Impact of hydroquinone used as a redox effector model on potential denitrification, microbial activity and redox condition of a cultivable soil

Abstract

In this microcosm study, we analyzed the effect produced by hydroquinone on the expression of soil biological denitrification, in relation to the redox state of the soil, both in terms of intensity factor (Eh') and capacity factor (amount of oxidized or reduced compounds). The supplementation of an Argiudoll soil with hydroquinone decreased the soil apparent reduction potential (Eh') and soil dehydrogenase activity (formazan production from tetrazolium chloride reduction; redox capacity factor), the relationship between both factors being highly significative, r=0.99 (p<0.001). The bacterial population (measured by colony forming units) increased, and the production of N2O was greater (p<0.001) at 200 and 400μg/g dry soil doses. Furthermore, there was an inverse relationship between soil dehydrogenase activity and the number of bacteria (r=-0.82; p<0.05), increased denitrification activity and changes in the CO2/N2O ratio value. These results suggest that hydroquinone at supplemented doses modified the soil redox state and the functional structure of the microbial population. Acetate supplementation on soil with hydroquinone, to ensure the availability of an energy source for microbial development, confirmed the tendency of the results obtained with the supplementation of hydroquinone alone. The differences observed at increased doses of hydroquinone might be explained by differences on the hydroquinone redox species between treatments.

Bisphenol A—A Dangerous Pollutant Distorting the Biological Properties of Soil

“…A need, therefore, arose to perform a multifaceted analysis of the research results, which implicated that the response of dehydrogenases to BPA applied to soil was different from the response of microorganisms to this compound. The tendencies demonstrated in this study attest to the results reported by Perotti [ 53 ], who maintained that hydroquinone, a toxic intermediate metabolite of phenols, inhibited the activity of dehydrogenases. According to Carvalho et al [ 54 ], this is a response to oxidative stress induced by the pressure of the phenolic compound, whose mechanism relies on the accumulation of nicotinamide adenine dinucleotide (NAD)-dependent lactate dehydrogenase by microorganisms.…”

Effect of Separate and Combined Toxicity of Bisphenol A and Zinc on the Soil Microbiome

“…The toxicity of bisphenol A could be linked to the fact that one of Deh cofactors is pyrroloquinoline quinol (PPQ), which is responsible for the transport of electrons from the substrate to ubiquinone during the process of oxidation [ 43 ]. In turn, quinones are considered to be toxic intermediate metabolites of phenols and inhibitors of the enzymatic activity of both dehydrogenases and urease [ 44 ]. The inhibitory effect of bisphenol A on the activity of Ure might be linked to the inactivation of this enzyme, which relies on the formation of stable covalent adducts between the inhibitor and the enzyme’s functional groups [ 45 ].…”

Perna canaliculus as an Ecological Material in the Removal of o-Cresol Pollutants from Soil

“…The ability of dehydrogenase (LOC100783159) to oxidise dihydroacetate (a quinone compound and an aromatic compound derivative) could also be the response to the positive effect of cresol on dehydrogenase activity in the authors' own study [100]. In a study by Perotti [101], hydroquinone, regarded as a compound toxic to microorganisms, actually increased their count and inhibited the activity of dehydrogenases. Certainly, it is related to the wide range of responses to various phenolic compounds resulted from the presence and position of selected substituents.…”