Study of antimicrobial activity of Bacillus megaterium isolated from honey on human and plant Pathogens

Abstract

Nowadays, multi antibiotic-resistant pathogens are an important health problem in medicine. Therefore finding novel sources of antimicrobial compounds is essential essue to introduce effective agents against resistant pathogen microorganisms. Microorganisms which produce antimicrobial agent are the origin of most of the antibiotics on the market today for example antibiotics that effect on cell wall of microorganisms (such as peniciline). One of the microorganisms producing antimicrobial is Bacillus. B. megaterium is a gram positive, aerobic and sporadic, and its natural habitat is the sea, sediments, honey and fish. The bactium is classified in the biggest bacteria and it is ten time bigger than E.coil. This bacterium has the ability to produce various proteins, including the penicillin-acylase-like protein used to produce synthetic penicillin, as well as the ability to produce different types of amylases, fungicidal toxins, etc. Objective: The present study looks to antimicrobial activity of Bacillus megaterium, which isolated from honey from south of Iran.

Materials and methods:

Firstly, Bacillus megaterum was cultured after that it was incubated at 37 ̊C for 72 h. The antimicrobial material was isolated by centrifugation. The antimicrobial effect was tested by well diffusion agar. After that, MIC and MBC were utilized for understanding the mimum inhibition cosentration.

Results: The antimicrobial test showed that B. megaterium has ability to produce antimicrobial against plant pathogens. It had antimicrobial effects on F. oxysporum, ، N. crassa and B. cinerea. The antimicrobial agent has antimicrobial effect on F. oxysporum until 12.5 mg/ml, N. crassa until 50 mg/ml and B. cinerea until 25 mg/ml. Conclusion: The isolated Bacillus megaterum has ability to produce antifungal agents.