U per gram of initial dry matter.
TL;DR: The addition of 6% (w/w) methanol into the substrate increased the concentration of citric acid from 176 to 264 g kg−1 dry pod, and the maximum citricacid concentration was obtained at a particle size of 0.5 mm.
TL;DR: The downstream processing parameters for recovery of the crude pectinases from the fermented bran were optimised and concentration and colour and polysaccharides in the enzyme extract could be minimised by treatment with sodium chloride and activated charcoal.
TL;DR: Qualitative relationships between medium composition, Aspergillus niger morphology, and phytase production were investigated in submerged and solid-state fermentations and found large pellets were not suitable as a morphological form for SSF inoculum, unless they were homogenized.
TL;DR: Tolypocladium inflatum strains are known to produce Cyclosporin-A under submerged culture conditions as discussed by the authors, however, they are not suitable for wheat bran medium.
TL;DR: In this article, the authors compared the performance of fixed bed and stirred tank extractors for the extraction of pectinases produced by Aspergillus niger in a solid state fermentation system and observed that three stages were enough for total recovery of the enzymes contained in the fermented solids.
TL;DR: In this article, the white-rot fungi Phanerochaete chrysosporium, Pleurotus eryngii, Phlebia radiata, and Ceriporiopsis subvermisporawas monitored during 60-day solid-state fermentation.
TL;DR: In this paper, the Doehlert design was applied to optimize water activity, pH, and fermentation time conditions for Aspergillus niger 148 pectinolytic activities production in solid-state (SSF) and submerged (SmF) fermentation.
Patent•
15 Oct 1999TL;DR: In this paper, an improved solid state fermentation device that combines all of the operations of microorganism cultivation (sterilization, inoculation, cultivation, extraction, and post extraction treatment) is presented.
Abstract: The present invention provides an improved solid state fermentation device that combines all of the operations of microorganism cultivation (sterilization, inoculation, cultivation, extraction, and post extraction treatment). This solid state fermentation device is modular in nature and operates in a contained manner so that the live microorganisms from the reactor cannot come into contact with the environment and pollute the environment and also so that the environment inside the bioreactor is aseptic. Another aspect of this invention allows fermentation of microorganisms without inhibiting the growth of the microorganism. Specifically, the bioreactor is designed to remove heat that accumulates inside the bioreactor during fermentation by conduction. Additionally, there is a mechanism to add fluid to the interior of the bioreactor that permits equal distribution and precise control of a variety of environmental parameters. For example, the bioreactor of the present invention provides a means to add nutritive media to the microorganisms at any time during the fermentation process without disturbing the fermenting microorganisms. Furthermore, the bioreactor of the present invention provides a mechanism to mix the contents of the bioreactor at any time and for any duration during the fermentation process. Finally, the present bioreactor provides a means of extracting desired microbial products from the bioreactor without opening the bioreactor.
TL;DR: Three agricultural wastes were evaluated for xylanolytic enzymes production by Aspergillus tamarii in solid state fermentation and the addition of xylan or β-methyl-xyloside in the cultures increased considerably the production of both xylanase and β- xylosidase without increasing theProduction of protease.
Abstract: Three agricultural wastes were evaluated for xylanolytic enzymes production by Aspergillus tamarii in solid state fermentation. A high production of xylanase and β-xylosidase was obtained in all waste materials. A high proteolytic activity was co-produced in wheat bran cultures, while a low proteolytic activity was detected in corn cob and sugar cane bagasse cultures. Optimal initial moisture contents for xylanolytic enzyme production were 86%, 80% and 75%, respectively to wheat bran, corn cob and sugar cane bagasse cultures. The addition of xylan or β-methyl-xyloside in the cultures increased considerably the production of both xylanase and β-xylosidase without increasing the production of protease. Neither heating, alkali nor hydrogen peroxide treatment of the milled substrate caused further improvement in enzyme production.
TL;DR: The overall performance of the bioreactor was promising for further investigation, and high levels of cellulolytic and hemicellulolytic activities were obtained.
