共查询到20条相似文献,搜索用时 78 毫秒
1.
生物可再生能源是最有前景的石油替代品之一.生物能源的生产原料包括:植物、有机废弃物和微生物.微生物在生物能源生产上有着广泛的应用,利用微生物制备的主要生物能源包括:生物柴油、生物乙醇、生物甲烷等.某些微生物如微藻和真菌可以生产大量油脂,这些油脂可以转化为生物柴油;有些微生物如酵母可以将糖类、淀粉以及纤维素转化为燃料乙醇,添加乙醇的汽油或柴油燃烧排放明显降低;还有些厌氧微生物可以将有机废弃物转化为甲烷,可用做家用燃气、车用燃气或发电.除此之外微生物还具有在生产能源的同时治理环境污染的优势.总之研究开发微生物在生物能源生产中的应用有利于世界可持续发展. 相似文献
2.
中国如何突破生物柴油产业的原料瓶颈 总被引:76,自引:4,他引:72
因应我国日益严峻的能源资源、能源环境和能源安全形势,国家大力倡导发展可再生能源。生物柴油是最重要的液体可再生燃料之一,在能源性质方面可以完全替代化石柴油,而且还具有安全环保等其它优良特性。当前利用动植物油脂生产生物柴油,原料成本偏高,而且稳定、充足的油脂原料供应体系尚未形成。我国是油脂资源短缺国家,近年来植物油进口量逐年增加。同时,我国耕地资源匮乏,粮食供应形势不容乐观,扩大油料作物种植的潜力非常有限。但是,我国宜林地丰富,农林废弃生物质资源量巨大。综合以上因素,我国应重点发展木本油料植物规模化种植和推广,加快微生物油脂发酵技术创新和产业化进程;同时,利用植物遗传育种技术提高油料作物产量以及选择性发展不与粮争地的油料作物。依靠各方面的进步,发展创新的油脂生产技术,保障我国生物柴油产业和油脂化工行业健康发展。 相似文献
3.
4.
加快微生物油脂研究为生物柴油产业提供廉价原料 总被引:51,自引:5,他引:46
赵宗保 《中国生物工程杂志》2005,25(2):8-11
当前国内外致力于发展生物柴油,因其性能优良,成为化石柴油的替代品。由于以植物油脂生产生物柴油原料成本占总成本的70%-85%,所以亟待开发廉价油脂资源。微生物油脂主要是微生物利用碳水化合物合成的甘油脂,其脂肪酸组成和植物油相近。产油微生物具有资源丰富、油脂含量高、碳源利用谱广等特点,开发潜力大。然而,目前微生物油脂生产成本偏高,研究工作仍以富含多不饱和脂肪酸的高附加值菌油为目标。随着现代分子生物学和生物化工技术的发展,对产油微生物菌种筛选、改良、代谢调控和发酵工程的研究日趋深入,将降低微生物油脂生产成本,为未来生物柴油产业提供廉价原料。 相似文献
5.
6.
清洁可再生能源生物柴油的开发利用是对当今能源短缺环境下化石燃料替代物的有益探索。微生物油脂作为一种可能实现生物柴油廉价、高效生产的原料引起了广泛的关注,但由于封闭式培养模式操作复杂、成本高制约了其大规模应用。美极梅奇酵母Metschnikowia pulcherrmia是一种新型产油酵母,具有适应性强、底物利用范围广、可在开放体系培养等特点,很有潜力代替传统产油微生物,实现基于生物柴油的废水及固废能源化工程应用。文中对美极梅奇酵母相关研究开展了全面调研,在分析其产油研究及应用现状的基础上,总结了美极梅奇酵母在油脂生产方面所具有的独特优势和关键影响因素,突出强调了其在开放体系培养及利用有机废弃物生产微生物油脂的可行性。此外,文中还指出了美极梅奇酵母在油脂产量、产油机理等方面存在的问题与不足,为实现生物柴油高效生产提供了新的方向和思路,有利于进一步促进其工业化应用。 相似文献
7.
提高微生物油脂生产能力的研究进展 总被引:1,自引:0,他引:1
微生物油脂是生物柴油生产领域具有广阔前景的新油脂资源。然而, 利用产油微生物进行油脂的工业化生产仍存在限氮条件下油脂生产强度不够高、对廉价高氮生物质原料的利用效率低等瓶颈问题。随着近年来发酵工程、生物信息学及分子生物学技术的发展, 国内外研究者利用不同策略优化微生物油脂的生产条件, 并对其油脂积累代谢途径进行改造, 旨在获得适用于工业化生产的产油性能优良的油脂菌。本综述总结了国内外利用生化工程、基因工程以及新兴的转录因子工程策略提高产油微生物油脂生产强度和扩大产油微生物廉价底物利用范围方面的研究进展, 并展望了基于组学研究、模块途径工程以及反向代谢工程的综合策略在理性改造产油微生物以提高其油脂发酵性能中的应用。 相似文献
8.
9.
10.
