一个以可再生资源为原料的新材料产业——"生态塑料"即将诞生

介绍了完全可生物降解塑料PLA、PHA等材料的研究进展和产业化进程。浅析了生物降解塑料国内外发展现状、面临的困难与机遇。建议抓住时机重视和发展来源于可再生资源的生物材料———生态塑料,使之成为一个可持续发展的新材料产业。     

代谢工程改造解脂耶氏酵母合成植物萜类化合物的研究进展

萜类化合物是一类广泛存在于植物中的天然产物,其在食品、药品和化工等多个领域中均有广泛的用途,市场潜力巨大。因此,开发生产萜类化合物等植物天然产物可再生的微生物资源来补充甚至代替原有稀少和珍贵的植物资源,具有重要的理论意义和潜在的应用价值。解脂耶氏酵母是目前使用最广泛的非常规酵母底盘细胞之一。近年来,利用代谢工程及合成生物学技术在解脂耶氏酵母底盘细胞中重构与优化萜类化合物的合成途径以实现目标代谢产物的高效合成,已经成为一项研究热点。本文系统总结了有关利用解脂耶氏酵母作为底盘细胞异源生产植物萜类化合物的具体实例和最新进展,包括所涉及的宿主菌株、关键酶、代谢途径及改造策略等,并在最后对该领域的未来发展方向进行了展望。     

The endophytic Aspergillus strains: A bountiful source of natural products

Fungi that invade plant inner tissues without inducing disease symptoms are known as fungal endophytes. They represent a promising and tremendous reservoir of natural products with valuable biological potentials for application in medicine, agriculture and industry. Among the numerous existing endophytic fungi, Aspergillus strains constitute one of the most prolific sources of secondary metabolites with diverse chemical classes and interesting biological activities. This review covers the literature of the year 2020, reporting the isolation of 202 compounds obtained from more than 10 different endophytic Aspergillus species associated with different host plants. Analysis and interpretation of the collected data revealed that chemical investigation of endophytes belonging to the genus Aspergillus may greatly contribute to the discovery of potential drug leads. The isolated metabolites were chemically various and exhibited diverse biological activities such as antibacterial, anti-cancer, anti-plasmodial, anti-inflammatory, antioxidant, immunosuppressive and antifungal activities. Moreover, adoption of advanced technology in molecular biology together with modern chemical tools is anticipated to improve the discovery of new biopharmaceuticals from this valuable microbial world in the future.     

Medical Geology: Emerging Discipline on the Ecosystem–Human Health Interface

Medical geology is an emerging discipline that, broadly defined, examines the public health impacts of geologic materials and geologic processes. The scope and range of medical geology include: (1) identifying and characterizing natural and anthropogenic sources of harmful materials in the environment; (2) learning how to predict the movement and alteration of chemical, infectious, and other disease-causing agents over time and space; and (3) understanding how people are exposed to such materials and what can be done to minimize or prevent such exposure. Participants of a Medical Geology Working Group that met recently in Washington, DC, identified lessons learned to date in the development of this new field, noted research gaps that should be addressed, and recommended key priorities and directions for a sustainable future for medical geology.     

煤矿固废资源化利用的生态效率与碳减排——以淮北市为例

工业固废的大量堆积产生多种环境危害,工业固废的资源化利用能够节约资源和缓解环境压力。建筑行业是能源消耗和碳排放的主要部门之一,其中建筑材料生产阶段的能耗和碳排放占有重要的地位。粉煤灰、煤矸石是常见的工业固体废物,尤其是在以煤炭为主要能源的地区。粉煤灰、煤矸石资源化利用的途径之一是用于制造新型墙体砖。本文以煤炭资源型城市淮北市的新型墙体砖(粉煤灰砌块、煤矸石砖)和传统墙体砖(粘土砖、粘土多孔砖)为案例,对墙体砖生产过程的生态效率和碳排放进行分析和比较。在淮北市墙体材料行业碳排放不增加的前提下,以最优生态效率为目标,建立线性规划模型,对淮北市4种主要墙体材料的产量进行规划。分析结果表明:新型墙体材料的生态效率高于传统墙体材料;煤矸石砖生产过程的碳排放系数高于传统墙体砖;粉煤灰砌块生产过程的碳排放系数介于粘土砖和粘土多孔砖之间。在淮北市墙体材料行业碳排放不增加的前提下,与现有的产量相比,淮北市应禁止粘土砖的生产,适当减少粘土多孔砖的产量,适当增加粉煤灰砌块和煤矸石砖的产量,以达到最优生态效率。在最优生态效率的情况下,淮北市新型墙体材料煤矸石砖对煤矸石工业固废的利用率将由目前的15.8%增加到25.2%。     

