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1.
In the present study, coconut coir was evaluated as an inert support for the production of cyclosporin A (CyA) using Tolypocladium inflatum MTCC 557 by solid state fermentation. Initially, four different inert supports such as coconut coir, polyurethane foam, polystyrene beads, and sugarcane baggase were screened using different production media as moistening agents for the maximum production of CyA. Different parameters such as fermentation time, carbon sources, moisture content, pH, and inoculum size were optimized. It was observed that coconut coir impregnated with medium modified with glycerol as carbon source, pH 6, at 80% moisture content, and inoculum size of 2.5 mL/2.5 g support produced 2641 mg/kg of CyA after 12 days as compared to 998 mg/kg before optimization. The yields were further increased to 3597 mg/kg substrate with addition of combination of amino acids after 48 h of fermentation.  相似文献   

2.
A tannase yielding fungal culture identified as Aspergillus fumigatus MA was isolated from the effluent collected from a local small scale tannery. The fungal culture produced high yields of extracellular tannase under solid-state fermentation (SSF) using different agro forest residues such as Amla leaves (Phyllanthus emblica), Ber leaves (Zyzyphus mauritiana), Jamun leaves (Syzygium cumini), Jamoa leaves (Syzygium sp.) and Keekar leaves (Acacia nilotica). Among different substrates used, Jamun leaves yielded maximal extra-cellular production of tannase. Various parameters were studied to optimize the extracellular yield of tannase under SSF. The maximum yield of 174.32 U g−1 was obtained at 25°C after 96 h of incubation at pH 5.0. The tap water was used as a moistening agent. A substrate to tap water ratio of 1:1 was found to best for tannase production. Supplementation of the medium with ammonium sulfate as nitrogen source had enhanced tannase production whereas glucose had decreased the enzyme production. This is the first report on production of tannase by Aspergillus fumigatus MA, giving a much higher yield of enzyme under SSF with Jamun leaves as the substrate.  相似文献   

3.
A lignocellulosic decomposing fungus Z5 was isolated and identified as Aspergillus fumigatus, its capacity to produce cellulase was assessed under solid-state fermentation (SSF) using lignocellulosic materials as substrates. Cultivation conditions of A. fumigatus Z5 for cellulase production were optimized, results showed that for carboxymethyl cellulase (CMCase) and filter paper enzyme (FPase), the best condition was 50 °C, 80% initial moisture, initial pH 4.0 and 7% initial inoculum, the average activity of CMCase activity, FPase activity reached 526.3 and 144.6 U g−1 dry weight (dw) respectively, much higher than most of previous reports of this genus. Optimal temperature and pH for the CMCase activity of the crude enzyme were found to be 50 °C and 5.0, respectively. Zymogram analysis showed that eight kinds of CMCase were secreted by A. fumigatus Z5 when cellulose-containing materials were supplied in the culture. The crude enzyme secreted by the strain was further applied to hydrolyze pretreated corn stover and the enzymatic hydrolysate was used as substrate for ethanol production by Saccharomyces cerevisiae. The yield of bio-ethanol was 0.112 g g−1 dry substrate (gDS), suggesting that it is a promising fungus in the bio-ethanol production process.  相似文献   

4.
The process parameters were optimized to obtain enhanced enzyme activity from the fungus Phoma herbarum isolate KU4 using rice straw and saw dust as substrate under solid-state fermentation using Response surface methodology (RSM). Genetic algorithm was used to validate the RSM for maximum laccase production. Six variables, viz., pH of the media, initial moisture content, copper sulphate concentration, concentration of tannic acid, inoculum concentration and incubation time were found to be effective and optimized for enhanced production. Maximum laccase production was achieved by RSM at pH 5·0 and 86% of initial moisture content of the culture medium, 150 µmol l−1 of CuSO4, 1·5% tannic acid and 0·128 g inoculum g−1 dry substrate inoculum size on the fourth day of fermentation. The highest laccase activity was observed as 79 008 U g−1, which is approximately sixfold enhanced production compared to the unoptimized condition (12 085·26 U g−1).  相似文献   

