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研究表明,苏云金杆菌(Bacillus thuringiensis)对马尾松毛虫(Dendrolimuspunctatus)幼虫的毒性与苏云金杆菌的不同亚种,同一亚种的不同菌株以及发酵培养基组分有相关性,而在发酵过程中培养基全氮、有机碳、碳氮比例的消长规律与对昆虫的毒性未见一定的相关性。在发酵过程中,同一菌株在同一培养基中的菌数与试虫毒性成正相关;而不同菌株在同一培养基或同一菌株在不同培养基中菌数与对试虫的毒性无关。因此,单纯以活孢子数为指标评价苏云金杆菌不同菌株和不同发酵条件下的杀虫活性是不科学的。 相似文献
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大豆秸秆纤维素固态发酵及酶解条件的研究 总被引:5,自引:0,他引:5
对经氨预处理的大豆秸秆纤维素固态发酵产酶及酶解产糖工艺过程进行了研究,影响康氏木霉(Trichoderma koningii)固态发酵的主要因素是温度、pH值、培养基液固质量比及培养时间,影响纤维素酶水解的条件主要是温度、pH值及时间,结果表明:较适宜的产酶条件为温度30℃,pH值5.0,培养基液固质量比2.5:1,时间96h,产纤维素酶活力为798.84FPU/mL,以所产纤维素酶进行酶水解,较适宜条件为温度55℃、pH值5.6、时间36h,酶解率为18.98%。由液相色谱分析可知酶解液的主要成分为葡萄糖、纤维二糖和木糖.为大豆秸秆的进一步综合利用提供了参考数据。 相似文献
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碱性纤维素酶发酵条件的研究 总被引:2,自引:0,他引:2
采用芽孢杆菌Bacillus sp.AC-2作为碱性纤维素酶的生产菌株,对其发酵条件进行了研究。适宜的种子茵龄为24h;适于产酶的培养温度为37℃,培养基初始pH值10.5;在碳源和氮源分别为1%的淀粉和2%的豆饼粉时,碱性纤维素酶活力可达到76.04U/mL。该酶反应的最适温度为60℃;酶液在70℃以下、pH值6.0~10.0范围内稳定。该酶制剂在棉织物洗涤和纸浆脱墨方面具有良好的应用前景。 相似文献
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正红菇(Russula vinosa)为出发菌株,对其液体发酵生产胞外多糖的培养基组成(碳源、氮源和无机盐)和培养条件(温度、pH值、发酵时间和装液量)对胞外多糖和菌丝体生物量的影响进行了研究。结果表明:液体发酵培养基的最佳碳源为蔗糖,质量浓度为40g/L;最佳氮源为酵母膏,质量浓度为9g/L;添加无机盐组分为KH2PO42g/L和MgSO41g/L;适宜的发酵条件为初始pH为5.5-6.5,发酵温度为28-30℃,250ml三角瓶装液量为50-60ml,发酵时间为5d。通过优化培养基和发酵条件,胞外多糖产量达到4.96 g/L和菌丝体生物量达到22.34 g/L。 相似文献
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通过平板涂布、划线分离、菌落观察等方法,从土耳其倍子提取液自然生长的菌落中分离纯化出11株菌,从中初筛出1#、2#、4#这3株降解没食子单宁的菌株,复筛出1株没食子单宁优良降解菌株1#菌,其没食子单宁降解率达65%以上,发酵液中没食子酸质量浓度为0.052 3 g/L,单宁酶活为0.920 U/mL;对1#菌株的发酵条件进行了响应面法优化,结果表明:1#菌最佳产酶条件为培养温度31℃,初始培养基pH值5.0,最适培养时间50 h,在该条件下1#菌单宁酶酶活可达1.170 U/mL,与优化前的最大酶活0.920 U/mL相比,提高了27.2%。 相似文献
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一品红组织培养技术研究 总被引:3,自引:1,他引:2
一品红组织培养以花轴序、叶片或顶芽、腋芽为外殖体,在MS BA2.0mg/L NAA0.50nm/L 蔗糖30g/L 琼脂5g/L CH70mg/L pH5.8的培养基上进行初代培养后转接到MS BA0.5 NAA0.20 蔗糖30g/L 琼脂5g/L。 pH5.8的培养基上扩繁,增殖率为13.1,丛生芽分化快;生长速度快,将2cm左右嫩梢剪下接种在1./2MS NAA0.1 蔗糖15g/L 琼脂5mg/L pH5.8的培养基上诱导生根,10d左右即可生根。一品红组培苗生根与继代次数关系密切,继代次数10次以下,生根率达100%,之后逐渐下降,需要重新建立培养系。试验总结出一品红12个品种组织培养的一整套技术,为一品红工厂化生产提供了技术依据。 相似文献
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通过优化复合微生物菌肥主要功能菌的发酵培养基配方及其发酵条件,提高发酵液中功能菌的活菌含量,以期为大规模生产复合微生物菌肥奠定基础。利用单因素实验结合正交的方法,以菌体生长量(OD600)为测定指标,对复合微生物菌肥主要功能菌中的固氮菌、溶磷菌和解钾菌的发酵培养基进行优化。结论:①固氮菌培养基的最优组合为麦芽糖7.5g、蛋白胨15g、NaH2PO4·H2O0.3g、K2HPO40.5g、FeCl30.2g、MgSO4·7H20.5g,最佳pH值6.8,最佳接种量为100mL,最佳转速为180r·min-1最佳发酵温度为30℃;②溶磷菌培养基的最优组合为麦芽糖7.5g、蛋白胨15g、NaH2PO4·H2O0.3g、K2HPO40.5g、FeCl30.5g、MgSO4·7H20.5g,最佳pH值6.4,最佳接种量为300mL,最佳转速为180r·min^-1最佳发酵温度为30℃;③解钾菌培养基的最优组合为甘露醇7.5g、牛肉膏15g、NaH2PO4·H2O0.3g、K2HPO40.5g、FeCl30.5g、MgSO4·7H20.5g,最佳pH值7.6,最佳接种量为100mL,最佳转速为180r·min^-1最佳发酵温度为34℃。 相似文献
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In vitro rooting constitutes a difficult step during the micropropagation process of forest species. The successive media culture technique represents one way to overcome this barrier and includes modifying physical (e.g. photoperiod) and chemical (e.g. flavonoids) factors during the rooting phases. The aim of this study was to obtain a successive media protocol based on the incorporation of flavonoids during the in vitro rooting of Nothofagus nervosa. The factors evaluated were the type, concentration, and combination of flavonoids in relation to the