Australian carbon biosequestration and bioenergy policy co-evolution: mechanisms, mitigation and convergence

The intricacies of international land-use change and forestry policy reflect the temporal, technical and political difficulty of integrating biological systems and climate change mitigation. The plethora of co-existing policies with varied technical rules, accreditation requirements, accounting methods, market registries, etc., disguise the unequal efficacies of each mechanism. This work explores the co-evolution and convergence of Australian voluntary and mandatory climate-related policies at the biosequestration-bioenergy interface. Currently, there are temporal differences between the fast-evolving and precise climate-change mechanisms, and the long-term 'permanence' sought from land use changes encouraged by biosequestration instruments. Policy convergence that favours the most efficient, appropriate and scientifically substantiated policy mechanisms is required. These policies must recognise the fundamental biological foundation of biosequestration, bioenergy, biomaterial industrial development and other areas such as food security and environmental concerns. Policy mechanisms that provide administrative simplicity, project longevity and market certainty are necessary for rural and regional Australians to cost-effectively harness the considerable climate change mitigation potential of biological systems

Economic and CO2 mitigation impacts of promoting biomass heating systems: an input-output study for Vorarlberg, Austria

This paper reports on an empirical investigation about the economic and CO2 mitigation impacts of bioenergy promotion in the Austrian federal province of Vorarlberg. We study domestic value added, employment and fiscal effects by means of a static input-output analysis. The bioenergy systems analysed comprise biomass district heating, pellet heating, automated wood chips heating systems, logwood stoves and boilers, ceramic stoves, and buffer storage facilities. The results indicate that gross economic effects are significant, both regarding investment and operation of the systems, and that the negative economic effects caused by the displacement of decentralised systems might be in the order of 20--40%. Finally, CO2 mitigation effects are substantial, contributing already in 2004 around 35% of the 2010 CO2 mitigation target of the Land Vorarlberg for all renewables set for 2010.Input-output analysis, Value added, Employment, Bioenergy

Overexpression of GA20-OXIDASE1 impacts plant height, biomass allocation and saccharification efficiency in maize

Increased biomass yield and quality are of great importance for the improvement of feedstock for the biorefinery. For the production of bioethanol, both stem biomass yield and the conversion efficiency of the polysaccharides in the cell wall to fermentable sugars are of relevance. Increasing the endogenous levels of gibberellic acid (GA) by ectopic expression of GA20-OXIDASE1 (GA20-OX1), the rate-limiting step in GA biosynthesis, is known to affect cell division and cell expansion, resulting in larger plants and organs in several plant species. In this study, we examined biomass yield and quality traits of maize plants overexpressing GA20-OX1 (GA20-OX1). GA20-OX1 plants accumulated more vegetative biomass than control plants in greenhouse experiments, but not consistently over two years of field trials. The stems of these plants were longer but also more slender. Investigation of GA20-OX1 biomass quality using biochemical analyses showed the presence of more cellulose, lignin and cell wall residue. Cell wall analysis as well as expression analysis of lignin biosynthetic genes in developing stems revealed that cellulose and lignin were deposited earlier in development. Pretreatment of GA20-OX1 biomass with NaOH resulted in a higher saccharification efficiency per unit of dry weight, in agreement with the higher cellulose content. On the other hand, the cellulose-to-glucose conversion was slower upon HCl or hot-water pretreatment, presumably due to the higher lignin content. This study showed that biomass yield and quality traits can be interconnected, which is important for the development of future breeding strategies to improve lignocellulosic feedstock for bioethanol production

Sustainable bioethanol production combining biorefinery principles using combined raw materials from wheat undersown with clover-grass

To obtain the best possible net energy balance of the bioethanol production the biomass raw materials used need to be produced with limited use of non-renewable fossil fuels. Intercropping strategies are known to maximize growth and productivity by including more than one species in the crop stand, very often with legumes as one of the components. In the present study clover-grass is undersown in a traditional wheat crop. Thereby, it is possible to increase input of symbiotic fixation of atmospheric nitrogen into the cropping systems and reduce the need for fertilizer applications. Furthermore, when using such wheat and clover-grass mixtures as raw material, addition of urea and other fermentation nutrients produced from fossil fuels can be reduced in the whole ethanol manufacturing chain. Using second generation ethanol technology mixtures of relative proportions of wheat straw and clover-grass (15:85, 50:50, and 85:15) were pretreated by wet oxidation. The results showed that supplementing wheat straw with clover-grass had a positive effect on the ethanol yield in simultaneous saccharification and fermentation experiments, and the effect was more pronounced in inhibitory substrates. The highest ethanol yield (80% of theoretical) was obtained in the experiment with high fraction (85%) of clover-grass. In order to improve the sugar recovery of clover-grass, it should be separated into a green juice (containing free sugars, fructan, amino acids, vitamins and soluble minerals) for direct fermentation and a fibre pulp for pretreatment together with wheat straw. Based on the obtained results a decentralized biorefinery concept for production of biofuel is suggested emphasizing sustainability, localness, and recycling principle

Agroforestry: Reconciling Production with Protection of the Environment A Synopsis of Research Literature

This is a synopsis of research literature that investigates the potential of temperate agroforestry as a sustainable production system. Agroforestry is a concept of integrated land use that combines elements of agriculture and forestry. An emphasis on managing rather than reducing complexity promotes a functionally biodiverse system that balances productivity with environmental protection

Municipal wastewater treatment and associated bioenergy generation using anaerobic granular bed baffled reactor

