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1.
PSO312是从土壤分离的1个青霉菌株,生长中能产生不同酸碱性条件下显黄色与紫红色等天然色素物质．通过菌株固体平板上恒温培养,168h测定菌落直径的方法研究了温度、pH及碳、氮源对菌株（Penicilliumsp．）生长的影响．研究表明31℃为菌株生长的最适温度．31℃培养以pH2—3的最快,pH8—9生长次之,24℃培养以pH8—9生长最快,pH3—4其次．菌株以蛋白胨4g／L、牛肉膏4g／L、酵母膏2g／L及尿素2g／L为氮源培养的菌落直径分别为55．75mm、51．5mm、55．5mm及25．3mm．在（NH4）2SO4 2g／L、NH4NO3 3g／L、NaNO3 4g／L、KN034g／L用量之上培养生长最快,菌落直径分别为35mm、34mm、35mm、及32mm．葡萄糖、蔗糖用量30g／L、果糖20g／L及乳糖25g／L的生长速率最快,菌落直径分别为45mm、38mm、38mm及39mm．丙三醇与淀粉25g／L培养的菌落直径均为39mm． 相似文献
2.
INTRODUCTION Carotenoids are a class of natural fat-solublepigments generally found in plants, algae, and pho-tosynthetic bacteria, where they play a critical role inthe photosynthetic process. Carotenoids also exist insome non-photo-synthetic bacteria, yeasts, and moldswhere they may carry out a protective functionagainst damages by light and oxygen. Although ani-mals can not synthesize carotenoids within theirbodies, they can intake carotenoids from their dietsleading to bright meat col… 相似文献
3.
Optimization of a process for extracting astaxanthin from Phaffia rhodozyma by acidic method was investigated,regarding several extraction factors such as acids, organic solvents, temperature and time. Fractional factorial design, central composite design and response surface methodology were used to derive a statistically optimal model, which corresponded to the following optimal condition concentration of lactic acid at 5.55 mol/L, ratio of ethanol to yeast dry weight at 20.25 ml/g, temperature for cell-disruption at 30 ℃, and extraction time for 3 min. Under this condition, astaxanthin and the total carotenoids could be extracted in amounts of 1294.7 μg/g and 1516.0 μg/g, respectively. This acidic method has advantages such as high extraction efficiency, low chemical toxicity and no special requirement of instruments. Therefore, it might be a more feasible and practical method for industrial practice. 相似文献
4.
本文研究了多种生物激活剂对红发夫酵母生长及虾青素形成的影响,实验结果表明适量添加肌苷、鸟苷和CMP促进作用明显. 相似文献
5.
对14份土样和7株实验室保藏菌株经初筛、摇瓶复筛,得到1株油脂产量较高的酵母菌,其油脂含量为7.34%。对影响该菌体产油脂的条件进行了单因素和正交实验,得出摇瓶发酵培养的最佳产油脂条件:发酵周期为4d,酵母膏和硫酸铵混合物为氮源,接种量为12%。在该条件下测得的菌体生物量为12.211g/L,油脂产量为1.524g/L,油脂含量为12.48%。 相似文献
6.
Bacillus subtilisis widely used for the productionof vitamins and other products including industrial en-zymes such as amylases, proteases and lipase. Butsyntheses of those products are repressed by the pres-ence of glucose, which is viewed as carbon catabolicrepression (CCR). InBacillus subtilis,CCR is main-ly mediated by the global regulator protein CcpAwhich was encoded byccpAgene[1]. It is therefore of crucial importance to relievingCCR ofBacillus subtilisfor industrial production. I… 相似文献
7.
