Identification of some of the biofilm forming bacteria from the pasteurized milk production line

Subject Areas : Food Microbial Contamination

Sayedeh Saleheh Vaezi ¹ , Arezoo Tahmoures ² , Mohammad Goli ³

1 - Young Researchers and Elite Club, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran.
2 - Department of Basic Medical Sciences, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran.
3 - Department of Food Industries Engineering, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran.

Received: 2015-11-20 Accepted : 2015-12-19 Published : 2015-12-01

Keywords: Milk, Bacteria, biofilm, Biochemical test,

Abstract :

Biofilm is a collection of microorganisms in an extracellular exopolysaccharide matrix (EPS) which is adhered to the surface. Biofilms are considered as the most important food industry`s problem, especially in the post-contamination of pasteurized products. It is due to the high resistance feature of biofilm to the antimicrobial factors and Cleaning in Place (CIP) process. In this study, the bacterial biofilm from the inner part of pasteurized milk production line were isolated and bacterial compositions were assessed in order to identification of effective agents of post-contamination of pasteurized products. In order to conduct this survey, after CIP process, sampling was done from ten different parts of the production line (in 3 replicates). Isolation, purification and probable identification of isolated bacteria according to Bergey’s Manual of systematic bacteriology were performed. Results showed the presence of bacteria from different genera of Listeria, Shigella, Staphylococcus, Pseudomonas, Escherichia, Corynebacterium, Bacillus, Aeromonas. Klebsiella, Proteus, Lactobacillus and Micrococcus in which Staphylococcus and Shigella sonnei were the most predominant isolated genus and specie with 19% and 11% of the whole population, respectively.