Lignin Degrading System of Phanerochaete chrysosporium and its Exploitation for Degradation of Synthetic Dyes Wastewater

Abstract

Azo dyes are the main group of dyes used in different industrial applications. These dyes are highly toxic for aquatic life, so their removal is of utmost importance before they can be disposed of in a main water body. The present study focused on degrading/mineralizing the synthetic reactive dye wastewater. Initial experiments were done with four indigenous white rot fungi. P. chrysosporium (PC) showed more potential toward degradation of synthetic dye wastewater than other three fungal strains, so it was selected for further optimization of different fermentation parameters. Maximum decolorization (84.8%) of reactive dye wastewater was obtained at pH 5, inoculum size 4 mL, and 30ºC. After optimizing experimental parameters, the effects of different nutritional factors like carbon and nitrogen sources were also studied. Decolorization of synthetic dye wastewater was increased from 84.8 to 89.2%, when rice bran was used as an additional carbon source. However, no increase in decolorization of synthetic dye wastewater was observed in the presence of nitrogen supplements. The screened fungal strain decolorized the wastewater up to 90%. The effect of different nutritional factors enhanced the degradation capability of the fungal strain under study. UV-visible and FTIR analyses confirmed the degradation of synthetic dye wastewater into simpler, non-toxic products.

Biodegradation of bio-sourced and synthetic organic electronic materials towards green organic electronics

“…Biosourced materials made of complex biopolymers such as lignocellulose or modified starch are biodegraded (composted) in a multi-step process. Initially, depolymerization takes place, i.e., enzymatic hydrolysis of cellulose or starch chains via, e.g., endoand exo-glucanases 53 and/or enzymatic oxidation of the lignin backbone via, e.g., manganese or lignin peroxidases 54,55 . Once the resulting oligomers, dimers, or monomers are released, they can be transported into the microorganisms 56 .…”

“…As Sepia Melanin is a heterogeneous substrate, we hypothesize that its biodegradation requires several types of extracellular enzymes to achieve complete biodegradation, via a mechanism very similar to the enzymatic oxidation of lignin, based on manganese peroxidase (Mn-P) and lignin peroxidase (Li-P) 54,68 . Moreover, a type of enzyme able to act on one type of eumelanin oligomer may have a different affinity towards different oligomers 33 , whereas a non-biodegraded oligomer will limit the exposure to extracellular enzymes of all the oligomers stacking beneath it.…”

Isolation of Lignin-Degrading Bacteria from Different Sources and Testing of Their Ligninolytic Activities

“…They used an initial dye concentration of about 10-50 mg/l, compared to the RBBR concentration of 200 mg/l used in this study. Kiran et al (2019) found that when synthetic dye wastewater concentration was increased from 0.01-0.05%, the percent decolourization decreased from 80.93% to 24.705%. Taking into consideration these previous findings and the dye concentration, we can say that our isolates were more effective at dye decolorization.…”

Assessment of anammox, microalgae and white-rot fungi-based processes for the treatment of textile wastewater

“…Nevertheless, laccase enzymatic activity was never detected and a limited colour removal (10-11%) was evidenced. Kiran et al [64] investigated the colour removal performance of four P. chrysosporium strains on a dye wastewater solution prepared by mixing Reactive Blue, Reactive Violet and Reactive Yellow: after 6 day of incubation, the decolorization efficiency ranged from 38.9 to 82.9% depending on the tested strain and on the concentration of synthetic dyes, suggesting that larger quantity of the dye may cause a slower rate of dye removal; contrarily to results obtained in the present experimentation, laccase was always found in the range 5-25 IU mL -1 . This comparison suggests that P. chrysosporium was able to grow but not to synthetize the enzymatic activity requested for colour removal.…”