Antimicrobial activity of partially purified bio-compounds of Brevibacillus laterosporus SA14 in saline with added amylase

Abstract

To study antimicrobial activity of biocompounds produced from bacteria which may lead to development of

a model for antimicrobial substances production,

Brevibacillus laterosporus SA14, isolated from air sample was

studies. The partially purified biocompounds (PPBs) were prepared from 600 ml Luria Bertani culture broth of

2 day

Brev. laterosporus SA 14 by means of 50 % ammonium sulfate precipitation. The PPbs could inhibit

the growth of Gram-positive bacteria (

Staphylococcus aureus, Viridans group), Gram-negative bacteria (Escherichia

coli & Pseudomonas aeruginosa

) and yeast-like fungi (Candida albicans). The antimicrobial activity was decreased

when incubated with 1 mg/ml amylase for 5 hours at 37

oC. Moreover, the PPBs could show hemolytic activity

which was disappeared at a titer higher than 1:8, but still had the antimicrobial activity when tested with agar well

diffusion. Interestingly, PPBs at a titer 1:128 could inhibit the growth of microorganisms in saliva when tested with

microbroth dilution. It is therefore interesting to conduct further study on the application of this PPBs in production

of alcohol free mouthwash.