Evaluation of the Enzymatic Activity of Immobilized Lysobacter sp.

The specific enzymatic activity of bacterial cultures illustrates the key applications of a studied strain of bacteria and the biological products based on it. The proteolytic activity of extracellular enzymes in the temperature range 20–45 and the activity of β-1,4-glucanase were studied, and the influence of pH and temperature on the activity and stability of the enzyme was revealed. The optimal cultivation conditions for the Lysobacter strain were selected for the highest production of β-1,4-glucanase: glucose, 1% by weight; yeast extract, 0.2% by weight; CMC, 0.75% by weight; pH 7; amount of inoculum, 3.5% by volume; optimal temperature for incubation, 30 °C. Enzyme stability results showed that the enzyme retained 90% of its activity after minimal preincubation at pH 5.5 and more than 60% of its maximum activity at pH 4–10, demonstrating stability over a wide pH range. More than 60% of β-1,4-glucanase's enzymatic activity is observed in the range of 20–45 °C. Consequently, biocompositions based on Lysobacter sp. can be used in a wide range of temperatures and pH, which represents its promising use as a probiotic drug.