共查询到19条相似文献，搜索用时 203 毫秒
1.
酵母中麦角固醇含量测定的研究 总被引：7，自引：0，他引：7
对测定酵母菌株中麦角固醇的“皂化-萃取-紫外检测”法进行了探讨，通过反复实验确定了最佳的皂化及测定条件：300g／L的KOH溶液，40%（V／V）的乙醇水溶液，麦角固醇在282nm处有最大紫外吸收值。 相似文献
2.
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
3.
这篇章着重比较分析了榛子的芽和幼茎愈伤组织中紫杉醇的合成能力。用高效液相色谱仪测定榛子，结果显示芽比幼茎含量更高。用2．0mg/L BA和1．4mg/C LNAA诱导幼芽，8天后的愈伤组织以100％的速度感应。较好的培养愈伤组织的方法是用0．5mg/L2，4-D、1．0mg/L NAA和0．5mg/L KT补充B5培养基。测得愈伤组织的生长速度和紫杉醇的含量分别是7．74g／L和0．13％。 相似文献
4.
酵母菌经过不同浓度的盐溶液、低温等不同方式的逆境处理,不同时间内取样,对海藻糖的含量进行测量,得出酵母菌海藻糖含量积累的最佳单一胁迫条件是：1．2mol／LNaCl溶液处理酵母菌30min;0．9mol／L KCl溶液处理酵母菌60min;0．6mol／LMgS04溶液处理酵母菌90min;1．2mol／LCaCl2溶液处理酵母菌90min;0．8mol／LAICl3溶液处理酵母菌6h;0．4mol／LFeCl3溶液处理酵母菌3h;0℃处理酵母菌15s． 相似文献
5.
以薄荷（Mentha haplocalyx Briq）幼嫩叶片为外植体，采用正交设计L9（3^3）考察6-BA，NAA，2，4-D3种植物生长调节物质对叶片愈伤组织诱导的影响，实验结果表明薄荷叶片愈伤组织诱导最佳培养基为MS＋6—BA10mg／L＋NAA1．0mg／L＋2，4-D0.5mg／L＋蔗糖30g／L．在此培养基上研究不同培养条件对愈伤组织增殖效应的影响，结果表明薄荷愈伤组织继代增殖适合且经济的培养条件为蔗糖20g／L，液体浅层静置培养． 相似文献
6.
在太阳光光照的条件下,采用正交实验法研究了Fe3O4／柠檬酸盐／H2O2催化氧化弱酸性红玉N-5BL废水的效果,探讨了染料浓度、Fe3O4和柠檬酸盐的用量以及溶液pH值对催化效果的影响．实验结果表明：在pH=2,1．5g／L柠檬酸钠,1．0g／LFe3O4和体积分数为0．5％H2O2体系中,0．04mg／L的弱酸性红玉N-5BL废水。在太阳光照射30min条件下。脱色率可达95％,弱酸性红玉N-5BL结构中的-N=N-和芳香环均被破坏． 相似文献
7.
微波消解石墨炉原子吸收法测定蔬菜中的痕量镉 总被引：1，自引：0，他引：1
采用微波消化技术，以自吸背景校正方式，在硝酸介质中，NH4H2PO4和Mg(NO3)2混合物为基体改进剂，直接用石墨炉原子吸收法测定了蔬菜中的镉，并研究了最佳的实验条件．该法在0-6μg／L范围内呈良好的线性关系，检出限为0．16μg／L，回收率为96．4％-103．8oA．用于蔬菜中痕量镉的测定，结果满意。 相似文献
8.
以平菇为材料,分析了不同浓度的Fe^2＋在其菌丝体和子实体中的富集及其生长的影响．试验表明：在液体培养基中添加150mg／L的Fe^2＋,平菇菌丝体中铁的含量最高为1．4mg／100g干重;在液体培养基中添加100mg／L和150mg／L的Fe^2＋,平菇菌丝体吸收铁的效率最高为2．0％;固体培养基Fe^2＋浓度为125mg／L时能明显促进菌丝体的生长;子实体中添加5gFeSO4．7H2O时能明显提高其产量,子实体中添加2．5gFeSO4．7H2O时吸收Fe^2＋的效率最高,为1．19％． 相似文献
9.
8种杀菌剂对苦瓜枯萎病菌的室内毒力测定 总被引：1，自引：0，他引：1
采用生长速率测定法和分生孢子萌发抑制率法,在舍药PDA平板上和凹玻片上分别测定8种杀菌剂对苦瓜枯萎病尖孢镰刀菌的毒力作用。结果表明：20％五氯硝基苯DP对菌丝生长的抑制作用最强,EC50值为8．37mg／L,其次为40％五硝·多菌灵WP、12．5％戊唑醇WP、50％多菌灵WP和75％百菌清、聊,EC50值分别为：10．61mg／L、10．65mg／L、12．62mg／L、15．40mg／L。12．5％戊唑醇WP和对孢子萌发抑制作用最强,EC50值为3．68,20％五氯硝基苯DP、25％腈菌唑EC、40％五硝·多菌灵Ⅵ巾、50％多菌灵WP次之,EC50值分别为4．81mg／L、8．51mg／L、9．90mg／L、11．17mg／L。 相似文献
10.
在高初糖谷氨酸发酵中，高玉米浆用量、高生物素用量可以明显降低高初糖对菌体细胞的抑制作用；且在接种量为10％，玉米浆用量为0．55％，生物素用量为10μg／L，初糖为190g／L的谷氨酸发酵中，流加500g／L的浓糖，30h的产酸率达到145.8g／L，糖酸转化率达到60．32％。 相似文献
11.
