生物法合成丙烯酸的研究进展

丙烯酸是一种重要的化工原料,被广泛应用于涂料、超吸附材料等领域。目前丙烯酸的获得主要通过丙烯氧化,但由于石油资源日渐枯竭以及生产过程造成的环境问题,利用生物质资源生产丙烯酸已成为研究热点。介绍了丙烯酸的性质及其在工业上的应用,并详细综述了生物法制备丙烯酸的研究进展。根据丙烯酸生产中是否应用传统的化工过程,将其分为半生物合成和全生物合成。半生物法主要包括乳酸化学法脱水以及丙烯腈、丙烯酰胺的生物转化;全生物法主要包括乳酸生物法脱水、3-羟基丙酸途径、糖直接发酵法以及DMSP(二甲基巯基丙酸内盐)途径。由于乳酸发酵的工艺成熟、原料易得,因此对乳酸脱水进行了重点介绍,其中生物法脱水符合可持续发展的要求,对其进行了详细介绍。同时还分析了各种方法的优缺点,探讨了利用生物质资源生产丙烯酸的研究趋势。     

甲烷利用菌研究概况

自从1905年Kaserer和Shngen分别报道发现利用甲烷细菌以来,随着有关微生物法勘探石油、天然气的研究,以及利用天然气生产单细胞蛋白的研究工作的开展,对于利用甲烷的微生物及其对甲烷的转化,逐步有了深入的认识,积累了大量资料。本文就甲烷利用菌的研究作一概述。     

我国生物技术在化工领域应用的重大进展──微生物法生产丙烯酰胺中试通过鉴定

我国生物技术在化工领域应用的重大进展──微生物法生产丙烯酰胺中试通过鉴定关键词：丙烯酰胺,生物催化,生物化工由化工部上海生物化工研究中心承担,浙江省桐庐农药厂协作的国家“八五”科技攻关项目（８５—０８—０３—０８）微生物法生产丙烯酸胺放１９９３年１１...     

美国Myriant公司开始工业放大生物丙烯酸生产工艺

2012年3月28日，美[]Myriant公司宣布，在利用可再生原料生产具有价格竞争力的生物丙烯酸（acrylic acid）的研发上取得突破性的进展。Myriant公司已经向美国专利商标局（USPTO）提交了生物丙烯酸生产工艺的专利申请。为了在2012年下半年向顾客提供丙烯酸样品，已经立即开始了规模放大的工作。Myriant公司的生物丙烯酸与用石油生产的丙烯酸相比，由于没有政府补助金或绿色溢价（green premium），所以在价格上具有竞争力。     

石油微生物学在中国科学院微生物研究所的发展

本文较详尽地综述了中国科学院微生物研究所50多年在涉及石油微生物学的科学研究成果,包括微生物勘探法和气态烃氧化菌、微生物与油气形成、有机酸的生产、油田微生物与提高采油量、微生物提高采油的现场应用.共引用了105篇文献.     

石油烃生物降解过程的研究进展

石油烃污染物属于难降解混合物,生物修复已经成为石油烃污染环境的主要修复方法.文中简述了微生物对石油烃的间期适应过程和转运过程,并通过对部分典型石油烃成分的微生物降解机理和代谢路径的梳理和综述,阐释了石油烃生物降解过程中的菌株、基因、代谢路径等研究进展.此外,利用基因工程和代谢工程等手段,可对野生型石油烃降解菌进行改造,...     

低温微生物修复石油烃类污染土壤研究进展

耐冷菌、嗜冷菌等低温微生物广泛存在于极地、高山以及高纬度等土壤环境中,是石油烃类污染物在低温条件下降解与转化的重要微生物资源.利用低温微生物的独特优势,石油污染土壤的低温生物修复技术的研究成为当前热点领域.本文系统综述了低温石油烃降解菌的分类及冷适机制,低温微生物对不同类型石油烃组分的降解特征和降解机理,低温环境中接种降解菌、添加营养物质和表面活性剂等强化技术在石油污染土壤中生物修复的应用.以及微生物分子生物学技术在低温微生物降解石油烃的研究现状,为拓展我国石油污染土壤生物修复技术提供参考.     

微生物-生物技术提高石油产率

石油的紧缺是未来一大趋势。多途径开发替代能源（或洁净新能源）也是必然趋势。现阶段如何确保石油品质，提高其采取率？是石油科学工作者、微生物一生物科学工作者关注的重要课题。微生物技术大有应用潜力，其中微生物生产的多糖用于石油开采早已为科技工作者所关注，如细菌生产的黄胞胶（Xanthan gum）作为石油开采的乳化剂，这种胞外杂多糖（酸性多糖）已于上世纪60年代末已实现工业化生产，     

