Aspergillus Niger QH27 in the Removal of Toxic Dyes: Biosorption of Eriochrome Black T Under Various Experimental Conditions

Water pollution by toxic dyes such as Eriochrome Black T (EBT) is an increasing environmental issue, and the use of biosorbents represents a sustainable alternative for their treatment. In this study, the ability of Aspergillus niger QH27 fungal biomass in removing EBT under various experimental conditions was investigated. The main objective was to evaluate biosorption efficiency and determine the optimal conditions for dye removal. The methodology consisted of performing experiments by varying pH (5, 7 and 9) and agitation speed (100, 150 and 200 rpm), and analysing dye removal efficiency and adsorption capacity. Results showed that EBT removal was most effective at low pH values and higher agitation speeds. At a pH of 5 and agitation of 200 rpm, the maximum removal efficiency (99.17 %) and adsorption capacity (1.24 mg/g) were achieved. Fourier transform infrared spectroscopy (FTIR) analyses were carried out to examine the changes in functional groups of fungal biomass before and after EBT biosorption. FTIR results suggested the active involvement of these groups in the dye removal process. In conclusion, Aspergillus niger QH27 biomass proved to be an efficient biosorbent for the removal of EBT dye in aqueous solutions. This study provides valuable information for the development of sustainable and low-cost strategies in treating wastewater contaminated with dyes and expands the knowledge of dye biosorption using fungal biomass

Characterization of Collagen from Three Genetic Lines (Gray, Red and F1) of <i>Oreochromis niloticus</i> (Tilapia) Skin in Young and Old Adults

From tilapia (Oreochromis niloticus) farming, the by-products have been identified as a source of collagen that could be used for the development of dermocosmetics or pharmaceutical products. However, the characteristics of collagen related to a specific strain or culture must be well defined prior to its application. Collagen was extracted from the skin of three strains of tilapia: red YY males (YY: two Y-type sex chromosomes), XX gray females, and the F1: offspring of crossing red YY males with XX gray females; at different ages in the adult phase, using acetic acid and pepsin enzyme. The characteristics of acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) were shown by SDS-PAGE band profiles to be similar to bovine collagen type I (SIGMA), the PSC of gray tilapia being more fragile to temperature changes, consistent with the results of fractional viscosity. The characteristics of the F1 progeny were prioritized for being a commercially productive and sustainable source for the extraction of collagen, and the ASC form, being the one with the greatest stability and advantage over PSC, of importance to our investigations, leads to a controlled digestion as in the case of peptide induction, and also in the development of natural products in the pharmaceutical and/or dermocosmetic industry. Evaluations of the triple helix structure by FT-IR, X-ray diffraction and UV–visible spectroscopy give similar results between the strains: red, gray, and F1, and between ages in the adult form F1 (15, 24, and 36 months of age). Consequently, the skin of tilapia in adult form is recommended sustainably for up to 24 months of age where the collagen is obtained with the use of acetic acid without enzymatic treatment