Wheat bran as an efficient agro-process waste for enhanced yellow laccase production by Lentinus tigrinus SSB_W2 and its application in anthraquinone dye degradation.

Lentinus tigrinus SSB_W2, isolated from Mahabaleshwar in the Western Ghats of Maharashtra, India, was employed to enhance laccase production in solid-state fermentation (SSF). The spectral analysis indicated that the laccase produced by L. tigrinus is a typical yellow laccase, exhibiting no absorption at 600 nm. Notably, this yellow laccase demonstrated exceptional catalytic activity, as confirmed by electrochemical analysis. Four agricultural processing wastes were evaluated as substrates for SSF, and the results showed that L. tigrinus effectively utilized wheat bran. Initial testing by one-factor-at-a-time method showed 3.79-fold increase in yellow laccase production, which subsequently increased to 6.51-fold after Plackett-Burman design. Moreover, employing response surface methodology resulted in 11.87-fold increase (108,472 IU gds-1) in laccase production. The utilization of yellow laccase for the biotransformation of various textile dyes was investigated, and it exhibited the highest degradation efficiency toward Reactive blue 4, a recalcitrant anthraquinone dye, with a rate of 18.36 mg L-1 h-1, for an initial concentration of 1000 mg L-1. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03881-9.

In situ treatment of real textile effluent in constructed furrows using consortium of Canna indica and Saccharomyces cerevisiae and subsequent biochemical and toxicity evaluation.

Emerging contaminants removals like dyes and heavy metals from the textile effluent have an immense challenge. The present study focuses on the biotransformation and detoxification of dyes and in situ textile effluent treatment by plants and microbes efficiently. A mixed consortium of perennial herbaceous plant Canna indica and fungi Saccharomyces cerevisiae showed decolorization of di-azo dye Congo red (CR, 100 mg/L) up to 97% within 72 h. Root tissues and Saccharomyces cerevisiae cells revealed induction of various dye-degrading oxidoreductase enzymes such as lignin peroxidase, laccase, veratryl alcohol oxidase and azo reductase during CR decolorization. Chlorophyll a, Chlorophyll b and carotenoid pigments were notably elevated in the leaves of a plant during the treatment. Phytotransformation of CR into its metabolic constituents was detected by using several analytical techniques, including FTIR, HPLC, and GC-MS and its non-toxic nature was confirmed by cyto-toxicological evaluation on Allium cepa and on freshwater bivalves. Mix consortium of plant Canna indica and fungi Saccharomyces cerevisiae efficiently treated textile wastewater (500 L) and reduced ADMI, COD, BOD, TSS and TDS (74, 68, 68, 78, and 66%) within 96 h. In situ textile wastewater treatment for in furrows constructed and planted with Canna indica, Saccharomyces cerevisiae and consortium-CS within 4 days reveals reduced ADMI, COD, BOD, TDS and TSS (74, 73, 75, 78, and 77%). Comprehensive observations recommend this is an intelligent tactic to exploit this consortium in the furrows for textile wastewater treatment.

Photophysical and NMR studies of encapsulation of 2-cyano-6-hydroxy benzothiazole in p-sulfonatocalix[6]arene and its biological applications.

This work deals with the study of the interaction between 2-cyano-6-hydroxy benzothiazole (CHBT) and p-sulfonatocalix[6]arene (SCX6) at different pH values in aqueous medium by UV-visible absorption spectroscopy and steady-state fluorescence spectroscopy. The results demonstrate the strong influence of SCX6 on the fluorescence properties of CHBT. The steady-state emission of CHBT shows strong sensitivity to its environment. The mode of inclusion complexation of CHBT and SCX6 has also been investigated using HR-MS, FT-IR, NMR, 2D NMR, and FESEM analysis. With the increase in SCX6 concentration, absorbance decreased with an isosbestic point at 305 nm. The binding constant is calculated by a spectrofluorimetric method and stoichiometry by Job's method. The formation of an inclusion complex has been confirmed by 2D NMR NOESY, COSY, ROESY, HMBC, and HSQC spectroscopic methods. The complex is seen to be stabilized by electrostatic interactions between CHBT and the nanocavity of SCX6. Studies with cellular systems support that the CHBT-SCX6 complex is more effective in killing cancerous cells and hence, SCX6 may prove to be an effective carrier for drug molecules like CHBT.

In vitro toxicological evaluation of ionic liquids and development of effective bioremediation process for their removal.

The present study deals with the cyto-genotoxicological impact of ionic liquids, 1-butyl-3-methylimidazolium bromide, trihexyl tetradecylphosphonium dicyanamide, 1-decyl-3-methylimidazolium tetrafluoroborate, benzyldimethyltetradecylammonium chloride, and 1-butyl-4-methylpyridinium chloride, on animal cells and their biodegradation. The long alkyl chain containing ionic liquids were found to be more toxic whereas benzene functional group in benzyldimethyltetradecylammonium chloride enhances its toxicity. Aerobic bacterial granules, a bacterial consortium, were developed that have promising ability to break down these organic pollutants. These aerobic bacterial granules have been applied for the biodegradation of ionic liquids. The biological oxygen demand (5 days) and chemical oxygen demand parameters confirmed that the biodegradation was solely due to aerobic bacterial granules which further decreased the time period needed for regular biodegradation by biological oxygen demand (28 days). The high resolution mass spectrometry analysis further approved that the degradation of ionic liquids was mainly via removal of the methyl group. Elevated N-demethylase enzyme activity supports the ionic liquids degradation which may be occurring through demethylation mechanism. The amplicon sequencing of aerobic bacterial granules gives insight into the involvement of the bacterial community in the biodegradation process.

