Влияние ингибиторов фенолоксидаз на эффективность деколоризации малахитового зеленого бактериями рода Azo spirillum

Abstract

Synthetic dyes are widely used in various branches of light industry. Due to the insufficient efficiency of industrial painting processes, a large percentage of dyes end up in the wastewater of enterprises in an unmodified form, which creates a huge risk of environmental pollution with these compounds. Triphenylmethane dyes, in particular malachite green, are toxic, allergenic and carcinogenic compounds. To date, biodegradability of triphenylmethane dyes has been shown for some bacteria and fungi producing phenol oxidase complex enzymes, including soil associative bacteria of the genus Azospirillum. Many factors are capable of inducing and inhibiting the biodegradation efficiency, in particular the enzymatic systems that are involved in bleaching processes. In the present work we studied the effects of typical deactivating agents of phenol oxidases, such as H2O2, EDTA, SDS-Na, β-mercaptoethanol, dithiothreitol, Tween, and sodium azide, on the azospirilla’s phenol oxidases activity and the ability to decolorize malachite green. It was found that Tween and sodium azide do not have an inhibitory effect on azospirillum enzymes and exhibit a total stabilizing effect on the entire complex. An inhibitory effect from 60 to 100% was noted for laccase and Mn-peroxidase activity under the action of β-mercaptoethanol, dithiothreitol and EDTA, which is directly proportional to the decolorization rate of malachite green. Compared with the latest issues on classical phenol-oxidizing enzymes, our data revealed non-typical properties of the phenol oxidase complex enzymes of azospirillum.