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1.
A newly isolated anti-Streptococcus suis bacteriocin-producing strain LPL1-5 was obtained from healthy unweaned piglets' fecal matter, and was designated as Lactobacillus pentosus LPL1-5 based on morphology, biochemical properties, and 16S rDNA sequencing analysis. The medium composition for enhanced bacteriocin production by L. pentosus LPL1-5 was optimized by statistical methodology. Yeast extract, K2HPO4 · 3H2O, and MnSO4 · H2O were identified as significant components influencing pentocin LPL1-5 production using the Plackett–Burman method. Response surface methodology was applied for further optimization. The concentrations of medium components for enhanced pentocin LPL1-5 production were as follows (g/L): lactose 20.00, tryptone 10.00, beef extract 10.00, yeast extract 14.00, MnSO4 · H2O 0.84, K2HPO4 · 3H2O 4.92, triammonium citrate 2.00, Na-acetate 5.00, MgSO4 · 7H2O 0.58, Tween 80 1.00. Under the optimized condition, a value of 3154.65 ± 27.93 IU/mL bacteriocin activity was achieved, which was 4.2-fold that of the original medium.  相似文献   

2.
The freshwater microalga Haematococcus pluvialis is one of the best microbial sources of the carotenoid astaxanthin, but this microalga shows low growth rates and low final cell densities when cultured with traditional media. A single-variable optimization strategy was applied to 18 components of the culture media in order to maximize the productivity of vegetative cells of H. pluvialis in semicontinuous culture. The steady-state cell density obtained with the optimized culture medium at a daily volume exchange of 20% was 3.77 · 105 cells ml−1, three times higher than the cell density obtained with Bold basal medium and with the initial formulation. The formulation of the optimal Haematococcus medium (OHM) is (in g l−1) KNO3 0.41, Na2HPO4 0.03, MgSO4 · 7H2O 0.246, CaCl2 · 2H2O 0.11, (in mg l−1) Fe(III)citrate · H2O 2.62, CoCl2 · 6H2O 0.011, CuSO4 · 5H2O 0.012, Cr2O3 0.075, MnCl2 · 4H2O 0.98, Na2MoO4 · 2H2O 0.12, SeO2 0.005 and (in μg l−1]) biotin 25, thiamine 17.5 and B12 15. Vanadium, iodine, boron and zinc were demonstrated to be non-essential for the growth of H. pluvialis. Higher steady-state cell densities were obtained by a three-fold increase of all nutrient concentrations but a high nitrate concentration remained in the culture medium under such conditions. The high cell productivities obtained with the new optimized medium can serve as a basis for the development of a two-stage technology for the production of astaxanthin from H. pluvialis. Received: 10 September 1999 / Received revision: 2 December 1999 / Accepted: 3 December 1999  相似文献   

3.
A fermentation medium for avilamycin production by Streptomyces viridochromogenes Tü57-1 has been optimized. Important components and their concentrations were investigated using fractional factorial design and Box–Behnken Design. The results showed that soybean flour, soluble starch, MgSO4·7H2O and CaCl2·2H2O are important for avilamycin production. A polynomial model related to medium components and avilamycin yield had been established. A high coefficient of determination (R 2 = 0.92) was obtained that indicated good agreement between the experimental and predicted values of avilamycin yield. Student’s T-test of each coefficient showed that all the linear and quadratic terms had significant effect (P > |T| < 0.05) on avilamycin yield. The significance of tested components was related to MgSO4·7H2O (0.37 g/L), CaCl2·2H2O (0.39 g/L), soybean flour (21.97 g/L) and soluble starch (37.22 g/L). The yield of avilamycin reached 88.33 ± 0.94 mg/L (p < 0.05) that was 2.8-fold the initial yield.  相似文献   