生物能源作为可再生能源,可以替代部分石化能源,有望缓解能源供给中对石油的依赖程度.本期专刊结合第6届国际生物能源会议,包括综述和研究报告两部分,报道了我国生物能源专家学者在燃料乙醇、生物柴油、微生物油脂、生物燃料标准、航空生物燃料等领域的最新研究进展. 相似文献
11.
Microbial signature lipid biomarker analysis – an approach that is still preferred,even amid various method modifications 下载免费PDF全文
C. Willers P.J. Jansen van Rensburg S. Claassens 《Journal of applied microbiology》2015,118(6):1251-1263
The lipid composition of microbial communities can indicate their response to changes in the surrounding environment induced by anthropogenic practices, chemical contamination or climatic conditions. A considerable number of analytical techniques exist for the examination of microbial lipids. This article reviews a selection of methods available for environmental samples as applied for lipid extraction, fractionation, derivatization and quantification. The discussion focuses on the origin of the standard methods, the different modified versions developed for investigation of microbial lipids, as well as the advantages and limitations of each. Current modifications to standard methods show a number of improvements for each of the different steps associated with analysis. The advantages and disadvantages of lipid analysis compared to other popular techniques are clarified. Accordingly, the preferential utilization of signature lipid biomarker analysis in current research is considered. It is clear from recent literature that this technique stays relevant – mainly for the variety of microbial properties that can be determined in a single analysis. 相似文献
12.
We investigated how the lipid composition (fatty acids and sterols) of benthic microbial mats, which represent an important basal food resource for stream food webs, differs between tropical streams located in protected pristine and agricultural Cerrado savannah areas. The total microbial biomass and lipid composition differed significantly between pristine and agricultural streams in parallel with differences in water quality and hydrodynamic characteristics. Agricultural streams exhibited lower total biomass of benthic microbial mats than pristine streams. However, the higher concentrations of essential polyunsaturated fatty acids, such as linoleic acid (LIN, 18:2ω6), α-linolenic acid (ALA, 18:3ω3), and eicosapentaenoic acid (EPA, 20:5ω3), that were observed in agricultural streams suggest enhanced lipid complexity and a higher nutritional quality of the microbial community relative to pristine streams. Meanwhile, pristine stream microbial communities had higher total concentrations of saturated fatty acids and cholesterol than those of agricultural streams, reflecting their heterotrophic microbial communities. Moreover, stream morphotype and associated differences in the hydrodynamic characteristics affected the community composition and thereby also the lipid composition of microbial mats. Land-use-induced changes in the total biomass and lipid composition of microbial communities may affect the trophic transfer of energy in stream food webs, leading to changes in the composition and productivity of primary consumers and their predators, and thereby affecting stream ecosystem functioning. 相似文献
13.
Prediction of lipid accumulation-degradation in oleaginous micro-organisms growing on vegetable oils 总被引:1,自引:0,他引:1
Oleaginous micro-organisms (yeasts, moulds), in culture media having the carbon source as limited factor, degrade reserve lipids and produce new biomass, after the onset of carbon exhaustion from the medium. In this paper the process of lipid accumulation-degradation in oleaginous micro-organisms, growing on a vegatable oil was simulated. The model was integrated with 4 different methods and the parameters were optimised with the least squares method. It was found that the degradation of endocellular carbon pool is a very slow process characterised, however, by a good yield in fat-free biomass. Low values of the specific growth rates of the fat-free microbial mass, both from consumption of extra cellular and endocellular carbon pools, favourite the production of microbial lipid. The maximum of the specific rate of lipid accumulation is positively affected by the low values of the specific growth rate of the fat-free microbial mass from consumption of extra cellular carbon pool, but remained unaffected by the specific growth rate of the fat-free microbial mass from consumption of endocellular carbon pool. On the other hand, lipid production and specific rate of lipid accumulation are positively influenced by the high values of the specific rate of storage lipid formation. In conclusion, this numerical model can be used in the laboratory as pilot for planing further experimental work. 相似文献
14.
Teresa Braunwald Lisa Schwemmlein Simone Graeff-Hönninger William Todd French Rafael Hernandez William E. Holmes Wilhelm Claupein 《Applied microbiology and biotechnology》2013,97(14):6581-6588
Due to the increasing demand for sustainable biofuels, microbial oils as feedstock for the transesterification into biodiesel have gained scientific and commercial interest. Also, microbial carotenoids have a considerable market potential as natural colorants. The carbon to nitrogen (C/N) ratio of the respective cultivation media is one of the most important parameters that influence the production of microbial lipids and carotenoids. Thus, in the present experiment, the influence of different C/N ratios, initial glucose loadings, and ammonium concentrations of the cultivation medium on microbial cell growth and lipid and carotenoid production by the oleaginous red yeast Rhodotorula glutinis has been assessed. As a general trend, both lipid and carotenoid production increased at high C/N ratios. It was shown that not only the final C/N ratio but also the respectively applied initial carbon and nitrogen contents influenced the observed parameters. The lipid yield was not affected by different ammonium contents, while the carotenoid production significantly decreased both at low and high levels of ammonium supply. A glucose-based increase from C/N 70 to 120 did not lead to an increased lipid production, while carotenoid synthesis was positively affected. Generally, it can be asserted that lipid and carotenoid synthesis are stimulated at higher C/N ratios. 相似文献
15.
