Using triage for environmental remediation in Antarctica

Remediation of sites impacted by human activity in Antarctica is a difficult and resource intensive process. With increasing activity and climate change, the extent of damage from human activities is expected to increase and it will not be feasible to protect the environment entirely. We recommend a triage process be used to provide informed and transparent management decisions for comprehensive and adequate environmental remediation in Antarctica. We provide examples that demonstrate realistic outcomes where we have avoided tying up resources on disturbed sites that will recover naturally, are stable, or too damaged to recover, and that also incorporate feasible operational practices. Not all disturbed sites will be remediated and many of those that are, are unlikely to be returned to pristine condition. The decisions around remediation are not based solely on the desired environmental outcome. In the absence of effective legal obligation, we recognize that financial, social, policy, health and safety, technological confidence, and operational feasibility are part of the decision‐making process.     

Tree gum-based renewable materials: Sustainable applications in nanotechnology,biomedical and environmental fields

The prospective uses of tree gum polysaccharides and their nanostructures in various aspects of food, water, energy, biotechnology, environment and medicine industries, have garnered a great deal of attention recently. In addition to extensive applications of tree gums in food, there are substantial non-food applications of these commercial gums, which have gained widespread attention due to their availability, structural diversity and remarkable properties as ‘green’ bio-based renewable materials. Tree gums are obtainable as natural polysaccharides from various tree genera possessing exceptional properties, including their renewable, biocompatible, biodegradable, and non-toxic nature and their ability to undergo easy chemical modifications. This review focuses on non-food applications of several important commercially available gums (arabic, karaya, tragacanth, ghatti and kondagogu) for the greener synthesis and stabilization of metal/metal oxide NPs, production of electrospun fibers, environmental bioremediation, bio-catalysis, biosensors, coordination complexes of metal–hydrogels, and for antimicrobial and biomedical applications. Furthermore, polysaccharides acquired from botanical, seaweed, animal, and microbial origins are briefly compared with the characteristics of tree gum exudates.     

Cell-free synthetic biology for environmental sensing and remediation

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Textile-based cyanobacteria biocomposites for potential environmental remediation applications

Journal of Applied Phycology - Microalgae and cyanobacteria are effective platforms for environmental remediation (phycoremediation), particularly of air and water. There is limited scope to deploy...     

Versatile microbial surface-display for environmental remediation and biofuels production

Surface display is a powerful technique that uses natural microbial functional components to express proteins or peptides on the cell exterior. Since the reporting of the first surface-display system in the mid-1980s, a variety of new systems have been reported for yeast, Gram-positive and Gram-negative bacteria. Non-conventional display methods are emerging, eliminating the generation of genetically modified microorganisms. Cells with surface display are used as biocatalysts, biosorbents and biostimulants. Microbial cell-surface display has proven to be extremely important for numerous applications, ranging from combinatorial library screening and protein engineering to bioremediation and biofuels production.     

The use of hydrocarbon analyses for environmental assessment and remediation

Battelle Ocean Sciences has developed an analytical approach to identify and’ quantify petroleum products, coal products, and individual hydrocarbon components at trace levels in complex environmental matrices. The hydrocarbon analysis strategy uses capillary gas chromatography/flame ionization detection for alkane and total oil analysis, combined with gas chromatography/mass spectrometry for polynuclear aromatic hydrocarbon analysis. The method provides environmentally realistic analyte detection limits (parts per trillion in water, parts per billion in sediments) and an analyte list that is designed specifically for petroleum and coal‐based products. Results are compared to a detailed computerized library of total, water‐soluble, and degraded hydrocarbon products. The systematic data interpretation strategy maximizes the accuracy of petroleum and coal product identification in environmental matrices and represents a vast improvement over standard EPA methodology.     

Diterpenoid biopolymers: New directions for renewable materials engineering

Most types of ambers are naturally occurring, relatively hard, durable resinite polymers derived from the exudates of trees. This resource has been coveted for thousands of years due to its numerous useful properties in industrial processes, beauty, and purported medicinal properties. Labdane diterpenoid‐based ambers represent the most abundant and important resinites on earth. These resinites are a dwindling nonrenewable natural resource, so a new source of such materials needs to be established. Recent advances in sequencing technologies and biochemical engineering are rapidly accelerating the rate of identifying and assigning function to genes involved in terpenoid biosynthesis, as well as producing industrial‐scale quantities of desired small‐molecules in bacteria and yeast. This has provided new tools for engineering metabolic pathways capable of producing diterpenoid monomers that will enable the production of custom‐tailored resinite‐like polymers. Furthermore, this biosynthetic toolbox is continuously expanding, providing new possibilities for renewing dwindling stocks of naturally occurring resinite materials and engineering new materials for future applications. © 2010 Wiley Periodicals, Inc. Biopolymers 95: 71–76, 2011.     

