共查询到20条相似文献,搜索用时 15 毫秒
1.
P.L. Pham P. Taillandier M. Delmas P. Strehaiano 《World journal of microbiology & biotechnology》1998,14(2):185-190
The concentrations of oat spelt xylan, casein hydrolysate and NH4Cl in the culture medium for production of xylanase from Bacillus sp. I-1018 were optimized by means of response surface methods. The path of steepest ascent was used to approach the optimal region of the medium composition. The optimum composition of the nutrient medium was then easily determined by using a central composite design and was found to be 3.16g/l of xylan, 1.94g/l casein hydrolysate, 0.8g/l of NH4Cl. The xylanase production was increased by 135% when the strain was grown in the optimized medium compared to initial medium. 相似文献
2.
The xylanase biosynthesis is induced by its substrate - xylan. The high xylan content in some of the wastes like corn cobs and wheat bran makes them an accessible and cheap source of inducers. Nutrient medium for xylanase biosynthesis in submerged cultivation of Aspergillus niger B03 has been optimized. The optimization process was analyzed using optimal composite experimental design and response surface methodology. The predicted by the regression model optimum components of nutrient medium are as follows (g/l): (NH(4))(2)HPO(4) 2.6, urea 0.9, corn cobs 24.0, wheat bran 14.6 and malt sprout 6.0. Five parallel experiments have been carried out, at definite, optimum components concentrations of the nutrient medium, and a mean value of the activity Y=996.30 U/ml has been obtained. The xylanase activity, obtained with the optimized nutrient medium is 33% higher than the activity, achieved with the basic medium. 相似文献
3.
A Haddar D Driss F Frikha S Ellouz-Chaabouni M Nasri 《International journal of biological macromolecules》2012,51(4):647-656
Medium composition and culture conditions for the xylanases production by Bacillus mojavensis A21 were optimized using two statistical methods: Plackett-Burman design applied to find the key ingredients and conditions for the best yield of enzyme production and Box-Behnken design used to optimize the value of the four significant variables: barley bran, NaCl, agitation, and cultivation time. The optimal conditions for higher production of xylanases were barley bran 18.66g/l, NaCl 1.04g/l, speed of agitation 176rpm and cultivation time 34.08h. Under these conditions, the xylanase experimental yield (7.45U/ml) closely matched the yield predicted by the statistical model (7.23U/ml) with R(2)=0.98. The medium optimization resulted in a 6.83-fold increase in xylanase production compared to that of the initial medium. Best xylanase activity was observed at the temperature of 50°C and at pH 8.0. The enzyme retained more 96% of its activity after 24h at pH ranges from 7.0 to 90.0. The enzyme preserved more 80% of its initial activity after 60min of pre-incubation from 30°C to 60°C. The main hydrolysis products yielded from corncob extracted xylan were xylobiose and xylotriose, suggesting the good potential of strain A21 in xylooligosaccharides production. 相似文献
4.
Bastawde K. B. Puntambekar U. S. Gokhale D. V. 《Journal of industrial microbiology & biotechnology》1994,13(4):220-224
Summary A novel yeast strain, NCIM 3574, isolated from a decaying wood produced up to 570 IU ml–1 of xylanolytic enzymes when grown on medium containing 4% xylan. The yeast strain also produced xylanase activity (40–50 IU ml–1) in the presence of soluble carbon sources like xylose or arabinose. No xylanase activity was detected when the organism was grown on glucose. The crude xylanase preparation showed no activity towards cellulolytic substrates but low levels of -xylosidase (0.1 IU ml–1) and -l-arabinofuranosidase (0.05 IU ml–1) were detected. The temperature and pH optima for the crude xylanase preparation were 55°C and 4.5 respectively. The crude xylanase produced mainly xylose from xylan within 5 min. Prolonged hydrolysis of xylan produced xylobiose and arabinose, in addition to xylose, as the end products. The presence of arabinose as one of the end products in xylan hydrolysate could be due to the low levels of arabinofuranosidase enzyme present in the crude fermentation broth. 相似文献
5.
