Aurasperone A Inhibits SARS CoV-2 In Vitro: An Integrated In Vitro and In Silico Study

Several natural products recovered from a marine-derived Aspergillus niger were tested for their inhibitory activity against SARS CoV-2 in vitro. Aurasperone A (3) was found to inhibit SARS CoV-2 efficiently (IC₅₀ = 12.25 µM) with comparable activity with the positive control remdesivir (IC₅₀ = 10.11 µM). Aurasperone A exerted minimal cytotoxicity on Vero E6 cells (CC₅₀ = 32.36 mM, SI = 2641.5) and it was found to be much safer than remdesivir (CC₅₀ = 415.22 µM, SI = 41.07). To putatively highlight its molecular target, aurasperone A was subjected to molecular docking against several key-viral protein targets followed by a series of molecular dynamics-based in silico experiments that suggested M^pro to be its primary viral protein target. More potent anti-SARS CoV-2 M^pro inhibitors can be developed according to our findings presented in the present investigation.     

纤维素酶产生菌黑曲霉X-15的选育及其产酶条件

突变型黑曲霉（Ａｓｐｅｒｇｉｌｌｒｓ ｎｉｇｅｒ）Ｍ００１分别经紫外线（ＵＶ）、亚消基胍（ＮＴＧ）、ＴＤＰ辐射仪及空间微重力辐射（ＳＣ）等因素的多级循环处理，得到１株形态发生改变的变异菌株Ｘ－１５。其固体培养纤维素酶的滤纸分解酶活力（ＦＰＡ）为１９Ｕ／g，羟甲基纤维素酶（ＣＭＣａｓｅ）活力为４５３Ｕ／g，β－葡萄糖苷酶（β－ｇｌｕａｓｅ）活力为１５４Ｕ／g，与出发菌株Ｍ００１相比，分别为其２．８倍、     

脂肪酶水解菜籽油脚料工艺条件的优化

[目的]优化脂肪酶水解菜籽油脚料的工艺,提高菜籽油脚料水解率。[方法]以菜籽油脚料为原料,选用黑曲霉脂肪酶水解菜籽油脚料,通过单因素试验、Box—Benhnken中心组合设计和响应面法对该脂肪酶水解油脂的工艺条件进行优化分析。[结果]单因素试验得出,黑曲霉脂肪酶水解菜籽油脚料的最适酶添加量为200u／ml,底物浓度75mg／ml,酶解pH7．0,酶解温度40℃,酶解时间45min以及摇床转数150r／min,此时菜籽油脚料水解率为16．4％。利用Box—Benhnken中心组合设计和响应面法确定了最优工艺条件是：酶添加量245U／ml,底物浓度为75mg／ml,酶解pH7．0,酶解温度是41℃,优化后的菜籽油脚料水解率达（26．92±0．86）％。[结论]研究可为菜籽油脚料的进一步开发利用提供参考依据。     

黑曲霉木聚糖酶基因（xynB）的克隆及真核分泌表达

通过RT-PCR方法,以黑曲霉(Aspergillus niger)GIM3.452总RNA为模板,克隆出木聚糖酶B(xy-lanase B,xynB)基因的成熟肽编码序列(567 bp),编码188个氨基酸.将其与猪腮腺分泌蛋白(parotid secretoryprotein,PSP)基因的信号肽序列通过重叠延伸PCR(SOE-PCR)得到拼接片段PSxynB,并将其克隆到真核表达载体pcDNA6/HisTMA中,得到重组质粒pcDNA-PSxynB,重组质粒经过酶切、测序鉴定,证实含有目的片段,且构建正确.在脂质体介导下将重组质粒pcDNA-PSxynB转染猪肾细胞(PK15),通过RT-PCR证实其在PK15细胞中表达,并在细胞培养液中测到了木聚糖酶活最高达36.4 IU/mL.     

Discrimination of Aphid Mutualists by an Ant Based on Chemical Cues

A chemical basis for discrimination between attended and unattended aphid mutualists by the ant Lasius niger (L.) (Hymenoptera, Formicidae) was investigated. In an arena bioassay, hexane extracts of the aphid Rhopalosiphum padi (L.) (Homoptera, Aphididae), which had been attended by the ant colony provoked significantly longer examination by ants than extracts of unattended aphids. Extracts of the ants themselves were significantly more active than hexane. In an olfactometer, ants spent significantly longer in the arm containing the odour of live aphids that had been attended by the ants than in arms containing the odour of unattended aphids. When unattended aphids were introduced onto an aphid-infested plant under attendance by L. niger, they suffered higher levels of attack and removal by the ants than did previously attended aphids. Unattended aphids treated with the extract of attended aphids suffered higher levels of attack than attended aphids, but lower levels of removal than unattended aphids. The results show that L. niger can discriminate between aphids that the colony have attended and unattended aphids of the same species using chemical cues.     