L-苹果酸的生理功能及应用前景

L-苹果酸队（L-MalicAcid简称LMA）是生物体糖代谢过程中产生的重要有机酸,广泛存在于自然界的水果和蔬菜中,未成熟的苹果中含量较高,约为04％。LMA有多种生产方法：直接提取法;DL-苹果酸拆分法;利用微生物发酵糖质原料生产法;利用微生物产生的延胡索酸酶转化法;微生物发”酵非糖质原糖生产法［1］.其中以第三和第四种方法为主。直接发酵法的研究可追溯到本世纪20年代,因产酸达不到工业生产水平的要求,很长一段时间都未能有所突破。1959年,日本在实验室以延胡索酸为原料,采用微生物酶转化法取得成功,1974年建小规模工厂生…     

石油污染地土壤微生物群落的碳源利用特性

应用Biolog微平板技术,研究了大庆油田开采36年的石油污染土壤不同土层（0～10 cm、10～20 cm、20～30 cm）土壤微生物群落对碳源的利用特性.结果表明: 石油污染明显提高了土壤微生物群落的代谢活性,3个土层的微生物代谢强度均高于无污染土壤（CK）,不同土层之间的微生物代谢强度存在显著差异,其中20～30 cm土层的碳源代谢能力最强,其次为10～20 cm土层,0～10 cm土层最弱.石油污染使10～20 cm和20～30 cm土层土壤微生物群落对底物碳源利用种类增多,代谢功能的多样性增强,而0～10 cm土层则无明显变化.10～20 cm土层土壤微生物对底物碳源的利用由对照土壤的羧酸类居多转为石油污染土壤的碳水化合物最多,而20～30 cm土层土壤微生物对底物碳源的利用以羧酸类居多.说明石油污染土壤的微生物群落具有独特的群落结构和特点.     

Electrochemical analysis of Clostridium propionicum and its acrylic acid production in microbial fuel cells

Currently, acrylic acid is produced at a low yield by the resting cells of Clostridium propionicum with the supplement of extra electron acceptors. As an alternative way, acrylic acid production coupled with electricity generation was achieved by C. propionicum‐based microbial fuel cells (MFCs). Electricity was generated in the salt‐bridge MFCs with cysteine and resazurin in the anode chamber as mediators, and K₃Fe(CN)₆ as the cathode electron acceptor. Power generation was 21.78 mW/m² with an internal resistance of 9809 Ω. Cyclic voltammograms indicated the main mechanism of power production was the electron transfer facilitated by mediators in the system. In the salt‐bridge MFC system, 0.694 mM acrylic acid was produced together with electricity generation.     

Biotechnological routes based on lactic acid production from biomass

Lactic acid, the most important hydroxycarboxylic acid, is now commercially produced by the fermentation of sugars present in biomass. In addition to its use in the synthesis of biodegradable polymers, lactic acid can be regarded as a feedstock for the green chemistry of the future. Different potentially useful chemicals such as pyruvic acid, acrylic acid, 1,2-propanediol, and lactate ester can be produced from lactic acid via chemical and biotechnological routes. Here, we reviewed the current status of the production of potentially valuable chemicals from lactic acid via biotechnological routes. Although some of the reactions described in this review article are still not applicable at current stage, due to their “greener” properties, biotechnological processes for the production of lactic acid derivatives might replace the chemical routes in the future.     

乳酸（酯）脱水制备丙烯酸（酯）研究进展

从植物淀粉发酵制备乳酸已经获得工业化生产,开发经济可行的生物质路线制备丙烯酸是生物资源利用的重要研究方向之一。因此,对近年来用乳酸脱水制备丙烯酸的研究工作进行了综述、分析和归纳,对应用前途可能性较大的几种新型的催化材料和方法进行了探索和讨论。     

Production of acrylic acid and propionic acid by constructing a portion of the 3-hydroxypropionate/4-hydroxybutyrate cycle from <Emphasis Type="Italic">Metallosphaera sedula</Emphasis> in <Emphasis Type="Italic">Escherichia coli</Emphasis>

Acrylic acid and propionic acid are important chemicals requiring affordable, renewable production solutions. Here, we metabolically engineered Escherichia coli with genes encoding components of the 3-hydroxypropionate/4-hydroxybutyrate cycle from Metallosphaera sedula for conversion of glucose to acrylic and propionic acids. To construct an acrylic acid-producing pathway in E. coli, heterologous expression of malonyl-CoA reductase (MCR), malonate semialdehyde reductase (MSR), 3-hydroxypropionyl-CoA synthetase (3HPCS), and 3-hydroxypropionyl-CoA dehydratase (3HPCD) from M. sedula was accompanied by overexpression of succinyl-CoA synthetase (SCS) from E. coli. The engineered strain produced 13.28 ± 0.12 mg/L of acrylic acid. To construct a propionic acid-producing pathway, the same five genes were expressed, with the addition of M. sedula acryloyl-CoA reductase (ACR). The engineered strain produced 1430 ± 30 mg/L of propionic acid. This approach can be expanded to synthesize many important organic chemicals, creating new opportunities for the production of chemicals by carbon dioxide fixation.     