碱性木聚糖酶在碱性条件下催化水解木聚糖,广泛应用于造纸、纺织等领域.着重对短小芽胞杆菌M-11产碱性木聚糖酶的发酵条件进行初步的探索.研究了菌株的生长曲线、确定最佳接种龄为16 h、最佳接种量为1%;确定最适碳源浓度为7%、最适单一氮源为氯化铵、其浓度为1.0%、最适无机盐为氯化铁、其浓度为3 mmol/L;在此基础之上进行6因素3水平的正交试验,确定最适产酶培养基组成:麸皮5%,接种量3%,氯化铵1.2%,氯化铁3.5 mmol/L,硫酸镁0.03%,氯化钠5 mmol/L,磷酸氢二钾0.4%;最适培养条件:接种龄16 h,初始pH 8.0,温度37℃,300 mL摇瓶装液量50 mL,摇床转速220 r/min,发酵周期48 h.通过对发酵条件的优化使发酵液酶活达613 IU/mL.无机氮源为其最适氮源,因此短小芽胞杆菌M-11在碱性木聚糖酶的产品开发上优于短小芽胞杆菌M -26. 相似文献
6.
M Kole A Iu Krivova L I Vorob'eva I P Bab'eva V V Voronkova 《Prikladnaia biokhimiia i mikrobiologiia》1979,15(5):660-664
In order to increase the yield of biotin produced by the culture Sporobolomyces pararoseus, the medium containing sucrose, asparagine, MgSO4 (NH4)2SO4, KH2PO4, vitamin complex and trace elements was optimized. With the aid of a fractional factor experiment (2(5-1)) and a complete factor experiment (2(4)), the proportion of constituents was chosen in such a way as to double biotin yield, i.e. to increase it to 55.25 micrograms/l. An enrichment of the medium with yeast autolysate, casein hydrolysate and peptone in the presence of adenine increased biotin yield to 105.7 micrograms/l and cell productivity from 6.1 to 8.0 micrograms/l dry biomass. 相似文献
7.
Kirimura K Watanabe T Sunagawa T Usami S 《Bioscience, biotechnology, and biochemistry》1999,63(1):226-228
Citric acid production from xylan and xylan hydrolysate was done by Aspergillus niger Yang no. 2 cultivated in a semi-solid culture using bagasse as a carrier. Yang no. 2 produced 72.4 g/l and 52.6 g/l of citric acid in 5 d from 140 g/l of xylose and arabinose, respectively. Yang no. 2 produced 51.6 g/l of citric acid in 3 d from a concentrated xylan hydrolysate prepared by cellulase treatment, containing 100 g/l of reducing sugars. Moreover, Yang no. 2 directly produced 39.6 g/l of citric acid maximally in 3 d from 140 g/l of xylan. 相似文献
8.
采用单因子实验分析了培养基成分及初始pH对漏斗多孔菌液体发酵产漆酶的影响。结果表明,米糠和甘蔗半纤维素组成复合碳源、NH4Cl和高C/N有利于漆酶的产生,Cu2+、米糠水解液和萘乙酸对漆酶合成具有诱导作用,1-萘酚、愈创木酚、联苯胺、乙醇、吐温80等抑制漆酶的合成,Cu2+和萘乙酸同时存在时也限制漆酶的产生,产酶培养基最适初始pH为5.2-5.7。利用优化的产酶培养基液体摇瓶培养漏斗多孔菌A08,产酶活力提高0.95倍,达到1480U/L。 相似文献
9.
Senthilkumar SR Ashokkumar B Chandra Raj K Gunasekaran P 《Bioresource technology》2005,96(12):1380-1386
Response surface methodology and central composite rotary design (CCRD) was employed to optimize a fermentation medium for the production of alkali-stable cellulase-free xylanase by Aspergillus fischeri in solid-state fermentation at pH 9.0 with wheat bran as substrate. The four variables involved in this study were sodium nitrite, potassium dihydrogen phosphate, magnesium sulphate and yeast extract. The statistical analysis of the results showed that, in the range studied, only sodium nitrite had a significant effect on xylanase production. The optimized medium containing (in g/l) NaNO(2)-7.0, K2HPO(4)-1.0, MgSO(4)-0.5 and yeast extract-5.0 resulted in 1.9-fold increased level of alkali-stable xylanase (1024 U/g wheat bran) production compared to initial level (540 U/g) after 72 h of fermentation, whereas its value predicted by the quadratic model was 931 U/g. The level of protease activity was considerably decreased in optimized medium, thus helping to preserve the xylanase activity and demonstrating another advantage of applying statistical experimental design. 相似文献
10.
