极端微生物及其相关功能蛋白研究进展

极端微生物是一类能够适应特殊环境的微生物,相关功能蛋白在其适应极端环境过程中发挥着重要作用,探索极端微生物的特性及其相关的功能蛋白有助于深入了解生命的起源与进化,为蛋白酶在工业领域的应用提供一定理论依据。现概述耐辐射球菌、嗜盐菌、嗜热菌、嗜酸菌和嗜碱菌、嗜冷菌、嗜压菌的特性及其相关的功能蛋白质,从蛋白质水平阐述极端微生物对极端环境的适应机制。     

极端嗜热微生物及其高温适应机制的研究进展

极端嗜热微生物在高温条件下生长繁殖,其必然具有适应高温环境的特殊细胞结构、基因类型以及生理生化机制。极端嗜热微生物的研究对探索生命的起源以及极端嗜热微生物的开发和应用具有重要意义。对极端嗜热微生物中细胞膜、核酸分子、蛋白质分子、代谢产物和辅酶的高温适应机制的研究进展进行了概述,旨为极端嗜热微生物以及来源于极端嗜热微生物的各种生物分子的开发和应用提供理论依据。     

微生物对低温极端环境适应性的研究进展

嗜冷微生物是地球寒冷环境中最主要的生物类群,并且是驱动全球生物地球化学循环的关键环节。嗜冷微生物在适应策略上显示出应对多种极端环境因素的巨大潜力,研究其适应和进化机制有助于更好地理解微生物与环境之间相互作用过程,并有效利用极端环境微生物资源。近年来,随着分子生物学和基因组学技术的高速发展,对微生物适应寒冷环境的机制及嗜冷微生物在指示气候变化和工农业应用方面均有一系列的突破。在此,本文将从基因组的GC含量、蛋白质稳定性、转录翻译调控、细胞膜流动性、渗透压调节、抗氧化损失和基因组适应性进化等方面总结当前在微生物适应低温环境机制上所取得的进展,并展望低温环境微生物在指示气候变化和工农业应用中的前景。     

嗜盐微生物在生物医药领域的应用研究进展

近年来抗生素耐药性问题日趋严重,患癌人数也在逐年增加,亟需开发新型药物。嗜盐微生物作为一类特殊的极端环境微生物,具有代谢多样性丰富、营养需求较低和能适应恶劣条件等特点,是发现新型药物的希望。目前,国内外学者已从嗜盐微生物中分离出了多种代谢产物和酶,具有明显的抗菌和/或抗肿瘤等活性。文中综述了嗜盐微生物及其相关产物在抗菌、抗炎、抗肿瘤、抗氧化、生物医学材料以及药物载体等生物医学方面的作用,尤其对近年来在嗜盐微生物中发现的新型抗菌和抗肿瘤物质以及嗜盐微生物特有的代谢产物四氢嘧啶等进行了总结,并对其后续在生物医药领域的开发和产业化应用进行了展望。     

深海微生物高压适应与生物地球化学循环

深海是典型的高压环境,嗜压微生物是深海生态系统中的重要类群.随着深海采样技术的发展及高压微生物特殊培养设备的开发,已从深海环境中分离到一系列嗜压微生物,包括一些常压环境不能生长的严格嗜压菌.对这些嗜压菌的研究,不仅对微生物适应极端高压环境的机制有一定了解,而且发现了一些特殊的代谢产物.研究微生物高压嗜压机理,还有助于探索地球生命的温度压力极限及生命起源和演化等科学问题.从深海嗜压微生物多样性、深海微生物高压环境适应机理及深海微生物在生物地球化学循环中的作用等方面对嗜压微生物的研究进展进行综述.     

极端微生物蛋白质组学的研究现状

本文概述了近年来蛋白质组学技术在极端微生物研究领域中存在的关键问题、解决途径和研究现状。迄今为止,虽然蛋白质组学技术快速发展,但极端微生物的蛋白质组学的研究仍然存在很多困难。由于极端微生物的蛋白质-蛋白质复合物解离不彻底,而嗜中温微生物的蛋白质解离和变性条件不适用于极端微生物合成的大多数蛋白质等特殊问题,致使蛋白质组学技术还没有广泛应用于嗜盐、嗜热/冷、嗜酸/碱等微生物的研究中。当然,蛋白质组学技术应用的潜能和前景吸引人们积极尝试各种各样的方法。目前,通过研究已经有效地解决了嗜盐蛋白质的分离、嵌合膜蛋白的鉴定和新蛋白质的功能推测,证实了基因组预测的一些结论,并揭示基因组不能充分解析的某些特性和新蛋白质。极端微生物蛋白质组学的研究表明,全面展示蛋白质表达谱需要不止一种蛋白质组学方法。此外,蛋白质组学和基因组学的互相印证和结合,将加速极端微生物的研究进程,深入全面地揭示微生物适应极端环境的特殊机制,进而阐明极端微生物生存的机理,为改善胁迫因素导致的伤害提供新的研究方向。     

