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1.
To investigate the effects of selenium and light wavelengths on the growth of liquid-cultured Cordyceps militaris and the main active components’ accumulation, culture conditions as selenium selenite concentrations and light of different wavelengths were studied. The results are: adenosine accumulation proved to be significantly selenium dependent (R 2 = 0.9403) and cordycepin contents were determined to be not significantly selenium dependent (R 2 = 0.3845) but significantly enhanced by selenium except for 20 ppm; there were significant differences in cordycepin contents, adenosine contents, and mycelium growth caused by light wavelengths: cordycepin, blue light > pink light > daylight, darkness, red light; adenosine, red light > pink light, darkness, daylight, blue light; and mycelium growth, red light > pink light, darkness, daylight > blue light. In conclusion, light wavelength had a significant influence on production of mycelia, adenosine, and cordycepin, so lightening wavelength should be changed according to target products in the liquid culture of C. militaris.  相似文献   

2.
The medicinal fungus Ganoderma lucidum was inoculated into the media with and without supplementation of medicinal insect extracts to screen stimulators from Chinese medicinal insects for mycelial growth and triterpenoids production in submerged fermentation. The methanol and ether extracts of the tested insects had no significant stimulatory effect on the mycelial biomass production (P > 0.05), and those of H. remigator and Mylabris phalerata markedly inhibited the mycelial growth. However, the ether extract of Catharsius molossus at a concentration of 200 mg l−1 led to a significant increase in triterpenoids concentration from 231.7 ± 9.77 to 313.7 ± 10.6 mg l−1 (P < 0.01). Analysis of fermentation kinetics of G. lucidum suggests that glucose concentration in the extract of C. molossus-added group decreased more quickly as compared to the control group from day 2 to day 7 of fermentation process, while the triterpenoids biosynthesis was promoted at the same culture period. However, the culture pH profile was not affected by the addition of the extract. Chemical study of the extract show that cis-9,10-methylenehexadecanoic acid (9,10-MEA) and hexadecanoic acid (especially 9,10-MEA) were the key active compounds of the extract responsible for the stimulatory effect on the triterpenoids production.  相似文献   

3.
《Analytical letters》2012,45(6):1031-1042
The major compound in Cordyceps militaris (C. militaris), cordycepin, has been known to have a variety of pharmacological properties. The cordycepin concentration in artificially cultivated fruiting bodies of C. militaris was determined using quantitative 1H nuclear magnetic resonance spectroscopy (NMR). The results were compared with a high performance liquid chromatography (HPLC) method. There were no statistically significant differences in the cordycepin concentration by the two methods. Validation of each method was performed in terms of linearity, limit of detection, limit of quantification, intra- and inter-day precision, repeatability, stability, and accuracy. Better inter-day precision, repeatability, stability, and accuracy were obtained by NMR than by HPLC. These results show that NMR is an alternative to HPLC for the determination of cordycepin in C. militaris fruiting bodies.  相似文献   

4.
Cordyceps militaris produces cordycepin (3′-deoxyadenosine), which has various activities, including anti-oxidant, anti-tumoral, anti-viral, and anti-inflammatory. Ribonucleotide reductase (RNR) seems to be a candidate to produce cordycepin in C. militaris because RNR catalyzes the reduction of nucleotides to 2′-deoxynucleotides, whose structures are similar to that of cordycepin. However, the role of RNR has not been confirmed yet. In this study, complementary DNAs (cDNAs) of C. militaris RNR (CmRNR) large and small subunits (CmR1 and CmR2) were cloned from C. militaris NBRC9787 to investigate the function of CmRNR for its cordycepin production. C. militaris NBRC9787 began to produce cordycepin when grown in a liquid surface culture in medium composed of glucose and yeast extract for 15 days. CmR1 cDNA and CmR2 cDNA were obtained from its genomic DNA and from total RNA extracted from its mycelia after cultivation for 21 days, respectively. Recombinant CmR1 and CmR2 were expressed individually in Escherichia coli and purified. Purified recombinant CmR1 and CmR2 showed RNR activity toward adenosine diphosphate (ADP) only when two subunits were mixed but only show the reduction of ADP to 2′-deoxyADP. These results indicate that the pathway from ADP to 3′deoxyADP via CmRNR does not exist in C. militaris and cordycepin production in C. militaris may be mediated by other enzymes.  相似文献   

