面向先进生物燃料的合成生物学

先进生物燃料一般指来自于非粮食原料的交通运输用生物燃料。近年来,先进生物燃料的发展引起了众多国家的浓厚兴趣,然而,先进生物燃料正处于关键的技术研发阶段,还需经过大量研发以突破技术障碍和示范生产活动后方能进行商业化部署。过去10年内,合成生物学研究大量兴起并不断取得突破,使人们有可能人工设计构建新的高效生命系统,克服生物燃料发展的技术瓶颈,进行先进生物燃料的生产。在介绍先进生物燃料与合成生物学的发展现状的基础上,分析了合成生物学在先进生物燃料研发中的重要价值与研发进展,探讨了合成生物学的发展潜力。     

纤维素乙醇气化发酵研究取得进展

在美国提出的2022年生产1360亿L生物燃料目标计划中,纤维素生物燃料的研发将发挥巨大作用。近10a来,美国俄克拉何马州立大学的生物燃料交叉学科研究小组在纤维素乙醇的气化发酵过程研究中取得了进展。该项工艺主要利用低成本、未处理过的生物质原料,如多年生牧草和作物秸秆,能够获取生物乙醇和其他增值产品。该研究小组正在进行进一步的整体分析研究,     

Catilin公司开发海藻生物燃料

作为生物燃料催化剂技术公司的美国Catilin公司宣布,将在今后3年内为开发海藻生物燃料项目投资530万美元,建成美国能源部启动先进生物燃料研究的基础设施,成为先进生物燃料和生物产品国家联盟（NAABB）投入4400万美元的组成部分。其合作伙伴爱荷华州立大学催化中心（ISU—CCAT）将提供关键的抽提、获取和转化技术。     

日本生物燃料政策的变迁

由干2000年下半年至2008年夏季国际原油价格持续高涨,因此近几年世界生物乙醇以及生物柴油等“生物燃料”的生产规模急剧扩大。美国和欧盟将生物燃料作为交通运输部门减排二氧化碳的法宝,十分重视相关技术研发和商业化。相形之下,日本一向不关注生物燃料。直到2002年1月修订《新能源法》时,     

Environmental Entrepreneurs公布2013年先进生物燃料市场报告

2013年8月27日,美国环保非营利组织Environmental Entrepreneurs（E2）发布2013年先进生物燃料市场报告,是E2公布的第3份年度报告。该报告将先进生物燃料的发展和问题进行分类,在2012年报告书的基础上就项目开发情况进行了数据更新。     

生物燃料最新发展态势分析

第一代生物燃料的生产工艺已经较为成熟,美国、欧盟和巴西等一些国家已经形成了较完善的产业链。以纤维素乙醇为代表的第二代生物燃料是更有希望的替代燃料,但目前还未获得关键性的技术突破,其大规模的商业化生产还有待时日。目前生物燃料正处于由第一代向第二代发展过渡的初期。各国纷纷将发展第二代生物燃料定为国策,为此制订了长期的发展规划与目标,并为生物燃料发展提供了良好的政策环境和大力的经费支持。各相关研究机构与企业也积极行动,力图解决生物燃料发展的各个关键问题。在此过程中,一些与生物燃料可持续发展有关的重要问题也引起了人们的关注。     

生物能源专刊序言

生物能源作为可再生能源,有望减少能源供给中对石油的依赖程度。近年来,我国生物能源的发展非常迅速,已经成为继巴西和美国后的第三大燃料乙醇生产国和消费国。为促进生物能源相关技术研究的发展,本期“生物能源”专刊收录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、生物燃料系统分析等领域的最新研究进展。     

生物燃料网站发布生物燃料和化学品项目数据库

重要的生物燃料网站BiofuelsDigest最近发布了先进生物燃料项目数据库2．0版,将跟踪报道2011～2016年先进的生物燃料和可再生化学品的计划生产能力。2011年是数据库建立以来,     

