Microorganisms’ Growth Inhibition in Poultry Meat Using Bacillus spp.

Abstract

Meat processing enterprises are currently seeking ways to improve the efficiency of their operations. This study aimed to assess the presence of harmful microorganisms in poultry meat treated with a probiotic complex of Bacillus spp. bacteria during storage. Of the 2,516 meat samples collected from broiler chickens across six poultry processing enterprises in the Dnipropetrovsk region over three years, 1,845 samples tested positive for pathogens. Listeria spp. were isolated in 52.7% of meat samples, S. aureus in 28.7%, P. aeruginosa – in 6.9%, E. coli in 4.2%, and Salmonella spp. in 7.5%. The next stage of the study was the infection of 10 samples of poultry meat with pathogens of test cultures (Escherichia coli UNCSM - 007, Pseudomonas aeruginosa UNCSM - 012, Staphylococcus aureus UNCSM - 017, Listeria ivanovii UNCSM - 042, Salmonella Enteritidis UNCSM - 081), followed by aerosol treatment with a probiotic complex of Bacillus spp. (1.5×108 in ml (0.5 Mac Farland) administered at a dose of 1 ml per sample with daily registration of colony growth. Following pathogen contamination and a single aerosol treatment with the probiotic complex of Bacillus spp., the growth of E. coli and S. aureus was already suppressed on the second day of meat storage. The probiotic complex of Bacillus spp. was able to displace Salmonella Enteritidis on the third day and P. aeruginosa on day 4, but the growth of L. ivanovii could be observed only on day 5. The probiotic complex of Bacillus spp. formed visible biofilms from the five strains of microorganisms and remained viable for five days, forming a dense biofilm with a high accumulation rate of 4.73 D620. A distinctly noticeable ability to form microbial biofilms within three days was observed in planktonic forms of L. ivanovii up to 2.88 D620, followed by P. aeruginosa at 2.28 D620. Low biofilm density was observed for Salmonella Enteritidis (1.77 D620) and S. aureus (1.76 D620). The probiotic complex of bacteria of the genus Bacillus spp. shows potential for use in meat processing plants to prevent the growth of harmful microbial biofilms on meat products stored under refrigeration.