Сharacteristics of glycosidases and peptidases in chironomid larvae - potential prey of benthophagous fish
Some characteristics of glycosidases and peptidases in homogenates of Chironomus plumosus chironomid larvae were studied. It was shown that the activity of glycosidases of chironomid larvae, depending on temperature, exceeds that of caseinlytic peptidases by 2.4-7.8 times, and hemoglobinlytic peptidases by 3.8-12.7 times. The optimum activity of glycosidases in small larvae was found at pH 7.0, and in large larvae at pH 8.0. The temperature optimum for glycosidases in small larvae at pH 7.4 was noted at 50° С, for casein and hemoglobin lytic peptidases, regardless of pH (7.4 and 5.0) at 40°С. The relative activity of glycosidases at 0°C is higher than that of casein- and hemoglobinlytic peptidases: 38.2, 25.4, and 23.9%, respectively. The maximum values of the temperature coefficient Q10 in the case of glycosidases are higher (40-50°С) than peptidases (usually 30-40°С). The activation energy (Eact) of hydrolysis of various substrates by glycosidases and peptidases of chironomid larvae in the zone of lower temperatures (up to the inflection point, 10 and 20 ° C, respectively) is lower than in the zone of higher temperatures. The revealed features of enzymes in chironomid larvae, including a relatively high level of activity in the low temperature zone and low Eact values, allow chironomid larvae to be not only consumers, but also food objects for fish, effectively participating in the processes of induced autolysis.