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
12.
研究了大豆根瘤菌AWCS13-4菌株在YMA、TY、PA、BSE 4种培养基中的生长情况,并通过单因素和正交试验确定最佳培养条件。结果表明,AWCS13-4菌株在YMA培养基中生长较好,蔗糖为最佳碳源,酵母粉为最佳氮源,最佳p H为7.0,最佳接种量为3%,最佳培养温度为30℃。在单因素的基础上,采用正交试验,对4个因素进行优化,其最佳培养组合为:每升培养基中添加蔗糖10 g,酵母粉3 g,Mg SO4·7H_2O 0.2 g,K2HPO40.5 g,NaCl 0.1 g,CaCl_2·5H_2O 0.05 g,Rh微量元素液4 m L;p H为7.0,接种量为3%,培养温度为30℃。 相似文献
13.
The influence of KH\-2PO\-4, peptone and brown sugar on Termitomyces fuliginosu's mycelium formation was studied with the application of the design of quadratic rotation general combination based on determining the growth curve. A quadratic regression model of biomass to the doses of the above three factors was established. The model fit well and therefore the optimum fermentation condition was obtained. Responses of biomass to the three single factors and to their interactions were discussed. Thus, the highest level of biomass, 21.1 g/L, appeared under the optimized conditions when the initial KH\-2PO\-4, peptone and brown sugar were 1 g/L, 4 g/L and 72 g/L respectively. 相似文献
14.
Studies on optimization of nitrogen sources for astaxanthin production by <Emphasis Type="Italic">Phaffia rhodozyma</Emphasis> 总被引：2，自引：0，他引：2
Ni H Chen QH Ruan H Yang YF Li LJ Wu GB Hu Y He GQ 《Journal of Zhejiang University. Science. B》2007,8(5):365-370
Fermentation ofPhaffia rhodozyma is a major method for producing astaxanthin, an important pigment with industrial and pharmaceutical application. To improve astaxanthin productivity, single factor and mixture design experiments were used to investigate the effects of nitrogen source on Phaffia rhodozyma cultivation and astaxanthin production. Results of single factor experiments showed nitrogen source could significantly affect P. rhodozyma cultivation with respect to carbon source utilization, yeast growth and astaxanthin accumulation. Further studies of mixture design experiments using （NH4）2SO4, KNO3 and beef extract as nitrogen sources indicated that the proportion of three nitrogen sources was very important to astaxanthin production. Validation experiments showed that the optimal nitrogen source was composed of 0.28 g/L （NH4）2SO4, 0.49 g/L KNO3 and 1.19 g/L beef extract. The kinetic characteristics of batch cultivation were investigated in a 5-L pH-stat fermentor. The maximum amount of biomass and highest astaxanthin yield in terms of volume and in terms of biomass were 7.71 mg/L and 1.00 mg/g, respectively. 相似文献
15.
不同浓度6-BA对春兰×大花蕙兰种间杂种原球茎增殖与分化的影响 总被引：2，自引：0，他引：2
郑立明 《浙江教育学院学报》2008,(6):68-72
以春兰“宋梅”X大花蕙兰“粉姬”种间杂种的一个株系的原球茎为材料,研究6．BAlmg／L、2mg／L、4mg／L三个浓度组对原球茎增殖以及叶芽和根的分化与生长的影响．实验发现,三个浓度组对该株系原球茎的个数增殖及叶芽分化量的增加都有极显著的促进作用,2mg／L、4rag／L两个浓度组对该株系原球茎的鲜重增长有极显著的促进作用,三个浓度组对该株系原球茎叶芽的生长以及根的分化与生长都有抑制作用． 相似文献
16.
The influence of membrane fouling on the retention of the trace organic contaminant sulfamethoxazole by a nanofiltration (NF)
process was investigated. Organic fouling caused a severe flux decline possibly due to pore blocking and adsorption directly
after the commencement of the fouling layer development. Such membrane-foulant interactions were absent for colloidal fouling,
which resulted in a more gradual flux decline. Membrane charge played a significant role in the separation process of inorganic
salts, where the retention was the highest in a caustic environment (high pH) due to more swollen membrane material caused
by the higher negative charge on the membrane. Organic fouling and a combination of colloidal and organic fouling led to a
significant increase in the membrane negative charge. The influence of membrane fouling on solute retention was dependent
on the fouling behaviour and the physicochemical properties of the model foulants, where the model foulants probably contributed
to an increase in the retention of charged solutes due to enhanced electrostatic interactions. Organic fouling caused an increase
in the retention of inorganic salts and sulfamethoxazole due to pore blocking. In contrast, colloidal fouling caused a decrease
in the retention of inorganic salts due to cake-enhanced concentration polarisation. However, the presence of a colloidal
fouling layer did not reduce the retention of sulfamethoxazole. A mixture of colloidal and organic matter improved the retention
of inorganic salts. A similar conclusion can be inferred for sulfamethoxazole at pH 4 when the compound exists in a neutral
form. 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.
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
19.
采用静态吸附法研究活性炭和硅藻土对3种实验废水在不同吸附条件下(吸附剂量、时间、pH值)的吸附效果。结果表明活性炭在投加量为40 g/L,振荡时间为1 h,无机、有机、混合样品pH分别为4、6、10时,可使样品色度和COD去除率达到最佳效果;硅藻土在投加量为30 g/L,振荡时间为20 min时,无机、有机、混合样品pH分别为8、4、4时,可使废水COD去除率达50%以上,但色度去除效果较差。实验表明硅藻土和活性炭串联吸附为较优方案。 相似文献