MINI-REVIEW Biological agents for 2,4-dichlorophenoxyacetic acid herbicide degradation Maria Pilar Serbent 1,2 & Andrey Martinez Rebelo 3 & Adilson Pinheiro 2 & Adriana Giongo 2 & Lorena Benathar Ballod Tavares 2 Received: 7 December 2018 /Revised: 12 March 2019 /Accepted: 7 April 2019 # Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract Phenoxy herbicides are the most widely used family of herbicides worldwide. The dichlorophenoxyacetic acid (2,4-D) is extensively used as a weed killer on cereal crops and pastures. This herbicide is highly water-soluble, and even after a long period of disuse, considerable amounts of both 2,4-D and its main product of degradation, 2,4 dichlorophenol (2,4-DCP), might be found in nature. Biological decomposition of pesticides is an expressive and effective way for the removal of these compounds from the environment. The role of bacteria as well as the enzymes and genes that regulate the 2,4-D degradation has been widely studied, but the 2,4-D degradation by fungi, especially regarding the ability of white-rot basidiomycetes as agent for its biocon- version, has been not extensively considered. This review discusses the current knowledge about the biochemical mechanisms of 2,4-D biodegradation, focused on the role of white-rot fungi in this process. Finally, the cultivation conditions and medium composition for the growth of 2,4-D-degrading microorganisms are also addressed. Keywords Chlorinated aromatic compounds . Bioconversion . White-rot fungi . Metabolic pathways . Catabolic genes Introduction The use of agricultural pesticides is closely associated with the generation of food. Their indiscriminate use represents high polluting potential, and environmental problems related to the extensive use of pesticides are of grave concern. The col- lateral effect of pesticides on non-target organisms is particu- larly alarming considering that only 5% or less of the amount of pesticide that is applied reaches the target organisms (Gill and Garg 2014; Javaid et al. 2016; Mahmood et al. 2016). The accumulation of pesticides in the soil (Baumgartner et al. 2017) is worrisome due to the environmental consequences. Similarly, the presence of pesticide residues in the environment represents a threat to humans and animals through drinking water (Pinheiro et al. 2010). In this sense, the World Health Organization (WHO) emphasized the need to prevent the con- centration of pesticides in water exceeding the guideline values or health-based values (WHO 2017). Pesticides have been used for centuries by humanity, and their roles, as well as fertilizers, became an essential component in agriculture dur- ing the last century for food production (Carvalho 2017). The compound 2,4-dichlorophenoxyacetic acid (2,4-D), a synthetic auxin for plant growth, was the first organic, system- ic, and selective herbicide for the control of broad-leaved weeds (Queiroz and Vidal 2014). It is one of the most exten- sively used chlorophenoxy herbicides worldwide (Chen et al. 2018), and the mixture of butoxyethanol esters of 2,4-D and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) gave rise to the military herbicide used in Vietnam war nicknamed Agent Orange (Stellman and Stellman, 2018). The widespread utili- zation of 2,4-D is a consequence of the resistance of geneti- cally engineered plants to glyphosate and paraquat (Hiran and Kumar 2017), and as new herbicide-resistant crops are to de- velop, it is considered that there will be an enormous increase in the use of 2,4-D (Schulz and Segobye 2016). 2,4-D is usually commercialized as salt, amine, and ester formulations and has post-emergence action activating the auxin receptor system what results in changes in the actin * Lorena Benathar Ballod Tavares lorena@furb.br 1 Department of Sanitary Engineering, State University of Santa Catarina, Ibirama, Santa Catarina, Brazil 2 Environmental Engineering Graduate Program, Regional University of Blumenau, Blumenau, Santa Catarina, Brazil 3 Santa Catarina State Agricultural Research and Rural Extension Enterprise, Itajaí, Santa Catarina, Brazil Applied Microbiology and Biotechnology https://doi.org/10.1007/s00253-019-09838-4