M. Perttula M. Rättö M. Kondradsdottir J. K. Kristjansson L. Viikari 《Applied microbiology and biotechnology》1993,38(5):592-595
Thermophilic, aerobic bacteria isolated from Icelandic hot springs were screened for xylanase activity. Of 97 strains tested, 14 were found to be xylanase positive. Xylanase activities up to 12 nkat/ml were produced by these strains in shake flasks on xylan medium. The xylanases of the two strains producing the highest activities (ITI 36 and ITI 283) were similar with respect to temperature and pH optima (80°C and pH 8.0). Xylanase production of strain ITI 36 was found to be induced by xylan and xylose. Xylanase activity of 24 nkat/ml was obtained with this strain in a laboratory-scale-fermentor cultivation on xylose medium. -Xylosidase activity was also detected in the culture filtrate. The thermal half-life of ITI 36 xylanase was 24 h at 70°C. The highest production of sugars from hydrolysis of beech xylan was obtained at 70°C, although xylan depolymerization was detected even up to 90°C.
Correspondence to: M. Rättö 相似文献
11.
AIMS: To optimize the media components for xylanase production by Aspergillus versicolor MKU3 in solid-state fermentation (SSF). METHODS AND RESULTS: Medium optimization was carried out using De Moe's fractional factorial design with seven components. Maximum production of xylanase 3249.9 U g(-1) was obtained in SSF with an optimized medium containing (g l(-1)): NaNO(3), 20; K(2)HPO(4), 20; MgSO(4), 10; FeSO(4), 0.001; KCl, 1; peptone, 10 and yeast extract, 10. Four components namely NaNO(3), MgSO(4), peptone and K(2)HPO(4) significantly increased the xylanase production by A. versicolor MKU3. CONCLUSIONS: Fractional factorial design was used to optimize the seven components in the fermentation medium for SSF. The optimized media increased xylanase production by 3.4-fold. SIGNIFICANCE AND IMPACT OF THE STUDY: Aspergillus versicolor MKU3 produced maximum xylanase after two steps of media optimization under alkaline condition. This medium will be significant value for xylanase production in SSF. 相似文献
12.
J. Gomes I. Gomes W. Kreiner H. Esterbauer M. Sinner W. Steiner 《Journal of biotechnology》1993,30(3):283-297
Thermomyces lanuginosus, isolated from self-heated jute stacks in Bangladesh, was studied for production of high level of cellulase-free thermostable xylanase at 50°C using xylan. Optimization of the medium composition was carried out on shake-flask level using Graeco-Latin square technique. This increased xylanase production from 527 nkat ml−1 in the original medium to 9168–9502 nkat ml−1 in the optimized medium under optimized culture conditions e.g. initial medium pH (6.0–6.5), culture temperature (50°C) and time (5–6 d). The lag phase was very much shorter in the laboratory reactor compared to which existed in the shake cultures and 7111 nkat of xylanase activity were obtained per ml of culture filtrate at 60 h of cultivation. With a 15 min reaction time, the optimal pH and temperature for the xylanase activity were at 6.5 and 65°C, respectively. The enzyme was almost stable over a broad range of pH 3–9 at 20°C, with an optimum stability at pH 6.5. After 51 h heating at 50°C the enzyme retained 60%, 100% and 90% activity at pH 5.0, 6.5 and 8.0, respectively. The crude enzyme could hydrolyse xylan effectively and in only 6 h 67.3%, 54.0% and 49.2% saccharifications were achieved for 2%, 5% and 10% substrate levels, respectively. The principal product of hydrolysis was xylobiose together with smaller amounts of xylooligosaccharides (degree of polymerization 3–7) and xylose. 相似文献
13.
The initial moisture content, cultivation time, inoculum size and concentration of basal medium were optimized in solid state fermentation (SSF) for the production of xylanase by an Aspergillus niger mutant using statistical experimental designs. The cultivation time and concentration of basal medium were the most important factors affecting xylanase activity. An inoculum size of 5 x 10(5) spores/g, initial moisture content of 65%, cultivation time of 5 days and 10 times concentration of basal medium containing 50 times concentration of corn steep liquor were optimum for xylanase production in SSF. Under the optimized conditions, the activity and productivity of xylanase obtained after 5 days of fermentation were 5,071 IU/g of rice straw and 14,790 IU l(-1) h(-1), respectively. The xylanase activity predicted by a polynomial model was 5,484 IU/g of rice straw. 相似文献
14.
