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1.
Summary A ubiquitous white rot fungus Schizophyllum commune was used for the first time to study the degradation of ferulic acid. Vanillic acid was observed as one of the major products of ferulic acid catabolism, with vanillin formed as an intermediate. Almost 99.9% ferulic acid with a initial concentration of 5 mM was consumed by this fungus after 16 days of incubation at 37 °C.  相似文献   

2.
The effects of cultivation medium compositions including soybean meal, peptone, soybean oil and cornstarch for actinomycin X2 production by Streptomyces spp JAU4234 were accessed by using response surface methodology. The 2(4) full factorial designs and the paths of steepest ascent were effective in searching for the major factors of actinomycin X2 production. In this study, cornstarch and soybean oil showed negative effect on actinomycin X2 production based on the first-order regression coefficients derived from MINITAB software. Subsequently, a central composite design for optimization was further investigated. Preliminary studies showed that soybean meal and peptone were believed to be the major factors for actinomycin X2 production. Estimated optimum compositions for the production of actionmycin X2 were as follows (g/l): soybean meal 21.65 and peptone 9.41, and result in a maximum actionmycin X2 production of 617.4 mg/l. This value was closed to the 612 mg/l actionmycin X2 production from actual experimental observations. The yield of actionmycin X2 was increased by 36.9% by culturing the strain Streptomyces spp JAU4234 in the nutritionally optimized fermentation medium.  相似文献   

3.
Glucuronoyl esterase is a novel carbohydrate esterase recently discovered in the cellulolytic system of the wood-rotting fungus Schizophyllum commune on the basis of its ability to hydrolyze methyl ester of 4-O-methyl-d-glucuronic acid. This substrate was not fully corresponding to the anticipated function of the enzyme to hydrolyze esters between xylan-bound 4-O-methyl-d-glucuronic acid and lignin alcohols occurring in plant cell walls. In this work we showed that the enzyme was capable of hydrolyzing two synthetic compounds that mimic the ester linkages described in lignin-carbohydrate complexes, esters of 4-O-methyl-d-glucuronic and d-glucuronic acid with 3-(4-methoxyphenyl)propyl alcohol. A comparison of kinetics of hydrolysis of methyl and 3-(4-methoxyphenyl)propyl esters indicated that the glucuronoyl esterase recognizes the uronic acid part of the substrates better than the alcohol type. The catalytic efficiency of the enzyme was much higher with the ester of 4-O-methyl-d-glucuronic acid than with that of d-glucuronic acid. Examination of the action of glucuronoyl esterase on a series of methyl esters of 4-O-methyl-d-glucopyranuronosyl residues α-1,2-linked to xylose and several xylooligosaccharides suggested that the rate of deesterification is independent of the character of the carbohydrate part glycosylated by the 4-O-methyl-d-glucuronic acid.  相似文献   

4.

Background

In this study, we optimized the process for enhancing amylase production from Pseudomonas balearica VITPS19 isolated from agricultural lands in Kolathur, India.

Methods

Process optimization for enhancing amylase production from the isolate was carried out by Response Surface Methodology (RSM) with optimized chemical and physical sources using Design expert v.7.0. A central composite design was used to evaluate the interaction between parameters. Interaction between four factors–maltose (C-source), malt extract (Nsource), pH, and CaCl2 was studied.

Results

The factors pH and CaCl2 concentration were found to affect amylase production. Validation of the experiment showed a nearly twofold increase in alpha amylase production.

