posted on 2024-02-09, 06:46authored byYongqiang Tian, Kangli Wu, Shenghong Lin, Meiling Shi, Yang Liu, Xu Su, Rehmat Islam
Microbial degradation
of dyes is vital to understanding the fate
of dyes in the environment. In this study, a fungal strain A-3 and
a bacterial strain L-6, which were identified as Aspergillus
fumigatus and Pseudomonas fluorescens, respectively, had been proven to efficiently degrade crystal violet
(CV) dye. The decolorization of CV dye by fungal and bacterial cocultivation
was investigated. The results showed that the decolorization rate
of cocultures was better than monoculture (P. fluorescens in L-6 (PF), and that of A. fumigatus A-3 (AF)). Furthermore, enzymatic analysis further revealed that
Lac, MnP, Lip, and NADH–DCIP reductases were involved in the
biodegradation of CV dyes. UV–visible spectroscopy, Fourier
transform infrared (FT-IR) spectroscopy, and gas chromatography–mass
spectrometry (GC–MS) were used to examine the degradation products.
GC–MS analysis showed the presence of 4-(dimethylamino) benzophenone,
3-dimethylaminophenol, benzyl alcohol, and benzaldehyde, indicating
that CV was degraded into simpler compounds. The phytotoxicity tests
revealed that CV degradation products were less toxic than the parent
compounds, indicating that the cocultures detoxified CV dyes. As a
result, the cocultures are likely to have a wide range of applications
in the bioremediation of CV dyes.