Next issue (December 2007): Energy Production

Edited by Dr. Stefan Nordhoff, Marl, Germany Highlight articles: – Sustainable production of biofuels – Coupled production in biorefineries – Biodegradation of fuel oil hydrocarbons – Biobutanol: an attractive biofuel – Sustainable biobased energy, fuels and materials – Renewable resources in the chemical industry – breaking away from oil? – Using waste from olive oil industry for fuel production – Economic impacts of bio-refinery and resource cascading systems – Agricultural raw materials – energy or food? ... and much more: Read the next issue of BTJ!     

A practical perspective on ulvan extracted from green algae

Researchers have many times turned their attention to nature and biological processes to develop novel technologies and materials. In a medical perspective, nature-based products are believed to be a strategic alternative approach to the use of fully synthetic materials, particularly in the design of medical devices. In the past decades, marine organisms have become the focus of considerable attention as potential sources of valuable materials. The sustainable exploitation and valorisation of natural marine resources constitutes a highly attractive and strategic platform for the development of novel biomaterials, with both economic and environmental benefits. In this context, algae are known to synthesise large quantities of polysaccharides and are well established sources of these particularly interesting molecules, many of which are known for their applicability in the design of biomaterials. Agar, carrageenan and alginates are some of the most known examples, and their uses can range from food to biomedical applications. However, few of the world’s available seaweed species are used commercially. Among the three main divisions of macroalgae (Chlorophyta, Phaeophyta and Rhodophyta), the green algae remain largely unexploited in this biomedical arena. While the demand for novel materials and technologies increases, so does the research of unexploited marine green algae including its unique polysaccharide ulvan.     

生物技术生产丁酸的研究进展

丁酸作为一种重要的化工原料,已经广泛应用于食品添加剂与医药等领域。目前,工业上生产丁酸主要是从石油中提取有机化合物进行化学合成。与有机化合物合成法相比,微生物发酵产丁酸的优势有：所用的原料来源非常广,发酵过程低能耗,不污染环境,而且可以持续添加原料发酵生产丁酸。因此,通过生物技术发酵生产丁酸越来越受到人们的重视。介绍了丁酸的性质、产丁酸菌株的特点、微生物发酵产丁酸的细胞代谢途径及其调控、发酵法生产丁酸的工艺运行方式和产丁酸菌株及其代谢产物的生理功能这五部分内容,以期为今后开展发酵法产丁酸的微生物基因工程改造以及生产工艺的优化提供参考。     

Raw plant-based biorefinery: A new paradigm shift towards biotechnological approach to sustainable manufacturing of HMF

Unlike petrorefinery, biorefinery uses carbon-based biomaterials, such as plant feedstocks, as the major feeding input materials in chemical manufacturing. To date, petroleum-based resources have been used for the production of wide spectrums of chemical products. However, petrorefinery is currently associated with a variety of issues, i.e., concerns over adverse impacts on the environment and human society. As an alternative technology, the sustainable biorefinery is a matter of great importance in industrial chemical manufacturing due primarily to its sustainability. As carbon-based resources, plants are paramount biomaterials for biorefinery process required in sustainable chemical manufacturing. In particular, raw plant-based biorefinery is a breakthrough technology for chemical manufacturing due mainly to its sustainable benefits. Nowadays, numerous biorefinery technologies have been developed for the production of industrially valuable chemicals. HMF, a versatile platform chemical, can be produced by dehydrating hexose sugars using raw plant feedstocks such as inulin-rich, starch-rich, and lignocellulosic plants and now, it is generally recognized as a chemical feedstock for future chemical manufacturing and bioenergy production. In this review article, this emerging hybrid technology is discussed in relation to the production of HMF from raw plant feedstocks mentioned above. In addition, the plant candidates useful for biorefinery processing of raw plant feedstocks are introduced and bioengineering strategy for their genetic modification is together described to provide current knowledge on sustainable biorefinery.     

Detection of small bioactive peptides from Atlantic herring (Clupea harengus L.)

Recent research has shown that fish residual materials contain a range of components with interesting biological activity. Therefore, there is a great potential in the marine bioprocess industry to utilize these by-products as starting material for generating more valuable products. The aim of the present study was to search for bioactive peptides (in particular small natural bioactive peptides with molecular weight lower than 10 kDa) in Atlantic herring (Clupea harengus L.) by-products such as skin and more general residual materials. By such means a range of peptides with claimed interesting biological activities was found. Herein the activity of the detected bioactive peptides and strategies for isolating peptide fragments containing the bioactive motif is discussed. Identification of bioactive peptides in crude peptide/protein sources (skin and residual materials) was performed directly using a combination of mass spectrometry (Orbitrap), bioinformatics and database search. This method was a good angle of approach in order to map the potential in new species and species that have been very little studied.     