5.
This work aims to evaluate the fermentability of cellulosic hydrolysates obtained by enzymatic saccharification of sugarcane bagasse pretreated by hydrothermal processing using Candida guilliermondii FTI 20037 yeast. The inoculum was obtained from yeast culture in a medium containing glucose as a carbon source supplemented with rice bran extract, CaCl2·2H2O and (NH4)2SO4 in 50 mL Erlenmeyer flasks, containing 20 mL of medium, initial 5.5 pH under agitation of an orbital shaker (200 rpm) at 30°C for 24 h. The cellulosic hydrolysates, prior to being used as a fermentation medium, were autoclaved for 15 min at 0.5 atm and supplemented with the same nutrients employed for the inoculum, except the glucose, using the same conditions for the inoculum, but with a period of 48 h. Preliminary results showed the highest consumption of glucose (97%) for all the hydrolysates, at 28 h of fermentation. The highest concentration of ethanol (20.5 g/L) was found in the procedure of sugarcane bagasse pretreated by hydrothermal processing (195°C/10 min in 20 L reactor) and delignificated with NaOH 1.0% (w/v), 100°C, 1 h in 500 mL stainless steel ampoules immersed in an oil bath.  相似文献   

6.

Parthenium hysterophorus biomass can be used as a non-conventional renewable feedstock for the production of bioethanol. Therefore, the present work was designed to hydrolyze P. hysterophorus biomass using cellulase enzyme produced from an actinomycete, i.e., Streptomyces sp. NAA2 using P. hysterophorus biomass as a substrate. The isolate NAA2 was identified by molecular characterization of 16SrDNA. The enzyme production by strain NAA2 was enhanced by optimization studies conducted under submerged fermentation conditions using P. hysterophorus as a substrate. The crude enzyme produced under optimized conditions was used to hydrolyze alkali-acid pretreated P. hysterophorus biomass. The highest CMCase production was achieved in 4–5 days when steam-pretreated P. hysterophorus biomass was used at 1% (w/v) concentration, using 2 discs (1 disc = 5 × 107 spores/ml) of inoculum, an initial pH 6.5, temperature at 40 °C, an agitation speed of 120–150 rpm, and by supplementing fermentation medium with 1.5% (w/v) carboxymethyl cellulose (CMC) as additional carbon source. Under optimized conditions, the actinomycete strain NAA2 showed production of 0.967 ± 0.016 U/ml CMCase, 0.116 ± 0.08 FPU/ml FPase, and 0.22 ± 0.012 U/ml β-glucosidase enzymes. On utilizing the cellulase enzyme for biomass hydrolysis, maximum 18.2% saccharification yield (of cellulose 0.202 g/g) was achieved in 96 h when enzyme and substrate levels were 30 FPU/100 ml and 2% (w/v) respectively. Parthenium hysterophorus biomass can be hydrolyzed enzymatically yielding considerable amounts of total reducing sugars. It can, therefore, be used as a feedstock for the production of bioethanol. Also, it has the potential to act as a substrate for the production of cellulases. Furthermore, the improved cellulolytic potential of Streptomyces sp. NAA2 can be exploited in various industrial applications.

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7.
Claviceps paspali FA produced high concentrations of alkaloid under submerged conditions. Their production was found to depend on the developmental stage and treatment of the filamentous culture inoculum. A medium containing Bacto-peptone with a constant composition of amino acids was selected for the preparation of the inoculum. A two-week fermentation in a synthetic medium with mannitol at 24 ± 1 °C resulted in an increased production of total alkaloids from the original value of 100–200 μg/mL to more than 2 000 μg/mL. Addition of tryptophan did not further increase the production of alkaloids but resulted in changes of the spectrum of some metabolites. 2,3-Dihydroxybenzoic acid accompanied the alkaloids in the fermentation medium. α-Hydroxyethyllysergamide was the predominant component of extracellular alkaloids (80 % in the first days of fermentation). During fermentation the level of this alkaloid continuously decreased while the concentration of the accompanying alkaloids,i.e. lysergamide and the corresponding minor isomers, increased. An erratum to this article is available at .  相似文献   

