Penicillin production by solid state fermentation

Summary Penicillin was produced by a non-sterile solid state fermentation (SSF) on bagasse impregnated with culture medium. The use of concentrated media greatly enhanced the antibiotic production in this system. It was observed that adequate initial moisture content (70%) of the impregnated solid medium results in higher production. A comparison between solid and liquid fermentation showed superior yield and productivity.     

Spore production ofPenicillium roqueforti by simulated solid state fermentation

Summary A culture technique, based on the growth of a microorganism on inert porous particles (e. g. pozzolano) impregnated and continuously fed with substrate is applied to the growth and spore production ofPenicillium roqueforti. The composition and the feed rate of the medium can be controlled, and the biomass is directly estimated.P. roqueforti exhibits a diauxic growth on the medium containing sucrose and malt extract used, and 1.5 10⁹ spores/g pozzolano may be obtained.     

Enhanced lovastatin production by solid state fermentation ofMonascus ruber

The purpose of this study was to optimize the solid state cultivation ofMonascus ruber on sterile rice. A single-level-multiple-factor and a single-factor-multiple-level experimental design were employed to determine the optimal medium constituents and to optimize carbon and nitrogen source concentrations for lovastatin production. Simultaneous quantitative analyses of the β-hydroxyacid form and β-hydroxylactone for of lovastatin were performed by the high performance liquid chromatography (HPLC) method with a UV photodiode-array (PDA) detector. The total lovastatin yield (4≈6 mg/g, average of five repeats) was achieved by adding soybean powder, glycerol, sodium nitrate, and acetic acid at optimal composition of the medium increased by almost 2 times the yield observed prior to optimization. The experimental results also indicated that the β-hydroxylactone form of lovastatin (LFL) and the β-hydroxyacid form of lovastatin (AFL) simultaneously existed in solid state cultures ofMonascus ruber, while the latter was the dominant form in the middle-late stage of continued fermentation. These results indicate that optimized culture conditions can be used for industrial production of lovastatin to obtain high yields.     

Cyclosporin-A production by Tolypocladium inflatum using solid state fermentation

Tolypocladium inflatum strains are known to produce Cyclosporin-A under submerged culture conditions. In the present study solid state fermentation was used to produce Cyclosporin-A. Tolypocladium inflatum strains when grown on moist wheat bran produced 310–459 mg of Cyclosporin-A kg of bran⁻¹. Tolypocladium inflatum ATCC 34921 which produced 459 mg of Cyclosporin-A kg of bran⁻¹ was improved to produce 1031±27 mg of Cyclosporin-A kg⁻¹ of bran, by subjecting the spores to different mutagenic treatments. The mutated strain, designated Tolypocladium inflatum DRCC 106, produced 4843 mg kg⁻¹ of bran under optimum fermentation conditions in 10 days when grown on wheat bran medium containing millet flour 20%, jowar flour 10%, zinc sulphate 0·15%, ferric chloride 0·25% and cobaltous chloride 0·05%. An inoculum of 60% initial moisture content 70%, initial bran pH 2·0 and incubation temperature 25°C were found to be optimal. Cyclosporin-A thus obtained was purified by solvent extraction, followed by column chromatography. The isolated product complies with the United States Pharmacopoeia specifications.     

Microbial production of gallic acid by modified solid state fermentation

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-à-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. Received 14 December 1998/ Accepted in revised form 17 June 1999     

