分子微生物学研究动态与发展趋势

在基因组学、蛋白质组学、转录组学和代谢组学等不同层次展开的分子微生物学研究取得了丰硕成果。分子微生物学正在从分析生物学迈向统一生物学的研究阶段,其研究成果必将对揭开生命活动的奥秘和推动第三生物产业的发展具有重要的意义。     

不同碳源诱导下牦牛瘤胃厌氧真菌Orpinomyces sp. YF3的产酶机制

为探究体外发酵牦牛瘤胃源厌氧真菌Orpinomyces sp. YF3在不同碳源诱导下的产酶机制,本研究利用厌氧培养管在10 mL基础培养基中分别添加不同碳源复杂度的葡萄糖(glucose, Glu)、滤纸(filter paper, Flp)、微晶纤维素(avicel, Avi)各8 g/L作为唯一碳源进行体外发酵,检测发酵液中的纤维降解酶活性和挥发性脂肪酸,并利用转录组学探究Orpinomyces sp. YF3的产酶机制。结果表明葡萄糖诱导下的发酵液中羧甲基纤维素酶、微晶纤维素酶、滤纸酶和木聚糖酶的活性,及乙酸的比例显著升高(P＜0.05),丙酸、丁酸、异丁酸的比例显著降低(P＜0.05)。进一步分析发现与纤维降解酶相关的差异表达基因(differentially expressed genes, DEGs)在Glu组中显著上调。基因本体论(gene ontology, GO)功能富集显示DEGs主要集中在木聚糖酶、纤维素酶、葡萄糖和碳水化合物等的分解代谢过程及相关酶活性,京都基因和基因组百科全书(Kyoto Encyclopedia of Genes and Genomes, KEGG)通路分析富集到的纤维降解酶相关的差异通路主要是淀粉和蔗糖代谢途径、其他聚糖降解途径。以上结果表明,以葡萄糖为碳源底物的Orpinomyces sp. YF3可增加纤维素降解酶活性,提高乙酸比例,通过调控纤维降解酶基因的表达及相关代谢通路来提高对底物的降解能力,提高能量利用效率。这为Orpinomyces sp. YF3在实际生产中的应用提供了理论基础。     

产脂肪酶真菌的选育及酶学性质研究

从富含油脂土壤中筛选出一株产碱性脂肪酶酶活达6.40U/mL的真菌菌株,经显微形态及ITS序列分析鉴定为产黄青霉Penicillium chrysogenum,该菌株命名为Penicillium chrysogenum J23。该菌的最佳产酶培养条件为：蔗糖1.0%、蛋白胨2.0%、橄榄油1.0%、MgSO4·7H2O 0.05%、接种量1.0%、初始pH 9.0、摇床转速200r/min、30℃培养48h。其所产脂肪酶的最适反应温度与pH分别为33℃和7.5,在pH6.0－10.0酶具有良好的稳定性,在50℃处理2h仍可保持30%以上的酶活力,50mmol/L的Ca2+、Mg2+、K+分别对酶有较强激活作用,而50mmol/L的Fe2+、Mn2+、Cu2+、Pb2+、Li2+对酶则有不同程度的抑制作用。     

菌根真菌与兰科植物互作的组学研究进展

兰科植物因其具有丰富的物种多样性和重要的社会经济价值,多年来一直是植物学及生态学界的重点研究对象.菌根真菌对兰科植物的种子萌发、营养吸收和种群动态等多个方面都具有十分重要的作用,因而近年来受到越来越多的关注.探究菌根真菌与兰科植物互作的内在机制是目前兰科菌根研究的一大热点领域,同时也为兰科植物野生资源保护和种群恢复提供...     

真菌细胞溶壁酶的产酶培养和应用效果

从土样中分离的７１株木霉（Ｔｒｉｃｈｏｄｅｒｍａ ｓｐ．）筛选出一株分解几丁质和葡聚糖能力较强的菌株。该菌株在麸皮、稻草粉、硫酸铵和诱导物为主成份的固体培养基上,经过２５℃、８４ｈ的培养,产生较高的真菌细胞溶壁酶,能溶解酵母、毛霉、黑曲霉及食用菌等丝状菌丝体的细胞壁,形成原生质体,经选用酵母、毛霉等进行原生质体再生,效果较优。     