Xu YX Li YL Xu SC Liu Y Wang X Tang JW 《Journal of Zhejiang University. Science. B》2008,9(7):558-566
Objective: To study the optimal medium composition for xylanase production by Aspergillus niger XY-1 in solid-state fermentation (SSF). Methods: Statistical methodology including the Plackett-Burman design (PBD) and the central composite design (CCD) was employed to investigate the individual crucial component of the medium that significantly affected the enzyme yield. Results: Firstly, NaNO3, yeast extract, urea, Na2CO3, MgSO4, peptone and (NH4)2SO4 were screened as the significant factors positively affecting the xylanase production by PBD. Secondly, by valuating the nitrogen sources effect, urea was proved to be the most effective and economic nitrogen source for xylanase production and used for further optimization.Finally, the CCD and response surface methodology (RSM) were applied to determine the optimal concentration of each sig-nificant variable, which included urea, Na2CO3 and MgSO4. Subsequently a second-order polynomial was determined by mul-tiple regression analysis. The optimum values of the critical components for maximum xylanase production were obtained as follows: x1 (urea)=0.163 (41.63 g/L), x2 (Na2CO3)=-1.68 (2.64 g/L), x3 (MGSO4)=1.338 (10.68 g/L) and the predicted xylanase value was 14374.6 U/g dry substrate. Using the optimized condition, xylanase production by Aspergillus niger XY-1 after 48 h fermentation reached 14637 U/g dry substrate with wheat bran in the shake flask. Conclusion: By using PBD and CCD, we obtained the optimal composition for xylanase production by Aspergillus niger XY-1 in SSF, and the results of no additional expensive medium and shortened fermentation time for higher xylanase production show the potential for industrial utilization. 相似文献
8.
以（NH4）2SO4为唯一氮源,经富集培养、平板涂布分离及平板划线纯化、摇瓶复筛等方法,从当地养殖池水体中分离、筛选氨氮降解菌。根据形态学、生理生化特征分析,对其进行归属鉴定,并研究其降解特性。通过对初步鉴定归属为沙雷氏菌属（Serratia．sp）,命名为N-2的氨氮降解菌降解特性的研究,得到其最适降解条件：N-2利用（NH4）：S04作唯一氮源时,最适碳源为蔗糖,降解温度为32—37℃,pH为7．0。在最适条件下,当NH4＋-N初始质量浓度为50mg／L时,该菌培养至72h氨氮降解率可达97．4％。结果表明,该菌为高效氨氮降解菌,这种土著微生物在修复富营养化水体方面有较好的应用前景。 相似文献
9.
Medium optimization for enhanced production of cytosine-substituted mildiomycin analogue （MIL-C） by Streptoverticillium rimofaciens ZJU 5119 总被引：1，自引：0，他引：1
Cytosine-substituted mildiomycin analogue (MIL-C) was produced effectively by supplementing cytosine into the culture of Streptoverticillium rimofaciens. In order to improve the yield of MIL-C, statistically-based experimental designs were applied to optimize the fermentation medium for S. rimofaciens ZJU 5119. Fifteen culture conditions were examined for their significances on MIL-C production using Plackett-Burrnan design. The Plackett-Burman design and one-variable-at-a-time design indicated that glucose and rice meal as the complex carbon sources, and peanut cake meal and NH4NO3 as the complex nitrogen sources were beneficial for MIL-C production in S. rimofaciens ZJU 5119. The results of further central composition design (CCD)showed that the optimal concentration of glucose, rice meal and peanut cake meal were 18.7 g/L, 64.8 g/L and 65.1 g/L,respectively. By using this optimal fermentation medium, the MIL-C concentration was increased up to 1336.5 mg/L, an approximate 3.8-fold improvement over the previous concentration (350.0 mg/L) with un-optimized medium. This work will be very helpful to the large-scale production of MIL-C in the future. 相似文献
10.