This study assesses a modified anaerobic granular bed baffled reactor (GRABBR) which was assessed for municipal wastewater treatment at high organic loading rates (chemical oxygen demand ≥ 1,100 mg/l) under varying temperatures. For the two mesophilic temperatures tested (37⁰C and 25⁰C) under steady state conditions, the removal of Chemical OxygenDemand (COD) and Biochemical Oxygen Demand (BOD) was 80 to 90 %. At lower organic loadings, the reactor operated as a completely mixed system with most of the treatment occurring in the first two compartments. The GRABBR also showed very high solids retention with low effluent suspended solids concentration for all organic and hydraulic conditions. Applications ofGRABBR as a single unit, two-phase treatment system could be an economical option reducing the cost to achieve similar treatment goals for high strength wastewaters. The findings of this research suggest that the application of GRABBR is suitable for the treatment of multiple pollutants present in wastewater where each compartment acts as a specialised treatment stagewith biogas production

Crystallization and preliminary X-ray analysis of neoagarobiose hydrolase from Saccharophagus degradans 2-40

Many agarolytic bacteria degrade agar polysaccharide into the disaccharide unit neoagarobiose [O-3,6-anhydro-α-L-galactopyranosyl-(1→3)-D-galactose] using various β-agarases. Neoagarobiose hydrolase is an enzyme that acts on the α-1,3 linkage in neoagarobiose to yield D-galactose and 3,6-anhydro-L-galactose. This activity is essential in both the metabolism of agar by agarolytic bacteria and the production of fermentable sugars from agar biomass for bioenergy production. Neoagarobiose hydrolase from the marine bacterium Saccharophagus degradans 2-40 was overexpressed in Escherichia coli and crystallized in the monoclinic space group C2, with unit-cell parameters a = 129.83, b = 76.81, c = 90.11 Å, β = 101.86°. The crystals diffracted to 1.98 Å resolution and possibly contains two molecules in the asymmetric unit

The 2002 Farm Bill: Revitalizing the Farm Economy Through Renewable Energy Development

2002 Policy Report.Reduced profit margins and low commodity prices have forced many to leave farming in the past decade, or rely increasingly on off-farm income, while more attractive opportunities in less volatile industries have deterred many young people from entering the farming profession. Currently, less than half of American farmers list farming as their primary source of income and the average American farmer is now 54.3 years old. The agricultural economy has always been volatile when compared to other industries due to (1) the inability of farmers to readily change production levels, (2) a fixed demand for food regardless of price, and (3) the unpredictability of climate events. But many uniquely modern challenges face U.S. agriculture as well, such as competition from foreign producers in an increasingly global economy, the proliferation of large-scale industrial agriculture, and the rising cost of energy inputs. Naturally, the economic hardships within the agricultural sector have had repercussions throughout Rural America. U.S. agriculture is at a crossroads. The decisions that shape this Farm Bill will determine the course of the agricultural sector for years to come. Although many challenges lie ahead, many new opportunities present themselves as well. Our fossil fuel-based economy, which heats our homes, powers our automobiles, and provides us with an array of products, is ultimately unsustainable in the long-term. But a new sustainable economy is slowly emerging, an economy which will rely increasingly on renewable sources of energy such as wind, solar, geothermal, and biomass. Farmers can be at the forefront of this revolution; utilizing the commodities they grow, and even the waste streams they now must dispose of, in innovative new ways to produce power, transportation fuels, and a new generation of biobased products and chemicals. Linking agriculture and renewable energy is key to diversifying our energy market, protecting our environment, and revitalizing rural America ñ truly a ìwin-win-winî opportunity that is good for American farmers and good for the country

Expression of a bacterial 3-dehydroshikimate dehydratase reduces lignin content and improves biomass saccharification efficiency.

Lignin confers recalcitrance to plant biomass used as feedstocks in agro-processing industries or as source of renewable sugars for the production of bioproducts. The metabolic steps for the synthesis of lignin building blocks belong to the shikimate and phenylpropanoid pathways. Genetic engineering efforts to reduce lignin content typically employ gene knockout or gene silencing techniques to constitutively repress one of these metabolic pathways. Recently, new strategies have emerged offering better spatiotemporal control of lignin deposition, including the expression of enzymes that interfere with the normal process for cell wall lignification. In this study, we report that expression of a 3-dehydroshikimate dehydratase (QsuB from Corynebacterium glutamicum) reduces lignin deposition in Arabidopsis cell walls. QsuB was targeted to the plastids to convert 3-dehydroshikimate - an intermediate of the shikimate pathway - into protocatechuate. Compared to wild-type plants, lines expressing QsuB contain higher amounts of protocatechuate, p-coumarate, p-coumaraldehyde and p-coumaryl alcohol, and lower amounts of coniferaldehyde, coniferyl alcohol, sinapaldehyde and sinapyl alcohol. 2D-NMR spectroscopy and pyrolysis-gas chromatography/mass spectrometry (pyro-GC/MS) reveal an increase of p-hydroxyphenyl units and a reduction of guaiacyl units in the lignin of QsuB lines. Size-exclusion chromatography indicates a lower degree of lignin polymerization in the transgenic lines. Therefore, our data show that the expression of QsuB primarily affects the lignin biosynthetic pathway. Finally, biomass from these lines exhibits more than a twofold improvement in saccharification efficiency. We conclude that the expression of QsuB in plants, in combination with specific promoters, is a promising gain-of-function strategy for spatiotemporal reduction of lignin in plant biomass