Biochemical activities of Brochothrix thermosphacta

Area of Science:

• Food Microbiology
• Enzymology
• Meat Science

Background:

• Brochothrix thermosphacta is a common bacterium found in meat and meat products.
• Understanding its enzymatic activities is crucial for predicting its role in food spoilage.
• Previous studies have focused on its growth but less on its specific hydrolase profiles.

Purpose of the Study:

• To characterize the hydrolase activities of Brochothrix thermosphacta strains isolated from various meat products.
• To investigate the proteolytic potential of these strains at different temperatures.
• To determine the contribution of enzymatic activity to the meat spoilage capabilities of B. thermosphacta.

Main Methods:

• API ZYM® test was employed to assess the activity of 19 hydrolases in 40 B. thermosphacta strains.
• Enzyme activities including acidic phosphatase, esterases, lipases, and proteases were quantified.
• Proteolytic activity on albumin was measured at 4 °C and 25 °C.

Main Results:

• All 40 strains exhibited activity for acidic phosphatase, esterase C4, esterase/lipase C8, and α-chymotrypsin.
• Extracellular lipolytic activity was limited to 4 strains, indicating esterase/lipase C8 is primarily cell-bound.
• Proteolytic activity on albumin was observed in 13 strains at 4 °C and 9 strains at 25 °C, with 4 strains active at both temperatures.

Conclusions:

• Brochothrix thermosphacta possesses a range of hydrolase activities, with variations among strains.
• The proteolytic activity of B. thermosphacta contributes significantly to its meat spoilage potential, alongside carbohydrate digestion.
• Understanding these enzymatic profiles is key to developing strategies for controlling spoilage in meat products.