Villanueva L Navarrete A Urmeneta J Geyer R White DC Guerrero R 《Microbial ecology》2007,54(3):523-531
Microbial mats are highly productive microbial systems and a source of not-yet characterized microorganisms and metabolic
strategies. In this article, we introduced a lipid biomarker/microbial isolation approach to detect short-term variations
of microbial diversity, physiological and redox status, and also characterize lipid biomarkers from specific microbial groups
that can be further monitored. Phospholipid fractions (PLFA) were examined for plasmalogens, indicative of certain anaerobes.
The glycolipid fraction was processed for polyhydroxyalkanoates (PHA) and the neutral lipid fraction was used to evaluate
respiratory quinone content. Data demonstrate an increase in the metabolic stress, unbalanced growth, proportion of anaerobic
bacteria and respiratory rate after the maximal photosynthetic activity. Higher accumulation of polyhydroxyalkanoates at the
same sampling point also suggested a situation of carbon storage by heterotrophs closely related to photosynthetic microorganisms.
Besides, the characterization of lipid biomarkers (plasmalogens, sphingolipids) from specific microbial groups provided clues
about the dynamics and diversity of less-characterized mat members. In this case, lipid analyses were complemented by the
isolation and characterization of anaerobic spore formers and sulfate reducers to obtain insight into their affiliation and
lipid composition. The results revealed that temporal shifts in lipid biomarkers are indicative of an intense change in the
physiology, redox condition, and community composition along the diel cycle, and support the hypothesis that interactions
between heterotrophs and primary producers play an important role in the carbon flow in microbial mats.
Dedicated to the memory of David C. White. 相似文献
16.
17.
David L. Balkwill Franklin R. Leach John T. Wilson James F. McNabb David C. White 《Microbial ecology》1988,16(1):73-84
An uncontaminated subsurface aquifer sediment contains a sparse microbial community consisting primarily of coccobacillary bacteria of relatively uniform size which can be counted directly with appropriate staining. The morphological simplicity and the relatively decreased cell numbers, when compared with surface soils and sediments, make the subsurface an ideal natural community with which to compare the utility of chemical measures of microbial biomass to direct microscopic counts. The membrane phospholipids (estimated as the polar lipid fatty acids, the lipid phosphate, and phosopholipid glycerol phosphate), lipopolysaccharide lipid A (estimated as the LPS hydroxy fatty acids), cell walls (estimated as the muramic acid), and adenosine triphosphate all give essentially identical estimates of cell numbers and dry weight as the direct counts, using conversion factors determined on subsurface microorganism monocultures. Assays of microbial cell components are thus validated by comparison with the classical direct count in at least one soil/sediment. 相似文献
18.
Single cell oil production from rice hulls hydrolysate 总被引:1,自引:0,他引:1
Rice hull hydrolysate was used as feedstock for microbial lipids production using the oleaginous fungus Mortierella isabellina. Kinetic experiments were conducted in C/N ratios 35, 44 and 57 and the oil accumulation into fungal biomass was 36%, 51.2% and 64.3%, respectively. A detailed mathematical model was used in order to describe the lipid accumulation process. This model was able to predict reducing sugar and nitrogen consumption, fat-free biomass synthesis and lipid accumulation. Neutral lipids constitute the predominant lipid fraction, while the major fatty acids were oleic, palmitic and linoleic acid. Fatty acids of long aliphatic chain were not detected, thus the microbial oil produced is a promising feedstock for biodiesel production. 相似文献
19.
转化N-乙酰-D-葡糖胺产油真菌的筛选 总被引:3,自引:0,他引:3
对21株真菌利用甲壳素解聚产物N-乙酰-D-葡糖胺(NAG)为碳源积累油脂的能力进行了筛选。碳源同化实验得到可同化NAG的真菌7株,进一步筛选出能利用NAG积累油脂的酵母3株。摇瓶实验表明,C. albidus ATCC 56298和T. fermentans CICC 1368利用NAG发酵菌体油脂含量可分别达到67%和48%。气相色谱分析表明菌油富含棕榈酸、硬脂酸和油酸,与常规植物油脂的脂肪酸组成相似。研究结果拓宽了微生物油脂发酵的原料。 相似文献
20.
Christopher Freeman Douglas M. Fiebig Maurice A. Lock 《Journal of Aquatic Ecosystem Stress and Recovery (Formerly Journal of Aquatic Ecosystem Health)》1993,2(4):329-334
A method is described which enables lipid biosynthesis to be determined within intact river biofilms. Significantly different rates of biosynthesis were detected in rivers of differing nutrient availability and during different seasons. Rapid changes in microbial physiology could be detected within 24 hours. The technique appeared to be well suited to investigation of factors affecting lipid biosynthesis within biofilms. Although in contrast, acetate incorporation did not correlate with microcalorimetric total activity measurements over a 12-month period, and so the method did not appear suitable for determining total metabolic activity. However, microbial lipid biosynthesis produces a valuable food resource for the ecosystems higher tropic levels and thus the acetate incorporation technique could prove useful as an indicator of aspects of aquatic ecosystem health. 相似文献