5.
Current research indicates the ethanol fuel production from lignocellulosic materials, such as residual wood chips from the cellulose industry, as new emerging technology. This work aimed at evaluating the ethanol production from hemicellulose of eucalyptus chips by diluted acid pretreatment and the subsequent fermentation of the generated hydrolysate by a flocculating strain of Pichia stipitis. The remaining solid fraction generated after pretreatment was subjected to enzymatic hydrolysis, which was carried out simultaneously with glucose fermentation [saccharification and fermentation (SSF) process] using a strain of Saccharomyces cerevisiae. The acid pretreatment was evaluated using a central composite design for sulfuric acid concentration (1.0–4.0 v/v) and solid to liquid ratio (1:2–1:4, grams to milliliter) as independent variables. A maximum xylose concentration of 50 g/L was obtained in the hemicellulosic hydrolysate. The fermentation of hemicellulosic hydrolysate and the SSF process were performed in bioreactors and the final ethanol concentrations of 15.3 g/L and 28.7 g/L were obtained, respectively.  相似文献   

6.
This paper is concerned with the optimization of effect factors for mycelial growth and exopolysaccharide production by Schizophyllum commune by one-factor-at-a-time and orthogonal methods. The one-factor-at-a-time method was adopted to investigate the effects of six different compounds (sodium carboxymethylcellulose, l-glutamic acid, VB1, naphthalene acetic acid, oleic acid, and Tween 80) on mycelial growth and exopolysaccharide production. Among these factors, oleic acid, VB1 and Tween 80 were identified to be the most important factors. Subsequently, the concentration of oleic acid, VB1 and Tween 80 were optimized using the orthogonal matrix method. The effects of the factors on the mycelial growth of S. commune were in the order of oleic acid > VB1 > Tween 80, and those on exopolysaccharide production were in the same order. The optimal concentration for mycelia and exopolysaccharide were determined as oleic acid 0.1% (v/v), VB1 0.5 mg/L, and Tween 80 6 mg/L. The subsequent verification experiments confirmed the validity of the models. Under this optimized conditions in shake flask culture, the mycelial yield and exo-biopolymer production were 25.93 and 2.79 g/L, respectively, which were considerably higher than those obtained in the preliminary studies. The result was further confirmed in a 7-L fermentor experiments.  相似文献   

7.
The optimization of process parameters for high amylase production by Saccharomycopsis fibuligera A11 in solid-state fermentation was carried out using central composite design. Finally, the optimal parameters obtained with the response surface methodology (RSM) were moisture 610.0 ml/kg, inoculum 30.0 ml (OD600 nm = 20.0)/kg, the amount ratio of wheat bran to rice husk 0.42, cassava starch concentration 20.0 g/kg, temperature 28 °C, and natural pH. Under the optimized conditions, 4,296 U/g of dry substrate of amylase activity was reached in the solid-state fermentation culture of the yeast strain A11 within 160 h, whereas the predicted maximum amylase activity of 4,222 U/g of dry substrate of amylase activity was derived from the RSM regression. It was found that cassava starch can be actively converted into monosaccharides and oligosaccharides by the crude amylase.  相似文献   

8.
An extracellular lipase was purified from the fermentation broth of Penicillium expansum PED-03 by DEAE-Sepharose chromatography, followed by sephacryl S-200 chromatography. The enzyme was purified 81.8-fold with 19.8% recovery and a specific activity of 85.94 U/mg. The molecular weight of the homogeneous enzyme was about 28 kDa, determined by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. The enzymatic resolution of racemic ibuprofen was carried out by the lipase from P. expansum PED-03, and the conversion reached 46% with excellent enantioselectivity(E > 200 ), which showed a good application potential in the production of optically pure ibuprofen.  相似文献   

9.
Laccase activity was detected in a soil bacterium Stenotrophomonas maltophilia AAP56 identified by biochemical and molecular methods. It was produced in cells at the stationary growth phase in Luria Bertani (LB) medium added by 0.4 mM copper sulfate. The addition of CuSO4 in culture medium improved production of laccase activity. However, one laccase enzyme was detected by native polyacrylamide gel electrophoresis. The enzyme showed syringaldazine (K m = 53 μM), 2,2’-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (K m = 700 μM), and pyrocatechol (K m = 25 μM) oxidase activity and was activated by addition of 0.1% (v/v) Triton-X-100 in the reaction mixture. Moreover, the laccase activity was increased 2.6-fold by the addition of 10 mM copper sulfate; the enzyme was totally inhibited by ethylenediaminetetraacetic acid (5 mM), suggesting that this laccase is a metal-dependant one. Decolorization activity of some synthetic dyes (methylene blue, methyl green, toluidine blue, Congo red, methyl orange, and pink) and the industrial effluent (SITEX Black) was achieved by the bacteria S. maltophilia AAP56 in the LB growth medium under shaking conditions.  相似文献   