Precursor-directed biosynthesis of stilbene methyl ethers in Escherichia coli

Stilbenes are bioactive compounds that show beneficial effects for humans, such as anti-tumor activity and survival improvement. Resveratrol, a representative of stilbenes and showing various health-improving activities, is rapidly metabolized in humans, and modified resveratrols are therefore desired as anti-cancer drugs and dietary polyphenols. An Escherichia coli system, in which an artificial stilbene biosynthetic pathway, including steps of phenylalanine ammonia-lyase, 4-coumarate:CoA ligase, and stilbene synthase, was reconstructed, produced stilbenes in high yields: resveratrol from tyrosine and pinosylvin from phenylalanine. To incorporate a stilbene methyltransferase gene into this E. coli system, cDNA of Os08g06100 in Oryza sativa was expressed and its O-methylating activity toward stilbenes was confirmed. Incorporation of the pinosylvin methyltransferase (OsPMT) gene into the pathway established in E. coli led to production of mono- and di-methylated stilbenes. Furthermore, the OsPMT gene turned out to be useful in production of unnatural stilbene methyl ethers due to its rather relaxed substrate specificity; various carboxylic acids supplemented as precursors, such as p-fluorocinnamic acid, 3-(2-furyl)acrylic acid, 3-(2-thienyl)acrylic acid, and 3-(3-pyridyl)acrylic acid, to the E. coli system carrying the steps of 4-coumarate:CoA ligase, stilbene synthase, and OsPMT were converted to stilbene dimethyl ethers with the corresponding carboxylic moiety.     

165 The Chloroplast Genome of the Toxic Stramenopile Heterosigma Akashiwo (Raphidophyceae)

Many temperate green macroalgae contain secondary meatbolites that provide protection from grazing by some herbivores. These include the production of dopamine hydrochloride by the ulvoid green alga Ulvaria obscura and the production of dimethylsulfoniopropionate (DMSP) by many species of Ulvales and Caulerpales. The dopamine hydrochloride defense was isolated using bioassay-guided fractionation and is effective against sea urchins ( Strongylocentrotus droebachiensis ) and littorinid snails ( Littorina sitkana ). The DMSP activated defense system involves enzymatic cleavage of DMSP into dimethyl sulfide (DMS) and acrylic acid. It is found in many of the Ulvales and several species of Codium in the northeastern Pacific and Australasian regions. Many green algae such as Ulva fenestrata and Enteromorpha linza are avoided by urchins, which are deterred by DMS and acrylic acid in laboratory assays. However, these algae are often preferred foods of snails, which are deterred by DMS and acrylic acid. Snails may preferentially consume ulvoid green algae, despite being deterred by DMS and acrylic acid, because these algae contain relatively high nitrogen concentrations.     

β-hydroxypropionic acid production by Byssochlamys sp. grown on acrylic acid

A strain of Byssochlamys sp. produced -hydroxypropionic acid when grown on media containing high concentrations of acrylic acid. The maximal production of -hydroxypropionic acid was 4.8% when the initial culture medium contained 7% acrylic acid and 2% glucose, and the initial culture pH was adjusted to 7.0. -Hydroxypropionic acid production from acrylic acid depended greatly on the pH of the culture medium. Calcium hydroxide was the best neutralizer. Correspondence to: K. Takamizawa     

164 Chemical Antiherbivore Defenses of Temperate Green Macroalgae

Many temperate green macroalgae contain secondary meatbolites that provide protection from grazing by some herbivores. These include the production of dopamine hydrochloride by the ulvoid green alga Ulvaria obscura and the production of dimethylsulfoniopropionate (DMSP) by many species of Ulvales and Caulerpales. The dopamine hydrochloride defense was isolated using bioassay‐guided fractionation and is effective against sea urchins (Strongylocentrotus droebachiensis) and littorinid snails (Littorina sitkana). The DMSP activated defense system involves enzymatic cleavage of DMSP into dimethyl sulfide (DMS) and acrylic acid. It is found in many of the Ulvales and several species of Codium in the northeastern Pacific and Australasian regions. Many green algae such as Ulva fenestrata and Enteromorpha linza are avoided by urchins, which are deterred by DMS and acrylic acid in laboratory assays. However, these algae are often preferred foods of snails, which are deterred by DMS and acrylic acid. Snails may preferentially consume ulvoid green algae, despite being deterred by DMS and acrylic acid, because these algae contain relatively high nitrogen concentrations.     

Biodiesel production with immobilized lipase: A review

Fatty acid alkyl esters, also called biodiesel, are environmentally friendly and show great potential as an alternative liquid fuel. Biodiesel is produced by transesterification of oils or fats with chemical catalysts or lipase. Immobilized lipase as the biocatalyst draws high attention because that process is “greener”. This article reviews the current status of biodiesel production with immobilized lipase, including various lipases, immobilization methods, various feedstocks, lipase inactivation caused by short chain alcohols and large scale industrialization. Adsorption is still the most widely employed method for lipase immobilization. There are two kinds of lipase used most frequently especially for large scale industrialization. One is Candida antartica lipase immobilized on acrylic resin, and the other is Candida sp. 99–125 lipase immobilized on inexpensive textile membranes. However, to further reduce the cost of biodiesel production, new immobilization techniques with higher activity and stability still need to be explored.