Efficient degradation of Malachite Green by Aeromonas sp. strain DH-6

Abstract

Microbial decolorization has been investigated extensively. Various microbes have been studied for their dye removing capability; however, microbial decolorizer with a strong environmental adaptability and wide substrate spectrum is of great potential for its possible practical application. Therefore, in this study, Aeromonas sp. DH-6, a wide dye spectrum decolorizer, was investigated in terms of its use for Malachite Green (MG) remediation. Results indicated that most of carbon sources have no effect on decolorization, while the nitrogen sources of beef extract and yeast extract could enhance MG decolorization significantly. Among the tested metal ions, Cu 2+ , Fe 2+ , and Zn 2+ could significantly inhibit decolorization. Moreover, the strain showed a very stable and efficient decolorization performance in the pH of 5.0-10.0 and at 20-40 o C. Besides, it could almost completely decolorize MG at concentrations 1000 mg/L within 36 h. Based on UV-visible, GC-MS, and FTIR analysis, biodegradation of MG by the strain DH-6 was confirmed and data showed that MG was decomposed into 4-(Dimethylamino)benzophenone and other metabolites containing-C=O,-NH, and-OH groups. Enzyme analysis showed that tyrosinase, laccase, LiP, NADH-DCIP reductase, and MG reductase might be involved in MG degradation by the strain DH-6. Overall, the results demonstrated that the strain DH-6 will have an effective use as an alternative in MG bioremediation.

Dynamics of the role of LacMeta laccase in the complete degradation and detoxification of malachite green

“…In the dye spectrum before treatment, a peak at 420 nm was evident, as observed in other studies as a characteristic of the MG spectrum, together with a peak at 315 nm (Yang et al 2015b; Barapatre et al 2017;Du et al 2018). The decrease in the peak at 420 nm demonstrates that the enzyme can degrade dye conjugates (Jiang et al 2016).…”

“…The optimum characteristics of crystal violet decolorization by the Dictyopanus pusillus laccase were pH 5 and 45 °C, which was the maximum temperature tested, and decolorization reached 81% at these optimized parameters (Rueda-Villabona et al 2021). The presence of metals is quite common in dye-containing wastewater, and therefore, studying their effects is important, as metals can impair dye decolorization (Du et al 2018).…”

Dye degradation by early colonizing marine bacteria from the Arabian Sea, India

“…Tyrosinase, MG reductase, lignin peroxidase (LiP), laccase and NADH-DCIP reductase were previously reported to degrade MG by Aeromonas sp. (Du et al 2018). Laccase and NADH-DCIP reductase were also known to degrade MG by Micrococcus sp.…”

The comprehension of bioremediation for the isolation and characterization of heavy metal tolerant Aeromonas sanarellii bacteria in the wastewater-contaminated soil

“…This species is remarkably e cient at converting and removing heavy metals and other toxins from polluted environments (Huang et al 2019;Min et al 2021;Qurbani et al 2022). For instance, some species of Aeromonas may break down oil hydrocarbons (Voverienė et al 2002) and remove nitrates (Rajta et al 2020) from wastewater while also destroying triphenylmethane hues like malachite green (Du et al 2018). Infections of the gastrointestinal tract and wounds are a couple of the illnesses linked to Aeromonas.…”