合成生物学在环境修复中的应用

环境问题是21世纪人类面临的最严重的挑战。随着现代工农业飞速发展,生态环境日益恶化,难降解污染物如新兴污染物逐渐显现,已成为制约社会经济可持续发展的重要因素。微生物具有强大的环境修复能力,但是其进化速度远不及新兴污染物出现的速度,亟需应用合成生物学的技术来解决这一难题。在充分认识难降解有机污染物微生物降解(途径)特性的基础上,利用我国丰富的微生物与基因资源,运用合成生物学的手段,定向设计和改造现有降解菌株,构建能够降解一种或多种污染物的工程菌株;同时针对复合型污染,如废水等,在建立典型有机污染物代谢、调控和抗逆相关基因元件的模块库基础上,引入人工菌群等策略,对生物系统进行理性设计和组装,构建典型环境污染物的高效降解菌群,可有效促进我国新兴污染物微生物分解代谢的研究,为环境修复的工程应用提供技术支持。     

Novel biotechnological approaches in environmental remediation research

Two novel approaches, the use of Agrobacterium-transformed plant roots and mycelia cultures of fungi, are considered as research tools in the study of the remediation of soil, groundwater, and biowastes. Transformed roots are excellent model systems for screening higher plants that are tolerant of various inorganic and organic pollutants, and for determining the role of the root matrix in the uptake and further metabolism of contaminants. Edible and/or medicinal fungi may also be natural environmental remediators. Liquid cultures of fungal mycelia are appropriate model systems with which to commence screening and biochemical studies in this under-researched area of biotransformation.     

受污染沉积物原位覆盖材料研究进展

原位覆盖技术是一种新兴的沉积物修复技术,它与传统的受控自然恢复技术和疏浚技术相比,具有较好的修复效果、更小的生态风险与更低廉的成本,引起了广泛的关注.在20世纪70年代后期,原位覆盖技术已经应用到受污染沉积物修复中.经过近30年的发展,原位覆盖技术已经在美国、德国、日本、澳大利亚、挪威与加拿大等国家的受污染现场应用中取得了成功,并且在工程实践和理论研究相互促进过程中,该技术得到进一步的完善.其中,原位覆盖材料表现得更为突出,使得原位覆盖技术的应用前景变得广阔.本文对近年来国际上原位覆盖工程实践中各种覆盖材料的应用状况和实际修复效果进行了总结,为其在我国的应用起到推动作用.     

Carbohydrates--the renewable raw materials of high biotechnological value

Carbohydrates are the potential biomolecules derived from nature. Their molecular diversity has led to a bewildering variety of species, structures and characteristics all performing a large array of functions of great significance. Biologically they are vital as message (immunological) carriers, physiologically they are useful as energy (nutritional) reserves, and technologically they are needed for altering the texture and consistency (functional) of foods. Recent advances in glycobiology have opened up a new understanding of the role of sugars in biology and medicine. Noncellulosic beta-(1-3)-linked D-glucans, a group of polysaccharides found as constituents of fungi, algae, and higher plants, exhibit many interesting properties, depending on their molecular conformation. They are excellent 'biological response modifiers' and show significant immunomodulatory activities. They elicit a variety of host defense biological responses, for example, potent antitumor activity. On the other hand, the mixed-linkage ((1-3/1-4)-beta-linked) glucans are important constituents of cereal cell walls, where they perform properties of physiological importance, such as water holding capacity, porosity, and plasticity, which are useful at different stages of growth/development of plants. Of late, carbohydrate-based therapeutics are becoming the promise against many chronic diseases of today and tomorrow. Some of the characteristic features, structural attributes, functional significance, and applications of a selected few carbohydrate species are the subject matter of this review.     

Pyrolysis of triglyceride materials for the production of renewable fuels and chemicals

Conversion of vegetable oils and animal fats composed predominantly of triglycerides using pyrolysis type reactions represents a promising option for the production of renewable fuels and chemicals. The purpose of this article was to collect and review literature on the thermo-chemical conversion of triglyceride based materials. The literature was divided and discussed as (1) direct thermal cracking and (2) combination of thermal and catalytic cracking. Typically, four main catalyst types are used including transition metal catalysts, molecular sieve type catalysts, activated alumina, and sodium carbonate. Reaction products are heavily dependant on the catalyst type and reaction conditions and can range from diesel like fractions to gasoline like fractions. Research in this area is not as advanced as bio-oil and bio-diesel research and there is opportunity for further study in the areas of reaction optimization, detailed characterization of products and properties, and scale-up.     