rooting phases, the presence of IBA in the culture medium, the photoperiod, and the effect of flavonoids on total tissue peroxidase activity. The photoperiod used included a darkness period during the rooting induction stage and the presence of 0.61 µMIBA in the culture medium. The results showed that flavonoid incorporation at a concentration of 20 µM accelerated the appearance of roots and improved the quality of the already formed ones. Each type and concentration of flavonoid produced different responses, with (±)naringenin giving the best results. The latter caused a peak in the peroxidase activity that was absent in the control treatments. This work allowed identifying an optimized rooting protocol through a successive media culture technique that improved the speed of appearance, as well as the quantity and quality of roots for a single N. nervosa clone. 相似文献
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Stress relaxation of water-saturated wood was examined at various temperatures and during the processes of elevation and lowering of temperature. The difference between relaxation at a lower temperature and that at a higher temperature was almost same as the increase in relaxation during temperature elevation. Similar results were obtained regardless of the elevating speed of the temperature and regardless of preheating the samples. On the other hand, relaxation behavior during temperature lowering was quite different from that during temperature elevation. The relaxation moduli during the process of lowering the temperature scarcely changed, although those at various constant temperatures decreased with increases in temperature. Marked sets occurred after relaxation measurements under temperature lowering, whereas only slight sets occurred during the process of elevating the temperature or at a constant temperature of 80°C. Furthermore, it was found that the sets that occurred during the process of temperature reduction were almost recovered when the samples were heated again in water. The mechanism of the relaxation behaviors observed in the present study under nonequilibrium temperature is discussed in relation to the occurrence of set after relaxation measurements.Part of this report was presented at the 48th annual meeting of the Japan Wood Research Society, Shizuoka, April 1998 相似文献
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在几种木本植物杨树、杉木、油茶根际存在着联合固氮体系 ,从它们根际分离到 2 6株具有较高固氮酶活性的菌株 .筛选了 4株具有高固氮活性的菌株 Aa33、Ba41、y12、Y2 2进行固氮特性研究 ,并选择菌株 y12、Y2 2进行形态、培养特征及生理生化研究 ,初步鉴定为黄杆菌属 F lavobacterium和产碱菌属 Alcaligenes.这对今后开展木本植物固氮领域的研究及其利用具有现实的指导意义 . 相似文献
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K. Rykowski 《Forest Pathology》1976,6(5):264-274
Studies on the nitrogen nutrition of several strains of Armillaria mella. II. The influence of different concentrations of carbon and of nitrogen (C:N). Mycelial production and the morphology of several isolates of Armillaria mellea and Clitocybe tabascens was investigated in relation to different concentrations of carbon (D-glucose) and nitrogen (L-asparagine) in the medium. The role of carbon and nitrogen and of the proportions C:N in the process of rhizomorphogenesis was established. Mycelial production and initiation and development of rhizo- 相似文献