8.
Bacillus cereus ZH14 was previously found to produce a new type of antiviral ribonuclease, which was secreted into medium and active against tobacco mosaic virus. In order to enhance the ribonuclease production, in this study the optimization of culture conditions using response surface methodology was done. The fermentation variables including culture temperature, initial pH, inoculum size, sucrose, yeast extract, MgSO4·7H2O, and KNO3 were considered for selection of significant ones by using the Plackett–Burman design, and four significant variables (sucrose, yeast extract, MgSO4·7H2O, and KNO3) were further optimized by a 24 factorial central composite design. The optimal combination of the medium constituents for maximum ribonuclease production was determined as 8.50 g/l sucrose, 9.30 g/l yeast extract, 2.00 g/l MgSO4·7H2O, and 0.62 g/l KNO3. The enzyme activity was increased by 60%. This study will be helpful to the future commercial development of the new bacteria-based antiviral ribonuclease fermentation process.  相似文献   

9.
Effect of medium composition and culture conditions on agarase production by Agarivorans albus YKW-34 was investigated in shake flasks. The most suitable carbon source, nitrogen source, and culture temperature were agar, yeast extract, and 25 °C, respectively, for agarase production by one-factor-at-a-time design. The nutritional components of the medium and culture conditions were analyzed by Plackett–Burman design. Among the nine factors studied, agar, yeast extract, and initial pH had significant effects on agarase production (p < 0.05). The optimum levels of these key variables were further determined using a central composite design. The highest agarase production was obtained in the medium consisting of 0.23% agar and 0.27% yeast extract at initial pH 7.81. The whole optimization strategy enhanced the agarase production from 0.23 U/ml to 0.87 U/ml. The economic medium composition and culture condition as well as the dominant occupation of agarase with high activity in culture fluid enlighten the potential application of A. albus YKW-34 for the production of agarase.  相似文献   

10.
In order to isolate inulinase overproducers of the marine yeast Pichia guilliermondii, strain 1, cells were mutated by using UV light and LiCl2. One mutant (M-30) with enhanced inulinase production was obtained. Response surface methodology (RSM) was used to optimize the medium compositions and cultivation conditions for inulinase production by the mutant in solid-state fermentation. The initial moisture, inoculum, the amount ratio of wheat bran to rice bran, temperature, pH for the maximum inulinase production by the mutant M-30 were found to be 60.5%, 2.5%, 0.42, 30°C and 6.50, respectively. Under the optimized conditions, 455.9 U/grams of dry substrate (gds) of inulinase activity was reached in the solid state fermentation culture of the mutant M-30 whereas the predicted maximum inulinase activity of 459.2 U/gds was derived from RSM regression. Under the same conditions, its parent strain only produced 291.0 U/gds of inulinase activity. This is the highest inulinase activity produced by the yeast strains reported so far.  相似文献   

11.
A suitable medium was developed from modified Richard's medium plus V8 juice (RM8) to produce high levels of desiccation-tolerant conidia ofTrichoderma harzianumstrain 1295-22. The addition of 9% (v/v) glycerol to RM8 improved both biomass production and desiccation tolerance of the conidia ofT. harzianum.This medium was then used in a laboratory scale fermenter (1.5 liter) to determine optimal operating conditions. The optimal temperature for conidial production and desiccation tolerance improvement in the fermenter was 32°C when dissolved oxygen was maintained at 50% saturation of air, and the stirring rate was 1000 revolutions per minute. The initial water potential of the medium (with 9% glycerol) was −3.7 MPa, the pH was 6, and neither was controlled during fermentation. Changes in medium pH and dissolved oxygen were associated with the stages of morphological development and conidiation. The pH of the medium decreased concurrently with germ-tube elongation and mycelium development and then increased to 6.0–6.2 at phialide formation. Intensive conidiation occurred at pH 6.3–6.5 and reached its maximal level at 6.9–7.1. Changes in pH values could be used as indicators to monitor the morphological development and conidiation ofT. harzianumduring fermentation. The use of a 48-h-old culture inoculum, rather than conidial inoculum, to start fermentation reduced the time required to complete the shift from vegetative growth to phialide formation. Intensive conidiation occurred immediately after the addition of culture inoculum and reached maximum levels within 68 h of fermentation. Dry weight of biomass increased with the duration of fermentation and was greatest at 96 h. However, no improvements in conidia/gram and CFU/gram were achieved after 72 h of fermentation. The desiccation tolerance of conidia harvested at 72 or 96 h was significantly (P = 0.05) greater than that of conidia harvested at 48 h of fermentation. Results obtained from this study could be used for further scale-up of the fermentation process.  相似文献   

