The article discusses the mechanisms of membrane toxicity of hydrocarbons, focusing on cyclic hydrocarbons, terpenes, aromatics, and cycloalkanes. It highlights the importance of microbial transformation of these compounds in environmental and industrial applications, such as bioremediation and biocatalysis. The toxicity of these compounds is primarily due to their lipophilic nature, which allows them to interact with the hydrophobic parts of the cell membrane. The availability of these compounds for intracellular metabolism depends on their solubility in water, and their uptake by cells is often a passive process. The partitioning of these compounds into the lipid bilayer of the cytoplasmic membrane is a key step in their uptake. The toxicity of these compounds can lead to changes in membrane structure and function, affecting energy transduction and enzyme activity. Microorganisms have developed various adaptations to cope with these toxic effects, including membrane modifications, active excretion, and immobilization. The article also discusses the bioavailability of cyclic hydrocarbons, the role of cell envelope components in their uptake and toxicity, and the effects of lipophilic compounds on microbial cells. It emphasizes the importance of understanding the mechanisms of membrane toxicity of hydrocarbons for the development of effective bioremediation strategies and the assessment of environmental and health risks associated with these compounds.The article discusses the mechanisms of membrane toxicity of hydrocarbons, focusing on cyclic hydrocarbons, terpenes, aromatics, and cycloalkanes. It highlights the importance of microbial transformation of these compounds in environmental and industrial applications, such as bioremediation and biocatalysis. The toxicity of these compounds is primarily due to their lipophilic nature, which allows them to interact with the hydrophobic parts of the cell membrane. The availability of these compounds for intracellular metabolism depends on their solubility in water, and their uptake by cells is often a passive process. The partitioning of these compounds into the lipid bilayer of the cytoplasmic membrane is a key step in their uptake. The toxicity of these compounds can lead to changes in membrane structure and function, affecting energy transduction and enzyme activity. Microorganisms have developed various adaptations to cope with these toxic effects, including membrane modifications, active excretion, and immobilization. The article also discusses the bioavailability of cyclic hydrocarbons, the role of cell envelope components in their uptake and toxicity, and the effects of lipophilic compounds on microbial cells. It emphasizes the importance of understanding the mechanisms of membrane toxicity of hydrocarbons for the development of effective bioremediation strategies and the assessment of environmental and health risks associated with these compounds.