4.
In order to overproduce biofungicides agents by Bacillus amyloliquefaciens BLB371, a suitable culture medium was optimized using response surface methodology. Plackett–Burman design and central composite design were employed for experimental design and analysis of the results. Peptone, sucrose, and yeast extract were found to significantly influence antifungal activity production and their optimal concentrations were, respectively, 20 g/L, 25 g/L, and 4.5 g/L. The corresponding biofungicide production was 250 AU/mL, corresponding to 56% improvement in antifungal components production over a previously used medium (160 AU/mL). Moreover, our results indicated that a deficiency of the minerals CuSO4, FeCl3 · 6H2O, Na2MoO4, KI, ZnSO4 · 7H2O, H3BO3, and C6H8O7 in the optimized culture medium was not crucial for biofungicides production by Bacillus amyloliquefaciens BLB371, which is interesting from a practical point of view, particularly for low-cost production and use of the biofungicide for the control of agricultural fungal pests.  相似文献   

5.
In order to obtain a high ethanol yield from the Jerusalem artichoke raw extract and reduce the fermentation cost, we have engineered a new recombinant Saccharomyces cerevisiae strain that could produce ex-inulinase. The response surface methodology based on Plackett–Burman and Box–Behnken design was used to optimize the medium for the ethanol production from the Jerusalem artichoke raw extracts by the recombinant strain. In the first optimization step, Plackett–Burman design was employed to select significant factors, including concentrations of yeast extract, inoculum, and MgSO4·7H2O. In the second step, the steepest ascent experiment was carried out to determine the center point with the three significant factors; the selected combinations were further optimized using the Box–Behnken design. The maximum ethanol production rate was predicted at 91.1 g/l, which was based on a medium consisting of yeast extract 9.24 g/l, inoculum 39.8 ml/l, and MgSO4·7H2O 0.45 g/l. In the validating experiment, the ethanol fermentation rate reached 102.1 g/l, closely matching the predicted rate.  相似文献   

6.
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   

7.
Microbial transformation of benzaldehyde into l-phenylacetylcarbinol by whole cell Saccharomyces cerevisiae has been carried out in a novel polyethylene glycol (PEG)-induced cloud point system. The system is composed of 80 g PEG 20,000, 75 ml Triton X-100, 20 g peptone, 10 g yeast extract, 25 g glucose, 1 g MgSO4·7H2O, 0.05 g CaCl2·2H2O, 35 g Na2HPO4·12H2O, and 10.7 g citric acid per liter of tap water. The microbial transformation is conducted at 0.6 ml of acetaldehyde (35% volume content), 0.9 ml of benzaldehyde, and 7 g of wet cell per 100 ml of the PEG-induced cloud point system. Under the conditions, a relatively longer-term bioactivity of whole cell microorganism in the PEG-induced cloud point system has been achieved. A fed-batch microbial transformation process with a discrete addition of glucose and substrate gets a high final product concentration of about 8 g/l.  相似文献   

8.
A synthetic medium for Opercularia coarctata was developed that contains 20 amino acids, 10 vitamins, an 8-component balanced salt solution, Fe2(SO4)3·(NH4)2SO4·24H2O, Tween 80, stigmasterol, a 7-component nucleic acid mixture, phenol red as an indicator, and 2,500 U.S.P. units/ml penicillin to maintain sterility. This medium supported axenic survival for 96 hr. Multiple supplements of thioctic acid, niacin, niacinamide, inositol, PABA, oleic acid, and Fe(NO3)2·9H2O instead of Fe2(SO4)3·(NH4)2SO4·24H2O coverted the survival medium into a growth medium, which permitted 36–45 days continuous cultivation of populations in excess of 4 × 103 cells/3.0 ml final volume. Five generations were produced during the 48 hr logarithmic growth period. Serial transfers at 72 hr and during periods of greatest cell density produced a maximum of 8 generations 96 hr after initiation but the medium failed to sustain growth through more than 6 serial transfers. Extension of this investigation to formulating a minimal axenic medium is discussed.  相似文献   

