Determination of Biogas Producers in Antibiotic-Containing Sewage

Treating sewage containing antibiotics is a complex process that needs research. An anaerobic method for organic matter removal from wastewater is the most optimal treatment option, which can provide antibiotic removal under the condition of prior adaptation of anaerobic microorganism association to antibiotic. The aims of the study were to obtain a microorganism association tolerant to antibiotics and to investigate the anaerobic association (methanogens) composition before and after adaptation. The subject of the study was the determination of microorganism association properties in conditions of high antibiotic concentration, which enables the determination of the adaptation mechanism. Adaptation of microorganism association to antibiotics was carried out by a gradual increase of antibiotic concentration in the nutrient medium (anaerobic conditions of detention, mesophilic regime). The qualitative and quantitative composition of biogas was determined by gas chromatography. DNA of microorganism associations was isolated by the agrobacteria DNA isolation method. The determination of archaeal 16SrRNA genes in DNA was performed by polymerase chain reaction (PCR). Information about gene structure was obtained by sequencing. It has been shown that the biogas output during anaerobic sewage treatment with antibiotic-adapted microorganism association increases regardless of antibiotic concentration. When enriching microorganism association with methanogens, tolerant to antibiotics, the biogas output grows by 32–38% depending on their amount. It was found that, when using tetracycline and norfloxacin, in the microorganism association methanogens of the genus Methanobacterium are dominant due to their resistance. Influence of antibiotics tetracycline and norfloxacin on raw materials leads to a decrease in the species volume of the Methanosarcinaceae family.