Thermolabile xylanase of the Antarctic yeast Cryptococcus adeliae: production and properties 总被引:4,自引:0,他引:4
Xylanase production by the Antarctic psychrophilic yeast Cryptococcus adeliae was increased 4.3 fold by optimizing the culture medium composition using statistical designs. The optimized medium containing
24.2 g l−1 xylan and 10.2 g l−1 yeast extract and having an initial pH of 7.5 yielded xylanase activity at 400 nkat (nanokatal) ml−1 after 168-h shake culture at 4°C. In addition, very little endoglucanase, β-mannanase, β-xylosidase, β-glucosidase, α-l-arabinofuranosidase, and no filter paper cellulase activities were detected. Among 12 carbon sources tested, maximum xylanase
activity was induced by xylan, followed by lignocelluloses such as steamed wheat straw and alkali-treated bagasse. The level
of enzyme activity produced on other carbon sources appeared to be constitutive. Among the complex organic nitrogen sources
tested, the xylanase activity was most enhanced by yeast extract, followed by soymeal, Pharmamedia (cotton seed protein),
and Alburex (potato protein). A batch culture at 10°C in a 5-l fermenter (3.5-1 working volume) using the optimized medium
gave 385 nkat at 111 h of cultivation. The crude xylanase showed optimal activity at pH 5.0–5.5 and good stability at pH 4–9
(21 h at 4°C). Although the enzyme was maximally active at 45°–50°C, it appeared very thermolabile, showing a half-life of
78 min at 35°C. At 40°–50°C, it lost 71%–95% activity within 5 min. This is the first report on the production as well as
on the properties of thermolabile xylanase produced by an Antarctic yeast.
Received: December 10, 1999 / Accepted: March 23, 2000 相似文献
15.
研究不同碳源、氮源和无机盐对毕赤酵母AX181菌株产木聚糖酶的影响。实验表明,分别采用葡萄糖和玉米浆干粉为碳源和氮源可以明显提高木聚糖酶的产量。无机盐单因子优化实验显示添加适量的(NH4)2SO4、KH2PO4、MnSO4·H2O、FeSO4·7H2O也可以部分提高木聚糖酶产量。在此基础上利用响应面法优化毕赤酵母产木聚糖酶培养基,利用12次实验的Plackett—Burman设计实验筛选出影响产木聚糖酶的3个主要因素,即玉米浆干粉、MnSO4·H2O和FeSO4·7H20。并进一步通过最陡爬坡路径逼近最大响应区域,采用中心组合实验设计确定最佳条件。优化后的产木聚糖酶培养基组分为(g/L):葡萄糖40.00,玉米浆干粉80.84,(NH4)2SO46.25,KH2PO41.25、MnSO4·H2O0.35,FeS04-7H2O1.31。培养基优化后,实际产酶2883.86u/mL,是优化前YPD培养基产酶的2.51倍。 相似文献
16.
Aspergillus ochraceus produced xylanase inductively in washed glucose-grown mycelia incubated with methyl β-d-xyloside. The production of xylan endo-l,4-β-xylosidase (xylanase) was 4.2 times greater than that obtained in xylan medium. The inducer was not metabolized and was most active at a concentration of 0.3 g/L with an incubation period of 16 h. The uptake of the inducer by the mycelia seemed to be energy-dependent. Methyl α-d-xyloside repressed xylanase synthesis. Glucose, cyeloheximide, actinomycin D and eAMP were found to inhibit xylanase induction by methyl β-D-xyloside. 相似文献
17.
Nam Keun Lee 《Biotechnology and Bioprocess Engineering》2018,23(1):55-63
Recombinant xylanase (rPcXynC) from Pichia pastoris was produced on large-scale by optimizing production-medium composition using statistical experimental methods. Production medium was optimized through the use of statistical methods such as one factor at a time (OFAT), Plackett-Burman design, fractional factorial design (FFD), steepest ascent method (SAM), and response surface methodology (RSM). The optimum medium composition was established to be (g/L); wheat bran 11.62, yeast extract 30, Tween 60.5, DL-β-Phenylalanine 0.5, Thiamine 0.5, FeSO4 0.01, KH2PO4 0.66, and KHSO4 0.09. The optimum medium composition yielded 3,051 mU/mL of xylanase activity which was three times higher than that obtained from the initial medium composition. Finally, fermentation conditions were examined using the optimized production medium in a laboratory bioreactor. The optimal fermentation conditions were found to be 25ºC, pH 6, 170 rpm and 1 vvm with intermittent feeding of methanol (67.5 mL) and the xylanase activity was 3,683 mU/mL. In repeated-batch fermentation using optimized production medium and fermentation condition, the xylanase activity was 3,680 mU/mL at the first cycle of 96 h harvesting time using 90% of the culture solution. The activity was similarly maintained until the last cycle of 264 h. 相似文献
18.
