Study of the microbiological composition of sludge during the cultivation of Chironomus larvae

Abstract

Silt (nutrition medium) is the habitat of many microorganisms that adapt well to water and soil. By extended aeration, it partially comes out of the sewage. The nature of organic impurities determines the composition of such a substrate, so its leading indicators may vary. Such a nutrient medium is one of the favorable conditions for the growth and development of Chironomus larvae and various microflora. The article presents the results of studies of bacteriological crops of the substrate for Chironomus larvae to establish the microbiological composition of the nutrient medium under various pasteurization modes. It was found that in native sludge, the growth of a colony of bacteria of the family Pseudomonas spesialis is 80 %, Bacillus subtilis is 15 %, and Micrococcus luteus is 5 % of the total number of colony-forming organisms. It was also found that different modes of pasteurization lead to a decrease in the number of microorganisms in the nutrient medium. When pasteurized at 65 °C (long-term), the number of microorganisms decreased by 16 times. When pasteurized at 75 °C (short-term), the number of colony-forming organisms decreased by 22 times, and at 95 °C (instant), it decreased by 358 times compared with the native form of the nutrient medium.

Keywords

• : sludge; bacteria; pasteurization modes; colony growth