9.
Many hazelnut (Corylus avellana L.) cultivars fail to thrive in vitro on standard growth medium and the reasons for poor growth are not well understood. Our initial study of five C. avellana cultivars showed that changes in the mineral nutrients of Driver and Kuniyuki walnut (DKW) medium, including doubling the minor nutrients, produced improved growth and shoot quality. The objectives of this study were to determine the effects of the individual minor mineral nutrients from DKW medium and if added nickel was required for optimal growth. Five factors were tested at 0.5 × to 4× DKW medium concentrations, [H3BO3, CuSO4·5H2O, MnSO4·H2O, Na2MoO4·2H2O and Zn(NO3)2·6H20], in a response surface design with 39 treatment combinations. Ni was not present in the DKW medium formulation so NiSO4·6H2O was varied from 0 to 6 µM. There were many significant interactions among the minor nutrients. Higher concentrations (4×) of B, Mo, and Zn increased overall shoot quality, length, and multiplication. Increased Mo improved some responses for each cultivar, and it interacted significantly with Cu and Zn. The addition of Ni greatly improved the shoot quality and length of ‘Sacajawea.’ Ni interactions were significant for the other cultivars as well, and altered the requirements for the other minor nutrients, but did not necessarily improve the overall shoot response. Improved growth and shoot quality for most cultivars required increased amounts of B, Mo, and Zn and less Mn and Cu. ‘Sacajawea’ required increased B, Cu, Zn, and Ni. All of the cultivars required minor nutrient formulations that differed greatly from DKW medium or other published minor nutrient formulations.  相似文献   

10.
The Doehlert experimental design was used to optimize the production of mycelial biomass and exopolymer from Hericium erinaceus CZ-2 in this study. Statistical analysis showed that the linear and quadric terms of 3 variables: corn flour, yeast extract, and corn steep liquor had significant effects. The optimized combination of these 3 variables was confirmed through validation experiments. The optimal conditions for higher production of mycelial biomass (19.92 g/L) were estimated when the media composition concentrations were set as: 30.85 g/L, corn flour; 2.81 g/L, yeast extract; 16.9 mL/L, corn steep liquor; 10 g/L, glucose; 1 g/L, KH2PO4; and 0.5 g/L, MgSO4·7H2O; while a maximal exo-polymer yield (1.653 g/L) could be achieved when setting concentrations of: 32.71 g/L, corn flour; 2.35 g/L, Yeast extract; 14.42 mL/L, Corn steep liquor; 10 g/L, glucose; 1 g/L, KH2PO4; and 0.5 g/L, MgSO4·7H2O. The upscale production was also investigated using a 15 L fermentor using the optimized medium.  相似文献   

11.
Lovastatin, an inhibitor of HMG-CoA reductase, was produced by submerged fermentation using Monascus purpureus MTCC 369. Five nutritional parameters screened using Plackett–Burman experimental design were optimized by Box–Behnken factorial design of response surface methodology for lovastatin production in shake flask cultures. Maximum lovastatin production of 351 mg/l were predicted in medium containing 29.59 g/l dextrose, 3.86 g/l NH4Cl, 1.73 g/l KH2PO4, 0.86 g/l MgSO4·7H2O, and 0.19 g/l MnSO4·H2O using response surface plots and point prediction tool of DESIGN EXPERT 7.0 (Statease, USA) software.  相似文献   

12.
We aimed to optimize a nutrient medium containing agricultural waste for xylanase production by Bacillus pumilus B20. Xylanase production with lignocellulosic material was optimized in two steps using DeMeo’s fractional factorial design. A 3.4-fold increase in xylanase production (313.3 U/mL) was achieved using the optimized culture medium consisting of (g/L): K2HPO4, 2; MgSO4·7H2O, 0.3; CaCl2·2H2O, 0.01; NaCl, 2; peptone, 5 yeast extract, 4; and wheat bran, 50. B. pumilus B20 produced a high level of xylanase, which may have potential industrial application.  相似文献   

