Biodegradation of Congo Red Azo Dye by Aspergillus spp,Isolated from Dye Contaminated Soils

In the present study, it has been aimed to determine the non target effects of Congo red on soil enzyme activities namely amylase, protease, catalase, glucose oxidase and laccases, following the standard procedures. Further, it is also aimed to decolourize the dye effluents by using immobilized fimgal cultures namely Aspergillus spp. isolated from textile effluents and estimate the percentage of decolourization by dye decolourization assay method. The selected fungi were found efficient and dominant type in dye decolourization with the production of laccase and other enzymes. Except laccase, all the enzymes showed maximum activity at 14 days followed by declining trend at 21 days. Maximum enzyme activity was noticed with Aspergillus niger. 95% of decolourization was found within 4-24 h in sodium alginate immobilized fungal cultures compared to controls. The above results clearly indicate the efficiency of these fungi in selective bioremediation of dye contaminated sites.     

Antagonizing Aspergillus parasiticus and Promoting Peanut Growth of Bacillus Isolated from Peanut Geocarposphere Soil

A set of 38 Bacillus strains isolated from peanut geocarposphere soil were screened as potential biological control agent anti-Aspergillus parasiticus. Tip-culture method with rapid and quantitative characteristics was used to determine anti-A. parasiticus activity and the process of isolation could be accelerated with this method. 12 out of 38 Bacillus strains showed high anti-alfatoxin production activity. These 12 Bacillus strains were selected to identify the characteristics of promoting peanuts germination rate. Pot experiment in greenhouse was carried out by using these strains which can promote peanuts germination. Phytohormones in the fermentation broth were also detected as another important reference factor to select the isolates as biological control agent with PGPR features. These Bacillus strains isolated from peanut geocarposphere soil not only had high ability anti-Aspergillus parasiticus, but also promoted peanut growth. Therefore, these Bacillus strains were well adapted to peanut production in the ifeld as biological control agent with plant growth promoting rhizobacteria （PGPR） features.     

饲料中杂色曲霉素检测方法的研究

杂色曲霉素在自然界广泛存在,毒性强,可经过多种途径吸收,诱发人和动物产生肿瘤,从而造成极大危害.本研究旨在寻找快速简单的方法测定饲料中的杂色曲霉素,通过蒸馏,提纯,浓缩及荧光显色,发现甲醇法和乙腈法都可以简便快速地检测饲料中的杂色曲霉素.     

无冠构巢曲霉与北冬虫夏草发酵液中虫草素及腺苷含量比较分析研究

采用高效液相色谱法首次同时检测了无冠构巢曲霉与北冬虫夏草菌株发酵液中虫草素和腺苷的含量,并对不同发酵条件下两菌株虫草素和腺苷含量进行了比较。结果表明,虫草素和腺苷在所设色谱条件下得到很好的分离,二组分的线性关系良好,回收率满意。其中虫草素峰保留时间为11.443 min,腺苷峰保留时间为9.054 min。结果还表明,无冠构巢曲霉菌株在培养的第9天,pH分别为5.0和7.0,温度分别为28℃和35℃时,产虫草素和腺苷的能力高于北冬虫夏草菌株。其中无冠构巢曲霉菌合成虫草素的最高值为249.46μg/mL,北冬虫夏草菌为228.45μg/mL;无冠构巢曲霉合成腺苷的最大值为46.98μg/mL,北冬虫夏草菌仅为16.95μg/mL。因此,无冠构巢曲霉菌作为新生物源发酵提取虫草素和腺苷比北冬虫夏草菌更具有应用价值。     

不同微生物添加组合对桑枝叶青贮效果的影响

[目的]为了有效合理地开发桑枝叶在饲料行业中的应用价值,并在生产中推广应用。[方法]试验以新鲜的桑枝叶为原料,对不同微生物组合青贮桑枝叶的发酵品质进行研究,试验分3个组,自然发酵组(对照组)、自备菌剂微贮组(试验组Ⅰ)、商品菌剂微贮组(试验组Ⅱ),每组设3个重复。30 d后测定各组青贮常规营养成分含量、pH、挥发性脂肪酸含量。[结果]结果表明,与对照组相比试验组Ⅰ、Ⅱ的CP含量差异显著(P0.05);NDF和ADF含量均显著降低(P0.05);与对照组pH相比,试验组Ⅰ、Ⅱ均有降低,但差异不显著(P0.05);试验组乳酸含量显著高于对照组(P0.05);试验组乙酸含量显著高于对照组(P0.05);试验组丙酸、丁酸含量与对照组相比差异不显著(P0.05);试验组中氨态氮含量均有所降低,差异不显著(P0.05)。[结论]最终得出,添加米曲霉(XMS01)、植物乳杆菌(XMS02)、植物乳杆菌(XMS03)、枯草芽孢杆菌等可提高桑枝叶青贮CP、乳酸和丁酸的含量,显著降低NDF和ADF含量,改善桑枝叶青贮的品质。     

