Scientists with ARS and Vision Paper, Inc., of Albuquerque, NM, have rolled up their sleeves and dirtied their hands to find new uses for "black liquor," a crude byproduct of pulping kenaf fiber. Black liquor is usually burned for fuel or chemical recovery, but often small paper mills can't afford expensive incinerators. The researchers found that chitosan, made from ground-up crab shells, helps transform the dissolved kenaf lignin into a solid cake. Next, the solid cake will be tested as an animal feed pellet binder. The remaining soluble black liquor can be converted to a low-sodium, dry fertilizer containing about 22 percent nitrogen. In the overall process, black liquor is turned into salable products instead of greenhouse gases. Originally from Africa, kenaf is a fast-growing, renewable fiber crop closely related to cotton. Twenty-five years ago, ARS scientists developed a process to turn kenaf into newsprint. Kenaf is currently being grown on 12,000 acres in Georgia, Texas, and Mississippi. U.S. farmers can grow it instead of corn, soybeans, cotton, or rice.

National Center for Agricultural Utilization Research, Peoria, IL
Thomas P. Abbott, (309) 681–6533, abbotttp@ncaur.mail.usda.gov

Natural rubber latex films made from a southwestern desert shrub called guayule are an effective barrier against disease-causing bacteria and viruses, according to preliminary tests by ARS and Food and Drug Administration researchers. The findings mean that surgical gloves, condoms, or other medical, home, and industrial products made from guayule's hypoallergenic latex may offer a safe, practical alternative for the estimated 20 million Americans allergic to latex products from the most common source, the Brazilian rubber tree. Prototype patient-examination gloves and condoms made of Arizona-grown guayule latex, formed to the same thickness as commercially produced gloves and condoms made from Brazilian rubber tree latex, passed standard virus-permeability tests, according to the scientists. A test virus known as phi X174—especially chosen for its small size—could not slip through the guayule latex. The virus is smaller than bacteria and is the same size, or smaller than, human pathogenic viruses such as HIV, hepatitis B, and herpes simplex. The researchers reported their findings in a recent issue of the Journal of Biomedical Materials Research. ARS scientists were the first to show, in 1994, that guayule latex is free of the allergens that can cause severe reactions such as anaphylactic shock or even death.

Crop Improvement and Utilization Research Unit, Albany, CA
Katrina Cornish, (510) 559–5950, kcf@pw.usda.gov