12.
This work aimed to develop the submerged cultivation conditions for improved exopolysaccharides (EPS) production by Armillaria luteo-virens Sacc. The effects of culture temperature, aeration rate, inoculum level, initial pH, and additives on EPS formation and mycelial growth are investigated. The aeration rate, initial pH, and inoculum level significantly affected EPS production under the submerged cultivation. The developed conditions were as follows: cultivation temperature 23 °C, initial pH 5.0, aeration rate 0.5 vvm, 0.5% Tween 80, inoculum level 5% (v/v), and shaking speed 120 r/min. Under the developed conditions, the highest EPS production was 13.01 g/L at 5 days culture time. EPS production was examined in a 5 L bioreactor, and an unstructured kinetic model for EPS formation was well developed. The verified investigations in the large-scale cultivation system showed that the developed models are able to predict the submerged cultivation process of EPS formation. Current results revealed that the submerged cultivation conditions can be utilized to control EPS production, and the unstructured models developed are suitable for explaining EPS production by A. luteo-virens Sacc QH in a large-scale cultivation bioreactor.  相似文献   

13.

The efficiency of Cryptococcusalbidus was evaluated for its abilities to assimilate onion and apple hydrolysates as a medium for lipid production. Onion waste (OW) and apple waste (AW) were hydrolysed at an organic load of 2% total solids by indigenous microbes under mesophilic conditions. The indigenous microbes effectively hydrolysed both wastes giving the highest reducing sugar content of 4.8 g/L and 10.8 g/L with OW and AW hydrolysates, respectively. The microbiome analysis revealed that most of the indigenous microbes belonged to genus Bacillus and a significant population of α-proteobacteria and γ-proteobacteria were also present. Cell retention culture of C. albidus at a dilution rate of 0.01 h−1 resulted in a total dry cell weight (DCW) of 13.5 g/L with an intracellular lipid content of 20.0% at 168 h, corresponding to an enhancement of 3.48-folds and 2.37-folds in DCW and lipid concentration, respectively, as compared to batch fermentation.

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14.
Abstract

The optimal fermentation medium and conditions for mycelial growth and water-soluble exo-polysaccharides production by Isaria farinosa B05 were investigated. The medium components and fermentation conditions were optimized according to the one at a time method, while the concentration of medium components was determined by the orthogonal matrix method. The results showed that the optimal fermentation medium was as follows: sucrose 3.5% (w/v), peptone 0.5%, yeast extract 0.2%, K2HPO4 0.1%, and MgSO4 0.05%. The suitable fermentation conditions were as follows: initial pH 7.0, temperature 25°C, medium volume 75 mL/250 mL, inoculum volume 5% (v/v), time 5d. In such optimal nutrition and environmental conditions, the maximal mycelial yield was 2.124 g/100 mL after 4 day's fermentation, while maximal water-soluble exo-polysaccharides production reached 2.144 g/L after 5 day's fermentation.  相似文献   

