共查询到19条相似文献，搜索用时 203 毫秒
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实验以杨树中的产脂内生真菌为出发菌株,以PDA培养基为种子培养基,探索了不同的碳源、氮源、无机盐、pH值和装液量等参数对产脂内生真菌种子培养的影响.实验确定最佳工艺参数为：碳源为4%,氮源为0.5%,KH2PO4为0.4%,MgSO4为0.2%,pH值为5.5,装液量为50%.在上述条件下,菌种量都最先进入稳定期. 相似文献
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《常熟理工学院学报》2015,(4)
研究了碳源、温度、溶氧、pH值及外源丙酮酸氧化酶表达对重组大肠杆菌DH5α/pSML-PyOD质粒稳定性的影响.结果表明,以甘油为碳源,37℃,装液量10%~15%条件下重组菌质粒稳定性最好.当发酵过程中体系pH值在6~7之间时,质粒稳定性较高,但当pH提高至7.5时,质粒稳定性会有所下降,重组菌在低pH值条件下有利于产丙酮酸氧化酶.外源蛋白表达使得重组菌质粒稳定性有所下降. 相似文献
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郭春芳 《福建教育学院学报》2003,4(1):65-66
研究了通气量、PH值、接菌量、发酵时间以及发酵培养基中不同氮源、碳源等发酵条件对碱性蛋白酶产生菌B1-2106产酶活力的影响.确定了碱性蛋白酶产生菌B1-2106发酵培养基的最适配方. 相似文献
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用刚果红染色羧甲基纤维素钠平板筛选方法,从土壤中筛选到一株具有高效产纤维素酶的菌株CMC-Z,经菌落形态观察及镜检,初步鉴定为放线菌.采用单因素及正交设计等试验对CMC-Z培养基、发酵条件进行了优化,碳源、氮源最佳添加量分别为可溶性淀粉1%、明胶2%;最佳发酵条件：接种量7.5%,培养基初始pH 7.0,装量100 mL,培养温度30℃,培养时间72 h.通过方差和极差分析,表明影响菌株CMC-Z纤维素酶产生的因素主次顺序为：可溶性淀粉浓度〉初始pH〉装量〉明胶浓度〉接种量〉温度〉发酵时间.经优化后,其酶活可达到38.37 u.mL-1. 相似文献
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通过三株红假单胞菌在不同碳源、氮源、pH值和不同温度等条件的混菌培养实验，筛选出适合其生长的最适碳源、氮源、pn值和培养温度、试验结果表明：该混合菌株在乙醇、丙酸钠、乙酸钠等5种碳源中，以乙酸钠为最适碳源；在氯化铵、硫酸铵等5种无机氮源中，以硫酸铵为最适氮；最适pH为8．5；最适培养温度为38℃。 相似文献
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利用杏鲍菇(pleurotus eyngii)降解啤酒糟液态发酵生产木聚糖酶,运用单因素与正交试验研究了啤酒糟、玉米芯与麸皮的不同组分、氮源、pH值、培养时间、转速、装瓶量等对产木聚糖酶活力的影响,并对其粗酶的酶学性质进行了研究。结果表明:碳源为3%啤酒糟、1%麸皮和1%玉米芯,氮源为0.5%酵母膏,pH值为5,培养时间为8d,转速为160 r/m in,接种量为10%,装瓶量为100 mL/250mL时,酶活力最高。其粗酶液的最适反应温度为50℃,最适反应pH为6,在pH4~6的范围内酶活性较稳定。但粗酶液的热稳定较差,当温度升至60℃时酶活力损失65%以上。 相似文献
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细黄链霉菌产木聚糖酶的研究 总被引：1，自引：0，他引：1
通过多因子摇瓶发酵优化实验,以细黄链霉菌为始菌,研究产木聚糖酶的情况.以甘蔗渣为惟一碳源,测定不同甘蔗渣含量的培养基中细黄链霉菌所产木聚糖酶的活力,同时测定氮源、接种量对该菌产木聚糖酶的影响,结果表明,其最适碳源含量为10%,最适氮源为酵母膏和硫酸铵的混合氮源,其最适接种量为5%;在装料50mL的三角摇瓶中于30℃、120rpm振荡培养5d后,发酵液中木聚糖酶活力达7.74IU/mL. 相似文献
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基于瓜环-磷光体-重原子微扰剂形成三元包络物,在亚硫酸钠除氧条件下诱导产生咖啡因室温磷光做了研究.并且针对体系的影响因素:重原子、Q[6]、亚硫酸钠用量、放置时间长短和最佳pH范围等做了较详细的研究.此外还对体系的分析性能做了测试,初步建立了检测咖啡因的室温磷光分析方法. 相似文献
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以测定的抑菌圈直径大小判定拮抗细菌的拮抗性能,并通过单因素及正交试验对拮抗细菌发酵培养基组分及发酵条件进行设计与优化.结果表明,最优化发酵培养基组成为淀粉3 g/L,蛋白胨12 g/L,氯化钙3 g/L,利用最佳发酵培养基进行条件为初始pH 8.0,接种量8%,装液量75 mL/250 mL,发酵时间24 h的发酵,此拮抗细菌的拮抗性能最佳,抑菌圈直径达2.6 cm左右.该研究为进一步提高拮抗细菌拮抗性能提供一定参考数据,同时也为拮抗细菌更好地应用提供必要的理论依据. 相似文献
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The production of butyric acid by Clostridium butyricum ZJUCB at various pH values was investigated. In order to study the effect of pH on cell growth, butyric acid biosynthesis and reducing sugar consumption, different cultivation pH values ranging from 6.0 to 7.5 were evaluated in 5-L bioreactor. In controlled pH batch fermentation, the optimum pH for cell growth and butyric acid production was 6.5 with a cell yield of 3.65 g/L and butyric acid yield of 12.25 g/L. Based on these results, this study then compared batch and fed-batch fermentation of butyric acid production at pH 6.5. Maximum value （16.74 g/L） of butyric acid concentration was obtained in fed-batch fermentation compared to 12.25 g/L in batch fermentation. It was concluded that cultivation under fed-batch fermentation mode could enhance butyric acid production significantly （P〈0.01） by C. butyricum ZJUCB. 相似文献