Gomes J Gomes I Terler K Gubala N Ditzelmüller G Steiner W 《Enzyme and microbial technology》2000,27(6):414-422
The culture medium for Rhodothermus marinus was optimised on a shake-flask scale by using statistical factorial designs for enhanced production of a highly thermostable alpha-L-arabinofuranosidase (AFase). The medium containing 3.6 g/l birch wood xylan and 8.2 g/l yeast extract yielded a maximum of 110 nkat/ml AFase activity together with 125 nkat/ml xylanase and 65 nkat/ml beta-xylosidase activity. In addition, low levels of beta-mannanase (30 nkat/ml), alpha-galactosidase (0.2 nkat/ml), beta-galactosidase (0.3 nkat/ml), endoglucanase (5 nkat/ml) and beta-glucosidase (30 nkat/ml) were detected in the culture filtrate. Among the various carbon sources tested, birchwood xylan was most effective for the formation of AFase and xylanase activities, followed by oat spelt and beechwood xylans, and xylan-rich lignocelluoses (e.g., starch-free sugar beet pulp and wheat bran). Constitutive levels of enzyme activities were detected when the bacterium was grown on other polysaccharides and low-molecular-weight carbohydrates. A fermentation in a 5-l fermenter (3-l working volume) using the optimised medium yielded 60 nkat/ml AFase associated with 65 nkat/ml xylanase and 35 nkat/ml beta-xylosidase activities. The crude AFase displayed optimal activity between pH 5.5 and 7 and at 85 degrees C. It had half-lives of 8.3 h at 85 degrees C and 17 min at 90 degrees C. It showed high stability between pH 5 and 9 (24 h at 65 degrees C). The combined use of AFase-rich xylanase and mannanase from R. marinus in the prebleaching of softwood kraft pulp gave a brightness increase of 1.8% ISO. To our knowledge, this is the first report on the production of a high AFase activity by an extreme thermophilic bacterium and this enzyme is the most thermostable AFase reported so far. 相似文献
19.
Diphtheria toxin is produced by growing Corinebacterium diphtheriae either in a semisynthetic casein-based medium or in the Pope-Lingood meat extract based medium. The World Health Organization advises the use of the semisynthetic one, as it has important advantages. Data on the composition of casein-based media and their ability to support high toxin production are not freely available. Important factors affecting toxin production during C. diphtheriae cultivation are the pH of the culture medium and the concentration of casein hydrolysate and of Fe2+. We established that the optimal pH for toxin production is 7.2. The highest yield of toxin was obtained using a casein hydrolysate concentration of 35.0 g/L and a Fe2+ concentration of 0.05-0.41 microg/mL. Under these conditions, diphtheria toxin with higher purity and yield compared with the batches obtained using the meat-based medium of Pope-Lingood was produced. 相似文献
20.
Lakshmi GS Rajeswari BU Prakasham RS 《Journal of microbiology and biotechnology》2012,22(8):1084-1091
Xylooligosaccharides are functional foods mainly produced during the hydrolysis of xylan by physical, chemical, or enzymatic methods. In this study, production of xylobiose was investigated using oil palm empty fruit bunch fiber (OPEFB) as a source material, by chemical and enzymatic methods. Xylanase-specific xylan hydrolysis followed by xylobiose production was observed. Among different xylanases, xylanase from FXY-1 released maximum xylobiose from pretreated OPEFB fiber, and this fungal strain was identified as Aspergillus terreus and subsequently deposited under the accession Number MTCC- 8661. The imperative role of lignin on xylooligosaccharides enzymatic synthesis was exemplified with the notice of xylobiose production only with delignified material. A maximum 262 mg of xylobiose was produced from 1.0 g of pretreated OPEFB fiber using FXY-1 xylanase (6,200 U/ml) at pH 6.0 and 45° C. At optimized environment, the yield of xylobiose was improved to 78.67 g/100 g (based on xylan in the pretreated OPEFB fiber). 相似文献