共查询到20条相似文献,搜索用时 15 毫秒
1.
Growing Phototrophic Cells without Light 总被引:8,自引:0,他引:8
Many phototrophic microorganisms contain large quantities of high-value products such as n-3 polyunsaturated fatty acids and carotenoids but phototrophic growth is often slow due to light limitation. Some phototrophic
microorganisms can also grow on cheap organic substrate heterotrophically. Heterotrophic cultivation can be well controlled
and provides the possibility to achieve fast growth and high yield of valuable products on a large scale. Several strategies
have been investigated for cultivation of phototrophic microorganisms without light. These include trophic conversion of obligate
photoautotrophic microorganisms by genetic engineering, development of efficient cultivation systems and optimization of culture
conditions. This paper reviews recent advances in heterotrophic cultivation of phototrophic cells with an emphasis on microalgae. 相似文献
2.
A. G. Dorofeev N. V. Grigor’eva M. N. Kozlov M. V. Kevbrina V. G. Aseeva Yu. A. Nikolaev 《Microbiology》2014,83(5):450-461
The work deals with more efficient procedures for the isolation and cultivation of “nonculturable” microorganisms (NM) from environmental sources. The techniques for NM cultivation in situ and under laboratory conditions are discussed. A new approach is considered, viz., cultivation under cyclically varying conditions with the cycle duration comparable to the duration of the cell cycle. Cyclic cultivation implies sequential changes of several cultivation phases with different growth conditions. An established sequence of growth phases provides for the competitiveness of the target microorganisms and for accumulation of their biomass. Cultivation of phosphate-accumulating bacteria, nonculturable microorganisms which have not been previously isolated in pure culture, in an SBR reactor is discussed as an example of cyclic cultures. 相似文献
3.
深海微生物高压适应与生物地球化学循环 总被引:3,自引:0,他引:3
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. 相似文献
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Daniel R 《Current opinion in biotechnology》2004,15(3):199-204
Soil microorganisms have been the most valuable source of natural products, providing industrially important antibiotics and biocatalysts. But, of late, the discovery rate of novel biomolecules using traditional cultivation techniques has been extremely low, as most soil microorganisms cannot be cultured in this way. The development of novel cultivation-dependent and molecular cultivation-independent approaches has paved the way for a new era of product recovery from soil microorganisms. In particular, gene-mining based on the construction and screening of complex libraries derived from the soil metagenome provides opportunities to fully explore and exploit the enormous genetic and metabolic diversity of soil microorganisms. This strategy has already resulted in the isolation of novel biocatalysts and bioactive molecules. 相似文献
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Om Prakash Yogesh Shouche Kamlesh Jangid Joel E. Kostka 《Applied microbiology and biotechnology》2013,97(1):51-62
Despite tremendous advances in microbial ecology over the past two decades, traditional cultivation methods have failed to grow ecologically more relevant microorganisms in the laboratory, leading to a predominance of weed-like species in the world’s culture collections. In this review, we highlight the gap between culture-based and culture-independent methods of microbial diversity analysis, especially in investigations of slow growers, oligotrophs, and fastidious and recalcitrant microorganisms. Furthermore, we emphasize the importance of microbial cultivation and the acquisition of the cultivation-based phenotypic data for the testing of hypotheses arising from genomics and proteomics approaches. Technical difficulties in cultivating novel microorganisms and how modern approaches have helped to overcome these limitations are highlighted. After cultivation, adequate preservation without changes in genotypic and phenotypic features of these microorganisms is necessary for future research and training. Hence, the contribution of microbial resource centers in the handling, preservation, and distribution of this novel diversity is discussed. Finally, we explore the concept of microbial patenting and requisite guidelines of the “Budapest Treaty” for establishment of an International Depositary Authority. 相似文献
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Molecular ecology of hydrothermal vent microbial communities 总被引:6,自引:0,他引:6
Jeanthon C 《Antonie van Leeuwenhoek》2000,77(2):117-133
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G A Smirnova V A Mel'nikova B M Raskin E L Tseligorova 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1987,(11):26-30
The parameters of the growth of three microbial strains cultivated in growth media prepared with the use of different nutrient bases, both locally produced and imported, have been studied. The characteristics of the processes of bacterial cultivation have been found to correlate with the peptide composition of hydrolysates used in the experiment. Nutrient bases containing a wide spectrum of peptides with different molecular weight have ensured the most favorable conditions for the growth of microorganisms belonging to the taxonomic groups under study. 相似文献
13.
