布朗葡萄藻培养方面的研究概况

对布朗葡萄藻培养方面的有关研究进行总结,内容涉及布朗葡萄藻常用的培养基、培养条件以及影响其生长的理化因素。重点概述和讨论了碳源、氮源、磷源、温度、光强、pH值、盐度、细菌、SC1058等理化因素对布朗葡萄藻生物量和烃产量的影响,并进一步提出获得高生物量和产烃量的可能研究方向。     

长茎葡萄蕨藻室外水泥池养殖技术

从长茎葡萄蕨藻的养殖材料与设施、养殖方法和采收方法等方面介绍了长茎葡萄蕨藻的室外水泥池养殖技术,以期为长茎葡萄蕨藻的养殖提供技术参考。     

大型海藻在石斑鱼育苗水体中的应用研究

设置海葡萄组、羽毛藻组及对照组3个处理,2次重复,将海葡萄和羽毛藻各15kg放入网框吊在育苗池中,每隔7 d测定1次水质指标。结果表明:35 d后,海葡萄、羽毛藻、对照组对TN的平均去除率分别为61.39%、63.70%和20.68%,COD的平均去除率分别为52.40%、53.98%和14.84%,海葡萄和羽毛藻对TN、COD的去除率显著优于对照组(P0.05),可见海葡萄和羽毛藻对育苗水体净化作用显著。     

利用污水和烟道气培养葡萄藻的研究进展

笔者概述了污水和烟道气在葡萄藻培养中应用的研究现状,并针对相关研究中存在的问题及其发展方向进行了分析和讨论,以期为实现葡萄藻燃料低成本规模化开发提供参考。     

氮磷营养及二氧化锗对长茎葡萄蕨藻生长的影响

研究了不同的氮磷浓度及二氧化锗水平对长茎葡萄蕨藻生长的影响。结果表明:水体中的不同浓度氮对长茎葡萄蕨藻的生长的影响差异显著,在试验范围内(0~50 mg/kg)氮浓度升高至15 mg/kg组藻体生长情况最好;水体中的磷浓度对长茎葡萄蕨藻的生长的影响无明显区别,在所设梯度中(0~5 mg/kg)4 mg/kg组藻体生物量相对最高;不同浓度的二氧化锗(0~50 mg/kg)对藻体的附生硅藻的生长有一定程度抑制作用,同时对藻体无明显的毒理效应,尤以2 mg/kg组的试验效果最理想。研究结果将为长茎葡萄蕨藻引种后的大规模人工养殖工作提供依据。     

长茎葡萄蕨藻营养成分分析

[目的]分析长茎葡萄蕨藻营养成分。[方法]选用深圳某养殖场不同生长期的长茎葡萄蕨藻，测定其蛋白质和氨基酸含量组成，分析主要营养成分。[结果]不同生长期的长茎葡萄蕨藻中氨基酸含量无明显差异；长茎葡萄蕨藻中蛋白质含量为235.8 g/kg(以干重计)、氨基酸含量为204.7 g/kg(以干重计);其中氨基酸含量较高的为呈味氨基酸Glu、Asp、Gly,氨基酸组成符合世界卫生组织推荐的理想蛋白模式谱，长茎葡萄蕨藻的必需氨基酸总量高于FAO/WHO氨基酸模式谱，其SRC值为70.3。[结论]长茎葡萄蕨藻含有丰富的营养价值，具有良好的食用及相关应用前景。     

盐度和光照强度对长茎葡萄蕨藻生长的影响

研究不同海水盐度和光照强度对长茎葡萄蕨藻生长的影响,结果表明:在试验范围内(盐度22‰~41‰;光照强度0～5 000 lx),盐度36‰试验组中的藻体重量最高;光强3 000 lx试验组中的藻体重量最高。该研究为长茎葡萄蕨藻的引种培育工作奠定了基础。     

长茎葡萄蕨藻的人工养殖技术研究

考察水温、光照强度和附着基质等因素对长茎葡萄蕨藻(Caulerpa lentillipera)生长的影响。结果表明:长茎葡萄蕨藻的合适生长温度为21~27℃,水温低于18℃或高于30℃均对其生长具有不利影响;其最适生长光照强度为8 000 lx左右,光照不足对藻体生长及形态特征产生显著影响;附着基质对长茎葡萄蕨藻的影响也较大,单面框网养殖效果总体要优于网格塑料筐。此外,在养殖过程中应注重防治杂藻污染。本研究为海南产长茎葡萄蕨藻的规模化人工养殖提供技术参考。     

