Mechanistic insights into fungal-bacterial synergy for DDT biotransformation

Pesticides comprise a diverse group of chemical agents designed to suppress, repel, or eradicate deleterious biological organisms—including phytopathogens, insect pests, and competing flora—that pose a threat to agricultural yields, ornamental plant integrity, and public health. Escalating reliance on these compounds, particularly in low- and middle-income nations, has raised critical concerns within the scientific and public health domains due to emerging evidence linking chronic exposure to a range of adverse health outcomes. Dichlorodiphenyltrichloroethane (DDT) is a widely used pesticide known for its persistence in the environment. The widely used DDT was heavily restricted in the United States due to its unwanted and hazardous effects on human health, wildlife, and the environment at the same time. Similarly, another insecticide, neonicotinoids, was restricted in the European Union because of its involvement in the decline of honeybee populations in the early twenty-first century. To remove such kind of chemicals from contaminated soil and water, various physical, chemical, and biological approaches have been applied. The most cost-effective and eco-friendly strategy to combat pollutants, in which the catabolic capabilities of a fungal-bacterial consortium are exploited for the purpose. Fungal-bacterial interactions play a synergistic role in the degradation of DDT through complementary metabolic capabilities and environmental changes. White rot fungi secrete non-specific extracellular oxidases, manganese peroxidase, and laccase, to initiate the breakdown of the complex aromatic ring of DDT into intermediate metabolites. These fungal activities usually result in the partial conversion of DDT into compounds such as DDD, DDE, or dichlorodiphenylacetone. Subsequently, the associated bacteria (which usually coexist within the mycelium) will utilize specific intracellular enzymes to further metabolize these intermediates through dechlorination, hydroxylation, or ring-opening pathways. In addition, fungi can alter the microenvironment by reducing the redox potential, changing the pH, or producing surfactants, thereby increasing the bioavailability of DDT and promoting its absorption by bacteria. This synergistic degradation not only accelerates the decomposition of DDT but also achieves more complete mineralization compared to microbial activity alone. Bacterial strains that can degrade pesticides include 2,6-dichlorobenzamide (BAM) degrading Aminobacter spp., along with some other microbes that are employed for bioremediation. In this review, we aimed to explore the role of bacterial and fungal interactions in the enhanced degradation of DDT from the environment. Scientific literature was explored using online databases, and data from already published literature were retrieved. The key focus of the current study was to identify fungal-bacterial (FBI) interaction mechanisms to provide the basis for the eco-friendly degradation of harmful pesticides. The study will help in developing smart strategies to deal with agricultural issues and will help develop sustainable, environment-friendly developmental goals.