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INTRODUCTION Butyric acid has several potential applications in industry. Its applications in the foodstuffs and beverage industries are widespread. It may be used as the pure acid in the dairy industry, or in the form of esters as a food additive to increase fruit fragrance. Furthermore, butyric acid could also have some important physiological functions. For example, butyric acid esters are the character-impact flavors in tropic fruits and dairy products (Centeno et al., 2002; Watson e… 相似文献
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Qian Jun-qing 《浙江大学学报(A卷英文版)》2001,2(2):209-213
Water extraction of soybean oil was studied to find the optimal conditions for recovery of oil preenriched protein and for
aqueous extraction of soybean oil. Orthogonal tests were employed in the procedures of oil pre-enrichment and aqueous extraction.
Soybeans were crushed to pass a 40 mesh sieve, soaked under the optimum conditions (solid/water=1/5(w/v), 40°C, pH 10, 3 h)
and water-ground to 100 mesh, stirred in 65 °C water for 20 min, and centrifuged at 1400 g to separate oil pre-enriched protein.
The protein yield was 17.8 g from 100 g soybeans, which contained 62.8% oil. The oil yield was 69.0%. Optimum conditions for
the aqueous extraction procedure were: solid-to-water ratio 1∶2, pH 9.0, time 30 min, stirring in boiling water bath, stationary
time 10 min, centrifuge at 3600 g for 10 min. Experimental values showed that the oil yield after aqueous extraction from
oil pre-enriched protein reached 88.3%, so the total oil extraction rate was 60.8%. 相似文献
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实验采用单因素试验优化纳豆菌液体发酵条件。通过蛋白凝块溶解时间法测定纳豆激酶活力,筛选出最佳培养条件。液态发酵选用甘油、乳糖以及木糖与葡萄糖的混合糖代替基础培养基中的麦芽糖;用酵母膏、干酪素、胰蛋白胨和黄豆汁代替基础培养基中的麸皮进行发酵产酶试验,筛选出最佳碳氮源,并在此基础上变换不同的碳、氮源浓度,筛选出最佳的碳、氮比。试验结果表明：液态发酵最佳条件为,甘油10％,酵母膏2％,明胶0．5％,NaCl 0．5％,KH2PO4 0．1％,K2HPO4 0．4％,MgSO4 0．05％,初始pH7．0。在此条件下培养,测得的纳豆激酶活力相当于尿激酶1081．22IU／mL。与此前报道结果800．50IU／mL相比有了明显的提高。 相似文献
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The cis and trans isomers separation of2-butene- 1,4-diol and lafutidine were studied by HPLC on two kinds of chiral columns: (S,S)-Whelk-O 1 and ChiraSpher. The isomers of 2-butene-1,4-diol can be separated on both chiral columns while the isomers of lafutidine can only be resolved on ChiraSpher column. The influence of different type and amount of mobile phase modifier on the isomers separation was extensively studied. The resolution of cis and trans isomers of 2-butene-1,4-diol was 2.61 on (S,S)-Whelk-O 1 column with hexane-ethanol (97:3, v/v) as the mobile phase. The resolution of lafutidine was 1.89 on ChiraSpher column with hexane-ethanol-THF-diethylamine (92:3:5:0.1, v/v/v/v) as the mobile phase. LC-MS methods were developed to identify the isomer peaks. 相似文献