Platform biochemicals for a biorenewable chemical industry

The chemical industry is currently reliant on a historically inexpensive, petroleum-based carbon feedstock that generates a small collection of platform chemicals from which highly efficient chemical conversions lead to the manufacture of a large variety of chemical products. Recently, a number of factors have coalesced to provide the impetus to explore alternative renewable sources of carbon. Here we discuss the potential impact on the chemical industry of shifting from non-renewable carbon sources to renewable carbon sources. This change to the manufacture of chemicals from biological carbon sources will provide an opportunity for the biological research community to contribute fundamental knowledge concerning carbon metabolism and its regulation. We discuss whether fundamental biological research into metabolic processes at a holistic level, made possible by completed genome sequences and integrated with detailed structural understanding of biocatalysts, can change the chemical industry from being dependent on fossil-carbon feedstocks to using biorenewable feedstocks. We illustrate this potential by discussing the prospect of building a platform technology based upon a concept of combinatorial biosynthesis, which would explore the enzymological flexibilities of polyketide biosynthesis.     

Laurie oil resources

Lauric oils and their derivatives have many applications both in the food and chemical industries. The major sources and some alternative raw materials for this multi-billon dollar business are discussed in the light of their ability to supply future market needs. There should be ample supply of lauric oils—except when drought and possibly disease affect large areas of coconut plantations—because of the rapid increase in palm kernel oil production expected from the African oil palm during the next decade. Most other sources are unlikely to be important in the short term because of the generally adequate supply of lauric oils and the considerable amount of research still needed to convert the best options into viable crops. However, a dramatic effect on supply can be expected if it becomes possible to manipulate the appropriate genes from lauric oil producing species of Cuphea into a conventional oil crop like rape. Future demand for lauric oils will be affected by the relative price of other vegetable oils and petroleum feedstocks that can be used to replace them in the manufacture of an increasing number of end products in both the food and chemical industries.     

New woody and ambery notes from cedarwood and turpentine oil

The development of a new product in the chemical industry is still driven by needs like technical properties, price/performance ratio, biodegradability, or product safety. However, in terms of improving more and more on ecological criteria, summarized under such catchphrases as sustainable development or green chemistry, another important aspect is to use renewable resources as starting materials. This is not significantly new in fragrance chemistry, and there are a lot of raw materials in the perfume oils that are derived from molecules of renewable resources. Two commonly used materials are: longifolene (from turpentine oil) and cedrene (from cedarwood oil). These compounds are very suitable for the synthesis of woody and ambery notes, and even though it seemed that all possibilities were exhausted, it is actually still feasible to discover new molecules with excellent olfactory properties such as Ambrocenide (50a), which is available in three steps from alpha-cedrene. Some of these molecules will be treated in this review, both with respect to synthesis as well as structural and sensory aspects.     

Building bridges: an integrated strategy for sustainable food production throughout the value chain

The food production and processing value chain is under pressure from all sides—increasing demand driven by a growing and more affluent population; dwindling resources caused by urbanization, land erosion, pollution and competing agriculture such as biofuels; and increasing constraints on production methods driven by consumers and regulators demanding higher quality, reduced chemical use, and most of all environmentally beneficial practices ‘from farm to fork’. This pressure can only be addressed by developing efficient and sustainable agricultural practices that are harmonized throughout the value chain, so that renewable resources can be exploited without damaging the environment. Bridges must, therefore, be built between the diverse areas within the food production and processing value chain, including bridges between different stages of production, between currently unlinked agronomic practices, and between the different levels and areas of research to achieve joined-up thinking within the industry, so that the wider impact of different technologies, practices and materials on productivity and sustainability is understood at the local, regional, national and global scales. In this article, we consider the challenges at different stages and levels of the value chain and how new technologies and strategies could be used to build bridges and achieve more sustainable food/feed production in the future.     

