## 1 Introduction
Consortia isolated directly from soils or effluents contaminated with petroleum hydrocarbons, as a rule, already contain the entire necessary list of producers because of the gradual formation of the microbiome necessary in composition due to the adaptation of microbial cells to pollutants present in their environment [46; 47; 48; 49]. As a rule, such consortia are in a stabilized state due to self-immobilization on solid particles and with the participation of their own exopolysaccharides [70; 71; 72]. At the same time, such consortia may not have the highest target activity for the degradation of pollutants and require the presence of specific additives (co-substrates, growth inducers, synthesis of certain enzymes, etc.) in the case of their practical use (Figure 2). An effective alternative in this case is synthetic (artificially created) consortia of microorganisms, which are deprived of a number of disadvantages of natural consortia due to the directed combination of highly active cells destructing toxicants and organic pollutants. When combining cells into consortia, individual characteristics of cultures and the possibilities of their combination are usually taken into account. It has been shown that it is expedient to stabilize such artificial consortia by immobilization into chemically stable, non-toxic carrier matrices [69; 73]. The most efficiently functioning aerobic BCs for the degradation of oil-containing pollutants include immobilized cells of hydrocarbon-oxidizing microorganisms [54; 55; 56; 58; 59] and synthetic and natural consortia [46; 47; 48; 49; 50; 51; 52; 53]. There are also successful variants of combining physical-chemical oxidative treatment of purified media with the use of nanomaterials in membrane aerobic bioreactors containing simultaneously working microbial consortia [68]. Anaerobic biotechnology is also widely used for wastewater treatment with petroleum hydrocarbons and their derivatives [2; 28; 61; 62; 74]. The effectiveness of its implementation depends on the interaction between the cells of microorganisms in an anaerobic environment, where many pollutants are converted into biogas. The properties of oil-containing wastewaters vary depending on the industry in which they are formed and significantly affect the composition of the microbiome in an anaerobic reactor [75]. New technologies of oxidative desulfurization of hydrocarbon raw materials using promising NCs represent a promising alternative to the traditional energy-intensive hydrodesulfurization [76; 77]. The waste of the technology contains oxidized sulfur-containing organic compounds extracted by adsorption or extraction from crude or treated oil. It has been shown that as a result of anaerobic conversion using immobilized artificially formed consortia, these wastes with residual concentrations of oil and high sulfur content can be successfully transformed into biogas with a high methane content [61; 62]. Interestingly, the consortia themselves can be used repeatedly, and their conversion activity can be restored through the reactivation procedure. It is known that under aerobic conditions, the aromatic ring in PAHs molecules is destroyed by a reaction with O\({}_{2}\), which, in addition to the co-substrate, is an electron acceptor, and the process proceeds with the participation of enzymatic BCs (monooxygenenses and dioxygenenses). In the absence of O\({}_{2}\), the aromatic ring is destroyed by the action of reductases and other electron acceptors. The biodegradation process is usually slowed down due to the cytotoxicity of hydrocarbons and their high concentrations due to unfavorable environmental conditions or the presence of metabolic restrictions [78; 79; 80]. The use of microbial fuel cells (MFCs) has been shown for wastewater treatment. Sodium benzoate (0.721 g/L) and conventional wastewater treatment plants provided an electrical voltage of 0.6-0.8 V and a decrease in COD by 50-89% when using an artificial microbial consortium consisting of four bacterial strains [81].