Microbial degradation of sparingly soluble diethyl phthalate (DEP) and dibutyl phthalate (DBP) by pure microbes using microcalorimetry

PAEs are synthesized in massive amounts to produce various plastics and have become ubiquitous/widespread in environments and have been found in the pedosphere (soils, landfills and leachates), plants, hydrosphere (i.e. natural waters, fresh and ocean waters, groundwaters), the atmosphere, and human and other living organisms’ fatty tissues (compounds are lipophilic/lyphophilic; i.e. fat-soluble) as a result of the production, usage, and disposal of plastics. Refractory water-soluble organic compounds perform a vital function in the etiology of certain chronic diseases in humans, reduce the viability of many plant and animal species, and pose a threat to one or more populations in natural ecosystems. Such worrying findings have aroused interest in the biodegradation of these compounds in soils and waters. Biodegradation of these compounds is a critical process affecting the environmental fate of PAEs. The sole aim of this study was to evaluate the microbial degradability of two potentially toxic PAEs (i.e., DEP and DBP) by two bacteria, (Escherichia coli and Staphylococcus aureus); and a fungus (Aspergillus niger) using microcalorimetry by monitoring their growth on media amended with/without DEP or DBP. To achieve this aim, the specific objectives were carried out and the results are presented: