D2-43病毒E蛋白在酵母细胞表面的展示

目的：在酵母细胞表面展示登革2型病毒43株(D2—43)的E基因，探索利用酵母表面展示系统建立DNA改组筛选平台的可行性。方法：通过RT-PCR扩增获得D2-43的E基因，将该基因亚克隆至T载体后，再克隆至酵母表面展示载体pYDI，于酿酒酵母EBY100中利用半乳糖进行诱导表达。表达产物采用间接免疫荧光法和FACS进行检测。结果：酵母表面展示产物可与D2-43的腹水抗体特异性地结合；在半乳糖诱导后24h，展示E蛋白的酵母细胞百分数达22．07％。结论：本研究为建立基于酵母表面展示系统的DNA改组筛选平台奠定了基础。     

用固定化啤酒酵母细胞合成胞嘧啶核苷二磷酸胆碱

κ－卡拉胶－魔芋多糖复配胶包埋的啤酒酵母细胞，经冻融处理后用于合成胞嘧啶核苷二磷酸胆碱（CDP－胆碱）。结果表明：250mL摇瓶中加入50mL反应液（葡萄糖400mol/L，CMP10mmol/L，磷酸碍碱50mmol/L,K2HPO4-KH2PO4缓冲液100mmol/L，MgSO410mmol/L,pH=8.0），固定化细胞1200g/L,34℃、150r/min下，反应4h后补加400mmol/L葡萄糖，反应8h可使60％以上的CMP转化为CDP－胆碱。反应液经灭菌和添加辅酶I（NAD^ ）后，固定化细胞可连续使用4次，CDP－胆碱转化率维持在40％以上。     

Aromatic ethers of 1-aryl 2-(1H-azolyl)ethanol: study of antifungal activity

Aromatic ethers related to antifungal azole miconazole were synthesized and tested against various strains of Candida. We found that activity is related to the nature of the aromatic ring and the position of substituents on this ring. Activity is more strongly dependent on the substituent in the 2 position of the ethyl chain than on the aromatic group linked through the oxygen. Triazoles were always less potent than the corresponding imidazole analogues.     

桑椹果酒酵母筛选及发酵性能

从桑椹成熟果实、桑叶以及桑果园的土壤采样，进行桑椹果酒专用酵母的筛选，得到一株在性能上优于对照菌葡萄酒干酵母的酵母菌Y11。该菌起酵快，从第2天开始糖度大幅度下降，酒精度快速上升，发酵第4天酒精体积分数即可达到10％以上。发酵过程pH值变化趋势比较平缓，发酵结束后高级醇量符合要求。综合发酵性能及感官评定，表明该菌能代替葡萄酒干酵母用于桑椹果酒的生产。     

Changes in gut bacterial communities in canaries infected by Macrorhabdus ornithogaster

Macrorhabdus ornithogaster is an opportunistic yeast that colonizes the gastric mucosa of many avian species. Until now, no studies have focused on the influence of a gastric infection on the balance of the intestinal microbiota of birds. In this study, 44 faecal samples from individual canaries, with and without M. ornithogaster infection, were analysed. The detection of the yeast was evaluated by 18S rRNA PCR. In order to evaluate the impact of the Macrorhabdus infection on the bacterial communities, culture-independent methods, by the use of amplicon-based sequencing as well as 16S rRNA-DGGE, were adopted. The different health status of animals affected the relative abundance of the main OTUs, with a greater diversification of the gut microbiota in healthy animals compared to the infected. In particular, Lactococcus, Pseudomonas, Acinetobacter, Lachnospiraceae, Propionibacterium and Weissella were found to be characteristic of uninfected animals (FDR?<?0.05), while Lactobacillus and Candidatus Arthromitus were characteristic of infected animals (FDR?<?0.05). Both these taxa have been reported as immunostimulatory, involved in immunological disorders. In infected animals the inferred metagenome assessed by PICRUST clearly showed a positive correlation between the presence of M. ornithogaster and KEGG genes related to ether lipid metabolism, already reported to be immunostimulatory by activation of macrophages and to play a pathophysiological role in several immunological disorders. Finally, our results show an interaction between infection of the digestive tract and intestinal microbiota of pet birds and provide insight into the changing of the complex enteric bacterial community.

• HIGHLIGHTS

• Macrorabdus ornithogaster is a gastric yeast that colonizes a wide range of birds.

• Differences were found between infected and healthy animals in gut microbiota.

• Candidatus Arthromitus was closely associated with infected birds.

• M. ornithogaster can affect intestinal microbiota composition of canaries.

     

Drug resistance in the fission yeast Schizosaccharomyces pombe: pleiotropic mutations affecting the oleic acid and sterol composition of cell membranes

Summary The whole cell lipid and sterol content of the drug resistant strains cyh1, cyh3 and cyh4 was compared with that of wild type by thin layer and gas liquid chromatography and by UV spectrophotometric analysis. The cyh3 and cyh4 strains had a decreased content of the unsaturated 18:1 fatty acid oleic acid, a decreased content of ergosterol and an increased content of 24,28 dehydroergosterol with respect to wild type. The cyh1 strain, however, only showed a decreased content of ergosterol and an increased content of 24,28 dehydro-ergosterol when compared to wild type.     

The molecular immunology of human susceptibility to fungal diseases: lessons from single gene defects of immunity

Introduction: Fungal diseases are a threat to human health. Therapies targeting the fungus continue to lead to disappointing results. Strategies targeting the host response represent unexplored opportunities for innovative treatments. To do so rationally requires the identification and neat delineation of critical mechanistic pathways that underpin human antifungal immunity. The study of humans with single-gene defects of the immune system, i.e. inborn errors of immunity (IEIs), provides a foundation for these paradigms.

Areas covered: A systematic literature search in PubMed, Scopus, and abstracts of international congresses was performed to review the history of genetic resistance/susceptibility to fungi and identify IEIs associated with fungal diseases. Immunologic mechanisms from relevant IEIs were integrated with current definitions and understandings of mycoses to establish a framework to map out critical immunobiological pathways of human antifungal immunity.

Expert opinion: Specific immune responses non-redundantly govern susceptibility to their corresponding mycoses. Defining these molecular pathways will guide the development of host-directed immunotherapies that precisely target distinct fungal diseases. These findings will pave the way for novel strategies in the treatment of these devastating infections.     

The Schizosaccharomyces pomberfc3 + gene encodes a homologue of the human hRFC36 and Saccharomyces cerevisiae Rfc3 subunits of replication factor C

In the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe replication factor C (RF-C) plays key roles both in chromosomal DNA replication and in DNA replication checkpoint function. At the replication fork, the five-subunit RF-C complex functions to load the trimeric polymerase accessory factor PCNA onto DNA. PCNA then acts as a sliding clamp, tethering Pol δ to the DNA to maximise its processivity. Here we describe the cloning of the S. pomberfc3 ⁺ gene, encoding a homologue of the S. cerevisiae Rfc3 and human hRFC36 proteins. The 1026 bp rfc3 ⁺ ORF is interrupted by five introns, ranging in size from 49 to 165 bp. The spliced ORF is predicted to encode a 342 amino-acid protein that is approximately 50% identical at the amino acid sequence level to the S. cerevisiae Rfc3 and human hRFC36 proteins. As expected, S. pomberfc3 ⁺ is an essential gene, with rfc3Δ cells being defective for DNA replication. Loss of rfc3 ⁺ function can be rescued by heterologous expression of either the S. cerevisiae Rfc3 or human hRFC36 proteins in S. pombe. Received: 15 October 1999