嗜酸嗜热浸矿微生物

随着人们对浸矿菌的研究不断加深,嗜热嗜酸菌的浸矿潜力及在微生物冶金中的作用和地位得到认识,利用嗜热菌对矿石进行高效浸出已成为微生物冶金领域的研究重点。嗜热微生物包括中度嗜热微生物和极端嗜热微生物,主要栖息于热泉、工厂高温废水排放区以及火山口等高温环境中。本综述总结了嗜热浸矿微生物种类,分析了嗜中温菌和极端嗜热菌等嗜酸菌种的生长习性、利用的能源物质、浸矿能力等,并进一步介绍了嗜热嗜酸微生物在高温生物冶金中的发展及应用。     

嗜酸菌研究进展

极端环境微生物是当今生命科学领域的研究热点。嗜酸菌是极端环境微生物的重要类群,在人们生活生产中发挥着巨大的作用。介绍了嗜酸菌的主要类群及特征,阐述了它们在自然界的主要行为、适应酸和重金属的生理机制以及分子遗传学研究进展,最后介绍了嗜酸菌在实际生产中的主要应用。     

四氢嘧啶微生物合成与应用研究进展

极端环境微生物定义了生命的边界。为了适应各种极端环境,极端环境微生物通过合成许多独特的活性化合物来保护自己。四氢嘧啶就是其中一种代表性的保护性物质。它最早是从极端嗜盐菌中发现的,作为调节细胞渗透压的一类相容性溶质,可以帮助微生物适应高盐等恶劣环境。研究发现四氢嘧啶不仅是一种重要的渗透压调节剂,还是一种高效的生物保护剂,可以帮助蛋白、核酸、生物膜乃至整个细胞对抗高温、干燥、冷冻和辐射等多种逆境。因此,四氢嘧啶在生物保护、生物医药和生物科技等众多领域展现出广阔的商业化应用前景。随着合成生物学和代谢工程技术的快速发展,传统的嗜盐菌四氢嘧啶生产方法已逐步被产率更高、环境更友好的生物工程菌及技术所取代。本文围绕四氢嘧啶的微生物合成及其应用研究进行综述,为后续四氢嘧啶的开发和应用提供重要参考。     

新的生命形式──极端微生物

近年来,在许多以前被认为是生命禁区的区域,发现了各式各样的新的生命形式。它们生存繁衍的理想场所恰恰是一些极端环境,如嗜热菌、嗜冷菌、嗜酸菌、嗜碱菌、嗜盐菌、嗜压菌等,这些统称为极端微生物（ｅｘｔｒｅｍｏｐｈｉｌｅｓ）。极端微生物具有独特的基因类型,特殊的生理机制及特殊的代谢产物,作为地球上的边缘生命现象,极端微生物颇为耐人寻味。它在生命起源、系统进化等方面将给人们许多重要的启示,在生命行为的原理上也将拓展人们的概念。极端微生物存在的原理,又具有极大的应用价值,极端微生物的特殊机制及特殊产物,将使…     

施用EM堆肥对土壤螨群落结构的影响

对不同施肥条件下农田中的土壤螨进行调查,结果表明：（1）EM堆肥区土壤有机层加深,土壤螨垂直分布下限下移;（2）施用EM堆肥土壤螨数量多,物种丰富,分布均匀,长期施用EM堆肥可以形成多层次的食物网络,传统堆肥区土壤螨数量和种类较化肥区多,单纯施用化肥的农田,土壤螨数量和种类呈减少趋势,群落结构稳定性差,土壤生物间的联系向单一化方向发展。     

微生态制剂EM原露对熊蜂蜂王产卵前期卵巢发育及卵子发生的影响

用60%蔗糖,60%蔗糖加EM原露,60%蔗糖加花粉,60%蔗糖加花粉加EM原露4种食料饲喂复苏熊蜂Bombus terrestris L.蜂王,研究EM原露对复苏蜂王产卵前期卵巢发育及卵子发生的影响。结果表明,EM原露对熊蜂蜂王产卵前期卵巢发育及卵子发生表现出一定抑制性,但影响不显著。虽然于第2天,EM原露对其开始发生显著抑制性影响(P=0.047),且EM原露与花粉的交互作用对其发育促进影响亦显著(P=0.014),但从第5天始,EM原露对其影响下降为不显著,而花粉开始表现出显著性促进熊蜂蜂王卵巢发育(P=0.000)。EM原露对熊蜂蜂王卵子发生并无促进或抑制作用,然而花粉的缺失促使熊蜂蜂王卵子发生停滞。     

