Aims: Carotenoids are pigments widely used in the food industry. The aim of this study was to evaluate the antimicrobial effect of pigment extracted from Micrococcus roseus.
Materials and Methods: In this experimental study, Micrococcus roseus cells were settled by centrifugation, and 10ml acetone was added and they were homogenized by homogenizer. Then, homogenized suspension was centrifuged, the supernatant was collected, and carotenoid pigments were extracted with equal volume of petroleum ether. After filtration of pigmented solution, the solution was concentrated by rotary evaporator and, then, it was converted to powder by freeze dryer. Antimicrobial activity was evaluated by disc diffusion method and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined, using the agar dilution method. For statistical analysis, Tukey test and Minitab 16 statistical software were used.
Findings: Pigment extracted from Micrococcus roseus influenced the growth of all tested bacteria; Bacillus cereus and Salmonella enteritidis had the highest (12.4mm) and lowest (10.9mm) sensitivity, respectively, to pigment extracted from Micrococcus roseus in 5mg. Salmonella enteritidis had the highest MIC (64mg/mL) between the tested bacteria, but MBC was not observed for Salmonella enteritidis at the tested pigment extracted from Micrococcus roseus concentrations. The antimicrobial effect of extracted pigment on gram-positive bacteria was higher than gram-negative bacteria.
Conclusion: The extracted pigment from Micrococcus roseus is natural and has antimicrobial activity. The antimicrobial effect of extracted pigment on gram-positive bacteria is higher than gram-negative bacteria.