13.
Intrinsic growth and substrate uptake parameters were obtained for Peptostreptococcus productus, strain U-1, using carbon monoxide as the limiting substrate. A modified Monod model with substrate inhibition was used for modeling. In addition, a product yield of 0.25 mol acetate/mol CO and a cell yield of 0.034 g cells/g CO were obtained. While CO was found to be the primary substrate, P. productus is able to produce acetate from CO2 and H2, although this substrate could not sustain growth. Yeast extract was found to also be a growth substrate. A yield of 0.017 g cell/g yeast extract and a product yield of 0.14 g acetate/g yeast extract were obtained. In the presence of acetate, the maximum specific CO uptake rate was increased by 40% compared to the maximum without acetate present. Cell replication was inhibited at acetate concentrations of 30 g/l. Methionine was found to be an essential nutrient for growth and CO uptake by P. productus. A minimum amount of a complex medium such as yeast extract (0.01%) is, however, required.  相似文献   

14.
The production of extracellular laccase by the Grammothele subargentea CLPS no. 436 strain in liquid cultures grown on a carbon-limited basal medium was significantly enhanced when culture conditions, including the addition of CuSO4·5H2O or veratryl alcohol, were consecutively optimized. A laccase activity as high as 1954.5 mU ml−1 of liquid medium was obtained under optimum conditions, which corresponded to non-agitated cultures supplemented with 0.6 mM CuSO4·5H2O. Veratryl alcohol at 1 mM was less effective than CuSO4·5H2O for increasing laccase activity levels; the supplementation of veratryl alcohol resulted only in maximum levels of 44 mU ml−1 in non-agitated cultures. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

15.
Aims: Aim of the study was to develop a medium for optimal heparinase production with a strain of Aspergillus flavus (MTCC‐8654) by using a multidimensional statistical approach. Methods and Results: Statistical optimization of intracellular heparinase production by A. flavus, a new isolate, was investigated. Plackett–Burman design was used to evaluate the affect of medium constituents on heparinase yield. The experimental results showed that the production of heparinase was dependent upon heparin, the inducer; chitin, structurally similar to heparin and NH4NO3, the nitrogen source. A central composite design was applied to derive a statistical model for optimizing the composition of the fermentation medium for the production of heparinase enzyme. The optimum fermentation medium consisted of (g l?1) Mannitol, 8·0; NH4NO3, 2·5; K2HPO4, 2·5; Na2HPO4, 2·5; MgSO4.7H2O, 0·5; Chitin, 17·1; Heparin, 0·6; trace salt solution (NaMoO4.2H2O, CoCl2.6H2O, CuSO4.5H2O, FeSO4.7H2O, CaCl2), 10?4 mol l?1. Conclusions: A 2·37‐fold increase in heparinase production was achieved in economic and effective manner by the application of statistical designs in medium optimization. Significance and Impact of the Study: Heparinase production was doubled by statistical optimization in a cost‐effective manner. This heparinase can find application in pharmaceutical industry and for the generation of low‐molecular‐weight heparins, active as antithrombotic and antitumour agents.  相似文献   

16.
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   

17.
ATP: nucleotide pyrophosphotransferase-producing microorganism was isolated from soil in Osaka prefecture. The morphological and physiological characteristics of this microorganism were studied. This strain was identified and named Streptomyces adephospholyticus nov. sp.