Strategies for PHA production by mixed cultures and renewable waste materials

Production of polyhydroxyalkanoates (PHA) by mixed cultures has been widely studied in the last decade. Storage of PHA by mixed microbial cultures occurs under transient conditions of carbon or oxygen availability, known respectively as aerobic dynamic feeding and anaerobic/aerobic process. In these processes, PHA-accumulating organisms, which are quite diverse in terms of phenotype, are selected by the dynamic operating conditions imposed to the reactor. The stability of these processes during long-time operation and the similarity of the polymer physical/chemical properties to the one produced by pure cultures were demonstrated. This process could be implemented at industrial scale, providing that some technological aspects are solved. This review summarizes the relevant research carried out with mixed cultures for PHA production, with main focus on the use of wastes or industrial surplus as feedstocks. Basic concepts, regarding the metabolism and microbiology, and technological approaches, with emphasis on the kind of feedstock and reactor operating conditions for culture selection and PHA accumulation, are described. Challenges for the process optimization are also discussed.     

Natural fermentation of plant tissues as environmental remediation materials to improve soil and enhance plant resistance to cadmium stress

Cadmium (Cd) pollution poses a serious threat to various ecosystems, and phytoremediation is an alternate method for developing the soil health. To better utilize phytoremediation for Cd-contaminated soil remediation, the ginkgo leaves, pine needles, and Eucommia bark were mixed and naturally fermented to obtain Ginkgo biloba–Pinus massoniana–Eucommia ulmoides (GPE) Jiaosu and Jiaosu residue, whose effects on Broussonetia papyrifera planted in Cd-contaminated soil were evaluated. The results showed that the contents of the protein, phenolic, vitamin E, and alcohol of GPE Jiaosu were 4400 ± 0.46, 0.22 ± 0.01, 0.88 ± 0.24, and 4.63 ± 0.25 μL/mL, accordingly, with fine antioxidant activity. The soil pH, electrical conductivity content, organic carbon, total nitrogen, total phosphorus, alkali-hydrolyzable nitrogen, available phosphorus, and Cd concentration were all significantly (p < 0.05) modified. The chlorophyll content of B. papyrifera was increased by using Jiaosu residue in 12 hours, while the promotion effect of Jiaosu appeared in the later stage (60 days). The Cd tolerance physiological indexes such as malondialdehyde content and antioxidant enzymes' activity were all regulated. Applying the Jiaosu residue, the Cd in stems was decreased by 72.61% under 1000 mg/kg Cd treatment. These results suggested that GPE Jiaosu and Jiaosu residue can improve the properties of Cd-contaminated soil, promote the Cd tolerance of B. papyrifera, and affect the Cd migration. The current study provides a new bioremediation method using the Jiaosu and Jiaosu residue as Cd environmental remediation materials in a recyclable pathway, which is a circular and healthy development concept that integrates economic, ecological, and social significance.     

Production of lactic acid from renewable materials by Rhizopus fungi

Lactic acid is a commonly occurring organic acid, which is valuable due to its wide use in food and food-related industries, and its potential for the production of biodegradable and biocompatible polylactate polymers. Lactic acid can be produced from renewable materials using various fungal species of the Rhizopus genus, which have advantages compared to the bacteria, including their amylolytic characteristics, low nutrient requirements and valuable fermentation by-product—fungal biomass. This paper reviews recent research in process engineering, metabolic and enzymetic mechanisms, and molecular biotechnology associated with lactic acid production by the Rhizopus fungi to get a better understanding of biochemical activities. The major process components: renewable materials, bioreactor systems and process modeling are reviewed. The role of key bioprocess parameters, such as nutrient composition, pH and growth morphology, involved in the production of lactic acid is discussed in detail. In addition, recent advances in simultaneous saccharification and fermentation, molecular genetic approaches, and enzymetic and metabolic pathways involved in the production of lactic acid by fungal strains are discussed.     

Critical review of applications of iron and steel slags for carbon sequestration and environmental remediation

Reviews in Environmental Science and Bio/Technology - One of the major concerns faced by the iron and steel industry, other than the abundant emission of carbon dioxide into the atmosphere, is the...