White-rot fungi capable of decolourising textile dyes under alkaline conditions

Twelve white-rot fungal strains belonging to seven different species were screened on plates under alkaline condition to study the decolourisation of the textile dyes Reactive Black 5 and Poly R-478. Three strains of Trametes versicolor (Micoteca da Universidade do Minho (MUM) 94.04, 04.100 and 04.101) and one strain of Phanerochaete chrysosporium (MUM 94.15) showed better decolourisation results. These four strains were used for decolourisation studies in liquid culture medium. All four selected strains presented more efficient decolourisation rates on Reactive Black 5 than on Poly R-478. For both dyes on solid and liquid culture media, the decolourisation capability exhibited by these strains depended on dye concentration and pH values of the media. Finally, the decolourisation of Reactive Black 5 by T. versicolor strains MUM 94.04 and 04.100 reached 100 %. In addition, the highest white-rot fungi ligninolytic enzyme activities were found for these two strains

White rot fungi capable of decolourising textile dyes under alkaline conditions

Four different white rot fungi were screened to study the decolourisation of the textile dyes Reactive Black 5 (RB5) and Poly R-478 on plates under alkaline condition. Three strains of Trametes versicolor (MUM 94.04 MUM 04.100 MUM 04.101) and one strain of Phanerochaete chrysosporium (MUM 94.15), showed better decolourisation results. The strains were used for decolourisation study in liquid culture medium (LCM). All four strains presented more efficient decolourisation on dye RB5, but they differed in decolourisation capacity depending on the analised pH value. In LCM the decolouration of dye reached 100% for the two strains of WRF studied

Metagenomic analysis of dental calculus in ancient Egyptian baboons

Dental calculus, or mineralized plaque, represents a record of ancient biomolecules and food residues. Recently, ancient metagenomics made it possible to unlock the wealth of microbial and dietary information of dental calculus to reconstruct oral microbiomes and lifestyle of humans from the past. Although most studies have so far focused on ancient humans, dental calculus is known to form in a wide range of animals, potentially informing on how human-animal interactions changed the animals' oral ecology. Here, we characterise the oral microbiome of six ancient Egyptian baboons held in captivity during the late Pharaonic era (9th-6th centuries BC) and of two historical baboons from a zoo via shotgun metagenomics. We demonstrate that these captive baboons possessed a distinctive oral microbiome when compared to ancient and modern humans, Neanderthals and a wild chimpanzee. These results may reflect the omnivorous dietary behaviour of baboons, even though health, food provisioning and other factors associated with human management, may have changed the baboons' oral microbiome. We anticipate our study to be a starting point for more extensive studies on ancient animal oral microbiomes to examine the extent to which domestication and human management in the past affected the diet, health and lifestyle of target animals

Use of filamentous fungi for improving electricity production and textile dye treatment in a microbial fuel cell

Urban and industrial wastewaters have received an increased interest towards energy harvesting using microbial fuel cells (MFC). The combined use of microbial anode oxidizing organic substrates and enzymatic cathode reducing oxygen is a promising new approach for the simultaneous treatment of wastewater and generation of electricity. In this context, our study evaluated the performance of a two-chambered MFC operated with three laccase producing strains of filamentous fungi (Ff), immobilized on the cathodic compartment and filled up with simulated textile dye effluent (TDE) and urban wastewater in the anodic compartment. The result indicated a rapid TDE decolourisation (>86 % within 72 h). Electrochemical monitoring of the MFC during TDE decolourisation indicated power density (>35 mW m2, control 3,61) and laccase activity (989.6 U l–1) in the presence of Pleurotus ostreatus on the cathodic compartment. Considering the initial COD value of 464 ± 20 mg.l-1, the organic removal in the anodic compartment after 20 days of MFC operation was 90.2%. Final toxicity measurements in the TDE treated indicated a much lower impact when compared to the original TDE. These are the initial studies to select Ff as models for MFC application and further adaptation for wastewater treatment and bioelectricity generatio

Utilization of white rot fungi for textile dye decolourisation under alkaline condition and high salt concentration in solid medium

A large amount of azo dyes are used for dyeing textiles. However, the dyes contaminate wastewaters and need to be treated. This is important because of the aesthetic, toxic and carcinogenic effects of the affected waters. Recently there has been an increase in interest in using white rot fungi (wrf) which degrade xenobiotic compounds including azo dyes. Wrf degrade lignin and others recalcitrant molecules using nonspecific extracellular enzymes. Four white rot fungi obtained from the Micoteca da Universidade do Minho (MUM) culture collection were used to screen for degradability capabilities. Reactice Black 5 (RB5) was selected in the present work because these dyes are most commonly used in the textile dyeing. Screening for RB5 decolourisation was carried out on solid medium in plates. Two wrf showed good growth and decolourisation abilities. These are now under study to determine which ligninolytic enzymes are produced

Effect of different carbon sources on decolourisation of an industrial textile dye under alkaline-saline conditions

White-rot fungal strains of Trametes versicolor and Phanerochaete chrysosporium were selected to study the decolourisation of the textile dye, Reactive Black 5, under alkaline–saline conditions. Free and immobilised T. versicolor cells showed 100 % decolourisation in the growth medium supplemented with 15 g l-1 NaCl, pH 9.5 at 30 C in liquid batch culture. Continuous culture experiments were performed in a fixed-bed reactor using free and immobilised T. versicolor cells and allowed 85–100 % dye decolourisation. The immobilisation conditions for the biomass and the additional supply of carbon sources improved the decolourisation performance during a long-term trial of 40 days. Lignin peroxidase, laccase and glyoxal oxidase activities were detected during the experiments. The laccase activity varied depending on carbon source utilized and glycerol-enhanced laccase activity compared to sucrose during extended growth