黑皮鸡枞菌液体培养基优化 总被引：1，自引：0，他引：1
试验比较不同pH条件及培养基配方对黑皮鸡枞菌丝体（球）生长的影响以探讨最佳液体培养黑皮鸡枞最佳的pH及配方条件．通过预实验筛选出玉米粉、麸皮、大豆粉、K2HPO4、MgSO4为碳源、氮源及微量营养因子;用四因素四水平正交表进行试验,以菌丝体的干物质量为基准比较．结果表明：液体培养条件下,获得最高黑皮鸡枞菌丝体生物量的最佳配方为：麸皮14g／L·玉米粉11g／L·大豆粉2g／L·KH：PO4 1.2g／L·MgSO40．9g／L;最适pH为6．0． 相似文献
11.
A menaquinone-7 (MK-7) high-producing strain needs to be isolated to increase MK-7 production, in order to meet a requirement of MK-7 given the low MK-7 content in food products. This article focuses on developing MK-7 high-producing strains via screening and mutagenesis by an atmospheric and room temperature plasma (ARTP) mutation breeding system. We isolated an MK-7-producing strain Y-2 and identified it as Bacillus amyloliquefaciens, which produced (7.1±0.5) mg/L of MK-7 with maize meal hydrolysate as carbon source. Then, an MK-7 highproducing strain B. amyloliquefaciens H.β.D.R.-5 with resistance to 1-hydroxy-2-naphthoic acid, β-2-thienylalanine, and diphenylamine was obtained from the mutation of the strain Y-2 using an ARTP mutation breeding system. Using strain H.β.D.R.-5, efficient production of MK-7 was achieved ((30.2±2.7) mg/L). In addition, the effects of nitrogen sources, prenyl alcohols, and MgSO4 on MK-7 production were investigated, suggesting that soymeal extract combined with yeast extract, isopentenol, and MgSO4 was beneficial. Under the optimized condition, the MK-7 production and biomass-specific yield reached (61.3±5.2) mg/L and 2.59 mg/L per OD600 unit respectively in a 7-L fermenter. These results demonstrated that strain H.β.D.R.-5 has the capacity to produce MK-7 from maize meal hydrolysate, which could reduce the substrate cost. 相似文献
12.
玉米浆作为氮源对透明质酸发酵的影响 总被引：1，自引：0，他引：1
采用玉米浆替代牛肉膏和蛋白胨作为氮源,在摇瓶和30 L发酵罐中进行透明质酸发酵,分析测定了直接利用玉米浆作为氮源和玉米浆酶解液作为氮源两种情况下透明质酸的发酵产量。结果表明,透明质酸产量太低,玉米浆不适合作为透明质酸发酵的氮源。 相似文献
13.
碳源、氮源及其比例对香菇液体深层培养的影响 总被引：1，自引：0，他引：1
通过摇瓶培养,研究香菇液体深层培养最适发酵培养时间、最适碳源、最适氮源及最佳碳源与氮源质量配比.结果表明最适发酵培养时间为168 h,所得菌丝体干重达0.399 g/50 mL菌液,最适碳源为蔗糖,菌丝体干重达到0.396 g/50 mL菌液;最适氮源为牛肉膏,菌丝干重达到0.421 g/50 mL菌液,并通过正交实验筛选出最佳碳源与氮源质量配比为:W(蔗糖):W(牛肉膏):W(麦芽糖)=2.5:1:1. 相似文献
14.
Xiang Hu Dominika Sobotka Krzysztof Czerwionka Qi Zhou Li Xie Jacek Makinia 《Journal of Zhejiang University. Science. B》2018,19(4):305-316
The effects of two different external carbon sources (acetate and ethanol) and electron acceptors (dissolved oxygen, nitrate, and nitrite) were investigated under aerobic and anoxic conditions with non-acclimated process biomass from a full-scale biological nutrient removal-activated sludge system. When acetate was added as an external carbon source, phosphate release was observed even in the presence of electron acceptors. The release rates were 1.7, 7.8, and 3.5 mg P/(g MLVSS·h) (MLVSS: mixed liquor volatile suspended solids), respectively, for dissolved oxygen, nitrate, and nitrite. In the case of ethanol, no phosphate release was observed in the presence of electron acceptors. Results of the experiments with nitrite showed that approximately 25 mg NO2-N/L of nitrite inhibited anoxic phosphorus uptake regardless of the concentration of the tested external carbon sources. Furthermore, higher denitrification rates were obtained with acetate (1.4 and 0.8 mg N/(g MLVSS·h)) compared to ethanol (1.1 and 0.7 mg N/(g MLVSS·h)) for both anoxic electron acceptors (nitrate and nitrite). 相似文献
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16.
