Assessment of Propionibacterium Metabolic Activity on Protein Substrate of Sarcoplasmic Fraction in Hydrobionts’ Muscle Tissue

Abstract

As a result of the conducted scientific researches, the authors analyzed methodical aspects of studying the proteolytic properties of Propionibacterium freudenreichii subsp. shermanii-KM 186 – the representatives of the probiotic group of microorganisms, which allowed not only to evaluate the enzymatic activity of the objects of study but also to discover how physical and chemical factors influence the proteins hydrolysis intensity in sarcoplasmic and myofibrillary fractions of hydrobionts’ muscle tissue. During the experiment which aimed at assessing the possibility of using individual protein fractions of fish muscle tissue as a substrate for proteolysis by Propionibacterium bacteria for the spectrophotometry analysis of their enzymatic activity, it was found that the sarcoplasmic fraction can be used as a substrate for studying the microorganisms’ proteolytic activity. Determination of the information content of tyrosine concentration measuring by spectrophotometry to characterize the proteolytic activity of bacterial suspensions showed that to assess the enzymatic activity of living microorganisms culture it is advisable to use not the absolute values of the bacterial suspension activity, expressed in μmolTYR/ml×min or the tyrosine concentration in the sample (μmol/L), but the change in the tyrosine level in comparison with its primary values. This way of expressing the results will allow us to assess the prevalence of processes (dissimilation/assimilation). In addition, the experiment revealed the characteristic response of the Propionibacterium bacteria’s metabolic activity to changes in the physical and chemical conditions.