The pollution of aquatic bodies by synthetic dyes is regarded as one of the most significant environmental issues, which has prompted greater research into effective and sustainable removal techniques. Even though there have been major efforts in the previous few decades, more study is still necessary to fully examine the long-term performance and usable applicability of adsorbents and different adsorption techniques for the removal of dye. In the present study, a brown marine macroalga Sargassum muticum was used as an effective and sustainable biosorbent for the crystal violet (CV) dye removal from aqueous solutions. The biosorbent was characterized by analysis of SEM, EDX, and FTIR. In order to evaluate the optimum conditions of CV biosorption, several parameters have been examined as a function of contact time, algal dose, initial concentration of CV, and pH. The maximum CV removal was obtained at 60 min contact time, 10 g/L algal dosage, 30 mg/L initial concentration of CV, and pH 6. The isothermal models of Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin are best explained the equilibrium data obtained. At the optimum conditions, the maximum biosorption capacity of the algal biomass achieved from the Langmuir model was 39.1 mg/g. The kinetic adsorption models were also better explained using the pseudo-second-order and Elovich model, and the effect of the boundary layer was indicated using the intraparticle diffusion model as well as the chemisorption-controlled biosorption process. Thermodynamically, the process of CV biosorption was shown to be random, spontaneous, and endothermic. Furthermore, the proposed mechanism of CV dye biosorption onto algal biomass is regulated by hydrogen bond formation, electrostatic interaction, and ion exchange. These findings revealed that the biomass of S. muticum is a sustainable and promising material for the biosorption of water pollutants.

Due to widespread overuse, pharmaceutical compounds, such as antibiotics, are becoming increasingly prevalent in greater concentrations in aquatic ecosystems. In this study, we investigated the capacity of the white-rot fungus, Coriolopsis gallica (a high-laccase-producing fungus), to biodegrade ampicillin under different cultivation conditions. The biodegradation of the antibiotic was confirmed using high-performance liquid chromatography, and its antibacterial activity was evaluated using the bacterial growth inhibition agar well diffusion method, with Escherichia coli as an ampicillin-sensitive test strain. C. gallica successfully eliminated ampicillin (50 mg L⁻¹) after 6 days of incubation in a liquid medium. The best results were achieved with a 9-day-old fungal culture, which treated a high concentration (500 mg L⁻¹) of ampicillin within 3 days. This higher antibiotic removal rate was concomitant with the maximum laccase production in the culture supernatant. Meanwhile, four consecutive doses of 500 mg L⁻¹ of ampicillin were removed by the same fungal culture within 24 days. After that, the fungus failed to remove the antibiotic. The measurement of the ligninolytic enzyme activity showed that C. gallica laccase might participate in the bioremediation of ampicillin.

The textile industry produces high volumes of colored effluents that require multiple treatments to remove non-adsorbed dyes, which could be recalcitrant due to their complex chemical structure. Most of the studies have dealt with the biodegradation of mono or diazo dyes but rarely with poly-azo dyes. Therefore, the aim of this paper was to study the biodegradation of a four azo-bond dye (Sirius grey) and to optimize its decolorization conditions. Laccase-containing cell-free supernatant from the culture of a newly isolated fungal strain, Coriolopsis gallica strain BS9 was used in the presence of 1-hydroxybenzotriazol (HBT) to optimize the dye decolorization conditions. A Box–Benken design with four factors, namely pH, enzyme concentration, HBT concentration, and dye concentration, was performed to determine optimal conditions for the decolorization of Sirius grey. The optimal conditions were pH 5, 1 U/mL of laccase, 1 mM of HBT, and 50 mg/L of initial dye concentration, ensuring a decolorization yield and rate of 87.56% and 2.95%/min, respectively. The decolorized dye solution showed a decrease in its phytotoxicity (Germination index GI = 80%) compared to the non-treated solution (GI = 29%). This study suggests that the laccase-mediator system could be a promising alternative for dye removal from textile wastewater.

