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91.
本文以枯草杆菌BF-7658的诱变菌株Ning作为试验菌株,分别在摇瓶条件下和10升发酵罐上进行α-淀粉酶的发酵工艺条件的试验研究。结果表明:该菌株的发酵培养基碳氮比为1.4∶1,最适pH为6.5,通风量的变化极大地影响产酶能力;在较佳的培养条件下,摇瓶产酶活力为409.0u/ml,10升发酵罐的产酶活力为397.2u/ml,比原菌提高约100u/ml。 相似文献
92.
赵英杰 《河南工业大学学报(自然科学版)》1987,(4)
本文叙述了苏云金杆菌的基本形态和杀虫机理,总结了苏云金杆菌的使用方法及应用范围,讨论了苏云金杆菌的稳定性及用于储粮害虫防治的可能性. 相似文献
93.
94.
对BacillusmucilaginosusYNUCC000116SrDNA的1481bp片段与GenBank中最相似的16个分类单位进行了比较。UPGMA,NJ,ME和MP方法构建的系统发育树显示B.mucilaginosusYNUCC0001与B.mucilaginosusHSCC1605T、B.mucilaginosus1480D及Paenibacillussp.NBT形成一个单系群分支。在50L全自动发酵罐中30℃发酵52h后,菌株YNUCC0001产生的胞外生物多聚絮凝剂(EBF)达到最大产率(粘度:3420C.P.)。在pH4.0、用量为0.25mlL-1的条件下,这种EBF对高岭土悬浊液的絮凝活性最大(99.8%);121℃高压灭菌60min后絮凝活性维持在98.6%。Hg2 ,Ca2 ,Mg2 ,K ,Zn2 对其絮凝活性有促进作用,而Fe3 、Al3 、EDTA和Cu2 则有强烈抑制。 相似文献
95.
蜡状芽孢杆菌 (Bacilluscereus)S - 1菌株具有强烈的广谱抗真菌活性。本文作者报道该菌株产生的抗菌物质的分离纯化方法。该菌株的发酵液经酸化沉淀、有机溶剂萃取、SephadesG1 0 0和DEAE52纤维素层析等步骤后 ,所得样品经硅胶薄层层析显色为单点 ,表明抗菌物质得到纯化 相似文献
96.
通过实验研究了纳豆芽孢杆菌的育种方法,对初始纳豆芽孢杆菌进行了紫外及微波诱变,采用牛奶-琼脂板筛选菌种,得到了目的菌株QBNW467.研究表明,采用牛奶-琼脂板法筛选诱变后的纳豆芽孢杆菌方法可行,用该法筛选出的菌株QBNW467的固体发酵产酶活性可达2200 IU.g-1. 相似文献
97.
The influence of several factors on recovery of heat-treated Bacillus thuringiensis spores was examined including treatment conditions (time/temperature), dilution buffer (phosphate buffer, peptone water at 15 mg/L), recovery temperature and enumeration medium constituents (lysozyme, catalase, lactic acid hemicalcium salt, glucose, MgSO4, sodium chloride). A fractional factorial design was used to determine the incidence and interactions of these factors. Specific significant factors (treatment conditions, dilution buffer, recovery temperature, glucose and NaCl addition) were derived from this analysis and then tested in a general linear regression model which assessed their influences. The maximal count was obtained when spores diluted in peptone buffer were incubated at 25°C in nutrient agar containing NaCl and glucose. 相似文献
98.
Vivek Rangarajan Gunaseelan Dhanarajan Ramya Kumar Ramkrishna Sen Mahitosh Mandal 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2012,87(12):1661-1669
BACKGROUND: Lipopeptide production is strongly influenced by trace metals. The availability of free Fe2+ in the media throughout the process of fermentation was found to be very critical. Since free Fe2+ was reported to be sequestered by the lipopeptide as it was produced, intermittent feeding of Fe2+ was strategized and optimized for enhanced lipopeptide production by marine Bacillus megaterium in glucose mineral salts medium (GMSM). RESULTS: Studies with the single‐dose Fe2+ (0.48 mmol L?1) supplementation after 8 h of fermentation resulted in lipopeptide concentration of 3.3 ± 0.1 g L?1. Lipopeptide production was further enhanced to 4.2 ± 0.15 g L?1 by adopting a multi‐dose Fe2+ feeding strategy. The maximum product yield (YP/S) of 0.24 ± 0.02 g g?1 with specific product formation rate (qp) of 0.124 ± 0.01 g g?1 h?1 was achieved when 0.48 mmol L?1 Fe2+ was fed intermittently at different times as per the designed strategy. CONCLUSION: Lipopeptide concentration was improved 4.7‐fold by single‐dosing and 5.8‐fold by multiple dosing of Fe2+, when compared with GMSM without Fe2+ supplementation. Copyright © 2012 Society of Chemical Industry 相似文献
99.
Bo Yu Zhao-Xin Lu Xiao-Mei Bie Feng-Xia Lu & Xian-Qing Huang 《International Journal of Food Science & Technology》2008,43(7):1143-1151
Responses surface methodology was employed to enhance the production of protease and soybean peptides by Bacillus subtilis SHZ. For screening of medium composition significantly influencing protease and soybean peptides yield, the two-level Plackett–Burman design was used. Among thirteen variables tested; KH2 PO4 , glucose and defatted soybean flour (DSF) were selected based on their high significant effect on both protease activity and soybean peptides yield. Then, a three-level Box–Behnken design was employed to optimise the medium composition for the production of the protease and soybean peptides in submerged fermentation. Mathematical models were then developed to show the effect of each medium composition and their interactions on the production of protease and soybean peptides. The model estimated that, the maximal protease activity (320 ± 1 U mL−1 ) could be obtained when the concentrations of glucose, KH2 PO4 , DSF were set at 8–9 g L−1 , 2–3 g L−1 , 55–65 g L−1 , respectively; while a maximal yield of soybean peptides (8.5 ± 0.1 g L−1 ) could be achieved when the concentrations of glucose, KH2 PO4 , DSF were set at 7–9 g L−1 , 3–4 g L−1 and 55–58 g L−1 , respectively. These predicted values were also verified by validation experiments. 相似文献
100.