Effects of integrated use of organic and inorganic nutrient sources with effective microorganisms (EM) on seed cotton yield in Pakistan

A field experiment was conducted to determine the effects of integrated use of organic and inorganic nutrient sources with effective microorganisms on growth and yield of cotton. Treatments included: control; organic materials (OM); effective microorganisms (EM); OM+EM; mineral NPK (170:85:60 kg); 1/2 mineral NPK+EM; 1/2 mineral NPK+OM+EM and mineral NPK+OM+EM. OM and EM alone did not increase the yield and yield attributing components significantly but integrated use of both resulted in a 44% increase over control. Application of NPK in combination with OM and EM resulted in the highest seed cotton yield (2470 kg ha-1). Integrated use of OM+EM with 1/2 mineral NPK yielded 2091 kg ha-1, similar to the yield (2165 kg ha-1) obtained from full recommended NPK, indicating that this combination can substitute for 85 kg N ha-1. Combination of both N sources with EM also increased the concentrations of NPK in plants. Economic analysis suggested the use of 1/2 mineral NPK with EM+OM saves the mineral N fertilizer by almost 50% compared to a system with only mineral NPK application. This study indicated that application of EM increased the efficiency of both organic and mineral nutrient sources but alone was ineffective in increasing yield.     

A Role of the Gelatinous Matrix in the Resistance of Root-Knot Nematode (Meloidogyne spp.) Eggs to Microorganisms

The survival of eggs of the root-knot nematode Meloidogyne javanica was studied in a series of experiments comparing the infectivity of egg masses (EM) to that of separated eggs (SE). The EM or SE were placed in the centers of pots containing citrus orchard soil and incubated for 24 hours, 10 days, or 20 days. Following each incubation time, 10-day-old tomato plants were planted in each pot, and 3 to 4 weeks later the plants were harvested and the galling indices determined. In the EM treatments, galling indices of ca. 4.0 to 5.0 were recorded after all three incubation periods; in the SE treatments, the infectivity gradually declined to trace amounts by 20 days. Incubating EM and SE for 2 weeks in four different soil types showed the same pattern in all the soil types: EM caused heavy infection of the test plants while the infection rate from the SE was extremely low. Incubating EM and SE in soil disinfested with formaldehyde resulted in comparable galling indices in most treatments. In petri dish experiments, 100 mg of natural soil was spread at the perimeter of a Phytagel surface and EM or SE of M. incognita were placed in the center. Light microscopy revealed that within 5 to 10 days the SE were attacked by a broad spectrum of microorganisms and were obliterated while the eggs within the EM remained intact. Separated eggs placed within sections of gelatinous matrix (GM) were not attacked by the soil microorganisms. When selected microbes were placed on Phytagel surfaces with EM of M. incognita, electron microscopy demonstrated that at least some microbes colonized the GM. As the major difference between the EM and the SE was the presence of the GM, the GM may serve as a barrier to the invasion of some microorganisms.     

Pressure-regulated metabolism in microorganisms.

There has been a renewal of interest in the survival strategies employed by deep-sea, high-pressure-adapted (piezophilic) microorganisms as well as in the effects of high pressure on mesophilic, 1-atmosphere-pressure-adapted microorganisms. This is partly the result of a greater appreciation of the adaptations of microorganisms to life in extreme environments and partly the result of the development of new techniques for examining physiological and molecular processes as a function of pressure.     

Perspectives on biotechnological applications of archaea

Many archaea colonize extreme environments. They include hyperthermophiles, sulfur-metabolizing thermophiles, extreme halophiles and methanogens. Because extremophilic microorganisms have unusual properties, they are a potentially valuable resource in the development of novel biotechnological processes. Despite extensive research, however, there are few existing industrial applications of either archaeal biomass or archaeal enzymes. This review summarizes current knowledge about the biotechnological uses of archaea and archaeal enzymes with special attention to potential applications that are the subject of current experimental evaluation. Topics covered include cultivation methods, recent achievements in genomics, which are of key importance for the development of new biotechnological tools, and the application of wild-type biomasses, engineered microorganisms, enzymes and specific metabolites in particular bioprocesses of industrial interest.     

潮间带盐生植物生境微生物药用前景

近海潮间带植物生境的微生物是最富有生物多样性的海洋种群,其生境的独特性决定了该区域微生物较高的药用价值。文中介绍了我国南北方海域近海潮间带植物生境和微生物的特性及药用前景,为该区域微生物的开发利用提供参考。