工业生物催化技术

以蛋白质酶的工程应用为核心的工业生物催化技术,被认为是生物技术继生物医药和转基因植物之后的第三次浪潮。它的发展与应用将对人类的工业化学过程带来根本的变革。工业生物催化的兴起与以下的两个关键技术因素有密切的关系：(1)蛋白质定向进化技术的出现,(2)基因组学和蛋白质组学的发展。探讨了工业生物催化技术的现状和发展趋势,并对我国如何发展该领域的基础和应用研究提出一些见解。     

Meta-analysis在多种组学领域的应用

Meta-analysis作为一种整合多特征、多数据的统计方法,上世纪90年代被引入生命科学领域。随着高通量测序技术的快速发展,以基因组学、转录组学和蛋白质组学为核心的生命组学逐渐成为生命科学研究的新热点。海量数据的快速产出推动了组学研究的发展,也引发了数据规模过大、难以系统整合等问题。针对上述情况,meta-analysis被广泛地应用于分析各组学数据,方法也不断得到改进。本文系统总结了有代表性的meta-analysis方法,考察了目前meta-analysis在多个组学领域的应用现状,最后讨论了meta-analysis尚待解决的问题并展望未来的发展方向。     

产β—葡萄糖苷酶真菌诱变菌株快速筛选方法

报道了一种快速筛选产β-葡萄糖管酶真菌诱变菌株的方法。该法利用ρNPG经β-葡萄糖苷酶水解,水解产物ρNP在碱性条件下显色的原理。采用自制的特殊初筛平皿.经一年多的实践应用表明此法具有简便、灵敏、筛子消耗量小、筛选效率高等优点。     

多组学前沿技术专刊序言

后基因组时代,基因组学、转录组学、蛋白质组学及代谢组学等技术应用日趋广泛,功能注释成为生命科学研究的中心任务,多组学整合分析成为全面解析生物学机理的主要手段。本专刊邀请了国内多组学领域的相关专家学者介绍了基因组学、转录组学、蛋白质组学及代谢组学等领域最新进展和应用成果,收录了相关文章28篇,以供从事多组学研究的科研工作者参考。     

系统生物学在工业微生物研究中的应用

功能基因组学以揭示基因组的功能及调控机制为目标,是21世纪最热门的研究领域之一。近来功能基因组学领域的研究被用于工业微生物的研究中,该文对功能基因组学在工业微生物中的应用做了简单综述。     

Screening for Ligninolytic Enzyme Production by Diverse Fungi from Tunisia

Summary This work represents the first report on the ability of autochthonous fungi from Tunisia to produce ligninolytic enzymes. Three hundred and fifteen fungal strains were isolated from different Tunisian biotopes. These fungal strains were firstly screened on solid media containing Poly R-478 or ABTS as indicator compounds that enabled the detection of lignin-modifying enzymes as specific color reactions. Of the 315 tested strains, 49 exhibited significant ABTS-oxidation activity expressed within the first week of incubation and only 18 strains decolorized the Poly R-478. Liquid cultivations and laccase, manganese peroxidase and lignin peroxidase activity assays of positive strains confirmed that eight efficient enzyme producers were found in the screening. These strains were attributed to the most closely related species using PCR amplification and sequencing of the internal transcribed spacer ‘ITS’ regions of the ribosomal DNA. The identification results showed fungal genera such as Oxyporus, Stereum and Trichoderma which have been only rarely reported as ligninolytic enzyme producers in the literature. Culture conditions and medium composition were optimized for the laccase producer Trametes trogii CTM 10156. This optimization resulted in high laccase production, 367 times more than in non-optimized conditions and which reached 110 U ml^-1 within 15 days of incubation.     

植物与病原真菌互作机制研究进展

植物与病原真菌之间的互作是当今植物病理学研究的热点问题之一,相关的研究有望为植物抗病机制的解析和抗病品种的选育奠定理论基础。我们从形态、细胞、生理生化和分子等水平综述了植物与病原真菌互作机制的研究进展。     

Arbuscular Mycorrhizal Fungi in Plant Production of Temperate Agroecosystems

Abstract

The importance of arbuscular fungi for plant development and health is now widely demonstrated. However, although it is more and more evident that they are not only an integral part of many cultivated plants but also an essential component of soil fertility, their rational use in plant production is still in its infancy. Because of their role as bioregulators, biofertilizers, and biocontrol agents, they represent potentially important tools for new orientations in agriculture, particularly in Europe, where there is increasing demand for development of new plant management techniques that are less dependent on chemical inputs. The discovery of mycmutants turned out to be an excellent tool for better understanding the ecophysiology of arbuscular mycorrhizas under field conditions and for allowing considerable progress in our knowledge on the genes controlling this symbiosis. Progress in this area, together with ongoing generation of specific nucleic acid probes for arbuscular mycorrhizal fungi, appear to be essential for promoting mycorrhizal biotechnology. Despite this, arbuscular mycorrhizal fungi can already be exploited successfully in certain areas of plant production, such as orchards and ornamental nurseries.     

