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• Phenol catabolism among three psychrotolerant yeast strains was examined. • For this, enzymatic and chromatographic (GC–MS) techniques were applied. • The impact of cell inoculum preparation on the enzymatic activity was examined. • All yeast strains utilized phenol via the ortho -cleavage pathway. • None of the yeast strains utilized phenol via the meta -cleavage pathway. In this study, three psychrotolerant phenol-degrading yeast strains Candida subhashii (strain A01 1), Candida oregonenis (strain B02 1) and Schizoblastosporion starkeyi-henricii (strain L01 2) isolated from Rucianka peatland were examined to determine which alternative metabolic pathway for phenol biodegradation is used by these microorganisms. All yeast strains were cultivated in minimal salt medium supplemented with phenol at 500, 750 and 1000 mg l−1 concentration with two ways of conducting phenol biodegradation experiments: with and without the starving step of yeast cells. For studied yeast strains, no catechol 2,3-dioxygenase activities were detected by enzymatic assay and no products of catechol meta -cleavage in yeast cultures supernatants (GC–MS analysis), were detected. The detection of catechol 1,2-dioxygenase activity and the presence of cis,cis -muconic acid in the analyzed samples revealed that all studied psychrotolerant yeast strains were able to metabolize phenol via the ortho -cleavage pathway. Therefore, they may be tested in terms of their use to develop biotechnology for the production of cis,cis -muconic acid, a substrate used in the production of plastics (PET) and other valuable goods. [ABSTRACT FROM AUTHOR]

The unplanned anthropogenic activities and raced industrial revolution detrimentally causes serious threat to terrestrial and aquatic life. A high discharge of wastewater from industries using dyes affects living organisms and the environment. This paper presents studies on polycationic selenides (PCS) synthesized by hydrothermal methods for photocatalytic degradation of dyes. The synthesized PCS were confirmed by various characterization techniques such as FTIR, SEM, EDX, UV/Vis, and XRD. The FTIR spectra revealed characteristic band at 843, 548 cm−1, and 417 cm−1 due to the M − Se stretching and intrinsic stretching vibrations, respectively. The optical bandgap of polycationic selenide lies in the visible light region (2.36 eV). The SEM images showed that PCS has a spherical shape with an average crystallite size of 29.23 nm calculated from XRD data using Scherer's equation. The PCS has a point of zero charge (PZC) at pH 7. The efficiency of synthesized PCS photocatalyst was confirmed in terms of its activity towards Eosin (EY) and Crystal violet (CV) dyes mineralization. The photocatalytic degradation for EY and CV dyes at optimum conditions was 99.47% and 99.31% and followed second order reactions kinetics with 1.4314 and 0.551 rate constant, respectively. The polynomial quadratic model is the best-fitted response surface methodology (RSM) model having a maximum desirability factors value and significant terms, with R2 (0.9994) and adj R2 values (1.0). [Display omitted] • Green fabrication of new ternary metallic selenides nanostructured materials. • Structural/morphological characteristics of ternary metallic selenides by advanced techniques. • Efficient photocatalytic degradation of textile contaminants under sunlight irradiation. • Operating factors influencing the degradation phenomena are investigated. [ABSTRACT FROM AUTHOR]