10.
Trimming vine shoot samples were treated with water under selected operational conditions (autohydrolysis reaction) to obtain a liquid phase containing hemicellulose-decomposition products. In a further acid-catalyzed step (posthydrolysis reaction), xylooligosaccharides were converted into single sugars for the biotechnological production of lactic acid using Lactobacillus pentosus. A wide range of temperatures, reaction times, and acid concentrations were tested during the autohydrolysis–posthydrolysis process to investigate their influence on hemicellulose solubilization and reaction products. The maximum concentration of hemicellulosic sugars was achieved using autohydrolysis at 210 °C followed by posthydrolysis with 1% H2SO4 during 2 h. Data from autohydrolysis–posthydrolysis were compared with the results obtained at the optima conditions assayed for prehydrolysis (3% H2SO4 at 130 °C during 15 min) based on previous works. Prehydrolysis extracted more hemicellulosic sugars from trimming vine shoots; however, the protein content in the hydrolysates from autohydrolysis–posthydrolysis was higher. The harsher conditions assayed during the autohydrolysis process and the higher content of protein after this treatment could induce Maillard reactions decreasing consequently the concentration of hemicellulosic sugars in the hydrolysates. Therefore, despite the several advantages of autohydrolysis (less equipment caused by the absence of mineral acid, less generation of neutralized sludges, and low cost of reagents) the poor results obtained in this work with no detoxified hydrolysates (Q P = 0.36 g/L h, Q S = 0.79 g/L h, Y P/S = 0.45 g/g, Y P/Sth = 61.5 %) or charcoal-treated hydrolysates (Q P = 0.76 g/L h, Q S = 1.47 g/L h, Y P/S = 0.52 g/g, Y P/Sth = 71.5 %) suggest that prehydrolysis of trimming vine shoots with diluted H2SO4 is more attractive than autohydrolysis-posthydrolysis for obtaining lactic acid through fermentation of hemicellulosic sugars with L. pentosus. Besides the higher hemicellulosic sugars concentration achieved when using the prehydrolysis technology, no detoxification steps are required to produce efficiently lactic acid (Q P = 1.14 g/L h; Q S = 1.64 g/L h; Y P/S = 0.70 g/g; Y P/Sth = 92.6 %), even when vinification lees are used as nutrients (Q P = 0.89 g/L h; Q S = 1.54 g/L h; Y P/S = 0.58 g/g; Y P/Sth = 76.1 %).  相似文献   

11.
A feeding technology that was suitable for improving the nisin production by Lactococcus lactis subsp. lactis W28 was established. The effects of initial sucrose concentration (ISC) in the fermentation broth, feeding time, and feeding rate on the fermentation were studied. It was observed that a fed-batch culture (ISC = 10 g l−1) with 100 ml sucrose solution (190 g l−1) being evenly fed (9–10 ml h−1) into the fermenter after 3-h fermentation gave the best performance in terms of biomass and nisin yield. Under these conditions, the total biomass and the total nisin yield were approximately 23% and 51% higher than those in batch fermentation, respectively. When the sucrose concentration was controlled at 5–10 g l−1 in variable volume intermittent fed-batch fermentation (VVIF) with ISC = 10 g l−1, the total biomass and the total nisin yield were 29% and 60% above those in batch fermentation, respectively. The VVIF proved to be effective to eliminate the substrate inhibition by maintaining sucrose at appropriate levels. It is also easy to be scaled up, since various parameters involved in industrial production were taken into account.  相似文献   

12.
A sensitive semi-micro column HPLC method with peroxyoxalate chemiluminescence (POCL) detection and column switching has been developed for simultaneous determination of 3,4-methylenedioxymethamphetamine (MDMA) and related compounds, for example 3,4-methylenedioxyamphetamine, methamphetamine, and amphetamine, in hair. After digestion of the hair with 1 mol L−1 sodium hydroxide the compounds were extracted with n-heptane and derivatized with 4-(N,N-dimethylaminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole. A mixture of hydrogen peroxide and bis(2,4,5-trichloro-6-carbopentoxyphenyl)oxalate in acetonitrile was used as post-column CL reagent. Calibration plots showed linearity was good (r = 0.999); detection limits were 0.02–0.16 ng mg−1 hair at a signal-to-noise ratio of 3. The precision of the method, as RSD (n = 5), in intra-day and inter-day assays was better than 5.0 and 6.9%, respectively. The proposed method was sufficiently sensitive to detect low ng mg−1 levels of MDMA and related compounds in hair, and could be used for quantification of the compounds in hair samples from patients treated in a chemical dependency unit.  相似文献   

