文摘
Yanyanku and Ikpiru made by the fermentation of Malcavene bean (Hibiscus sabdariffa) are used as functional additives for Parkia biglobosa seed fermentations in Benin. A total of 355 aerobic endospore-forming bacteria (AEFB) isolated from Yanyanku and Ikpiru produced in northern and southern Benin were identified using phenotypic and genotypic methods, including GTG5-PCR, M13-PCR, 16S rRNA, gyrA and gyrB gene sequencing. Generally, the same 5-6 species of the genus Bacillus predominated: Bacillus subtilis (17-41 % of isolates), Bacillus cereus (8-39 % ), Bacillus amyloliquefaciens (9-22 % ), Bacillus licheniformis (3-26 % ), Bacillus safensis (8-19 % ) and Bacillus altitudinis (0-19 % ). Bacillus aryabhattai, Bacillus flexus, and Bacillus circulans (0-2 % ), and species of the genera Lysinibacillus (0-14 % ), Paenibacillus (0-13 % ), Brevibacillus (0-4 % ), and Aneurinibacillus (0-3 % ) occurred sporadically. The diarrheal toxin encoding genes cytK-1, cytK-2, hblA, hblC, and hblD were present in 0 % , 91 % 15 % , 34 % and 35 % of B. cereus isolates, respectively. 9 % of them harbored the emetic toxin genetic determinant, cesB. This study is the first to identify the AEFB of Yanyanku and Ikpiru to species level and perform a safety evaluation based on toxin gene detections. We further suggest, that the gyrA gene can be used for differentiating the closely related species Bacillus pumilus and B. safensis.