生物燃料用酶专利现状与分析

随着石油资源的日益枯竭和环境污染的日益严重,生物能源的研发引起了全球各界的广泛重视。生物能源包括燃料乙醇（玉米乙醇和纤维素乙醇）、生物柴油、生物制氢、生物发电、沼气等,     

美国能源部向生物燃料投资超过7．8亿美元

2009年5月5日,美国能源部（DOE）宣布作为促进美国国内增加可再生燃料使用量的措施之一,计划投资7．865亿美元。为了加速先进生物燃料的研究开发,将向商业规模生物炼制中间试验项目追加资金。该措施是根据American Recovery and Reinvestrnent法（Recovery法）提出的。     

Maßgeschneiderte Mikroorganismen

Tailor‐made microorganisms Microbial diversity provides unlimited resources for the development of novel industrial processes and products. Since the beginning of the 20th century microorganisms have been successfully applied for the large scale production of bio‐based products. In recent years, modern methods of strain development and Synthetic Biology have enabled biotech engineers to design even more sophisticated and tailor‐made microorganisms. These microbes serve industrial processes for the production of bulk chemicals, enzymes, polymers, biofuels as well as plant‐derived ingredients such as Artemisinin in an ecologically and economically sustainable and attractive fashion. In the future, production of advanced biofuels, microbial fuel cells, CO₂ as feedstock and microbial cellulose are research topics as well as challenges of global importance. Continuous efforts in microbiology and biotechnology research will be pivotal for white biotechnology to gain more momentum in transforming the chemical industry towards a knowledge based bio‐economy.     

Systems biology of yeast: enabling technology for development of cell factories for production of advanced biofuels

Transportation fuels will gradually shift from oil based fuels towards alternative fuel resources like biofuels. Current bioethanol and biodiesel can, however, not cover the increasing demand for biofuels and there is therefore a need for advanced biofuels with superior fuel properties. Novel cell factories will provide a production platform for advanced biofuels. However, deep cellular understanding is required for improvement of current biofuel cell factories. Fast screening and analysis (-omics) methods and metabolome-wide mathematical models are promising techniques. An integrated systems approach of these techniques drives diversity and quantity of several new biofuel compounds. This review will cover the recent technological developments that support improvement of the advanced biofuels 1-butanol, biodiesels and jetfuels.     

Development and status of dedicated energy crops in the United States

The biofuel industry is rapidly growing because of increasing energy demand and diminishing petroleum reserves on a global scale. A multitude of biomass resources have been investigated, with high-yielding, perennial feedstocks showing the greatest potential for utilization as advanced biofuels. Government policy and economic drivers have promoted the development and commercialization of biofuel feedstocks, conversion technologies, and supply chain logistics. Research and regulations have focused on the environmental consequences of biofuels, greatly promoting systems that reduce greenhouse gas emissions and life-cycle impacts. Numerous biofuel refineries using lignocellulosic feedstocks and biomass-based triglycerides are either in production or pre-commercial development phases. Leading candidate energy crops have been identified, yet require additional efforts to realize their full potential. Advanced biofuels, complementing conventional biofuels and other renewable energy sources such as wind and solar, provide the means to substantially displace humanity’s reliance on petroleum-based energy.     

Advanced Biofuels from Thermochemical Processing of Sustainable Biomass in Europe