粘细菌产生的水解酶类研究进展 总被引:2,自引:2,他引:0
粘细菌隶属于δ变形菌纲(Deltaproteobacteria),是重要的药源微生物类群,但是其分离培养困难,严重限制了粘细菌资源的发掘和开发利用。粘细菌是微生物捕食者,通过产生丰富多样的胞外水解酶,如淀粉酶、蛋白酶、几丁质酶、纤维素酶、磷酸酶、蛋白酶等来裂解其他微生物或分解纤维素等作为营养物质来源。目前,粘细菌分离纯化技术主要是利用被捕食菌或纤维素诱导法。可以说,粘细菌胞外水解酶是研究其分离培养方法的物质基础。然而,目前研究者们对粘细菌产生的水解酶类关注较少。本文主要对粘细菌产生的水解酶种类、性质及其功能进行归纳总结,为今后粘细菌分离培养技术和开发利用等相关研究提供参考。 相似文献
14.
微生物在生物圈中分布广泛,并且在地球物质循环中占有重要地位,但是约99﹪的微生物目前还不能通过传统的培养方法得到纯培养物(即未培养微生物),给这些未培养微生物的研究带来很大的困难。随着分子生物学的快速发展及其在微生物研究中的广泛运用,促进了以环境中未培养微生物为研究对象的新兴学科--环境基因组学的产生和发展。在不进行相关微生物培养分离的情况下,通过从环境样品中直接提取获得所有微小生物的全部遗传物质,并构建环境基因组文库;进一步利用功能基因组学研究策略,从文库中寻找编码产生新的有生物活性产物的基因;通过对系统发育相关锚定位点基因序列分析,从而确定特定生态环境体系中未培养微生物的种类结构组成及进化地位,并最终重建该体系中微生物群体的基本物质循环模式。此外,环境基因组学也可以在对未培养微生物生理生化特性深入了解的基础上,建立发展合适的培养体系,最终获得某些特定微生物的纯培养物。本文对环境基因组的构建及相关分析研究策略的进展进行了综述;同时介绍了其在微生物分类及生态学研究的应用。 相似文献
15.
The silver sorption capacity of three methylotrophic bacteria and one gelatinotrophic Pseudomonas strain has been investigated in dependence of the cultivation conditions. Whereas the maximum loading capacity of the microorganisms was not appreciable influenced by the variation of the dilution rate in the range between 0.05 h?1 to 0.5 h?1, a change of the carbon source or the modification of the limitation conditions during the chemostatic cultivation process provokes a strong alteration in the sorption behaviour. The maximum silver loading values were obtained, when the microorganisms are cultivated under N-limitation and the minimum values were measured under P-limitation. 相似文献
16.
To study thraustochytrids from temperate and cold environments of Southern Argentina, the standard cultivation methodologies
have been modified because many of the microorganisms detected by microscopic examination in both the original samples and
the colonized baits failed to be successfully isolated in standard culture media. As a result, 35 strains, most of them having
a very low growth rate, were isolated. Alternative procedures are proposed according to the nature of the sample, the characteristics
of the thraustochytrid to be isolated, and the presence of contaminating microorganisms. Modifications proposed include the
use of a newly formulated culture medium (Mar Chiquita, containing glucose, gelatine hydrolysate, peptone, and corn steep
liquor as main carbon and nitrogen sources). In addition, the effects of the nutrient composition and agar concentration of
culture media on the relative growth rates of the isolates were studied in an attempt to determine the most suitable conditions
for the cultivation of new strains of thraustochytrids. The goal of this study is to develop a standard methodology, allowing
us to grow baitable “elusive” thraustochytrid strains, and that could be applied to improve the isolation and the study of
the undocumented biodiversity of this group of microorganisms from different environments. 相似文献
17.
