赭曲霉43的甾醇成分研究

从赭曲霉43的菌丝体甲醇提取物中分离得到3个甾醇和1个腺苷，根据波谱数据，将它们鉴定为：5α，8α-表二氧-(20S，22E，24R)-麦角甾-6，22-二烯-3β-醇(1)、(20S，22E，24R)-麦角甾-7，22-二烯-3β，5α，6β-三醇(2)、(20S，22E，24R)-麦角甾-7，22-二烯-3β，5α，6β，9α-四醇(3)以及尿苷(4)，其中化合物3首次从曲霉属中分离得到．图2表1参16。     

预处理烟束曲霉死菌体与Cr的相互作用及机理

采用投加预处理烟束曲霉(Aspergillus fumisynnematus)死菌体的方法去除含铬废水中的Cr(Ⅵ).考察了不同溶液初始pH值、Cr(Ⅵ)初始浓度、死菌体投加量及温度条件下,CTAB预处理烟束曲霉死菌体对Cr(Ⅵ)还原速率和总Cr的平衡吸附率的影响,并根据红外光谱分析初步探讨了CTAB预处理烟束曲霉死菌体与Cr的相互作用机理.结果表明:CTAB预处理烟束曲霉死菌体对总Cr有良好的吸附效果,在30℃.150 r·min-1,pH 2.0的条件下,在100mL浓度20gg·L-1的Cr(Ⅵ)溶液中投加0.5 g CTAB预处理烟束曲霉死菌体,2h内总Cr最大吸附率达到了72%,约为原死菌体总Cr吸附率的2倍,但反应达到平衡后的总Cr吸附率下降到30%左右.吸附平衡后的解吸实验结果表明Cr(Ⅵ)几乎全部被还原为Cr(Ⅲ).在实验pH值范围内,pH值越低、Cr(Ⅵ)初始浓度越小、预处理死菌体投加量越大以及温度越高,越有利于Cr(Ⅵ)的还原;pH值越高、Cr(Ⅵ)初始浓度越小、预处理死菌体投加量越大以及温度越低,对总Cr的平衡吸附率越大.预处理死菌体与Cr的相互作用主要是氨基和羧基与不同形态Cr的吸附作用以及菌体对Cr(Ⅵ)的还原作用.     

降解毒死蜱曲霉Y的分离和降解效能测定

毒死蜱在灭菌土壤、施用过和未施用过毒死蜱的土壤中的降解速率测定表明：土壤中的微生物在毒死蜱的降解中起着重要的作用。同时，毒死蜱在连续使用后，降解速度大大加快，说明毒死蜱可诱发降解菌的产生，从连续使用毒死蜱的土壤中分离了1株可降解毒死蝗的真菌曲霉Y。测定了曲霉Y在不同接菌量、不同温度、不同毒死蜱浓度及不同碳源浓度下对毒死蜱的降解能力，同时，还测定了曲霉Y其他杀虫剂的降解能力。图6参13。     

黑曲霉Aspergillus niger SL2-111所产酸性蛋白酶的分离纯化及酶学特性

采用硫酸铵盐析、Sephadex G-25柱脱盐、DEAE-Sepharose Fast Flow离子交换层析、Sephacryl S-200分子筛层析和高效液相色谱等方法,从黑曲霉菌株Aspergillus niger SL2-111的发酵曲中提取了一种酸性蛋白酶,经SDS-PAGE验证,该酶纯化水平已达到电泳纯.该酶的表观分子量(Mr)约为47×103,最适pH值为3.0,pH稳定性范围为2.5～6.0,最适温度为50℃,温度稳定性范围为30～60℃;Gu2+、Mn2+对其有激活作用,Hg2+、Ag+对其则有轻度的抑制作用;该酶的氨基酸组成为中极性酸性氨基酸占17.29%,极性碱性氨基酸占4.50%,极性中性氨基酸占38.50%,其它为非极性氨基酸;N端氨基酸序列为SKGSAVTTPQ,经序列同源性比对,表明该酶与其它曲霉酸性蛋白酶具有极高的同源性.图4表5参15     