Tetracycline production with sweet potato residue by solid state fermentation

For saving energy in antibiotic production and reducing the amount of agricultural wastes, solid state fermentation was used in this study to produce tetracycline with sweet potato residue by Streptomyces viridifaciens ATCC 11989. It was found that the optimal media for tetracycline production were sweet potato residue 100 g, organic nitrogen (rice bran, wheat bran, or peanut meal) 20 g, (NH(4))(2)SO(4) 2.4 g, KH(2)PO(4) 0.4 g, CaCO(3) 1.8 g, NaCl 0.6 g, MgCl(2) 0.8 g, soluble starch 10 g, methionine 0.2 g, histidine 0.8 g, and monosodium glutamate 1.6 g with initial moisture content 68-72%, and initial pH 5.8-6.0. Each gram of dry weight substrate was inoculated with 1.0 x 10(8) conidia and incubated at 26 degrees C for 5-7 days, producing 4720 mug of total tetracycline equivalent potency. When incubated at 26 degrees C with the initial moisture content 68%, the conidia in solid media germinated on the second day, mycelia grew abundantly on the third day and reached stationary phase on the sixth day. The antibiotic production was consistent with the morphogenesis of S. viridifaciens: activity could be detected on the third day, had the maximal potency on the sixth day, and decreased slightly on the tenth day. (11-3-88 tly).     

Extracellular xylanase production by Fusarium species in solid state fermentation

Fusarium sp. has been shown to be a promising organism for enhanced production of xylanases. In the present study, xylanase production by 21 Fusarium sp. isolates (8 Fusarium culmorum, 4 Fusarium solani, 6 Fusarium verticillioides and 3 Fusarium equiseti) was evaluated under solid state fermentation (SSF). The fungal isolate Fusarium solani SYRN7 was the best xylanase producer among the tested isolates. The effects of some agriculture wastes (like wheat straw, wheat bran, beet pulp and cotton seed cake) and incubation period on xylanase production by F. solani were optimized. High xylanase production (1465.8 U/g) was observed in wheat bran after 96 h of incubation. Optimum pH and temperature for xylanase activity were found to be 5 and 50 degrees C, respectively.     

Citric acid production by solid state fermentation using sugarcane bagasse

A solid state fermentation (SSF) method was used to produce citric acid by Aspergillus niger DS 1 using sugarcane bagasse as a carrier and sucrose or molasses based medium as a moistening agent. Initially bagasse and wheat bran were compared as carrier. Bagasse was the most suitable carrier, as it did not show agglomeration after moistening with medium, resulting in better heat and mass transfer during fermentation and higher product yield. Different parameters such as moisture content, particle size, sugar level and methanol concentration of the medium were optimised and 75% moisture level, 31.8 g sugar/100 g dry solid, 4% (v/w) methanol and particles of the size between 1.2 and 1.6 mm were found to be optimal. Sucrose and clarified and non-clarified molasses medium were also tested as moistening agents for SSF and under optimised conditions, 20.2, 19.8 and 17.9 g citric acid /100 g of dry solid with yield of 69.6, 64.5 and 62.4% (based on sugar consumed) was obtained in sucrose, clarified and non-clarified molasses medium respectively, after 9 days of fermentation.     

Xylanase production by Ganoderma lucidum on liquid and solid state fermentation

Ganoderma lucidum, a white rot fungus, was exploited for its potentials to produce xylanase employing shake and solid-state culture conditions. Different culture conditions such as pH, temperature, carbon and nitrogen requirements for its growth and production of xylanase were optimized. The culture media pH 6.0-7.0 and temperatures 30 degrees-35 degrees C significantly promoted the growth as well as xylanase secretion into the media. Xylan and peptone were found to be the suitable carbon and nitrogen sources. Among the different agrowastes used, wheat bran was found to be the best substrate for the test fungus for the production of xylanase than sugarcane bagasse and rice bran in solid-state fermentation.     