Evaluation of bioremediation and detoxification potentiality of Aspergillus niger for removal of hexavalent chromium in soil microcosm

Aspergillus niger isolated from soil of leather tanning effluent had higher activity to remove chromium then the other fungal isolates. The potency of A. niger was evaluated in shake flask culture by absorption of chromium at pH 6, temperature 30 °C. The toxicity of chromium evaluated in petriplates and soil microcosm seed bioassay test had indicated increase in toxicity with the higher concentration of chromate. A. niger introduced in soil microcosm (40% moisture content) with different concentration of chromate (250, 500, 1000, 1500 and 2000 ppm) removed more than 70% chromium in soil contaminated by 250 and 500 ppm of chromate. However, chromium-contaminated soil (2000 ppm of potassium chromate) mixed with compost (5% and 10%) significantly removed chromium in presence of fungus, A. niger. The results of chromate toxicity in the wheat plants revealed that the peroxidases was induced due to increase of metal stress which was reversed in soil microcosm amended with compost.     

臭氧对两种主要储粮真菌的抑制作用研究

研究了常温下不同浓度臭氧、不同处理时间对两种主要储粮霉菌黄曲霉、黑曲霉的生长抑制作用（菌落生长法）,以及臭氧对两种霉菌的菌落形态、菌丝结构的影响。结果表明,臭氧对两种霉菌菌落生长均表现出抑制作用,并且随着臭氧浓度的提高、处理时间的延长,抑制效果愈加显著;臭氧处理可使两种霉菌菌落褪色,菌丝发生弯曲、断裂或局部膨大,甚至使细胞发生胞溶。分析可知,在本实验条件下臭氧浓度170mg/m^3～190mg/m^3、处理6h对两种霉菌的抑制效果较为理想。     

黑曲霉中国株(3.758)葡萄糖氧化酶(GOD)基因的克隆与结构分析

[目的]为充分开发黑曲霉在轻工业中的用途。[方法]以黑曲霉中国株(3.758)基因组DNA为模板,用LATaqDNA聚合酶对葡萄糖氧化酶(GOD)基因进行PCR扩增,扩增片段纯化后与pUCm-T载体连接后,转化到大肠杆菌DH5α感受态细胞,经琼脂糖凝胶电泳法、酶切和PCR鉴定获得阳性克隆。对获得含GOD基因的克隆进行测序,分析其蛋白质氨基酸序列及限制性内切酶的图谱。[结果]经PCR扩增获得约1.8kb的片段。获得的GOD基因编码序列共1818bp,与报道的黑曲霉(ATCC9029)GOD基因序列仅有3个碱基之差。该基因序列具有多个限制性内切酶位点。黑曲霉不同菌株与中国株(3.758)GOD基因的同源性比较表明,不同黑曲霉菌株中GOD基因不同,而菌株ATCC9029与菌株NRRL-3是同一菌株。[结论]该研究获得了GOD基因的全长序列,为GOD的生物工程生产和相关植物基因工程奠定了基础。     

黑曲霉和里氏木霉原生质体形成与再生条件选择──Ⅱ．菌龄、酶配比及酶解温度和时间的选择

用正交试验比较了菌龄、酶种类及浓度配比、酶解温度和酶解时间４个主要因素，对黑曲霉（Ａｓｐｅｒｇｉｌｌｕｓｎｉｇｅｒ）ＡＭＳ１１和里氏木霉（Ｔｒｉｃｈｏｄｅｒｍａｒｅｅｓｅｉ）ＱＭ９４１４两菌株原生质体形成与再生的影响。结果表明，ＡＭＳ１１和ＱＭ９４１４两菌株原生质体形成与再生的４个因素的合理参数分别是：菌龄１４～１６小时和１８～２０小时；三种酶配比（纤维素酶：蜗牛酶：溶菌酶）（ｍｇ／ｍｌ）为（８：４：２）和（５：２．５：２．５）；酶解温度均为３２℃；酶解时间均为２～３小时。