When this strain was aerobically cultured in a fermentor at 30°C in a medium containing 2% glycerol, 4% polypepton, 0.1 % KH2PO4, 0.04% MgSO4 · 7H2O, 2 ppm FeSO4 · 7H2O and 2 ppm MnSO4 · 6Н2О at pH 7.0, ATP; nucleotide pyrophosphotransferase was produced in the culture filtrate. The highest activity was obtained after 30 to 40 hr cultivation. The maximum enzyme production was 3000 to 4000 unit per liter.  相似文献   

18.
Itaconic acid (IA), a building block platform chemical, is produced industrially by Aspergillus terreus utilizing glucose. Lignocellulosic biomass can serve as a low cost source of sugars for IA production. However, the fungus could not produce IA from dilute acid pretreated and enzymatically saccharified wheat straw hydrolyzate even at 100-fold dilution. Furfural, hydroxymethyl furfural and acetic acid were inhibitory, as is typical, but Mn2+ was particularly problematic for IA production. It was present in the hydrolyzate at a level that was 230 times over the inhibitory limit (50 ppb). Recently, it was found that PO43− limitation decreased the inhibitory effect of Mn2+ on IA production. In the present study, a novel medium was developed for production of IA by varying PO43−, Fe3+ and Cu2+ concentrations using response surface methodology, which alleviated the strong inhibitory effect of Mn2+. The new medium contained 0.08 g KH2PO4, 3 g NH4NO3, 1 g MgSO4·7H2O, 5 g CaCl2·2 H2O, 0.83 mg FeCl3·6H2O, 8 mg ZnSO4·7H2O, and 45 mg CuSO4·5H2O per liter. The fungus was able to produce IA very well in the presence of Mn2+ up to 100 ppm in the medium. This medium will be extremely useful for IA production in the presence of Mn2+. This is the first report on the development of Mn2+ tolerant medium for IA production by A. terreus.  相似文献   

19.
An amylase inhibitor-producing microorganism was identified as a subspecies of Strepto- myces diastaticus from morphological and physiological studies and was named Streptomyces diastaticus subsp. amylostaticus No. 2476.

When this strain was aerobically cultured in a shaking flask containing 100 ml of medium consisting of 4% corn starch, 2% soy bean flake extract, 0.3 % NaCl, 0.1 % K2HPO4, 0.05% MgSO4·7H2O, 0.001% FeS04 · 7H2O, 0.0001% CuSO4-5H2O, 0.0001% ZnSO4·7H2O, and 0.0001% MnS04 nH2O (pH 7.0) at 30°C, the highest inhibitory activity was obtained after 70 ~ 80 hr of cultivation.

This amylase inhibitor (S-AI) had inhibitory activity on α-amylases and glucoamylase, but not on β-amylases and pullulanase.  相似文献   

20.
A chemically defined media was developed for growing Agrobacterium tumefaciens at large scale for commercial production of recombinant proteins by transient expression in plants. Design of experiments was used to identify major and secondary effects of ten media components: sucrose, ammonium sulfate ((NH4)2SO4), magnesium sulfate heptahydrate (MgSO4*7H2O), calcium chloride dihydrate (CaCl2*2H2O), iron (II) sulfate heptahydrate (FeSO4*7H2O), manganese (II) sulfate monohydrate (MnSO4*H2O), zinc sulfate heptahydrate (ZnSO4*7H2O), sodium chloride (NaCl), potassium chloride (KCl) and a sodium/potassium phosphate buffer (Na2HPO4/KH2PO4). Calcium and zinc were found to have no detectable impact on biomass concentration or transient expression level, and concentrations of the other components that maximized final biomass concentration were determined. The maximum specific growth rate of Agrobacterium strain C58C1 pTFS40 in this media was 0.33 ± 0.01 h?1 and the final biomass concentration after 26 h of batch growth in shake flasks was 2.6 g dry cell weight/L. Transient expression levels of the reporter protein GUS following infiltration of a recombinant Agrobacterium strain C58C1 into N. benthamiana were comparable when the strain was grown in the defined media, Lysogeny Broth (LB) media, or yeast extract‐peptone (YEP) media. In LB and YEP media, free amino acid concentration was measured at three points over the course of batch growth of Agrobacterium strain C58C1 pTFS40; results indicated that l ‐serine and l ‐asparagine were depleted from the media first, followed by l ‐alanine and l ‐glutamic acid. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1218–1225, 2017  相似文献   

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