Host and tissue preferences of Enterobacter cloacae and Bacillus amyloliquefaciens for endophytic colonization

Enterobacter and Bacillus are common endophytes in many plants. Endophytic Enterobacter cloacae 344 and Bacillus amyloliquefaciens 629 from cacao had their colonization patterns assessed in different plants and organs. The 344’s colonization in all plants was ~12x higher than those observed for 629. CFU countings were 16 and 3 times lower for 344 and 629, respectively, in non-sterile than in sterile conditions. The results suggested that 344 is a better endophytic colonizer than 629, but this seems a better competitor than 344. Indigenous endophytic fungi interfered with the colonization levels of both strains in all plants. Plant species, tissue and competing microbes appear to define the levels of endophytic colonization by these bacteria. Key words: Cacao, endophytic bacteria, population densities.