Business Sphere, Vol. 19, no.1

Ethanol, the clean-burning, high octane fuel distilled from Iowa’s corn fields, has the potential to free the U.S. from its foreign oil dependence. Transforming corn into ethanol, however, takes energy, usually in the form of natural gas or coal. Ames-based Frontline BioEnergy is developing biomass-to-energy conversion methods that reduce an ethanol plant’s consumption of fossil fuels, making ethanol an even greener product. As Iowa’s ethanol industry continues to grow, developing energy from biomass could result in huge savings for the state’s production facilities

A fast ethanol assay to detect seed deterioration

The most common way to test seed quality is to use a simple and reliable but time- and space-consuming germination test. In this paper we present a fast and simple method to analyse cabbage seed deterioration by measuring ethanol production from partially imbibed seeds. The method uses a modified breath analyser and is simple compared to gas chromatographic or enzymatic procedures. A modified method using elevated temperatures (40°C instead of 20°C) shortened the assay time and improved its sensitivity. The analysis showed an inverse correlation between ethanol production and seed quality (e.g. the final percentages or speed of germination and the number of normal seedlings). The increase in ethanol production was observed when cabbage seeds were deteriorated by storage under ambient conditions or hot water treatments, both of which reduced the number of normal seedlings. Premature seeds produced more ethanol upon imbibition than mature seeds. Ethanol production occurred simultaneously with oxygen consumption, indicating that lack of oxygen is not the major trigger for ethanol production

Ethanol triggers grape gene expression leading to anthocyanin accumulation during berry ripening

Recent studies have shown that low doses of ethanol stimulate the maturation of some fruits. The present work showed that spraying Cabernet Sauvignon grapes, with 5% ethanol at veraison enhances the anthocyanin accumulation. Veraison is the time when the berries turn from green to purple. HPLC analysis showed a marked increase in the total concentrations of the derivatives of delphinidin, cyanidin, petunidin, peonidin and malvidin from the fourth day after the ethanol treatment until harvest. This was not linked to a difference in berry weight in comparison to controls. Two distinct expression patterns were found for anthocyanin biosynthesis genes in the treated and untreated berries. For one group, consisting of chalcone synthase, flavanone-3-hydroxylase, dihydroxyflavonol-4-reductase and leucoanthocyanidin dioxygenase, the expression was inhibited or unchanged by the ethanol treatment, whereas for UDP glucose-flavonoid 3-O-glucosyltransferase (UFGT) there was a marked increase in expression from 1 to 20 days after ethanol treatment. These results suggest that the UFGT gene is a key factor in the observed anthocyanin accumulation following ethanol treatment

Ethanol internal reforming in solid oxide fuel cells: A path toward high performance metal-supported cells for vehicular applications

Internal reforming of ethanol fuel was investigated on high-performance metal-supported solid oxide fuel cells (MS-SOFCs) with infiltrated catalysts. The hydrogen concentration and internal reforming effects were evaluated systematically with different fuels including: hydrogen, simulated reformate, anhydrous ethanol, ethanol water blend, and hydrogen-nitrogen mixtures. A simple infiltration of Ni reforming catalyst into 40 vol% Ni-Sm0.20Ce0.80O2-δ (Ni-SDCN40) and fuel-side metal support leads to complete internal reforming, as confirmed by comparison to simulated reformate. The performance difference between hydrogen and fully-reformed ethanol is attributed entirely to decrease in hydrogen concentration. High peak power density was achieved for a range of conditions, for example 1.0 W cm−2 at 650 °C in ethanol-water blend, and 1.4 W cm−2 at 700 °C in anhydrous ethanol fuel. Initial durability tests with ethanol-water blend show promising stability for 100 h at 700 °C and 0.7 V. Carbon is not deposited in the Ni-SDCN40 anode during operation

Adaptation to high ethanol reveals complex evolutionary pathways

Tolerance to high levels of ethanol is an ecologically and industrially relevant phenotype of microbes, but the molecular mechanisms underlying this complex trait remain largely unknown. Here, we use long-term experimental evolution of isogenic yeast populations of different initial ploidy to study adaptation to increasing levels of ethanol. Whole-genome sequencing of more than 30 evolved populations and over 100 adapted clones isolated throughout this two-year evolution experiment revealed how a complex interplay of de novo single nucleotide mutations, copy number variation, ploidy changes, mutator phenotypes, and clonal interference led to a significant increase in ethanol tolerance. Although the specific mutations differ between different evolved lineages, application of a novel computational pipeline, PheNetic, revealed that many mutations target functional modules involved in stress response, cell cycle regulation, DNA repair and respiration. Measuring the fitness effects of selected mutations introduced in non-evolved ethanol-sensitive cells revealed several adaptive mutations that had previously not been implicated in ethanol tolerance, including mutations in PRT1, VPS70 and MEX67. Interestingly, variation in VPS70 was recently identified as a QTL for ethanol tolerance in an industrial bio-ethanol strain. Taken together, our results show how, in contrast to adaptation to some other stresses, adaptation to a continuous complex and severe stress involves interplay of different evolutionary mechanisms. In addition, our study reveals functional modules involved in ethanol resistance and identifies several mutations that could help to improve the ethanol tolerance of industrial yeasts

Can the U.S. Ethanol Industry Compete in the Alternative Fuels' Market?

