Bacillus 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.

The production of antifungal volatiles by Bacillus subtilis

“…3). Again this is in complete agreement with the work of Wright and Thompson (1985). At temperatures lower than 25°C volatile antifungal activity was poor.…”

“…The results of this study closely parallel those of Wright and Thompson (1985) on Bacillus volatiles antagonizing cyanobacteria. The production of antifungal volatiles by B.…”

“…This finding is somewhat different from that of Wright and --.--, OSR R . solani + volatile presence Thompson (1985) who observed a great reduction in the growth of cyanobacteria when B. subtilis was grown on nutrient agar. This may reflect differences in the metabolism of the strains of B. subtilis used in the research programmes, or differences in sensitivity of cyanobacteria and fungi to components of the volatiles produced.…”

“…These effects on the hyphae may be indicative of toxin(s) accumulation, with the physiological response of the fungus being compartmentalization and removal of the toxin from the growing cells. T h e fact that cyanobacteria cells lysed relatively easily (Wright and Thompson 1985) suggests that they are more sensitive to B . subtilis volatiles than are fungi.…”

“…As yet no such compounds have been associated with B. subtilis, but Wright and Thompson (1985) reported that Bacillus volatiles were highly antagonistic to cyanobacteria. Since then Wright (personal communication) has found that these volatiles are also antagonistic to algae, free-living protozoa, plants and some fungi.…”