13.
Ten Aspergillus oryzae strains were screened in solid substrate fermentation for α-amylase production on spent brewing grain (SBG) and on corn fiber. SBG proved to be a better substrate for enzyme production than corn fiber. A Plackett-Burman experimental design was used to optimize the medium composition for the best strain. Solid substrate fermentation on optimized medium with A. oryzae NRRL 1808 (=ATCC 12892) strain in stationary 500-mL Erlenmeyer flask culture yielded 4519 U of α-amylase/g of dry matter substrate in 3 d. The whole solid substrate fermentation material (crude enzyme, in situ enzyme) may be considered a cheap biocatalytic material for animal feed rations and for bioalcohol production from starchy materials.  相似文献   

14.
To analyze the relationship between biomass of microorganisms and methane production, the total biomass of bacteria and archaea (BA) during methane fermentation was analyzed by the environmental DNA analysis method. In the case of using methanogenic sludge as a seed which is generally used for methane fermentation, the total BA biomass reached to 1.5 × 108 to 3.6 × 108 cells/ml when methane was produced. On the other hand, soil suspension was used as a seed; methane was not produced for 14-day cultivation. However, the total BA biomass reached to above 1.5 × 108 cells/ml. The methanogen biomass was counted by using a fluorescence microscope (coenzyme F420), and the methanogen biomass and the ratio of methanogens in the total of BA were analyzed during methane fermentation. At the methane-producing phase, the methanogen biomass reached to 1.3 × 108 cells/ml, and the ratio of methanogens was above 70% of the total BA. When the ratio of methanogens in a seed was changed, the methane-producing phase was moved. However, the relationship between methanogens and other microorganisms at the methane-producing phase was almost similar.  相似文献   

15.
Superporous monolithic hydrogels (cryogel monoliths) are elastic, sponge-like materials that can be prepared in an aqueous medium through a cryotropic gelation technique. These monoliths show interesting properties for the development of high-throughput solid-phase extraction supports to treat large volumes of aqueous samples. In this work, a cryogel-supported molecularly imprinted solid-phase extraction approach for the endocrine disruptor bisphenol A (BPA) from river water and wine samples is presented. An imprinted polymer with molecular recognition properties for BPA was prepared in acetonitrile by thermal polymerization of a mixture of 4,4′-dihydroxy-2,2-diphenyl-1,1,1,3,3,3-trifluoropropane as a mimic template of BPA, 4-vinylpyridine and trimethylolpropane trimethacrylate in a molar ratio of 1 + 6 + 6. Fine imprinted particles (<10 μm) were embedded in a poly-acrylamide-co-N,N′-methylenbisacrylamide cryogel obtained by ammonium persulfate-induced cryopolymerization at −18 °C. The resulting monolithic gel was evaluated for its use as a sorbent support in an off-line solid-phase extraction approach to recover BPA from dilute aqueous samples with minimum pre-loading work-up. The optimized extraction protocol resulted in a reliable MISPE method suitable to selectively extract and preconcentrate BPA from river water and red wine samples, demonstrating the practical feasibility of cryogel-trapped imprinted polymers as solid-phase extraction materials  相似文献   

16.
The production of cellulolytic enzymes by the fungus Aspergillus phoenicis was investigated. Grape waste from the winemaking industry was chosen as the growth substrate among several agro-industrial byproducts. A 2 × 2 central composite design was performed, utilizing the amount of grape waste and peptone as independent variables. The fungus was cultivated in submerged fermentation at 30 °C and 120 rpm for 120 h, and the activities of total cellulases, endoglucanases, and β-glucosidases were measured. Total cellulases were positively influenced by the linear increase of peptone concentration and decrease at axial concentrations of grape waste and peptone. Maximum activity of endoglucanase was observed by a linear increase of both grape waste and peptone concentrations. Concentrations of grape waste between 5 and 15 g/L had a positive effect on the production of β-glucosidase; peptone had no significant effects. The optimum production of the three cellulolytic activities was observed at values near the central point. A. phoenicis has the potential for the production of cellulases utilizing grape waste as the growth substrate.  相似文献   

17.
In solid-state fermentation, among various solid supports evaluated, banana peel was found to be an ideal support and resulted into higher levels of laccase (6281.4 ± 63.60 U l−1) along with notable levels of manganese peroxidase production (1339.0 ± 131.23 U l−1) by Aspergillus fumigatus VkJ2.4.5. Maximum levels of laccase was achieved under derived conditions consisting of 80% of moisture level, 6 days of incubation period, 6% inoculum level, and an aeration level of 2.5 l min−1. A column-tray bioreactor was designed to scale up and economize the enzyme production in three successive cycles of fermentation using the same fungal biomass. Thermal and pH stability profiles revealed that enzyme was stable up to 50°C and at varying pH range from 5–9 for up to 2 h. The apparent molecular weight of laccase was found to be 34 ± 1 kDa. MALDI-TOF/TOF analysis of the protein showed significant homology with maximum identity of 67% to other laccases reported in database.  相似文献   