Conclusion

Amylase production was thus optimized and increased yield was achieved.
  相似文献   

5.
Lactic acid is considered a commodity and its production is boosted by the synthesis of polylactic acid. d-lactic acid (DLA) isomer offers greater flexibility and biodegradability and it can only be obtained in its pure form through fermentation. The lactate dehydrogenase is stereospecific for homofermentative production of DLA isomer in the metabolic pathway of Lactobacillus coryniformis subsp. torquens, with optical purity of ≥?99.9% under oxygen-deprived condition. A simple culture medium that increases DLA production and reduces fermentation costs is fundamental for industrial applicability. A central composite rotatable design was used to evaluate significant components influencing the DLA production. Concentrations were adjusted using the Design-Expert 7.0 optimization tool with a desirability coefficient of 0.693 and the best concentrations of each component were determined. Finally, an assay in the bioreactor with the modified culture medium resulted in a product yield of 0.95 g/g, volumetric productivity of 0.85 g/L.h and 95% of efficiency.  相似文献   

6.
Optimization of the medium components which enhance sporulation of the two mating types of the fungus Blakeslea trispora ATCC 14271 and ATCC 14272 (a heterothallic Zygomycota producing carotene) was achieved with the aid of response surface methodology (RSM). Glucose, corn steep liquor, yeast extract, and ammonium sulfate were investigated as carbon and nitrogen sources in a basal medium. RSM was adopted to optimize the medium in order to obtain a good growth of the fungus as a prerequisite for enhanced sporulation. In the second step, the basal medium was supplemented with different trace elements which significantly affect sporulation (i.e. CuSO4·5H2O, FeCl3·6H2O, Co(NO3)2·6H2O, and MnCl2·4H2O). Central composite design proved to be valuable in optimizing a chemically defined solid medium for spore production of B. trispora. The composition of the new solid medium to enhance spore production by B. trispora (ATCC 14271) is as follows (per liter): 7.5 g glucose, 3.2 g corn steep liquor, 1.7 g yeast extract, 4.1 g ammonium sulfate, 6 mg CuSO4·5H2O, 276 mg FeCl3·6H2O, 2 mg Co(NO3)2·6H2O, and 20 g agar (pH 6.0). Practical validation of this optimum medium gave spore number of 1.2 × 108 spores/dish which is 77% higher than that produced in Potato Dextrose Agar (PDA). In the case of B. trispora (ATCC 14272) the new solid substrate for enhanced sporulation consists of (per l) 6.4 g glucose, 3.3 g corn steep liquor, 1.4 g yeast extract, 4.3 g ammonium sulfate, 264 mg CuSO4·5H2O, 485 mg FeCl3·6H2O, 223 mg MnCl2.4H2O, and 20 g agar (pH 6.0). Spore numbers of 2 × 107 spores/dish were obtained on the new medium by B. trispora (ATCC 14272), which is 95% higher than that produced on PDA. The results corroborated the validity and the effectiveness of the models. The new media considerably improved sporulation of both strains of B. trispora compared to the production of spores on PDA, which is the medium usually used for sporulation of the fungus.  相似文献   

7.
In this study, diluted and fortified carrot juice was used for modelling and optimization of citric acid production by a new mutant strain, Yarrowia lipolytica K-168. Protein concentrate obtained from fine flour -a byproduct of semolina production- was used as a nitrogen source in the fermentation medium. Interactive effects of selected independent variables, initial total sugar concentration, initial pH, initial concentration of protein concentrate obtained from fine flour of semolina and temperature, on the growth and citric acid production of the yeast were investigated. An experimental design including 30 experiments was conducted by using the method of central composite design. Modelling the effects of these independent variables on maximum citric acid concentration, maximum citric acid production rate, citric acid yield, the ratio of maximum citric acid concentration to maximum isocitric acid concentration and specific growth rate were performed by response surface methodology. The variations of all of the responses with the independent variables were defined by a quadratic model. Numeric optimization was performed by using the desireability function. The conditions with 190.83 g/L initial sugar concentration, 5.90 initial pH, 0.07 g/L initial concentration of fine flour protein concentrate and 27.86 °C were determined as optimal conditions for citric acid production. The maximum citric acid concentration reached to 80.53 g/L in optimal conditions.  相似文献   