利用曲霉sp.HS-6发酵玉米秸秆进行固体纤维素酶的制备

以玉米秸秆为原料,分别以氯化铵、硫酸铵、硝酸铵、硝酸钾和尿素为氮源,设置了氮源的3个浓度梯度:0.5、1和2 g·L-1,对曲霉sp.HS-6产纤维素酶条件进行探究,主要确定了最佳发酵时间、最佳氮源种类和最佳氮源浓度,再利用得到的最佳条件,进行盐析,低温冷冻干燥等技术发酵得到酶制剂。结果表明,通过测定酶活,确定了该曲霉的最佳发酵时间为3 d,筛选得到最佳的氮源种类为硝酸铵,硝酸铵最佳的氮源浓度为0.5 g·L-1。基于此最佳条件,将60 g玉米秸秆粉末发酵培养3 d,最终从发酵液中提取得到纤维素酶干品酶制剂8.0 g,并计算出酶的回收率为48.0%。此实验对以后纤维素酶的规模化制备提供了一定的工艺参考。     

红曲霉高产水溶性色素菌株的筛选

通过紫外诱变筛选出一株高产水溶性色素的红曲霉菌株,并对其生长特性进行研究,为开拓红曲色素的应用领域奠定了基础。     

一种微生物产物曲霉素C9H12O4晶体和分子结构

本文从一种微生物代谢产物中分离到一种曲霉素Ｃ９Ｈ１２Ｏ４，采用２ＤＮＭＲ、ＩＲ、ＭＳ和元素分析等手段对此化合物进行了结构表征，推导出其化学结构，并通过Ｘ－晶体衍射测定进一步肯定了上述结论。     

菌物生物技术：外源蛋白在米曲霉中的表达及分泌

米曲霉是与工业用酶及食品发酵相关的重要微生物,其分泌蛋白的能力有望将其用于外源蛋白表达的遗传工程研究。为了构建米曲霉的转化系统,首先由紫外照射,分离获argB^-突变株,再通过CaCl2调节的化学方法和电穿孔技术将携带构巢曲霉argB基因的质粒导入米曲酶受体细胞,经筛选获得多拷贝及遗传稳定的转化子,转化频率为10～50转化子/ug DNA。虽然构巢曲霉与米曲霉argB基因的同源性不高,但前者对后者argB^-突变能起到补偿作用。在电场调节的转化中--电穿孔,适宜条件为6.3kV/cm和1540ohm。电场中,原生质体相对于非原生质体在1.3kV/cm条件成活率为80%,而6.3kV/cm下为50%。为了实现外源基因在米曲霉中的表达,天然植物源的蜜饯--奇甜蛋白基因及构巢曲霉中作为营养选择标记的argB通过共转化被引入受体细胞中,然后从培养基中获得与纯化的奇甜蛋白相似的具免疫活性的22kDa分子量的蛋白质,这说明植物中的信号序列同样可在米曲霉中起作用,调节奇甜蛋白分泌到细胞外。     

有机磷农药乐果降解菌株L3的分离鉴定及其性质的初步研究

从常年施用农药乐果的土壤中,通过富集培养和平板稀释法,分离得到一株具有较强降解有机磷农药乐果能力的真菌菌株L3,通过形态观察及真菌的ITS检测,对其进行了鉴定,同时对其性质进行了初步研究。结果表明,该菌株为Aspergillus nomius。是以共代谢方式降解乐果的。在查氏培养基中最高能耐受6 000 mg.L-1的乐果;在28℃、pH6.0的条件下生长较好,120 h对乐果的降解率达29.2%,并且对其他有机磷农药也有较好的降解作用,120 h对乙酰甲胺磷和辛硫磷的降解率分别达65.9%和95.3%,初步确定菌株L3对有机磷农药的降解有一定的广谱性。