Rhizopus sp.PW358菌脂肪酶固态发酵生产

研究了Rhizopus sp.PW358菌的固态生长和产脂肪酶条件。结果表明：黄豆饼粉为培养基的基本成分,用来生产脂肪酶。培养基中可加入淀粉和蛋白胨作为碳源和源,有利于脂肪酶的合成,培养基的含水量以及金属离子Ca^2 ,Mg^2 的浓度也影响Rhizopus sp.PW358菌和脂肪酶 产生。在优化条件下,12g豆粉中含1.0g淀粉及0.5g蛋白胨、15ml营养盐中Ca^2 ,Mg^2 离子浓度分别为8．0和4．0g/L,培养基含水量为55．6％,在接种后培养48h,酶活力可达最大值320IU／g干培养基。脂肪酶的基本性质研究表明,酶的最适反应温度和PH分别为35℃和7．0,酶的半失活温度为53．5℃,不同的PH环境中,30℃保温1h后酶在PH6．5－8．5范围内较为稳定。     

樟绒枝霉(Malbranchea cinnamomea)固体发酵产木聚糖酶的发酵条件优化

[目的] 研究樟绒枝霉(Malbranchea cinnamomea) CAU521利用农业废弃物固体发酵产木聚糖酶的发酵条件.[方法]采用单因素试验法优化影响菌株产酶的各个条件,包括碳源种类、氮源种类、初始pH、初始水分含量、培养温度及发酵时间共6个因素.[结果]获得的最佳产酶条件为:稻草为发酵碳源、2％(W/W)的酵母提取物为氮源、初始pH 7.0、初始水分含量80％和发酵温度45℃.在此条件下发酵6d后木聚糖酶的酶活力达到13 120 U/g干基碳源.[结论]樟绒枝霉固体发酵产木聚糖酶的产酶水平高,生产成本低,具有潜在的工业化应用前景.     

黑曲霉固态发酵生产单宁酶的条件优化

研究采用响应面法优化黑曲霉固态发酵生产单宁酶的培养条件。应用Plackett—Burman试验筛选出重要影响因子：五倍子粉含量、（NH4）2SO4浓度以及接种孢子量,最陡爬坡试验逼近最大响应区域。应用Box．Behnken响应面试验对重要影响因子进一步优化。得到最佳培养条件：每250mL三角瓶中装入1．0g五倍子粉、4．4g稻壳和0．5g麸皮、液固比（mL／g）2：1且营养盐溶液组成为（NH4）2s0421g/L、MgSO4·7H2O1g／L、NaCl1g／L,培养基pH自然,接种5．7×10^7个孢子后在30℃温度下培养4d。在此条件下,单宁酶产量从40U／g提高到114U／g,3次重复验证性试验平均值为115U／g,验证了模型的可靠性。     

A mathematical approach for the estimation of biomass production rate in solid state fermentation

The oxygen uptake rate (OUR) was studied in a solid state fermentation process of dried citrus peel with the strain Aspergillus niger QH-2 in order to obtain the growth estimation of the microorganism in the system. The relationship between OUR, the maintenance coefficient (m) and the yield for oxygen consumption Y_O2 allows the estimation of the biomass rate if we consider that both parameters are not constants in some periods of the process. It was estimated that in the first 24th the strain has an specific growth rate of 0.174 h^?1 with values for Y_O2 and m in the order of 2.84 g-cell/g-oxygen and 0.006 g-oxygen/g-cell ·h respectively.     

Cellulase production in a new mutant strain of Penicillium decumbens ML-017 by solid state fermentation with rice bran

To produce cellulolytic enzyme efficiently, Penicillium decumbens strain L-06 was used to prepare mutants with ethyl methane sulfonate (EMS) and UV-irradiation. A mutant strain ML-017 is shown to have a higher cellulase activity than others. Box-Behnken's design (BBD) and response surface methodology (RSM) were adopted to optimize the conditions of cellulase (filter paper activity, FPA) production in strain ML-017 by solid-state fermentation (SSF) with rice bran as the substrate. And the result shows that the initial pH, moisture content and culture temperature all have significant effect on the production of cellulase. The optimized condition shall be initial pH 5.7, moisture content 72% and culture temperature 30°C. The maximum cellulase (FPA) production was obtained under the optimized condition, which is 5.76 IU g(-1), increased by 44.12% to its original strain. It corresponded well with the calculated results (5.15 IU g(-1)) by model prediction. The result shows that both BBD and RSM are the cellulase optimization methods with good prospects.     