8.
In this research, ethanol production from carob pod extract (extract) using Zymomonas mobilis with medium optimized by Plackett–Burman (P–B) and response surface methodologies (RSM) was studied. Z. mobilis was recognized as useful for ethanol production from carob pod extract. The effects of initial concentrations of sugar, peptone, and yeast extract as well as agitation rate (rpm), pH, and culture time in nonhydrolyzed carob pod extract were investigated. Significantly affecting variables (P = 0.05) in the model obtained from RSM studies were: weights of bacterial inoculum, initial sugar, peptone, and yeast extract. Acid hydrolysis was useful to complete conversion of sugars to glucose and fructose. Nonhydrolyzed extract showed higher ethanol yield and residual sugar compared with hydrolyzed extract. Ethanol produced (g g−1 initial sugar, as the response) was not significantly different (P = 0.05) when Z. mobilis performance was compared in hydrolyzed and nonhydrolyzed extract. The maximum ethanol of 0.34 ± 0.02 g g−1 initial sugar was obtained at 30°C, initial pH 5.2, and 80 rpm, using concentrations (g per 50 mL culture media) of: inoculum bacterial dry weight, 0.017; initial sugar, 5.78; peptone, 0.43; yeast extract, 0.43; and culture time of 36 h.  相似文献   

9.
Summary Spore production of Coniothyrium minitans was optimized by using response surface methodology (RSM), which is a powerful mathematical approach widely applied in the optimization of fermentation process. In the first step of optimization, with Plackett–Burman design, soluble starch, urea and KH2PO4 were found to be the important factors affecting C. minitans spore production significantly. In the second step, a 23 full factorial central composite design and RSM were applied to determine the optimal concentration of each significant variable. A second-order polynomial was determined by the multiple regression analysis of the experimental data. The optimum values for the critical components for the maximum were obtained as follows: soluble starch 0.643 (36.43 g. l−1), urea −0.544 (3.91 g l−1) and KH2PO4 0.049 (1.02 g l−1) with a predicted value of maximum spore production of 9.94 × 109 spores/g IDM. Under the optimal conditions, the practical spore production was 1.04 × 1010 spores/g IDM. The determination coefficient (R2) was 0.923, which ensure an adequate credibility of the model.  相似文献   

10.
Response surface methodology employing central composite design (CCD) was used to optimize fermentation medium for the production of cellulase-free, alkaline xylanase from Streptomyces violaceoruber under submerged fermentation. The design was employed by selecting wheat bran, peptone, beef extract, incubation time and agitation as model factors. A second-order quadratic model and response surface method showed that the optimum conditions for xylanase production (wheat bran 3.5 % (w/v), peptone 0.8 % (w/v), beef extract 0.8 % (w/v), incubation time 36 h and agitation 250 rpm) results in 3.0-fold improvement in alkaline xylanase production (1500.0 IUml−1) as compared to initial level (500.0 IUml−1) after 36 h of fermentation, whereas its value predicted by the quadratic model was 1347 IUml−1. Analysis of variance (ANOVA) showed a high coefficient of determination (R2) value of 0.9718, ensuring a satisfactory adjustment of the quadratic model with the experimental data. The economical and cellulase-free nature of xylanase would enhance its applicability in pulp and paper industry.  相似文献   

11.
Response surface methodology (RSM) was applied to optimize the critical medium ingredients of Agaricus blazei. A three-level Box–Behnken factorial design was employed to determine the maximum biomass and extracellular polysaccharide (EPS) yields at optimum levels for glucose, yeast extract (YE), and peptone. A mathematical model was then developed to show the effect of each medium composition and its interactions on the production of mycelial biomass and EPS. The model predicted the maximum biomass yield of 10.86 g/l that appeared at glucose, YE, peptone of 26.3, 6.84, and 6.62 g/l, respectively, while a maximum EPS yield of 348.4 mg/l appeared at glucose, YE, peptone of 28.4, 4.96, 5.60 g/l, respectively. These predicted values were also verified by validation experiments. The excellent correlation between predicted and measured values of each model justifies the validity of both the response models. The results of bioreactor fermentation also show that the optimized culture medium enhanced both biomass (13.91 ± 0.71 g/l) and EPS (363 ± 4.1 mg/l) production by Agaricus blazei in a large-scale fermentation process.  相似文献   