海南几种大型绿藻18S rRNA基因的克隆与序列分析

对海南沿岸采集到的团集刚毛藻(Cladophora glomerata)、细毛横丝藻(Acrochaete leptochaete)、石莼(Ulva reticulata)和长茎葡萄蕨藻(Caulerpa lentillifera)进行了形态学观察,采用18S rRNA通用引物,通过PCR技术,从这4种绿藻的基因组中扩增到各自的18S rRNA基因序列,并测序。与Genebank中已收录的6种绿藻18S rRNA基因序列进行比较分析,所得10种绿藻的18S rRNA基因长度为727 bp,变异位点为266个,保守位点为453个。刚毛藻目与蕨藻目的遗传距离最大,为0.376;刚毛藻属内的种间遗传距离最小,为0.010。采用NJ法构建的系统进化树的拓扑结构显示:细毛横丝藻、葡枝横丝藻、石莼、礁膜、羽状尾孢藻和皱溪菜聚为一支;团集刚毛藻与扭曲刚毛藻单独聚为一支;长茎葡萄蕨藻与总状蕨藻聚为一支。说明18S rRNA序列可以作为大型绿藻系统发育研究的分子标记。     

能源微藻——葡萄藻生物学特性的研究进展

简要概述了葡萄藻的生物学特性、下游回收处理技术、基因工程等方面的研究进展。     

Olefins of high molecular weight in two microscopic algae

The hydrocarbon composition of two algae, a golden-brown (Bot-ryococcus braunii) and a blue-green (Anacystis montana), has been investigated by gas chromatography-mass spectrometry. Both show distributions of aliphatic hydrocarbons of odd carbon numbers in the medium and high ranges of molecular weight, with maxima at n-C(17) and n-C(29) for B. braunii and n-C(17) and n-C(29) for A. montana. With the exception of the n-heptadecane of A. montana all the hydrocarbons are monoenes, dienes, or trienes. Since certain continental sediments and oils show similar distributions of alkanes with respect to carbon number, these organisms may be the precursors of the hydrocarbons in these formations.     

生物修复对石油污染土壤微生物活性的影响

以陕北地区石油污染土壤为研究对象,利用微生物修复法对油污土壤进行了修复处理,对修复过程中不同组分烃浓度的变化、土壤四种酶活(多酚氧化酶、过氧化氢酶、脱氢酶、脂肪酶)、微生物对不同组分烃的代谢活性等生物因素进行了测定,并利用SPSS软件对不同组分烃的浓度变化及土壤生物性因素进行相关性分析。研究结果表明,微生物修复技术可有效去除土壤中不同组分烃,修复进行11周,土壤中烷烃、多环芳烃去除率分别为46.8%和39.9%。修复处理可提高土壤过氧化氢酶、脂肪酶活性,以及土壤微生物对烷烃、多环芳烃的代谢能力,土壤多酚氧化酶和脱氢酶活性呈先升后降的趋势。相关性分析结果表明,烷烃的降解与微生物对烷烃的代谢活性、土壤脱氢酶和过氧化氢酶活性相关,多环芳烃的生物降解与脱氢酶和过氧化氢酶活性相关;微生物修复作用可提高土壤中不同组分烃与微生物活性之间的相关关系。     

Polynuclear aromatic hydrocarbons,steroids and carcinogenesis

In addition to the electronic factors, there is a steric factor responsible for the carcinogenicity of polynuclear aromatic hydrocarbons. A carcinogenic polynuclear aromatic hydrocarbon must bear steric resemblance to steroids. One possible implication to this requirement for carcinogenicity is that these hydrocarbons may act on the same sites as steroid hormones.     

A new mechanism for the formation of meteoritic kerogen-like material

The carbon in ancient carbonaceous chondritic meteorites is mainly in a hydrocarbon composite similar to terrestrial kerogen, a cross-linked structure of aliphatic and aromatic hydrocarbons. Until recently, the composite has been commonly thought to have been produced in the early solar nebula by a Fischer-Tropsch-type process, involving the catalytic synthesis of hydrocarbons from carbon monoxide and hydrogen on grain surfaces. Instead, the aromatic hydrocarbons may form in gas-phase pyrolysis of simple aliphatics like acetylene and methane by a mechanism developed recently to explain formation of soot in combustion and of aromatic molecules in circumstellar envelopes. Nonequilibrium chemical kinetic calculations indicate that this mechanism can produce meteoritic aromatics if the initial concentration of simple hydrocarbons in the solar nebula was sufficiently but not unreasonably high.     