A practical approach to biosurfactant production using nonaseptic fermentation of mixed cultures

Non-aseptic production of biosurfactant from molasses by a mixed culture was investigated in stirred batch reactors. Biosurfactant production was quantified by surface tension reduction, critical micelle dilution (CMD), and emulsification capacity (EC). Biosurfactant production was directly correlated with biomass production, and was improved by pH control and addition of yeast extract. Centrifugation of the whole broth increased emulsifying capacity and reduced surface tension. Acidification of the whole broth increased the emulsification capacity but reduced the apparent biosurfactant concentration (CMD), without affecting the surface tension. The emulsification capacity of the cell-free broth was equivalent to that of a 100 mg/L solution of sodium dodecyl sulfate. The emulsification capacity of the whole broth and cell-free broth were reduced by about 50% at and above NaCl concentrations of 100mM. Preliminary characterization suggests that the biosurfactant activity is primarily associated with one or more protease-sensitive species, released from cells in larger quantities after more vigorous centrifugation.     

Economic production of Lysinibacillus sphaericus under solid state fermentation

A highly active mosquitocidal Lysinibacillus sphaericus namely Ls 9B24 was isolated from soil of Alexandria governorate in Egypt. It was more active than the standard strain, L. sphaericus 2362. The sporulation and toxin formation of both cultures grown on different leguminous seeds and by-products under solid state fermentation (SSF) were studied. Among the tested substrates, 6% cotton seed meal enhanced sporulation and the mosquitocidal activity of L. sphaericus 2362, while 6% fodder yeast enhanced sporulation and the mosquitocidal activity of Ls 9B24. The optimum SSF growth conditions for maximum mosquitocidal activity by both cultures were using coarse wheat bran as a carrier material, 50% initial moisture content, 4–64 × 10⁶ colony forming units (CFU)/g solid medium inoculum and 6 days’ incubation period at 30°C. Addition of 0.5% yeast extract enhanced toxicity about 2.2 and 1.8 fold for L. sphaericus 2362 and Ls 9B24, respectively.     

Optimization studies on the production of cyclosporin A by solid state fermentation

Several parameters including (a) tray fermentation with and without perforation (b) thickness of solid substrate bed (c) type of inoculum (d) size of inoculum (e)?effect of relative humidity were studied for the optimum production of Cyclosporin A by solid state fermentation using Tolypocladium sp. The results indicate that while perforations in the trays had no significance on the yield of Cyc A, the other parameters had an influence on the production of Cyc A. The results indicate that under the optimized conditions, Cyc A can be produced in bulk quantities economically.     

Utilisation of fruits waste for citric acid production by solid state fermentation

A solid state fermentation method was used to utilise pineapple, mixed fruit and maosmi waste as substrates for citric acid production using Aspergillus niger DS 1. Experiments were carried out in the presence and absence of methanol at different moisture levels. In the absence of methanol the maximum citric acid was obtained at 60% moisture level whereas in the presence of methanol the maximum citric acid was obtained at 70% moisture level. The stimulating effect of methanol was less at lower moisture level. The inhibitory effect of metal ions was also not observed and maximum citric acid yield of 51.4, 46.5 and 50% (based on sugar consumed) was obtained from pineapple, mixed fruit and maosmi residues, respectively.     

Lipase production from an alkalophilic yeast sp. by solid state fermentation

The present investigation has been carried out with the aim to produce lipase from an alkalophilic yeast species by solid state fermentation using rice and wheat brans as alternative cheap solid substrates.     

Approaches to KL a measurements in solid state fermentation

Summary A convenient method for measuring K_L a in a solid state medium is proposed. Due to the particular nature of the substrate used in solid state fermentation, different modifications of the sulfite oxidation method have been necessary. This first approach allows to study the influence of air inflow rate and dry matter percentage of the medium on the oxygen volumetric mass transfer coefficient.