Carbon Solving Carbon's Problems: Recent Progress of Nanostructured Carbon‐Based Catalysts for the Electrochemical Reduction of CO2

The electrochemical reduction of CO₂ to useful molecules offers an elegant technological solution to current energy security and sustainability issues because it sequesters carbon from the atmosphere, provides an energy storage solution for intermittent renewable sources, and can be used to produce fuels and industrial chemicals. Nanostructured carbon materials have been extensively used to catalyse some key electrochemical processes because of their excellent electrical conductivity, chemical stability, and abundant active sites. This progress report focuses on nanostructured carbon materials, namely graphene materials, carbon nanotubes, porphyrin materials, nanodiamond, and glassy carbon, which have recently shown promise as high performing CO₂ reduction electrocatalysts and supports. Along with discussion regarding materials synthesis, structural characterisation, and electrochemical performance characterisation techniques used, this report will discuss the findings of recent computational CO₂RR studies which have been key to elucidating active sites and reaction mechanisms, and developing strategies to break conventional scaling relationships. Lastly, challenges and future perspective of these carbon‐based materials for CO₂ reduction applications will be given. Much work is still required to realise the commercial viability of the technology, but advanced experimental techniques coupled with theoretical calculations are expected to facilitate future development of the technology.     

Fermentative production of butanol--the academic perspective

As mobility is a major pillar of World's economic system and burning fuels from fossil resources leads to a dramatic increase in greenhouse gas emissions, the production and use of appropriate biofuels offer at least a partial solution to this problem. Butanol represents a biofuel extender or replacement with properties clearly superior to ethanol (higher mileage, not hygroscopic, usable without engine modifications, not corrosive). In addition, it is a valuable feedstock for the chemical industry. Scientific challenges for an economically competitive fermentation process include employment of cheap carbon sources, not competing with nutrition, a detailed understanding of the metabolic reactions of the biological process, development of appropriately engineered construction strains, and adaption of process technology to modern standards.     

Microbial deterioration of cultural heritage and works of art — tilting at windmills?

Microorganisms (bacteria, archaea and fungi), in addition to lichens and insect pests, cause problems in the conservation of cultural heritage because of their biodeteriorative potential. This holds true for all types of historic artefacts, and even for art made of modern materials, in public buildings, museums and private art collections. The variety of biodeterioration phenomena observed on materials of cultural heritage is determined by several factors, such as the chemical composition and nature of the material itself, the climate and exposure of the object, in addition to the manner and frequency of surface cleaning and housekeeping in museums. This study offers a review of a variety of well-known biodeterioration phenomena observed on different materials, such as stone and building materials, objects exhibited in museums and libraries, as well as human remains and burial-related materials. The decontamination of infected artefacts, exhibition rooms and depots incurs high expenditure for museums. Nevertheless, the question has to be raised: whether the process of biodeterioration of cultural heritage can or should be stopped under all circumstances, or whether we have to accept it as a natural and an implicit consecution of its creation. This study also highlights critically the pros and cons of biocide treatments and gives some prominent examples of successful and unsuccessful conservation treatments. Furthermore, an outlook on the future research needs and developments in this highly interesting field is given.     

Functional receptors for the insulinotropic hormone glucagon-like peptide-I(7-37) on a somatostatin secreting cell line.

For the first time, a pectin lyase (poly(methoxygalacturonide)lyase; EC 4.2.2.10) from a member of the generus Penicillium was isolated, purified to homogeneity and characterized. The monomeric enzyme from Penicillium italicum CECT 2294 culture filtrates showed a molecular mass of 34 kDa after SDS-electrophoresis in polyacrylamide gradient gels, and the isoelectric point was 8.6 as determined by isoelectric focusing. The optimum pH (9.0), the high pH and temperature stabilities, the ability to degrade pectins from different sources and with a wide range of degrees of esterification (from 37% to 86%) as well as the importance of this type of biocatalysts in the food industry make this enzyme an interesting subject of study.     

Waste Recycling in Thermoelectric Materials

Thermoelectric (TE) technology enables the efficient conversion of waste heat generated in homes, transport, and industry into promptly accessible electrical energy. Such technology is thus finding increasing applications given the focus on alternative sources of energy. However, the synthesis of TE materials relies on costly and scarce elements, which are also environmentally damaging to extract. Moreover, spent TE modules lead to a waste of resources and cause severe pollution. To address these issues, many laboratory studies have explored the synthesis of TE materials using wastes and the recovery of scarce elements from spent modules, e.g., utilization of Si slurry as starting materials, development of biodegradable TE papers, and bacterial recovery and recycling of tellurium from spent TE modules. Yet, the outcomes of such work have not triggered sustainable industrial practices to the extent needed. This paper provides a systematic overview of the state of the art with a view to uncovering the opportunities and challenges for expanded application. Based on this overview, it explores a framework for synthesizing TE materials from waste sources with efficiencies comparable to those made from raw materials.