乙醇脱氢酶Ⅱ活性低谷胱甘肽含量高的啤酒酵母工程菌

微生物代谢工程是当前国内外研究的热点.在食品、能源、环境等领域,通过遗传修饰改变微生物的物质和能量代谢流向以获得期望产物的研究已广泛地开展.乙醛是啤酒中重要的风味物质之一,过高的乙醛含量已成为国内啤酒风味改良的瓶颈,一直难有突破.     

丝状真菌高效表达异源蛋白研究进展

丝状真菌是具有高效分泌蛋白质潜力的真核表达系统, 能对蛋白质进行翻译后修饰, 如蛋白质糖基化等; 并且比植物、昆虫和哺乳动物细胞具有更快的生长速率。近年来, 随着真菌分子遗传技术和菌种改良策略的进步, 尤其是真菌基因组学的发展, 利用丝状真菌生产异源蛋白越来越受到关注。综述了丝状真菌作为细胞工厂生产异源蛋白的最新探索与进展, 其中包括功能基因组学在蛋白表达与分泌研究中的应用, 同时探讨了异源蛋白表达和生产的改进策略。     

丝状真菌高效表达异源蛋白研究进展

丝状真菌是具有高效分泌蛋白质潜力的真核表达系统, 能对蛋白质进行翻译后修饰, 如蛋白质糖基化等; 并且比植物、昆虫和哺乳动物细胞具有更快的生长速率。近年来, 随着真菌分子遗传技术和菌种改良策略的进步, 尤其是真菌基因组学的发展, 利用丝状真菌生产异源蛋白越来越受到关注。综述了丝状真菌作为细胞工厂生产异源蛋白的最新探索与进展, 其中包括功能基因组学在蛋白表达与分泌研究中的应用, 同时探讨了异源蛋白表达和生产的改进策略。     

Structure and Function of the DUF2233 Domain in Bacteria and in the Human Mannose 6-Phosphate Uncovering Enzyme

DUF2233, a domain of unknown function (DUF), is present in many bacterial and several viral proteins and was also identified in the mammalian transmembrane glycoprotein N-acetylglucosamine-1-phosphodiester α-N-acetylglucosaminidase (“uncovering enzyme” (UCE)). We report the crystal structure of BACOVA_00430, a 315-residue protein from the human gut bacterium Bacteroides ovatus that is the first structural representative of the DUF2233 protein family. A notable feature of this structure is the presence of a surface cavity that is populated by residues that are highly conserved across the entire family. The crystal structure was used to model the luminal portion of human UCE (hUCE), which is involved in targeting of lysosomal enzymes. Mutational analysis of several residues in a highly conserved surface cavity of hUCE revealed that they are essential for function. The bacterial enzyme (BACOVA_00430) has ∼1% of the catalytic activity of hUCE toward the substrate GlcNAc-P-mannose, the precursor of the Man-6-P lysosomal targeting signal. GlcNAc-1-P is a poor substrate for both enzymes. We conclude that, for at least a subset of proteins in this family, DUF2233 functions as a phosphodiester glycosidase.     

低乙醇脱氢酶Ⅱ活性的抗老化啤酒酵母工程菌的构建

采用自克隆技术,破坏啤酒酵母工业菌株YSF31的ADH2基因,在ADH2基因位点插入来源于YSF31的编码γ-谷氨酰半胱氨酸合成酶的GSH1基因和铜抗性筛选标记CUP1基因.通过铜抗性筛选转化子,经PCR和乙醇脱氢酶Ⅱ(ADH Ⅱ)活性测定验证,获得了1株啤酒酵母工程菌.10°P麦芽汁发酵实验显示,自克隆菌株的乙醇脱氢酶Ⅱ活性是受体菌的65%,谷胱甘肽含量比受体菌YSF31的高34%.其他发酵指标并没有发生明显改变.由于DNA操作过程中没有外源基因介入,因此啤酒酵母工程菌为生物安全的自克隆菌株,具有重要的应用价值.