New chemical products formation from textile dye degradation, chitinolytic and antioxidant activity in new strain nbpc5–18 of Cellulosimicrobium sp. TH-20

Abstract

The new strain nbpc5–18 of Cellulosimicrobium TH-20, isolated from the filaments of Scytonema sp., was characterized by phenotypic, chemotaxonomic and 16S rRNA gene sequencing. Nucleotide homology and phylogenetic analysis indicated the affiliation of bacterium strain nbpc 5–18 (accession No. MH298840) with Cellulosimicrobium TH-20 but chemotaxonomic features differed from the related taxa. G + C content of test isolate was found to be 57%. Scanning electron microscopy showed rod-circular shaped isolate with length and width of 790 nm and 469.8 nm. The strain showed maximum growth in nutrient broth medium, at 35 ± 2ᵒ C and pH at 6.0–8.0. The strain was efficiently able to decolorize a wide range of laboratory (67–98%) and textile (74–94%) dyes. Structures of the products resulting from the bacterial degradation of dyes were identified by GC–MS and HR-MS. Mass spectra revealed the presence of some new low molecular weight compounds in the degradation products of dyes (Methylene blue, Bromocresol purple, Methyl orange, Rhodamine 6 G, Coomasie brilliant blue R-250 and Crystal violet). Azoreductase, laccase, lignin peroxidase, tyrosinase, and NADH-DCIP reductase activity were found to be higher in dye treated samples as compared to control signifying crucial role played by enzymes in degradation of dyes. This is the first attempt on application of bacterium strain form Cellulosimicrobium associated with cyanobacteria for dye degradation. The methanolic extract of the bacterial pigment showed potential free radical scavenging activity. Moreover, isolate also exhibited significant antifungal and chitinolytic activity. These properties show the potential use of this strain in bioremediation and drug development.