Journal of Pure and Applied MicrobiologyVol. 9 No. Special Edition May. 2015

Optimization of Environmental Conditions for Biofilm Formation of Bacterial Strains Salmonella aerizonae, Micrococcus luteus and Aerococcus viridans

Resaual Haque Mostafa Chowdhury1, Nigar Sultana2, Wahhida Shumi1*, Md. Aktar Hossain3,4* and Hazandy Abdul Hamid4,5

1Department of Microbiology, University of Chittagong, Chittagong-4331, Bangladesh. 2Department of Microbiology, University of Science and Technology Chittagong, Chittagong-4000, Bangladesh. 3Institute of Forestry and Environmental Sciences, University of Chittagong, Chittagong-4331, Bangladesh. 4Faculty of Forestry, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor , Malaysia. 5Institute of Tropical Forestry and Forest Products, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia.

Received on 11 November 2014 and accepted on 07 January 2015



Biofilm forming ability is an inherent property of the microorganisms for their multiplication and substantial infection. By forming this protective layer (biofilm) microorganisms gain resistance against antibiotics, antibodies and phagocytosis. An attempt was made to investigate the biofilm forming ability of three bacterial strains Salmonella aerizonae, Micrococcus luteus and Aerococcus viridans isolated from poultry wastes (PW) dental plaques (DP) and hospital effluents (HE) respectively under various environmental conditions. The effects of different environmental factors such as growth media, pH, salt concentration, incubation period, temperature and condition (shaking or stationary) on biofilm forming ability of these isolates were determined for their optimum growth and development. The study reveals that LB was the best media for maximum yield of biofilm after 24 h of incubation for M. luteus and 48 h for S. arizonae and A. viridians. All the strains showed their maximum biofilm formation in LB media at 37°C temperature supplemented with 1% salt concentration at medium pH 6.5 in shaking (S. arizonae) or stationary (M. luteus and A. viridians) condition. The inhibitory effects of penicillin and erythromycin on the biofilm formation of the isolates were also investigated. The results indicate that increasing concentration of antibiotics decreased the biofilm formation of these strains progressively.

Keywords : Biofilm, Environment factors, Salmonella aerizonae, Micrococcus luteus, Aerococcus viridans