Current technologies for bio-ethanol production from plants can use only the storage sugars, such as glucose, sucrose or starch. These sugars are converted into ethanol in a fermentation process using yeasts, as in beer brewing or in distilleries. However, this technology is in competition with food and feed production.

One of the major problems using other parts of plants, which today are considered as waste, is the inability of the yeasts to ferment some of the sugars of a large part of the plant material says Dr. Eckhard Boles, a professor at the Goethe-University Frankfurt, Germany, and co-founder of the Swiss biofuel company Butalco GmbH. Yeasts readily convert glucose, but leave xylose, or waste sugars, unused. Now, Dr. Boles and his colleagues report in the journal Applied Environmental Microbiology success in genetically modifying yeast, which enable the production of ethanol from waste sugars as well.

The researchers discovered a new enzyme from a bacterial organism and inserted this enzyme into yeast cells taken from a commercial ethanol plant. With just minor effort, we were able to teach the yeast cells how to ferment the waste sugar xylose into ethanol. The new enzyme can convert xylose in a single step, unlike the current cellulosic ethanol technologies. Further, it is not inhibited by other chemical compounds normally present within the yeast cells. This is a breakthrough in the commercial production of cellulosic ethanol, claimed Dr. Bole.

Source: bioenergy.checkbiotech.org

Nigerian farmers who tested new maize crops resistant to the widespread Striga plant parasite are so enthusiastic about their increased crop yields that they are selling more seeds than the official distribution channels. The varieties, known as Sammaz 15 and 16 contain genes that diminish the growth of parasitic flowering plants such as Striga, which attaches to the maize root. Both Sammaz varieties tolerate heavy Striga infestations without suffering crop losses.

The crops were developed in the Nigerian laboratories of the International Institute for Agricultural Research (IITA). They dramatically cut maize losses from the root-infecting Striga, or witchweed, during two years of trial cultivation by farmers. Nigerias Institute for Agricultural Research began distributing the new parasite-resistant maize seeds in December 2008.

While a maize variety without Striga resistance can sustain from 60 per cent to 100 per cent grain yield loss in farmers fields that are severely infested, Sammaz 16 loses just 10 per cent of yield in an extreme invasion. Sammaz 16 is a late-maturing variety requiring 110 to 120 days of growth, while Sammaz 15 can often be harvested in 100 days and is more suitable for regions with short growing periods or unpredictable water supplies.

Source: www.scidev.net

Scientists have pinpointed two genes that protect wheat against devastating fungal diseases found worldwide, potentially paving the way to hardier wheat strains, international researchers report. New research published in the journal Science showed how the genes provide resistance to leaf rust, stripe rust and powdery mildew, diseases responsible for millions of hectares of lost wheat yield each year.

Dr. Simon Krattinger of the Institute of Plant Biology, Switzerland, and colleagues isolated a gene called Lr34 using a resistant wheat line, knocking out genes until they found the one that offered protection. They do not know exactly what the gene does but believe it produces a protein that transports molecules in a cell that help fight off diseases. Unlike other resistance genes that only offer short-term protection because of mutations, the Lr34 gene is far more durable, Dr. Krattinger said. The gene has been active for more than 50 years, he said.

In another study, scientists led by Dr. Cristobal Uauy of John Innes Centre, the United Kingdom, identified a gene called Yr36 found in wild wheat but absent in modern pasta and bread varieties. The gene confers resistance to stripe rust. We have recovered a gene that has been lost during domestication, Dr. Uauy said, adding We now have a new tool to combat this disease. The researchers do not know what the gene does but believe it recognizes a lipid from a disease and somehow triggers a resistance response. Like the Lr34 gene, Yr36 appears to offer longer protection and it also seems to fight off more than one strain of stripe rust, Dr. Uauy added.

Source: www.reuters.com