Biofuels can play an important role in decreasing the use of fossil fuels, in particular in the transport sector, which absorbs about 30 % of the EU energy requirements. This review illustrates the motivations behind biofuel development, the government incentives and regulations and the current approaches on sustainable biomass conversion in Europe, and provides an overview on the major steps involved in thermochemical processes and on the issues challenging their deployment at large scale, with particular emphasis on the pyrolysis of biomass and bio-oil upgrading using conventional oil refinery settings. Distribution of sustainable biofuels in Europe and future prospects towards achieving success of transport biofuels were also addressed. The literature suggests that importing biofuels and increasing the cost of CO₂ to at least €60/t CO₂ will be necessary to meet the renewable obligation targets in the EU. Algae represent the future feedstock for biofuels but currently are limited by their high production costs and high N content. Pyrolysis is cost competitive compared to other technologies such as fermentation and gasification, but the quality of bio-oils requires upgrading mainly to lower their oxygen content and enhance their thermal stability. The recent advances in bio-oil upgrading using catalytic cracking and hydro-treating are very promising for the future deployment of advanced biofuels in the coming decades. However, significant investments in applied research and demonstration are still required to meet the 2020/2030 biofuel targets.     

β-Xylosidases and α-l-arabinofuranosidases: Accessory enzymes for arabinoxylan degradation

Arabinoxylan (AX) is among the most abundant hemicelluloses on earth and one of the major components of feedstocks that are currently investigated as a source for advanced biofuels. As global research into these sustainable biofuels is increasing, scientific knowledge about the enzymatic breakdown of AX advanced significantly over the last decade. This review focuses on the exo-acting AX hydrolases, such as α-arabinofuranosidases and β-xylosidases. It aims to provide a comprehensive overview of the diverse substrate specificities and corresponding structural features found in the different glycoside hydrolase families. A careful review of the available literature reveals a marked difference in activity between synthetically labeled and naturally occurring substrates, often leading to erroneous enzymatic annotations. Therefore, special attention is given to enzymes with experimental evidence on the hydrolysis of natural polymers.     

Advanced biofuel production in microbes

The cost-effective production of biofuels from renewable materials will begin to address energy security and climate change concerns. Ethanol, naturally produced by microorganisms, is currently the major biofuel in the transportation sector. However, its low energy content and incompatibility with existing fuel distribution and storage infrastructure limits its economic use in the future. Advanced biofuels, such as long chain alcohols and isoprenoid- and fatty acid-based biofuels, have physical properties that more closely resemble petroleum-derived fuels, and as such are an attractive alternative for the future supplementation or replacement of petroleum-derived fuels. Here, we review recent developments in the engineering of metabolic pathways for the production of known and potential advanced biofuels by microorganisms. We concentrate on the metabolic engineering of genetically tractable organisms such as Escherichia coli and Saccharomyces cerevisiae for the production of these advanced biofuels.     

Biofuels are dead: long live biofuels(?) – part two

Whilst obsessing over the policy catastrophe surrounding biofuels, we could easily lose sight of the prospects for science and technology to increase the sustainability of biofuel production by orders of magnitude. Part two of this feature examines the research and development of more sustainable biofuels.     

Metabolic engineering for advanced biofuels production from Escherichia coli

Global energy and environmental problems have stimulated increasing efforts toward synthesizing liquid biofuels as transportation energy. Compared to the traditional biofuel, ethanol, advanced biofuels should offer advantages such as higher energy density, lower hygroscopicity, lower vapor pressure, and compatibility with existing transportation infrastructure. However, these fuels are not synthesized economically using native organisms. Metabolic engineering offers an alternative approach in which synthetic pathways are engineered into user-friendly hosts for the production of these fuel molecules. These hosts could be readily manipulated to improve the production efficiency. This review summarizes recent progress in the engineering of Escherichia coli to produce advanced biofuels.     

Metabolic engineering of microbial pathways for advanced biofuels production

Production of biofuels from renewable resources such as cellulosic biomass provides a source of liquid transportation fuel to replace petroleum-based fuels. This endeavor requires the conversion of cellulosic biomass into simple sugars, and the conversion of simple sugars into biofuels. Recently, microorganisms have been engineered to convert simple sugars into several types of biofuels, such as alcohols, fatty acid alkyl esters, alkanes, and terpenes, with high titers and yields. Here, we review recently engineered biosynthetic pathways from the well-characterized microorganisms Escherichia coli and Saccharomyces cerevisiae for the production of several advanced biofuels.