美科学家发现：柳枝稷能生成乙醇关键靠球囊

• http://www.aweb.com.cn 2007年11月21日09:02 美国农业部网

　　美国农业部网10月12日消息，美国农业研究局土壤科学家发现，柳枝稷之所以能生成乙醇，球囊起了很大的作用。球囊是土壤真菌合成的一种糖蛋白，它可以运输水分和营养到植物根系。它还像“胶水”一样，把土壤颗粒粘结在一起，有助于土壤中碳的储存。球囊不仅有助于生物燃料作物在干旱等不利条件下的成长，而且在燃烧生物燃料作物时，二氧化碳的释放实现了全球碳循环。（国际情报研究室译）

　　【原文】

　　Glomalin: A Key to Switchgrass Ethanol Success 

　　By Don Comis

　　October 12, 2007 

　　If switchgrass succeeds as an ethanol crop, it will owe some of its success to glomalin, the key ingredient of soil organic matter.

　　Glomalin was discovered in 1996 by Agricultural Research Service (ARS) soil scientist Sara F. Wright—now retired—and ARS microbiologist Kristine A. Nichols, then both at Beltsville, Md. Nichols is now at the ARS Northern Great Plains Research Laboratory in Mandan, N.D., where glomalin work continues. 

　　A sugar protein, glomalin is excreted by soil fungi and helps them funnel water and nutrients into plant roots. It also helps store carbon in the soil and acts as a “glue” to hold soil particles together.

　　In assessing glomalin levels and their role in biofuel crops, Nichols has measured higher levels of glomalin in the roots of switchgrass, big bluestem and other warm-season grasses than in the roots of cool-season grasses such as wheatgrass and Russian wild rye. Switchgrass is a fast-growing, warm-season perennial with potential as a feedstock for cellulosic ethanol production. 

　　Preliminary results show that warm-season grasses such as switchgrass and big bluestem also give soil more stability. Nichols found a strong association between warm-season grasses and the arbuscular mycorrhizal fungi that live on plant roots and produce glomalin. 

　　Glomalin may be partly responsible for the ability of switchgrass to store more soil carbon than corn—and to store it deeper, so it’s less likely to be lost to the atmosphere as carbon dioxide. Thus, glomalin might not only help biofuel crops grow and flourish under adverse conditions like drought, but also close the carbon cycle by storing carbon released as carbon dioxide during the burning of biofuels for energy.