12.
Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes.  相似文献   

13.
To produce 1,3-propanediol (1,3-PD) from crude glycerol, cultivation conditions were optimized by response surface methodology (RSM) based on a 25 factorial central composite design (CCD). RSM was adopted to derive a statistical model for the individual and interactive effects of crude glycerol, (NH4)2SO4, pH, cultivation time and temperature on the production of 1,3-PD. Optimal conditions for maximum 1,3-PD production were as follows: crude glycerol, 35 g/L; (NH4)2SO4, 8 g/L; pH, 7.37; cultivation time, 10.8 h; temperature, 36.88°C. Under these optimal conditions, the design expert presented the maximal numerical solution with a predicted 1,3-PD production level of up to 13.74 g/L. The experimental production of 1,3-PD yielded 13.8 g/L, which was in close agreement with the model prediction.  相似文献   

14.
Statistical methodologies were employed to optimize submerged culture medium for the production of a novel antineoplastic compound aspergiolide A by a marine-derived fungus Aspergillus glaucus HB1-19 for the first time. Orthogonal design was preformed to determine the initial composition. Then Plackett–Burman design was applied to evaluate the influence of related nutrients, and yeast extract paste, soybean powder and sodium glutamate were confirmed as critical factors in the medium. Response surface methodology (RSM) was finally taken as an effective approach to optimize the combination of the obtained three significant factors. The predicted maximal aspergiolide A production of 62.4 mg/L appeared at the region where the concentrations of sodium glutamate, soybean powder, and yeast extract paste were 2, 1, and 1.07 g/L, respectively. Under the proposed optimized conditions, the experimental aspergiolide A production reached 71.2 mg/L. The correlation between predicted value and measured value of these experiments proved the validity of the response model. After optimization, aspergiolide A production increased 4.22 times compared to that of the original medium. Elemental analysis was finally taken into consideration, and carbon–nitrogen ratio in the medium increased from 20.1:1 to 86.6:1. This great difference was inferred as the most important reason for production enhancement by metabolic pathway analysis.  相似文献   

15.
Resveratrol is a polyphenolic compound produced in very low levels in grapes. To achieve high yield of resveratrol in wild grape, three Agrobacterium rhizogenes strains, Ar318, ArA4 and LBA9402, were used to induce hairy roots following infection of internodes, nodes or petioles of in vitro grown Vitis vinifera subsp. sylvesteris accessions W2 and W16, and cultivar Rasha. The effects of inoculation time, age of explants, bacterial concentration and co-cultivation times were examined on the efficiency of the production of hairy roots. Strains Ar318, ArA4 and LBA9402 all induced hairy roots in the tested genotypes, but the efficiency of ArA4 strain was higher than the other strains. The highest hairy root production was with using internodes as explants. The transformation of hairy roots lines was confirmed by PCR detection of rolB gene. Half Murashige and Skoog (MS) medium was better for biomass production compared with MS medium. HPLC analysis of resveratrol production in the hairy root cultures showed that all the genotypes produced higher amounts of resveratrol than control roots. The highest amount of resveratrol was produced from W16 internode cultures, which was 31-fold higher than that of control root. Furthermore, TLC analysis showed that treatments of hairy roots with sodium acetate and jasmonate elevated resveratrol levels both in hairy root tissue and excreted into the half MS medium. These results demonstrate that endogenous and exogenous factors can affect resveratrol production in hairy root culture of grape, and this strategy could be used to increase low resveratrol production in grapes.  相似文献   

