Effect of Treatment and Cultivar on the Ensiling of Corn Stover

Nine cultivars of corn stover selected for ethanol potential were harvested (34 to 40% dry matter) and each ensiled with six treatments: untreated, lactic acid bacteria, cell-wall degrading enzymes, sulfuric acid, bacteria-enzyme combination and enzyme-acid combination. Ensiling was carried out in vacuum-sealed bags at ~22°C for 60 d. The untreated stovers ensiled well. Lactic acid bacteria and enzyme treatments had no effect on pH, but the bacteria-enzyme combination lowered pH in some cultivars. The acid and acid-enzyme treatments had low pH values ranging from 1.3 to 1.5. Lactic acid was generally highest in the bacteria-enzyme treatment whereas acetic acid was highest for the acid treatments. The acid treatments substantially reduced hemicellulose. Potential ethanol yield on average was highest in the bacteria-enzyme treatments

Forage quality and composition measurements as predictors of ethanol yield from maize (Zea mays L.) stover

<p>Abstract</p> <p>Background</p> <p>Improvement of biofeedstock quality for cellulosic ethanol production will be facilitated by inexpensive and rapid methods of evaluation, such as those already employed in the field of ruminant nutrition. Our objective was to evaluate whether forage quality and compositional measurements could be used to estimate ethanol yield of maize stover as measured by a simplified pretreatment and simultaneous saccharification and fermentation assay. Twelve maize varieties selected to be diverse for stover digestibility and composition were evaluated.</p> <p>Results</p> <p>Variation in ethanol yield was driven by glucan convertibility rather than by glucan content. Convertibility was highly correlated with ruminal digestibility and lignin content. There was no relationship between structural carbohydrate content (glucan and neutral detergent fiber) and ethanol yield. However, when these variables were included in multiple regression equations including convertibility or neutral detergent fiber digestibility, their partial regression coefficients were significant and positive. A regression model including both neutral detergent fiber and its ruminal digestibility explained 95% of the variation in ethanol yield.</p> <p>Conclusion</p> <p>Forage quality and composition measurements may be used to predict cellulosic ethanol yield to guide biofeedstock improvement through agronomic research and plant breeding.</p

Development of a fluorescence-based method for monitoring glucose catabolism and its potential use in a biomass hydrolysis assay

<p>Abstract</p> <p>Background</p> <p>The availability and low cost of lignocellulosic biomass has caused tremendous interest in the bioconversion of this feedstock into liquid fuels. One measure of the economic viability of the bioconversion process is the ease with which a particular feedstock is hydrolyzed and fermented. Because monitoring the analytes in hydrolysis and fermentation experiments is time consuming, the objective of this study was to develop a rapid fluorescence-based method to monitor sugar production during biomass hydrolysis, and to demonstrate its application in monitoring corn stover hydrolysis.</p> <p>Results</p> <p>Hydrolytic enzymes were used in conjunction with <it>Escherichia coli </it>strain CA8404 (a hexose and pentose-consuming strain), modified to produce green fluorescent protein (GFP). The combination of hydrolytic enzymes and a sugar-consuming organism minimizes feedback inhibition of the hydrolytic enzymes. We observed that culture growth rate as measured by change in culture turbidity is proportional to GFP fluorescence and total growth and growth rate depends upon how much sugar is present at inoculation. Furthermore, it was possible to monitor the course of enzymatic hydrolysis in near real-time, though there are instrumentation challenges in doing this.</p> <p>Conclusion</p> <p>We found that instantaneous fluorescence is proportional to the bacterial growth rate. As growth rate is limited by the availability of sugar, the integral of fluorescence is proportional to the amount of sugar consumed by the microbe. We demonstrate that corn stover varieties can be differentiated based on sugar yields in enzymatic hydrolysis reactions using post-hydrolysis fluorescence measurements. Also, it may be possible to monitor fluorescence in real-time during hydrolysis to compare different hydrolysis protocols.</p

Onderzoek naar de energetische waarde van monsters saucijzebroodjes en boterhamworst

In februari 1988 werden 26 monsters saucijzebroodjes en 27 monsters boterhamworst onderzocht op de gehalten aan vocht en vet. Met behulp van deze gehalten werden de energetische waarden van de monsters berekend. De gemiddelde energetische waarde van de monsters saucijzebroodjes was 1622 kJ/100 g, die van boterhamworst 1266 kJ/100 g. Vergelijking van de waarden van de boterhamworst met die van een in 1982 uitgevoerd onderzoek leert dat de gemiddelde energetische waarde van boterhamworst sinds 1982 met 12,5% is gedaald

Nitraat- en nitrietgehalte van een aantal rauwe en toebereide groenten

De gehaltes zijn bepaald van 9 groentes: sla, andijvie, Chinese kool, rode bieten, witte kool, zuurkool, witlof, spruiten en radijs. De monsters sla en radijs zijn alleen rauw onderzocht, de overige monsters ook in toebereide vor

The ethics of using transgenic non-human primates to study what makes us human

An ongoing flood of comparative genomic data is identifying human lineage specific (HLS) sequences of unknown function, and there is strong interest in investigating their functional effects. Transgenic apes, our closest evolutionary relative, have the highest potential to express HLS sequences as they are expressed in Homo sapiens and likewise experience harm from such transgenic research. These harms render the conduct of this research ethically unacceptable in apes, justifying regulatory barriers between these species and all other non-human primates for transgenic research

Human Health Risk Assessment (HHRA) for environmental development and transfer of antibiotic resistance

Background: Only recently has the environment been clearly implicated in the risk of antibiotic resistance to clinical outcome, but to date there have been few documented approaches to formally assess these risks. Objective: We examined possible approach

Koriander en venkel : I. Ontwikkeling van een gaschromatografische methode voor de bepaling van petroselinezuur : II. Inventariserend onderzoek naar olie- en petroselinezuurgehalte

In het kader van het DLO-programma "Plantaardige technische oliën als niemo1e landbouwgrondstoffen voor de industrie" is een gaschromatografische methode ontwikkeld voor de bepaling van petroselinezuur in koriander- en venkelzaad. Met een capillaire CP Sil 88 kolom is het mogelijk om de in koriander en venkel voorkomende octadeceenzuurisomeren petroselinezuur, oliezuur en vacceenzuur als methylester zodanig van elkaar te scheiden dat deze kwantitatief te bepalen zijn. Met deze methode is onderzoek gedaan naar de genetische variatie van de vetzuursamenstelling van 22 monsters koriander en naar het verschil in zomer- en winterteelt van koriander en venkel. Tevens is van alle monsters het oliegehalte bepaald