Submarine seepage of natural gas in norton sound, alaska

Unusual concentrations of dissolved two- to four-carbon alkanes were observed in the waters in Norton Sound in a localized area approximately 40 kilometers south of Nome, Alaska, in 1976. The hydrocarbons were identified in the near-bottom waters downcurrent for more than 100 kilometers from a sea-floor point source. Preliminary dynamic modeling estimates of the initial gas phase composition predict methanelethane and ethanelpropane ratios of 24 and 1.7, respectively, assuming the hydrocarbons were introduced by bubbles. The low ethanelpropane ratio is indicative of gas from a liquid petroleum source rather than from nonassociated or biogenic natural gas. Preliminary data on the structural geology of Norton Basin lend support to the interpretation based on the hydrocarbon plume. Unconformably truncated strata dip basinward from the seep locus; acoustic anomalies and numerous steeply dipping faults in the immediate vicinity of the seep are corroborating evidence that shallow gas- or petroleum-charged sediments and strata coincide with avenues for migration of mobile hydrocarbons to the sea floor. These factors, taken in concert with the sedimentological regime, the recent revision (increase) of basin depth estimates, and the highly localized hydrocarbon source, strongly suggest a thermogenic rather than a recent biogenic origin for these gaseous compounds.     

Polycyclic aromatic hydrocarbons in soils and recent sediments

Soils and recent marine sediments contain a complex polycyclic aromatic hydrocarbon assemblage. There is a high degree of similarity in the molecular weight distribution of the many series of alkyl homologs of these aromatic hydrocarbons, and this distribution varies little over a wide range of depositional environments. The evidence suggests that these hydrocarbons are formed in natural fires, are dispersed and mixed by air transport, and are eventually deposited into surface sediments. The analytical, geochemical, and environmental implications of these findings are discussed.     

Microsomal hydroxylase induction in liver cell culture by phenobarbital, polycyclic hydrocarbons, and p,p'-DDT

Aryl hydrocarbon hydroxylase induction by phenobarbital, polycyclic hydrocarbons, and the insecticide, 2.2-bis(p-chlorophenyl)-1,1,1-trichloroethane (p,p'-DDT), occurs in rat fetal liver cell cultures. The maximum net rate at which the hydroxylase activity accumulates is about the same when phenobarbital, 3-methlcholanthrene, or benz[a]anthracene is in the growth medium at optimum concentrations. An additive effect is obtained when either phenobarbital or p.p'-DDT is present with a polycyclic hydrocarbon in the growth medium, but not when the cells are treated with phenobarbital plus p.p'-DDT or with the combination of two polycyclic hydrocarbons.     

生物修复对黄土壤中石油烃的去除作用及影响因素

利用微生物法对石油污染黄土壤进行实验室模拟修复研究,通过测定修复过程中的不同组分烃、不同形态氮和有效磷含量,石油烃降解菌数量对修复效果及影响因素进行了评价。结果发现,经过5周的修复处理,生物刺激法处理的土壤中总石油烃、烷烃、多环芳烃的去除率分别为14.54%、21.98%、33.14%,土壤铵态氮含量由初始添加的210.4 mg·kg-1降低至97.2 mg·kg-1,土壤硝态氮含量在修复过程中基本保持不变。经过生物刺激修复的土壤中石油烃、烷烃、多环芳烃降解菌数分别为1.60×105、3.09×105、7.08×103,而未经修复处理的土壤中三种烃降解菌数量分别为2.69×10~4、2.57×10~4、4.07×103。结果表明利用生物刺激法可有效去除黄土壤中的石油烃。影响石油污染黄土壤生物修复作用的限制性因素为土壤中铵态氮和有效磷含量,与未经修复处理的石油污染土壤相比,生物刺激处理使土壤中烃降解菌数量增加。     

Petroleum hydrocarbons: uptake and discharge by the marine mussel Mytilus edulis

The common marine mussel Mytilus edulis has been observed to rapidly take up mineral oil, [(14)C]heptadecane, 1,2,3,4-tetrahydronaphthalene, [(14)C]toluene, [(14)C]naphthalene, and [(3)C]3,4-benzopyrene from seawater solution. This species of mussel did not metabolize any of these compounds, and transfer of the mussel to fresh seawater, after exposure to the hydrocarbon in solution, resulted in the discharge of most of the hydrocarbon, although significant amounts remained (between 1 and 400 micrograms per mussel). The nontoxic paraffinic hydrocarbons mineral oil and heptadecane were taken up (10 milligrams per mussel) to a much greater extent than the aromatic hydrocarbons (2 to 20 micro-grams per mussel).     

Chemistry of molecular growth processes in flames

Chemical mechanisms of pyrolysis, growth, and oxidation processes in flames have traditionally been inferred from spatial profile measurements of species concentrations. Experimental investigations now include the detection of numerous minor species such as reactive radicals and intermediate hydrocarbons. In assessing a proposed mechanism important new constraints can be established when the detailed species profile data are combined with velocity and temperature measurements and analyzed to determine production and destruction rates for specific molecules. Recent results on hydrocarbon diffusion flames provide new information on the interplay between chemical and transport processes. These measurements have led to direct tests of proposed routes for the formation of aromatic hydrocarbons and the first, small soot particles. The inception chemistry of hydrocarbon growth reactions and initial particle formation is thought to control soot formation, flame radiation and energy transfer, and pollutant emission in combustion environments.