18.
Development of inexpensive and simple culture media and appropriate induction conditions are always favorable for industry. In this research, chemical composition and stoichiometric data for γ-interferon production and recombinant Escherichia coli growth were used in order to achieve a simple medium and favorable induction conditions. To achieve this goal, the effects of medium composition and induction conditions on the production of γ-interferon were investigated in batch culture of E. coli BL21 (DE3) [pET3a-ifnγ]. These conditions were considered as suitable conditions for the production of γ-interferon: 2.5× M9 medium, supplemented with a mixture of amino acids (milligram per liter), including glutamic acid 215, aspartic acid 250, lysine 160, and phenylalanine 90, and induction at late-log phase (OD600 = 4.5). Under these conditions, dry cell weight of 6 ± 0.2 g/l and γ-interferon concentration of 2.15 ± 0.1 g/l were obtained. Later, without changing the concentration ratio of amino acids and glucose, the effect of increase in the primary glucose concentration on productivity of γ-interferon was investigated. It was found that 25 g/l glucose will result in maximum attainable biomass and recombinant human γ-interferon. At improved conditions, a dry cell weight of 14 ± 0.2 g/l, concentration and overall productivity of γ-interferon 4.2 ± 0.1 g/l and 420 ± 10 mg/l h, respectively, were obtained.  相似文献   

19.
Micelles with azo dye and UV absorbent at their cores or coronas were prepared from non-amphiphilic random diblock copolymers by α,ω-diamine. Poly[4-(phenylazophenoxymethyl)styrene-ran-4-(2-hydroxybenzophenoxymethyl)styrene-ran-vinylphenol]-block-polystyrene (P(AS-r-HBS-r-VPh)-b-PSt) and poly(vinylphenol)-block-poly[4-(phenylazophenoxymethyl)styrene-ran-4-(2-hydroxybenzophenoxymethyl)styrene-ran-styrene] (PVPh-b-P(AS-r-HBS-r-St)) diblock copolymers were prepared by living radical polymerization mediated by 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl. The former copolymer had a molecular weight of Mn[P(AS-r-HBS-r-VPh)-b-PSt] = 10,000-b-250,000 by 1H NMR and a molar ratio of AS:HBS:VPh = 0.01:0.01:0.98, while the latter had a molecular weight of Mn[PVPh-b-P(AS-r-HBS-r-St)] = 10,000-b-111,000 and a molar ratio of AS:HBS:St = 0.02:0.03:0.95. The copolymers showed no self-assembly in 1,4-dioxane because this solvent was non-selective to the copolymers. Dynamic light scattering demonstrated that the copolymers formed micelles in the solvent in the presence of α,ω-diamine. The hydrodynamic radii of the micelles slightly increased with the copolymer concentration decrease, while the aggregation numbers were almost independent of the copolymer concentration. It was found that P(AS-r-HBS-r-VPh)-b-PSt formed smaller micelles with a lower aggregation number than PVPh-b-P(AS-r-HBS-r-St) because of the steric hindrance of the AS and HBS units present at the micellar coronas.  相似文献   

20.
In the present paper, endo-β-1,4-xylanase production by Aspergillus fumigatus was evaluated in solid-state fermentation using low-cost substrates such as sugarcane bagasse (SCB), brewer’s spent grain (BSG), and wheat bran (WB). The partial characterization of the crude enzyme was also performed. In the experimental conditions, the highest levels of endo-β-1,4-xylanase production by A. fumigatus FBSPE-05 occurred within 8 days incubation when using SCB/liquid medium at 1:2 ratio (219.5 U g−1) and 4 days incubation when using WB/liquid medium at 1:1 ratio (215.6 U g−1). Crude enzyme from this last condition was used to enzyme characterization, showing best enzyme activity at 60 °C and pH 6.0, which suggests a thermophilic endoxylanase. The crude enzyme retained 73% of its activity after 1 h at 60 °C, and zymogram has shown three bands of endo-β-1,4-xylanase activity, with different molecular masses. A. fumigatus FBSPE-05 was able to grow and produce good levels of endo-β-1,4-xylanase using agro-industrial by-products, making this strain worthy for further investigation. To our knowledge, this is the first study reporting the use of SCB and/or BSG as sole substrates for endoxylanase production by solid-state fermentation using A. fumigatus.  相似文献   

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