English

N A Zubbair,E O Adeyemo,D O Adeniyi,A T Ajao

doi:10.5897/ajest2017.2362

English

N A Zubbair, E O Adeyemo + Show 2 more

Open Access

https://doi.org/10.5897/ajest2017.2362

Copy DOI

Abstract

In this study, the decolourization potential of the white-rot fungus Ganoderma tsugae, which is capable of producing laccase was investigated to degrade reactive black dye. Biodegradation of reactive black dye was analyzed by using spectrophotometer at an absorbance of 585 nm. Laccase, manganese peroxidase and pH were served as biodegradation indices. Fourier transform infrared (FTIR) and gas chromatography mass spectrometry (GCMS) were used to analyze degradation products. Seed germination study was carried out on maize and beans seeds with distilled water (control), degraded dye products and non-degraded dye. Microtoxicity assay was also performed on the test cultures Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae using the degraded dye metabolite/non-degraded dye. The non-degraded dye components inhibited the growth of P. aeruginosa (clear zone of 6 mm) and E. coli (clear zone of 3 mm). K. pneumoniae was resistant to the toxicity of the dye components. The following metabolites were detected; 3-Benzyl hexahydropyrrolo[1,2-a]pyrazine-1,4-dione, 5-Isopropylidene-3,3-dimethyl-dihydrofuran-2-one, N-[(Z)-1-Ethylpentylidene] methanamine and 10-Undecenyl aldehyde with retention time of 23.317, 16.475, 16.850 and 23.500 min, respectively. Key words: Detoxification, reactive black, phytotoxicity, white rot, Fourier transform infrared (FTIR), gas chromatography mass spectrometry (GCMS).

Highlights

Reactive black dye is a high-toxic compound containing rigid aromatic molecules with azo-based chromophores possessing different reactive groups and regarded as commonly used synthetic reactive dyes in the dyeing industry (El Bouraie and El Din, 2016; Kaneva et al, 2016)
Ligninolytic enzymes are one of the important groups of enzymes involved in bioremediation, which are produced by various white rot fungi in greater extent
The results indicate that the non-degraded dye components inhibited the growth of the test cultures of P. aeruginosa and E. coli due to the presence of toxic compounds in the dye

Summary

Introduction

Reactive black dye is a high-toxic compound containing rigid aromatic molecules with azo-based chromophores possessing different reactive groups and regarded as commonly used synthetic reactive dyes in the dyeing industry (El Bouraie and El Din, 2016; Kaneva et al, 2016). The release of dye-containing effluents into the aquatic environment is undesirable without proper treatment because it can remain persistent in the environment for an extended period (Irshad et al, 2012; Iqbal and Asgher, 2013; El Bouraie and El Din, 2016) Such practice of discharging untreated textile effluents into nearby water bodies and soil constitute a serious threat to human health and aquatic life (Asgher et al, 2013a, b; Shilpa and Shikha, 2015). Biological treatment methods are eco-friendly, have been proven to be efficient and more cost-effective and are gaining importance in today’s situation Microorganisms such as actinomycetes, fungi, algae, yeast, aerobic and anaerobic bacteria and their enzymes have been successfully utilized to degrade a wide variety of dyes (Kaushik and Malik, 2009; Gupta et al, 2010; Srinivasan et al, 2014; Asgher et al, 2016). There are two important mechanisms for treatment of dye by white-rot fungi which are by biosorption of dye to the fungal biomass and biodegradation of dye into another compound by an extracellular enzyme (Banat et al, 1996)

Methods

Results

Discussion

Conclusion