Effective biotransformation and detoxification of anthraquinone dye reactive blue 4 by using aerobic bacterial granules.

Treatment of textile wastewater containing anthraquinone dye is quite a huge challenge due to its complex aromatic structure and toxicity. Present study deals with the degradation and detoxification of anthraquinone dye reactive blue 4 using aerobic bacterial granules. Bacterial granules effectively decolorized reactive blue 4 at wide range of pH (4.0-11.0) and temperature (20-55 °C) as well as decolorized and tolerated high concentration of reactive blue 4 dye upto 1000 mg l-1 with Vmax 6.16 ± 0.82 mg l-1 h-1 and Km 227 ± 41 mg l-1. Metagenomics study evaluates important role of Clostridia, Actinobacteria, and Proteobacterial members in biotransformation and tolerance of high concentrations of reactive blue 4 dye. Up-regulation of xenobiotic degradation and environmental information processing pathways during dye exposure signifies their noteworthy role in dye degradation. Biotransformation of dye was confirmed by significant decrease in the values of total suspended solids, biological and chemical oxygen demand. The metabolites formed after biotransformation was characterized by FT-IR and GC-MS analysis. The reactive blue 4 dye was found to be phytotoxic, cytotoxic and genotoxic whereas its biotransformed product were non-toxic. This study comprehensively illustrates that, bacterial aerobic granules can be used for eco-friendly remediation and detoxification of wastewater containing high organic load of anthraquinone dye.

Simultaneous decolorization of reactive Orange M2R dye and reduction of chromate by Lysinibacillus sp. KMK-A.

Azo dyes constitute the largest and diverse group of dyes, widely used in number of industries that are contributing toward organic and inorganic load of effluent treatment. In the present study, Lysinibacillus sp. KMK-A was able to effectively decolorize Orange M2R dye up to 2000 mg l(-1) (Vmax of 19.6 mg l(-1) h(-1) and Km of 439 mg l(-1)) and reduce Cr(VI) up to 250 mg l(-1) (Vmax of 3.6 mg l(-1) h(-1) and Km 28.3 mg l(-1)). It also has an ability of simultaneous decolorization of Orange M2R dye (200-1000 mg l(-1)) with reduction of Cr(VI) (50-200 mg l(-1)). Significant reduction in total organic carbon content, chemical and biological oxygen demand along with spectroscopic and chromatographic analysis confirmed the biotransformation of Orange M2R. Involvement of enzymes namely azoreductase and chromate reductase was observed during biotransformation. The phyto and geno toxicity studies demonstrated that metabolites of dye degradation were non-toxic. Higher tolerance with simultaneous decolorization and detoxification of azo dyes in presence of Cr(VI) makes Lysinibacillus sp. KMK-A, a potential candidate for eco-friendly remediation of metal contaminated dye effluents.

Effective bioremoval and detoxification of textile dye mixture by Alishewanella sp. KMK6.

Alishewanella sp. strain KMK6 was able to degrade mixture of textile dyes (0.5-2.0 g l(-1)) within 8 h. An initial 28 % reduction in COD was observed immediately after decolorization at static anoxic conditions which on further incubation at shaking conditions reduced by 90 %. Partially purified azoreductase was able to utilize different azo dyes as substrates. The HPLC profile of dye degradation showed formation of metabolic products. Further FTIR analysis showed significant changes in the peaks corresponding to functional groups present in dye mixture and its degradation products. The genotoxicity assessment showed that the dye degradation products were non-toxic compared to dye mixture.

Biodegradation of thiocyanate using co-culture of Klebsiella pneumoniae and Ralstonia sp.

Thiocyanate-degrading microbial co-culture was isolated from thiocyanate-contaminated site and tested for thiocyanate degradation potential and thiocyanate-toxicity tolerance and identified as Klebsiella pneumoniae and Ralstonia sp. by 16S rDNA sequencing. The co-culture was able to degrade thiocyanate with degradation rate of 500 mg L(-1)d(-1) at 2,500 mg L(-1) thiocyanate concentration at pH 6.0 and 37 degrees C following thiocyanate hydrolase pathway. The Haldane kinetic model elucidates the growth and thiocyanate biodegradation kinetics of the co-culture with Ki value of 1,876 mg L(-1). The thiocyanate biodegradation kinetics was not affected by the additional supply of glucose. The very high activities of thiocyanate hydrolase, cyanide oxygenase, and cytochrome P-450 content during growth on thiocyanate were observed, showing the induction mechanism.