15.
Several fungal endophytes of the Egyptian marine sponge Latrunculia corticata were isolated, including strains Trichoderma sp. Merv6, Penicillium sp. Merv2 and Aspergillus sp. Merv70. These fungi exhibited high cellulase activity using different lignocellulosic substrates in solid state fermentations (SSF). By applying mutagenesis and intergeneric protoplast fusion, we have obtained a recombinant strain (Tahrir-25) that overproduced cellulases (exo-β-1,4-glucanase, endo-β-1,4-glucanase and β-1,4-glucosidase) that facilitated complete cellulolysis of agricultural residues. The process parameters for cellulase production by strain Tahrir-25 were optimized in SSF. The highest cellulase recovery from fermentation slurries was achieved with 0.2% Tween 80 as leaching agent. Enzyme production was optimized under the following conditions: initial moisture content of 60% (v/w), inoculum size of 106 spores ml−1, average substrate particle size of 1.0 mm, mixture of sugarcane bagasse and corncob (2:1) as the carbon source supplemented with carboxymethyl cellulose (CMC) and corn steep solids, fermentation time of 7 days, medium pH of 5.5 at 30°C. These optimized conditions yielded 450, 191, and 225 units/gram dry substrate (U gds−1) of carboxylmethyl cellulase, filter-paperase (FPase), and β-glucosidase, respectively. Subsequent fermentation by the yeast, Saccharomyces cerevisiae NRC2, using lignocellulose hydrolysates obtained from the optimized cellulase process produced the highest amount of ethanol (58 g l−1). This study has revealed the potential of exploiting marine fungi for cost-effective production of cellulases for second generation bioethanol processes.  相似文献   

16.

New ideas on production of yeast origin β-glucan preparations for industrial application are attracting interest considering market development of that high-value functional polysaccharide. Sellecting an efficient yeast producer and designing culture conditions are a prerequisite for obtaining high yield of β-glucan. The aim of this study was to describe at the first time the influence of the mode of cultivation (shake-flasks and batch fermentation) and time of culture on characteristic and yield of biomass and β(1,3)/(1,6)-glucan preparations of Candida utilis ATCC 9950 after cultivation in medium based on waste potato juice water supplemented with 10% of glycerol. After shake-flask culture, the biomass was characterized by higher protein content (app. 26.5%) compared to 19% after batch fermentation while the cultivation on a biofermentor scale promoted polysaccharides biosynthesis. The highest output of purified β(1,3)/(1,6)-glucan preparation (5.3 gd.w./L), containing app. 85% of that polysaccharide, was found after 48 h cultivation in biofermentor. Batch fermentation promoted biosynthesis of alkali-insoluble β(1,3)/(1,6)-glucan fraction, decreasing the content of β(1,6)-glucan. The yield of β(1,3)/(1,6)-glucan synthesis was 0.063 (g/g glycerol), while the productivity of that polysaccharide reached 0.094 (g/L/h). Longer batch fermentation (72 h) resulted in reduction of production efficiency of β-glucan preparation under studied conditions. The results of the study provide a new efficient biotechnological solution to produce high-value β-glucan preparations of C. utilis origin based on valorization of agro-waste potato juice water with glycerol.

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17.

Much research has been conducted about different types of fermentation at high temperature, but only a few of them have studied cell viability changes during high-temperature fermentation. In this study, Acetobacter senegalensis, a thermo-tolerant strain, was used for gluconic acid production at 38 °C. The influences of different carbon sources and physicochemical conditions on cell viability and the resuscitation of viable but nonculturable (VBNC) cells formed during fermentation were studied. Based on the obtained results, A. senegalensis could oxidize 95 g l− 1 glucose to gluconate at 38 °C (pH 5.5, yield 83%). However, despite the availability of carbon and nitrogen sources, the specific rates of glucose consumption (qs) and gluconate production (qp) reduced progressively. Interestingly, gradual qs and qp reduction coincided with gradual decrease in cellular dehydrogenase activity, cell envelope integrity, and cell culturability as well as with the formation of VBNC cells. Entry of cells into VBNC state during stationary phase partly stemmed from high fermentation temperature and long-term oxidation of glucose, because just about 48% of VBNC cells formed during stationary phase were resuscitated by supplementing the culture medium with an alternative favorite carbon source (low concentration of ethanol) and/or reducing incubation temperature to 30 °C. This indicates that ethanol, as a favorable carbon source, supports the repair of stressed cells. Since formation of VBNC cells is often inevitable during high-temperature fermentation, using an alternative carbon source together with changing physicochemical conditions may enable the resuscitation of VBNC cells and their use for several production cycles.