一株产微生物絮凝剂菌株的筛选及特性

从活性污泥及土壤中筛选出一株产絮凝剂的霉菌－黑曲霉，该菌所产絮凝剂对高岭土的絮凝活性可达90％以上，黑曲霉的培养实验表明，其适宜生长的碳源为葡萄糖或蔗糖，氮源为豆芽汁或马铃薯汁；适宜的初始pH值为6.0；生长与分泌絮凝剂的合适温度范围为30－34℃；受培养温度的影响，絮凝效果最好的时间在50－60h。絮凝实验表明，用培养液处理高岭土悬浊液时有明显的絮凝效果，当废水pH左右时，絮凝效果最好。     

Screening of flocculant-producing strains by NTG mutagenesis

Screening of new microorganism being able to produce efficiently flocculants was carried out. A new model for screening efficient flocculant-producing strains was designed and tested. The results showed that this model for screening efficient flocculant-producing strains is very reliable and can greatly shorten the screening period. 13 flocculant-producing strains were isolated from activated sludge by conventional method. A strain, designated as HHE6, produced the bioflocculant with the turbidity removal 98% for kaolin suspension. Six of 13 strains selected as the original strains were treated with NTG as mutagen, and five mutant strains(HHE-P7, HHE-A8, HHE-P21,HHE-P24, HHE-A26) with high flocculation efficiency was obtained by selection, which exhibited the flocculation rate for kaolin suspension above 90%. Strains HHE6, HHE-P7, and HHE-P24 were classified as Penicillium purpurogenum, HHE-P21 as Penicillium cyclopium,HHE-A26 as Aspergillus versicolor and HHE-A8 as Aspergillus fumigatus, and it is hitherto unreported for biofloccutant-producing strains of Penicillium. The growth of the six strains(HHE6, HHE-P7, HHE-A8, HHE-P21, HHE-P24, HHE-A26) had similar curves, i.e. firstly increasing rapidly, keeping relatively constant then and finally decreasing gradually with cultivation time. The production of bioflocculants by strains showed the similar pattern to strain growth.     

一株黑曲霉(Aspergillus niger)对孟加拉红和水溶性色浆的脱色特性研究

以从土壤中分离得到的黑曲霉(Aspergillus niger)菌株为研究对象,采用液体培养的方法,研究其在不同碳源、氮源、起始pH值、金属离子种类及浓度条件下对孟加拉红和水溶性色浆的脱色效果.结果表明,在以豆芽汁培养基为基本培养基、甘油为碳源、(NH4)2SO4为氮源、初始pH值为6.0～8.0条件下的脱色效果最佳,...     

Antimicrobial activities of flavonoids against bamboo-destroying fungi and molds

It is well-known that Poria vaporaria (Pers.:Fr.) Cooke, Paecilomyces variotii Bainier and Aspergillus niger are fungi and molds which destroy bamboo. The aim of this study was to compare the effectiveness of antibacterial activity of 16 flavonoids in preventing the actions of these three bamboo-destroying fungi and molds (Poria vaporaria (Pers.:Fr.) Cooke, Paecilomyces variotii Bainier and Aspergillus niger). The results showed that baicalein(1) exerted the highest inhibitory effect on Poria vaporaria (Pers.:Fr.) Cooke and Paecilomyces variotii Bainier indicating that baicalein(1) may be considered as a potential agent to develop as natural bactericide to preserve natural bamboo.     

Na-CMC固定化烟曲霉对活性艳蓝KN-R的吸附脱色研究

采用羧甲基纤维素钠(Na-CMC)固定化烟曲霉对活性蒽醌染料活性艳蓝KN-R吸附脱色.通过批式吸附实验探讨了吸附体系的pH值、温度、供氧条件、盐度,固定化小球的粒径、接种量等对吸附脱色效率的影响.结果表明,适合于固定化小球吸附脱色的吸附体系的pH值在弱酸或碱性(4.3～9.0)范围内,不调pH值时(pH=4.3),48h的吸附率为94.5%,pH值为6～9时,48 h的吸附率在98%以上;固定化小球的最佳脱色温度为40℃,该温度下24h的吸附率达94.4%;氧充足情况下(摇床转速调节为50r·min-1)的吸附体系较静止状态能显著提高吸附脱色率;固定化小球脱色过程中能承受一定的盐度,NaCl浓度为0.1%时,吸附脱色效果最好;盐度为2.5%时,48h的吸附率降低至68.4%;粒径为2.0～3.85mm的固定化小球对活性艳蓝KN-R的吸附率相差不大;接种量为3.0%时的吸附脱色效果最好,24h对活性艳蓝KN-R的吸附率达91.0%.在烟曲霉生长期内,固定化小球吸附脱色动力学符合一级动力学方程.