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Title: INCIDENCE OF FUSARIUM AND LEVELS OF FUMONISIN B1 IN MAIZE IN WESTERN KENYA

Author
item KEDERA, CHAGEMA - KENYA AGR RES INST
item Plattner, Ronald
item Desjardins, Anne

Submitted to: Applied and Environmental Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/14/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: Fumonisins are toxic compounds produced by a fungus that is frequently found in corn from most parts of the world. Fumonisins are of interest because they cause health problems in farm animals when they consume corn heavily contaminated with this fungus and containing high fumonisin levels. Fumonisins have also been associated with health problems in parts of the world where people subsist on a diet that contains primarily low quality corn. The fungus that makes fumonisins is found throughout the world, but the levels of fumonisins in corn from Kenya has not been studied. In this study, we found only low levels of fumonisins in Kenya corn samples in spite of the fact that the corn was often moldy and contained the fungus that produces fumonisins. It is not known if the low levels of fumonisin are a result of the presence of other fungi in the corn or because environmental conditions were unfavorable to fumonisin production.

Technical Abstract: Maize kernel samples were collected in 1996 from smallholder farm storages in the districts of Bomet, Bungoma, Kakamega, Kericho, Kisii, Nandi, Siaya, Trans Nzoia, and Vihiga in the tropical highlands of western Kenya. Two-thirds of the samples were good quality maize, and one-third were poor quality maize with a high incidence of visibly diseased kernels. One hundred and fifty-three maize samples were assessed for Fusarium infection by culturing kernels on a selective medium. The isolates obtained were identified to species based on morphology and on formation of the sexual stage in G. fujikuroi mating population tests. Fusarium moniliforme (G. fujikuroi mating population A) was isolated most frequently, but F. subglutinans (G. fujikuroi mating population E), F. graminearum, F. oxysporum, F. solani, and other Fusarium species were also isolated. The high incidence of kernel infection with the fumonisin-producing species F. moniliforme indicated a potential for fumonisin contamination of Kenyan maize. However, analysis of 197 maize kernel samples by high performance liquid chromatography found little fumonisin B1 in most of the samples. Forty-seven percent of the samples contained fumonisin B1 above the detection limit (100 ng/g), but only 5% were above 1,000 ng/g, a proposed level of concern for human consumption. The four most contaminated samples, ranging from 3,600 to 11,600 ng/g fumonisin B1, were from moldy maize collected in Kisii district. Many visibly moldy samples, however, contained little or no fumonisin B1 despite the presence of F. moniliforme.