TL;DR: In this article, a central composite rotatable design and response surface methodology were employed to derive a statistical model for media optimization towards production of mycophenolic acid, and five levels with a five factorial design were adopted.
Abstract: Mycophenolic acid (MPA) can be produced in solid state fermentation. An isolate of Penicillium brevi-compactum ATCC 16024 grown on moist wheat bran produced a titre of 425 mg per kg of wheat bran. Central composite rotatable design and response surface methodology were employed to derive a statistical model for media optimization towards production of mycophenolic acid. Five levels with a five factorial design were adopted. The correlation coefficient was 0.82, ensuring a satisfactory adjustment of the model to the experimental values. This statistical design was very effective in improving the titre of mycophenolic acid up to 3286 mg per kg of wheat bran.
TL;DR: An attempt has been made to enrich the protein content of sugar beet pulp, wheat bran and citrus waste by solid state fermentation using Neurospora sitophila using SSF, and optimal moisture content for growth on SBP and CW was 75–80% whereas for WB it was 65%.
Abstract: In this research study an attempt has been made to enrich the protein content of sugar beet pulp (SBP), wheat bran (WB) and citrus waste (CW) by solid state fermentation (SSF) using Neurospora sitophila. Optimum conditions for protein enrichment of these lignocellulosic byproducts by N. sitophila under SSF were investigated. From these experimental studies, optimal moisture content for growth on SBP and CW was 75–80% (w/w) whereas for WB it was 65% (w/w). The protein content of untreated SBP, WB and CW after 5 days SSF on surface was increased from 15, 13 and 7% (w/w) to 30, 30 and 18.2%, respectively.
TL;DR: Typical samples of the solid waste from olive oil processing were subjected to delignification by Phanerochaete chryosporium, Phlebia radiata, Pleurotus ostreatus or Dacrymyces stellatus, and it is suggested that this solid-state fermentation process could be used to manufacture an animal feed for the poultry industry in Jordan.
Abstract: Typical samples of the solid waste (50% moisture) from olive oil processing were subjected, after an alkaline pretreatment, to delignification by Phanerochaete chryosporium, Phlebia radiata, Pleurotus ostreatus or Dacrymyces stellatus. The fermented material was then saccharified by Trichoderma spp to provide a substrate for the yeasts, Candida utilis or Saccharomyces cerevisiae. Success was judged by the level of crude protein generated, and a combination fermentation involving Phan chryosporium, T reesei and S cerevisiae increased the level of crude protein from 5.9% in the raw pomace to 40.3% in the fermented material. It is suggested that this solid-state fermentation process could be used to manufacture an animal feed for the poultry industry in Jordan.
© 1999 Society of Chemical Industry
TL;DR: In this article, the ability of Aspergillus tamarii V12A25 to use caffeine as sole nitrogen source was investigated in solid state fermentation (SSF) using two different supports, polyurethane foam (PUF) and sugarcane bagasse.
TL;DR: Catabolite repression by glucose of the biosynthesis of alpha amylase and amyloglucosidase by Aspergillus niger CFTRI 1105 was studied in a solid state fermentation (SSF) and in submerged fermentation (SMF) systems and the results were compared.
Abstract: Catabolite repression by glucose of the biosynthesis of alpha amylase and amyloglucosidase by Aspergillus niger CFTRI 1105 was studied in a solid state fermentation (SSF) and in submerged fermentation (SMF) systems and the results were compared. The addition of glucose did not enhance the production of alpha-amylase and
amyloglucosidase in an earlier fermentation system. However, a drastic reduction in alphaamylase
production was observed in submerged fermentation by the addition of 5·0 mg ml-1 glucose and of amyloglucosidase production by 10 mg ml-1 glucose. Glucose
concentrations above 50 mg ml-1 completely suppressed the production of both enzymes in the initial hours. In contrast, in the SSF system the repression was negligible,
even when the glucose level was raised to 150 mg g�1 wheat bran for both alpha and amyloglucosidase synthesis.