16.
A newly isolated Zygosaccharomyces rouxii NRRL 27,624 produced d-arabitol as the main metabolic product from glucose. In addition, it also produced ethanol and glycerol. The optimal conditions were temperature 30°C, pH 5.0, 350 rpm, and 5% inoculum. The yeast produced 83.4 ± 1.1 g d-arabitol from 175 ± 1.1 g glucose per liter at pH 5.0, 30°C, and 350 rpm in 240 h with a yield of 0.48 g/g glucose. It also produced d-arabitol from fructose, galactose, and mannose. The yeast produced d-arabitol and xylitol from xylose and also from a mixture of xylose and xylulose. Resting yeast cells produced 63.6 ± 1.9 g d-arabitol from 175 ± 1.8 g glucose per liter in 210 h at pH 5.0, 30°C and 350 rpm with a yield of 0.36 g/g glucose. The yeast has potential to be used for production of xylitol from glucose via d-arabitol route. Mention of trade names or commercial products in this article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. department of Agriculture.  相似文献   

17.
Effects of illumination spectrum on the morphogenesis of chrysanthemum plantlets (Chrysanthemum morifolium Ramat. ‘Ellen’) grown in vitro were studied using an illumination system consisting of four groups of light-emitting diodes (LEDs) in the following spectral regions: blue (450nm), red (640nm), red (660nm), and far-red (735nm). Taking into account all differences in shoot height, root length, and fresh and dry weight (FW and DW, respectively), observed while changing the total photon flux density (PFD), the optimal total PFD for growth of chrysanthemum plantlets in vitro was estimated. For 16 h photoperiod and typical fractions of the spectral components (14%, 50%, 28%, and 8%, respectively), the optimal total PFD was found to be 40 μmol m−2 s−1. Our study shows that the blue component in the illumination spectrum inhibits the plantlet extension and formation of roots and simultaneously increases the DW to FW ratio and content of photosynthetic pigments. We demonstrate photomorphogenetic effects in the blue region and its interaction with the fractional PFD of the far-red spectral component. Under constant fractional PFD of the blue component, the root number, length of roots and stems, and fresh weight of the plantlets have a correlated nonmonotonous dependence on the fractional PFD of the far-red component.  相似文献   

18.
A mixed trophic state production process for algal lipids for use as feedstock for renewable biofuel production was developed and deployed at subpilot scale using a green microalga, Auxenochlorella (Chlorella) protothecoides. The process is composed of two separate stages: (1) the photoautotrophic stage, focused on biomass production in open ponds, and (2) the heterotrophic stage focused on lipid production and accumulation in aerobic bioreactors using fixed carbon substrates (e.g., sugar). The process achieved biomass and lipid productivities of 0.5 and 0.27 g/L/h that were, respectively, over 250 and 670 times higher than those obtained from the photoautotrophic cultivation stage. The biomass oil content (over 60 % w/DCW) following the two-stage process was predominantly monounsaturated fatty acids (~82 %) and largely free of contaminating pigments that is more suitable for biodiesel production than photosynthetically generated lipid. Similar process performances were obtained using cassava hydrolysate as an alternative feedstock to glucose.  相似文献   

19.
A genetic transformation system has been developed for callus cells of Crataegus aronia using Agrobacterium tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with 5 mg l−1 Indole-3-butyric acid (IBA) and 0.5 mg l−1 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red colored callus was obtained on MS medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l−1 hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this is the first time to report an Agrobacterium-mediated transformation system in Crataegus aronia.  相似文献   

20.
Seol E  Jung Y  Lee J  Cho C  Kim T  Rhee Y  Lee S 《Plant cell reports》2008,27(7):1197-1206
Notocactus scopa cv. Soonjung was subjected to in planta Agrobacterium tumefaciens-mediated transformation with vacuum infiltration, pin-pricking, and a combination of the two methods. The pin-pricking combined with vacuum infiltration (20-30 cmHg for 15 min) resulted in a transformation efficiency of 67-100%, and the expression of the uidA and nptII genes was detected in transformed cactus. The established in planta transformation technique generated a transgenic cactus with higher transformation efficiency, shortened selection process, and stable gene expression via asexual reproduction. All of the results showed that the in planta transformation method utilized in the current study provided an efficient and time-saving procedure for the delivery of genes into the cactus genome, and that this technique can be applied to other asexually reproducing succulent plant species.  相似文献   

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