Seven yeast strains were isolated from Tunisian dates. The strains were identified by sequence analysis of the D1/D2 domain of the nuclear large subunit (LSU) rRNA gene. Based on this all strains in the study were almost identical with that of the type strain of Wickerhamomyces subpelliculosus (CBS 5767) indicating that they belong to this species. All strains were characterized physiologically and biochemically. All strains grew in the presence of 50 % sucrose, 10 % sodium chloride and at 42 °C. The potential of these yeasts as biocontrol agent against mycotoxigenic Penicillium species inhabiting date, was evaluated. All yeast strains inhibited the growth of P. citrinum P10 and P. chrysogenum C17 previously isolated from dates, with inhibition percentages ranging between 43.6 % and 70.3 % on dual culture plate assays. Moreover, the volatile compounds (VCs) produced by these yeasts inhibited the mycelial growth rate and sporulation of both fungus strains, up to 76.5 and 100 %, respectively, on inverted culture plate assay. The VCs of W. subpelliculosus strains Y4 and Y24, which exhibit strong inhibitory activity against toxigenic Penicillium, were determined by head-space solid-phase microextraction (HS-SPME) combined with gas chromatography coupled with mass spectrometry (GC–MS) analysis. Results revealed significant levels of alcohols (27.36 % for Y4 and 23.35 % for Y24) and esters (66.19 % for Y4 and 75.82 % for Y24). Their significant bioactivity, along with the lack of reported adverse effects on consumer health or the environment, makes them a sustainable and effective alternative to synthetic fungicides for the biocontrol of mycotoxigenic Penicillium affecting stored dates.

The aim of the present research was the efficient degradation of industrial textile wastewater dyes using a very active cloned laccase enzyme. For this purpose, potent laccase-producing bacteria were isolated from soil samples collected from wastewater-replenished textile sites in Punjab, Pakistan. The laccase gene from locally isolated strain LI-81, identified as Bacillus megaterium, was cloned into vector pET21a, which was further transformed into E. coli BL21 codon plus. The optimized conditions for the increased production of laccase include fermentation in a 2% glucose, 5% yeast extract and 250 mg/L CuSO₄ medium with pH 7.5; inoculation with 5% inoculum; induction with 0.1 mM IPTG at 0.5 O.D.; and incubation for 36 h at 37 °C. The crude enzyme produced was employed for the removal of commercially used textile dyes. The dyes were quickly precipitated under optimized reaction conditions. Rose bengal, brilliant green, brilliant blue G, Coomassie brilliant blue R and methylene blue were precipitated at rates of 10.69, 54.47, 84.04, 78.99 and 7.40%, respectively. The FTIR and UV–Vis spectroscopic analyses of dyes before and after confirmed the chemical changes brought about by the cloned laccase that led to the dye removal.

The over use of pharmaceutical compounds, essentially antibiotics, led to an increase of their concentrations in aquatic ecosystems. In this study, the white-rot fungus Coriolopsis gallica (high-laccase-producing fungus) was investigated for the biodegradation of ampicillin (AMP) under different cultivation conditions. The biotransformation of the antibiotic was confirmed by means of high-performance liquid chromatography (HPLC), and the antibacterial activity was evaluated via the bacterial growth inhibition agar well diffusion method using Escherichia coli as an ampicillin-sensitive test strain. The results showed that AMP (50 mg L-1) was totally removed by C. gallica after 6 days of incubation in a liquid medium. The antibiotic removal rate was maximal with a fungal culture aged 9 days. Such a culture achieved the removal of a higher concentration of up to 500 mg L-1 of ampicillin in 3 days. This higher antibiotic removal rate was concomitant with the maximal laccase production in culture supernatant. In addition, four consecutive doses of 500 mg L-1 of ampicillin were transformed by the same fungal culture in 24 days. After that, the fungus was unable to remove the antibiotic. The measurement of ligninolytic enzyme activity showed that laccase of C. gallica might participate in the biotransformation of AMP.