The U.S. ethanol fuel industry has experienced preferential treatment from federal and state governments ever since the Energy Tax Act of 1978 exempted 10% ethanol/gasoline blend (gasohol) from the federal excise tax. Combined with a 54¢/gal ethanol import tariff, this exemption was designed to provide incentives for the establishment and development of a U.S. ethanol industry. Despite these tax exemptions, until recently, the U.S. ethanol fuel industry was unable to expand from a limited regional market. Ethanol was dominated in the market by MTBE (methyl-tertiary-butyl ether). Only after MTBE was found to contaminate groundwater and consequently banned in many states did the demand for ethanol expand nationally. Limit pricing on the part of MTBE refiners is one hypothesis that may explain this lack of ethanol entry into the fuel-additives market. As a test of this hypothesis, a structural vector autoregression (SVAR) model of the ethanol fuel market is developed. The results support the hypothesis of limit-pricing behavior on the part of MTBE refiners, and suggest the U.S. corn-based ethanol industry is vulnerable to limit-price competition, which could recur. The dependence of corn-based ethanol price on supply determinants limits U.S. ethanol refiners' ability to price compete with sugar cane-based ethanol refiners. Without federal support, U.S. ethanol refiners may find it difficult to complete with cheaper sugar cane-refined ethanol, chiefly from Brazil.Resource /Energy Economics and Policy,

Methanol and isopropanol embryo dosage response curves for wild-type and ethanol-sensitive zebrafish

It is well established that ethanol has an array of negative effects on developing embryos, from craniofacial abnormalities to cognitive deficits and behavioral disorders. Fetal Alcohol Spectrum Disorders (FASD) describes this phenotypic spectrum caused by embryonic ethanol exposure. However, the effects of other small alcohols, such as methanol and isopropanol, have on development are poorly understood. Multiple factors can contribute to the teratogenicity of small alcohols, including timing, dosage and genetic background. Zebrafish (Danio rerio) has been shown to be a powerful model in the study ethanol teratogenesis and can serve as a model to study methanol and isopropanol teratogenicity. Here we provide evidence of the dose response to methanol and isopropanol in a wild type and an ethanol- sensitive mutant zebrafish line. We determine the lethal concentrations of methanol and isopropanol on wild type and ethanol-sensitive mutants. We also show effective dose that leads to malformations of the craniofacial skeleton, including defects to the lower jaw and palate. Our data suggest that ethanol-sensitivity may predict sensitivity to other small alcohols. Overall, our results begin to characterize the effects of methanol and isopropanol on developing embryos.Molecular Bioscience

Activity of Zymomonas mobilis on ethanol products made of cashew nut apple (Anacardium occidentale) with different sources of nitrogen

Mustofa A, Suranto. 2009. Activity of Zymomonas mobilis on ethanol production made of cashew nut apple (Anacardium occidentale) with different sources of nitrogen. Nusantara Bioscience 1: 105-109. This research is aimed at identifying Zymomonas mobilis in producing ethanol through batch fermentation process (in 24, 48 and 72 hours) using cashewnut apple extract (red, green and yellow variety) and urea, ammonium sulphate, extract of green peanut sprout and extract koro (Mucuna pruriens) as sources of nitrogen. The research showed that green cashewnut extract with ammonium sulphate in 24 hours of fermentation produced ethanol in optimum result. This treatment had pH of 5.87, 7.64 g/100 mL of sugar (with 48.44% of consumption), 8.0x10 7 amount of bacterium (µ = 0.154) and production of ethanol equal to 33.02 g/L (Ye = 90.19%). Key words: Zymomonas mobilis, cashewnut apple extract, ethanol

Possibilities of upgrading solid underutilized lingo-cellulosic feedstock (carob pods) to liquid bio-fuel: Bio-ethanol production and electricity generation in fuel cells - A critical appraisal of the required processes

The exploitation of rich in sugars lingo-cellulosic residue of carob pods for bio-ethanol and bio-electricity generation has been investigated. The process could take place in two (2) or three (3) stages including: a) bio-ethanol production originated from carob pods, b) direct exploitation of bio-ethanol to fuel cells for electricity generation, and/or c) steam reforming of ethanol for hydrogen production and exploitation of the produced hydrogen in fuel cells for electricity generation. Surveying the scientific literature it has been found that the production of bio-ethanol from carob pods and electricity fed to the ethanol fuel cells for hydrogen production do not present any technological difficulties. The economic viability of bio-ethanol production from carob pods has not yet been proved and thus commercial plants do not yet exist. The use, however, of direct fed ethanol fuel cells and steam reforming of ethanol for hydrogen production are promising processes which require, however, further research and development (R&D) before reaching demonstration and possibly a commercial scale. Therefore the realization of power generation from carob pods requires initially the investigation and indication of the appropriate solution of various technological problems. This should be done in a way that the whole integrated process would be cost effective. In addition since the carob tree grows in marginal and partly desertified areas mainly around the Mediterranean region, the use of carob’s fruit for power generation via upgrading of its waste by biochemical and electrochemical processes will partly replace fossil fuels generated electricity and will promote sustainability