<i>Bacillus</i>volatiles antagonize cyanobacteria

Abstract

Evidence is presented showing that commonly isolated Bacillus spp. liberate volatiles which inhibit growth and cause lysis of cyanobacteria. Anabaena spp. were particularly sensitive. A simple, convenient method is described which allows the culture of permutations of physically segregated Bacillus and cyanobacteria, whilst sharing a common atmosphere. The extent of antagonism of cyanobacteria was directly related to the amount of Bacillus growth and appears to be temporally linked with sporulation in the bacilli. Low incubation temperatures (approx. 20°C) decreased the antagonistic effect, as did the presence of activated charcoal or soil at normal temperature (30°C). Gram-negative bacteria and some green algae were also affected.