Degradation of 2,6-dicholorophenol by Trichoderma longibraciatum Isolated from an industrial Soil Sample in Dammam, Saudi Arabia

Amira H Alabdalall,Azzah I Alghamdi,Sahar K Al Dosary,Sumayh A Aldakeel,Ines Hammami,Fatimah A Aldakheel,Hesham M Elkomy,Ahmed M Albarrag,Nada Al Qurin,Hanen Chakroun,Ibtisam M Ababutain,Rawan Aldughaish,Tamer E Youssef

doi:10.1038/s41598-022-07016-7

Abstract

2,6-Dichlorophenol (2,6-DCP) is an aromatic compound with industrial importance in making insecticides, herbicides, and other organic compounds. However, it poses serious health and ecological problems. Microbial degradation of 2,6-DCP has been widely applied due to its effectiveness and eco-friendly characteristics. In this study, Trichoderma longibraciatum was isolated from an industrial soil sample in Dammam, Saudi Arabia using the enrichment method of mineral salt's medium (MSM) amended with 2,6-DCP. Morphological and molecular identification (using the internal transcribed spacer rRNA gene sequencing) of the 2,6-DCP tolerating fungal isolate were charactraized. The fungal isolate has demonstrated a tolerance to 2,6-DCP up to 300 mg/L. Mycelial growth and fungal sporulation were reduced with increasing 2,6-DCP concentrations up to 96 h incubation period. However, after 168 h incubation period, the fungal isolate recorded maximum growth at all the tested 2,6-DCP concentrations up to 150 mg/L. Carboxy methyl cellulase production by tested fungus was decreased by increasing 2,6-DCP concentration up to 75 mg/L. The biodegradation pattern of 2,6-DCP in GM liquid medium using GC–mass analysis as well as the degradation pathway was presented. This study provides a promising fungal isolate that could be used in the bioremediation process for chlorinated phenols in soil.

Highlights

Chlorophenols (CPs) are aromatic compounds with at least one chlorine atom and one hydroxyl g roup[1]
Cultural and morphological characterization of the 2,6DCP tolerant fungal isolate showed that it was belonging to the genus Trichoderma (Ascomycetes)
Sequence-based molecular identification of the fungal isolate further confirmed as Trichoderma longibraciatum.The consensus sequence of internal transcribed spacer (ITS) gene was submitted to NCBI GenBank record with accession number of MT328534

Summary

Introduction

Chlorophenols (CPs) are aromatic compounds with at least one chlorine atom and one hydroxyl g roup[1] These compounds are used as mothproofing agents, miticides, germicides, algicides, fungicides and wood preservatives, as well as in the synthesis of dyes and drugs[2, 3]. White rot fungi are promising organisms because of their ability to completely degrade aromatic x enobiotics[7, 9] This ability is associated with the production of extracellular oxidoreductases (laccases, peroxidases and tyrosinases) that can remove chlorophenols from wastewater through an oxidative coupling reaction. The present study aimed to (i) isolate fungi from an industrial soil sample in Dammam, Saudi Arabia to screen these fungal strains for 2,6-DCP degradation, (ii) identify the isolated 2,6-DCP tolerant fungus molecularly, (iii) investigate the transformation pattern and pathway of 2,6-DCP and (iv) study the effect of 2,6-DCP on its growth and carboxy methyl cellulase activity

Methods

Results

Conclusion