黑曲霉β-葡萄糖苷酶基因在大肠杆菌中的克隆与表达

目的构建糖类标记载体筛选克隆。方法以pPIC9K-βGl2为模板,通过PCR扩增得到全长的Bgl2基因片段,克隆至pET-28a载体,转化E.coli BL21(DE3),Cel-M9培养基筛选阳性克隆,经DNA测序分析,成功构建pET28a-Bgl2表达载体。SDS-PAGE显示,重组菌经IPTG诱导后表达了目的蛋白,其相对分子质量与预期结果相符。结果 PCR扩增得到Bgl2基因片段,SDS-PAGE显示蛋白以包涵体形式表达,克隆可用Cel-M9培养基筛选。结论用Cel-M9培养基筛选出阳性克隆为构建食品级载体奠定基础。     

米曲菌胰酶片治疗功能性消化不良的上市后药物经济学评价

目的:对米曲菌胰酶片治疗功能性消化不良的成本-效果进行分析。方法:收集多中心非随机同期病例数据,采用成本-效果分析对其进行药物经济学评价。结果:米曲菌胰酶片组相对于对照组(非米曲菌胰酶片治疗),每增加1个效果单位,成本可节约768.52元。使用米曲菌胰酶片治疗可通过提高治疗效果而降低病人的总费用。结论:米曲菌胰酶片治疗功能性消化不良有效、经济。     

深海来源真菌Aspergillus sp .SCSIOW3抗A-beta多肽聚集活性成分的研究

摘要：目的 对一株南海深海来源真菌（Aspergillus sp .SCSIOW3）的抗Aβ聚集活性成分进行了分离、鉴定。方法 利用ThT荧光模型活性追踪分离 Aspergillus sp .SCSIOW3发酵产物中抗Aβ42多肽聚集活性物质,结合理化性质、波谱数据并参阅文献确定活性化合物的结构。结果 从Aspergillus sp .SCSIOW3中分离鉴定了2个具有抗Aβ42多肽聚集活性的桔霉素类衍生物：phenol A acid（1）和Penicitrinone A（2）,其中化合物2在100 uM表现出与阳性对照EGCG同等程度的活性。结论 phenol A acid（1）和Penicitrinone A（2）为橘霉素衍生物,这是首次报导该类化合物的抗Aβ多肽聚集活性,具有潜在的理论和实际应用研究价值。     

Fungal transformation of androsta-1,4-diene-3,17-dione by Aspergillus brasiliensis

Background

The biotransformation of steroids by fungal biocatalysts has been recognized for many years. There are numerous fungi of the genus Aspergillus which have been shown to transform different steroid substances. The possibility of using filamentous fungi Aspergillus brasiliensis cells in the biotransformation of androsta-1,4-diene-3,17-dione, was evaluated.

Methods

The fungal strain was inoculated into the transformation medium which supplemented with androstadienedione as a substrate and fermentation continued for 5 days. The metabolites were extracted and isolated by thin layer chromatography. The structures of these metabolites were elucidated using ¹H-NMR, broadband decoupled ¹³C-NMR, EI Mass and IR spectroscopies.

Results

The fermentation yielded one reduced product: 17β-hydroxyandrost-1,4-dien-3-one and two hydroxylated metabolites: 11α-hydroxyandrost-1,4-diene-3,17-dione and 12β-hydroxyandrost-1,4-diene-3,17-dione.

Conclusions

The results obtained in this study show that A. brasiliendsis could be considered as a biocatalyst for producing important derivatives from androstadienedione.     

Hydrolysis of timosaponin BII by the crude enzyme from Aspergillus niger AS 3.0739

Timosaponin BII (1), a steroidal saponin showing potential anti-dementia activity, was regioselectively hydrolyzed into its deglycosyl derivatives by the crude enzyme from Aspergillus niger AS 3.0739. Three biotransformation products, timosaponin BII-a (2), timosaponin BII-b (3), and timosaponin BII-c (4), were purified and their structures were elucidated on the basis of 1D NMR, 2D NMR, FAB-MS, and HR-ESI-MS spectral data. Compounds 2 and 3 are new compounds.     

Insect Management to Facilitate Preharvest Mycotoxin Management

Many species of insects can facilitate the entry of mycotoxin‐producing fungi to commodities such as cotton seed, maize, peanuts, and tree nuts. The mycotoxins most commonly associated with insect damage are aflatoxin and fumonisin. Insecticides will likely remain an important management tool, especially as predictive models for forecasting mycotoxigenic fungi or mycotoxins become available. Plants with high levels of resistance to insects that facilitate mycotoxins are likely to assist in mycotoxin management. Several studies now indicate Bt maize hybrids that express the protein throughout the plant can prevent fumonisin levels rising above guideline levels of 1–2 ppm when European corn borers (Ostrinia nubilalis) are the predominant insect pests.     

Aflatoxins in Maize: A Mexican Perspective

Aflatoxins are carcinogenic metabolites produced by Aspergillus flavus, a fungal pathogen that infects maize both in the field and during storage. Mexico is the center of origin of maize and its production in most parts in the country is characterized by the employment of a wide diversity of open‐pollinated genotypes adapted to certain environments. In most regions, maize is produced under rain fed conditions with low fertilizer and pesticide input and consequent low yields, probably fostering A. flavus infection in drought‐stressed plants. In addition, poor pest control increases insect damage, facilitating fungal infection and aflatoxin contamination. Ideally, management of aflatoxin contamination should begin with the employment of resistant genotypes as has been demonstrated by several U.S. breeding programs. However, in Mexico the wide genetic diversity of maize has not been fully exploited to identify resistance to aflatoxin contamination in breeding programs, thus impeding the reduction of aflatoxin levels in the field. Additional complications come from the fact that transgenic maize expressing insecticidal protein or any other trait to reduce aflatoxin is not viable in Mexico due to a government prohibition on the use of genetically modified maize. Maize is a staple crop in Mexico with high consumption in forms such as tortillas; thus, aflatoxin contamination is a significant threat to human health. Although aflatoxins are partially destroyed during the alkaline cooking procedure (called nixtamalization) to prepare tortillas, residual levels of aflatoxins might be considerable. Although important research has been conducted in several aspects of aflatoxin contamination of maize by universities, agricultural centers, and some government agencies, a full mycotoxin research program is needed in Mexico to ascertain the extents of aflatoxin contamination in different parts of the country and to develop economically viable technology to reduce aflatoxin exposure.