ABSTRACT
Biochemical cycles and microorganisms (primarily heterotrophic micro-organisms) are responsible for the maintenance of the biosphere. They exploit the chemical reactions favorably to obtain carbon and energy from biomass. As a result of the microbial degradation processes, the essential nutrients present in the biomass of a generation of organisms are available for the next generation. The impact of human activities on the quality of environmental factors has intensified over the last decades due to population growth and extensive exploitation of natural resources, including soils. The following processes can be mentioned as the main sources of impact on the quality of environmental factors: atmosphere emissions-mainly from industry and traffic; agricultural practices, in particular, the use of organic or mineral fertilizers and pesticides; waste deposited on the soil surface. The rate of production and dispersion of pollutants from agricultural waste has now surpassed biodegradation’s natural processes. In the search for technological remedies for pollution with pollutants from agricultural waste, physical, chemical, and biochemical processes can be essential, but microbiological processes also provide important insights. The purpose of this review is to support 166the knowledge of biochemical cycles involving microorganisms and the need to include biological parameters in environmental impact assessment studies and environmental quality monitoring strategies that are currently based only on the determination of physicochemical parameters. In natural ecosystems, there are fluctuations in the nutrient and energy concentrations, against which microorganisms constantly modulate their rate of energy-producing reactions (through the genetic regulation of enzyme synthesis involved, induction/repression) to match energy-consuming reactions and ensure the survival of cells.
