Multiplication of Pseudomonas fluorescens in refrigeration temperatures and its proteolytic potential

Abstract

The multiplication of Pseudomonas fluorescens strains 07A and 041 under refrigeration conditions was evaluated in this work, as well as its proteolytic potential using milk agar and azocaseína as substrate. It was possible to observe the multiplication of the isolates at the cooling temperatures, and an increase in multiplication occurred as the temperature and the storage period were increased. The proteolytic activity of the isolates was demonstrated by milk agar, and that of isolate 07A was higher than that of 041, which was also observed by the azocasein technique. This result is due to the genetic variability between psychrotrophic microorganisms and the expression of their proteolytic enzymes. Brazilian legislation recommends the use of refrigeration temperatures for storage of raw milk in the rural property and in the processing establishment. However, established temperatures do not inhibit the multiplication of psychrotrophic microorganisms. Therefore, it is essential to ensure the adoption of good production practices to avoid contamination, as well as the effective control of the time and temperature of storage of raw milk to avoid contamination during production and thus not compromise its quality and its derivatives.

Keywords

• psicrotrófico
• proteólise
• leite cru
• substrato.