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18.
The ability of xylanolytic enzymes produced by Aspergillus fumigatus RP04 and Aspergillus niveus RP05 to promote the biobleaching of cellulose pulp was investigated. Both fungi grew for 4–5 days in liquid medium at 40°C, under static conditions. Xylanase production was tested using different carbon sources, including some types of xylans. A. fumigatus produced high levels of xylanase on agricultural residues (corncob or wheat bran), whereas A. niveus produced more xylanase on birchwood xylan. The optimum temperature of the xylanases from A. fumigatus and A. niveus was around 60–70°C. The enzymes were stable for 30 min at 60°C, maintaining 95–98% of the initial activity. After 1 h at this temperature, the xylanase from A. niveus still retained 85% of initial activity, while the xylanase from A. fumigatus was only 40% active. The pH optimum of the xylanases was acidic (4.5–5.5). The pH stability for the xylanase from A. fumigatus was higher at pH 6.0–8.0, while the enzyme from A. niveus was more stable at pH 4.5–6.5. Crude enzymatic extracts were used to clarify cellulose pulp and the best result was obtained with the A. niveus preparation, showing kappa efficiency around 39.6% as compared to only 11.7% for that of A. fumigatus.  相似文献   

19.

Pfaffia glomerata has potential pharmacological and medicinal properties due to the production of a secondary metabolite known as the phytoecdysteroid 20-hydroxyecdysone (20E). There have been increasing efforts for massive in vitro propagation of Pfaffia plants due to high extractivism and overharvesting of this species. Research on the species has shown that photoautotrophic cultivation can improve the production of 20E. In addition, other abiotic factors such as the formulations of culture media can influence the morphophysiological behavior of the plants in vitro. Therefore, the objective of this study was to analyze the morphological and physiological performances of P. glomerata plants in different formulations of culture media, under photoautotrophic and photomixotrophic propagation conditions. Six medium formulations, the Driver and Kuniyuki medium (DKW), Correia et al. medium (JADS), Murashige and Skoog medium (MS), Quoirin and Lepoivre medium (QL), Rugini medium (OM), and Woody Plant medium (WPM), all supplemented with DKW vitamins, 100 mg L−1 myo-inositol, 6.5 g L−1 agar, and with or without 3% (w/v) sucrose, were evaluated. Cultures were maintained at 25 ± 2°C, with a 16 h-photoperiod under 60 μmol m−2 s−1 of irradiance under a fluorescent lamp for 50 d. Results showed that the presence or absence of sucrose, and the different nutritional formulations influenced growth, photosynthetic pigment content, endogenous levels of sugars, leaf morphology, levels of 20E, and transport of water and minerals in P. glomerata. Notably, OM, DKW, QL, and WPM media promoted higher production of 20E under photomixotrophic growth conditions.

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20.
Direct utilization of untreated oil palm trunk (OPT) for cellulases and xylanase production by Aspergillus fumigatus SK1 was conducted under solid-state fermentation (SSF). The highest activities of extracellular cellulases and xylanases were produced at 80% moisture level, initial pH 5.0, 1 × 108 spore/g (inoculum) with 125 μm of OPT as sole carbon source. The cellulases and xylanase activities obtained were 54.27, 3.36, 4.54 and 418.70 U/g substrates for endoglucanase (CMCase), exoglucanase (FPase), β-glucosidase and xylanase respectively. The crude cellulases and xylanase required acidic condition to retain their optimum activities (pH 4.0). Crude cellulases and xylanase were more stable at 40 °C compared to their optimum activities conditions (60 °C for FPase and 70 °C for CMCase, β-glucosidase and xylanase). SDS-PAGE and zymogram analysis showed that Aspergillus fumigatus SK1 could secrete cellulases (endoglucanase, exoglucanase and β-glucosidase), xylanase and protease. Enzymatic degradation of alkaline treated OPT with concentrated crude cellulases and xylanases resulted in producing polyoses.  相似文献   

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