凯氏定氮法测定虾壳中氮含量 总被引：1，自引：0，他引：1
自组一套简易凯氏定氮装置,对提高装置气密性方法进行研究,并采用单次单因子法对加入双氧水测定虾壳中氮含量的消化条件进行了研究,通过与国标法进行对比,确定该方法测定虾壳中氮含量的可行性。结果表明,加氢氧化钠的漏斗采用水封能提高蒸馏装置的气密性;最佳消化条件为:虾壳0.2 g,五水硫酸铜0.2 g,硫酸钾0.6 g,浓硫酸8 mL,双氧水4 mL,消化40 min。所测虾壳氮含量为(63.48±0.88)mg/g(P=0.95),加标回收率在95%~100%。该法准确度与国标法相当,且省时、经济、环保,适用于实验教学、科研和生产实践。 相似文献
17.
对3种共25株酵母菌进行了富铁能力的筛选,经过抗性筛选和摇瓶发酵培养筛选到一株生物量及细胞铁含量均较高的酵母菌株R4-5,该菌株能以甘蔗糖蜜作为唯一碳源发酵培养富铁酵母,在培养条件下,生物量为8.78 g/L发酵液,细胞铁含量为5.45 mg/g干菌体,总铁含量达47.851 mg/L发酵液。 相似文献
18.
营养盐对小球藻生长及胞内蛋白质含量的影响 总被引：2，自引：0，他引：2
微藻含有的蛋白质、糖蛋白等活性物质具有许多重要的生物活性和生理功能.在24～26℃、自然光照的条件下,首先考察小球藻生长与胞内蛋白质积累的关系,其次利用正交设计实验考察不同浓度的营养盐对小球藻生长及胞内蛋白质含量的影响.结果表明,小球藻中蛋白质的合成与积累主要发生在生长过程的平衡期.利于小球藻生长的营养盐的优化组合为:C6H12O6:2g/L,KNO3:0.8g/L,Na2PO4:0.2g/L,细胞的最大密度为6.46×107个细胞/L培养液.获得最高蛋白质含量的营养盐的优化组合为:C6H12O6:6g/L,KNO3:1.6g/L,NaH2PO4:0.2g/L,与之对应蛋白质含量为:655.4mg/g.此结果为进一步从微藻中获取单一组成的,具有重要生物和生理活性的蛋白质及糖蛋白提供了优化培养微藻的实验依据和规模化生产的基础条件. 相似文献
19.
以饲料为原料筛选出一株既产乳酸又产芽孢的益生菌,经过分子生物学鉴定为凝结芽孢杆菌(Bacillus coagulans),命名为T-8。从培养基碳源、氮源、有机物浸出液、培养基pH、培养温度、培养时间等方面对菌株T-8展开发酵特性研究,结果表明,最优培养基配方为:玉米粉6 g/L、豆粕粉15 g/L、小麦麸皮浸出液60%、酵母粉5 g/L、蛋白胨10 g/L、氯化钠10 g/L,pH 5.0。以5%的接种量将种子液转接至最优培养基,在47℃的摇床中以200 r/min的转速振荡培养28 h,菌株T-8的细胞密度达到4.8×109 CFU/mL,芽孢率达到95.2%。本试验可为益生菌凝结芽孢杆菌应用于饲用微生物菌剂的工业化生产提供参考。 相似文献