ISOLATION, CHARACTERIZATION, AND APPLICATION OF BACTERIOPHAGES AGAINST SEVERAL FOOD SPOILAGE BACTERIA: Bacillus subtilis, Bacillus cereus, AND Shewanella Putrefaciens

Abstract

Introduction: Bacteriophages can be the natural alternative method to prevent food spoilage caused by bacteria. This research was conducted to isolate bacteriophages from a soil sample, retail food, and wastewater from fish and then the bacteriophages will be characterized for their activity against several food spoilage bacteria, such as Bacillus cereus, Bacillus subtilis, and Shewanella putrefaciens and will be further investigated for application as food preservation.

Experimental: B. cereus (Atma Jaya culture collection), B. subtilis ATCC 6633, and S. putrefaciens ATCC 8071 were used for bacteriophage isolation. Food samples (rice, pasta, tofu, tempeh), soil samples (black soil and laterite), and wastewater sample of freshwater fish and seawater fish were used in this research. The overall process consists of eight steps: inoculum preparation, sample collection, bacteriophage isolation, purification and enrichment, titer determination, host range determination, the efficiency of plating (EOP), and bacteriophage application.

Results: A total of four bacteriophages were isolated with B. cereus, B. subtilis, and S. putrefaciens as host bacteria. Bacteriophage titers observed around 10⁹ PFU mL^-1. Bacteriophages that isolated with B. cereus and B. subtilis as host bacteria tend to have high EOP with the same species bacteria. All the Bacillus phages (S1-BC, S2-BC, and S1-BS) can reduce the Bacillus species bacteria concentration for more than 90%.

Conclusion: Refers to their activity, the isolated bacteriophages in this study might have a great prospect to be used as food biocontrol and also can be further tested to make a phage cocktail.