昆虫肠道微生物分离培养策略及研究进展 总被引:3,自引:0,他引:3
昆虫肠道作为一种特殊生境,生存着多种多样的共生微生物,并且肠道内的很多微生物与自然界其他生境的微生物种类显著不同。基于对纯培养微生物的研究,科学家们发现,肠道微生物与昆虫营养、生长发育及免疫等功能密切相关。因此,分离培养是发现微生物新种类、新基因和新功能的基础。然而,自然界可培养的微生物大约只占总数的1%。为了能够对更多的微生物进行分离和培养,近二十年来,微生物学家们发展了诸多新的培养技术和策略并利用它们从昆虫肠道分离出了很多新的难培养微生物。这些新的微生物种类极大地丰富了我们对肠道共生微生物生理作用与功能的认识。以此为基础,本文综述了昆虫肠道微生物分离培养的策略及研究进展,并对未来该领域的发展进行了展望。 相似文献
18.
Extremophiles as a source for novel enzymes 总被引:14,自引:0,他引:14
van den Burg B 《Current opinion in microbiology》2003,6(3):213-218
Microbial life does not seem to be limited to specific environments. During the past few decades it has become clear that microbial communities can be found in the most diverse conditions, including extremes of temperature, pressure, salinity and pH. These microorganisms, called extremophiles, produce biocatalysts that are functional under extreme conditions. Consequently, the unique properties of these biocatalysts have resulted in several novel applications of enzymes in industrial processes. At present, only a minor fraction of the microorganisms on Earth have been exploited. Novel developments in the cultivation and production of extremophiles, but also developments related to the cloning and expression of their genes in heterologous hosts, will increase the number of enzyme-driven transformations in chemical, food, pharmaceutical and other industrial applications. 相似文献
19.
Perspectives of microbial oils for biodiesel production 总被引:7,自引:0,他引:7
Biodiesel has become more attractive recently because of its environmental benefits, and the fact that it is made from renewable
resources. Generally speaking, biodiesel is prepared through transesterification of vegetable oils or animal fats with short
chain alcohols. However, the lack of oil feedstocks limits the large-scale development of biodiesel to some extent. Recently,
much attention has been paid to the development of microbial, oils and it has been found that many microorganisms, such as
algae, yeast, bacteria, and fungi, have the ability to accumulate oils under some special cultivation conditions. Compared
to other plant oils, microbial oils have many advantages, such as short life cycle, less labor required, less affection by
venue, season and climate, and easier to scale up. With the rapid expansion of biodiesel, microbial oils might become one
of potential oil feedstocks for biodiesel production in the future, though there are many works associated with microorganisms
producing oils need to be carried out further. This review is covering the related research about different oleaginous microorganisms
producing oils, and the prospects of such microbial oils used for biodiesel production are also discussed. 相似文献
20.
Phylogenetic and functional marker genes to study ammonia-oxidizing microorganisms (AOM) in the environment 总被引:3,自引:0,他引:3
Pilar Junier Verónica Molina Cristina Dorador Ora Hadas Ok-Sun Kim Thomas Junier Karl-Paul Witzel Johannes F. Imhoff 《Applied microbiology and biotechnology》2010,85(3):425-440
The oxidation of ammonia plays a significant role in the transformation of fixed nitrogen in the global nitrogen cycle. Autotrophic
ammonia oxidation is known in three groups of microorganisms. Aerobic ammonia-oxidizing bacteria and archaea convert ammonia
into nitrite during nitrification. Anaerobic ammonia-oxidizing bacteria (anammox) oxidize ammonia using nitrite as electron
acceptor and producing atmospheric dinitrogen. The isolation and cultivation of all three groups in the laboratory are quite
problematic due to their slow growth rates, poor growth yields, unpredictable lag phases, and sensitivity to certain organic
compounds. Culture-independent approaches have contributed importantly to our understanding of the diversity and distribution
of these microorganisms in the environment. In this review, we present an overview of approaches that have been used for the
molecular study of ammonia oxidizers and discuss their application in different environments. 相似文献