Production of a new chitinase from Nocardiopsis halophila TN-X8 utilizing bio-waste from the blue swimming crab: enzyme characterization and immobilization

• Published in: Environmental science and pollution research international 2024-07, Vol.31 (32), p.45217-45233
• Main Authors: Mechri, Sondes, Jabeur, Fadoua, Bessadok, Boutheina, Moumnassi, Sara, Idrissi Yahyaoui, Meryem, Mannani, Nysrine, Asehraou, Abdeslam, Mensi, Fethi, Vita, Stefano, D’Amore, Paolo, Di Bella, Calogero, Lo Monaco, Daniela, Abousalham, Abdelkarim, Sadok, Saloua, Le Roes-Hill, Marilize, Jaouadi, Bassem
• Format: Article
• Language: English
• Subjects: Ammonium; Ammonium sulfate; Antifungal activity; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Binders; Biotransformation; Blue economy; Charcoal; Chitin; Chitinase; Colloid chitin; Column chromatography; Earth and Environmental Science; Ecotoxicology; Encapsulation; Energy sources; Environment; Environmental Chemistry; Environmental Health; Environmental Sciences; Fractionation; Fungicides; Glucosamine; Heat treatment; Heat treatments; Immobilization; Kaolin; N-Acetylglucosamine; Nocardiopsis; Research Article; Residues; Strain analysis; Substrates; Swimming; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 1614-7499; 0944-1344; 1614-7499
• DOI: 10.1007/s11356-024-34088-x

In accordance with the framework of the Circular Blue Bioeconomy in the Mediterranean region, the objective of this study was to evaluate the biotransformation of blue swimming crab ( Portunus segnis ) residues obtained from the port of Sfax by an extracellular chitinase produced by Nocardiopsis halophila strain TN-X8 isolated from Chott El Jerid (Tozeur, Tunisia). From the analysis of multiple extremophilic Actinomycetota , it was determined that strain TN-X8 exclusively utilized 60 g/L of raw blue swimming crab as its carbon and energy source, achieving a chitinase activity of approximately 950 U/mL following a 6-day incubation period at 40 °C. Pure chitinase, designated as ChiA-Nh30, was obtained after heat treatment, followed by ammonium sulfate fractionation and Sephacryl® S-200 column chromatography. The maximum ChiA-Nh30 activity was observed at pH 3 and 75 °C. Interestingly, compared with cyclohexamidine, ChiA-Nh30 showed a good antifungal effect against four pathogenic fungi. Furthermore, when using colloidal chitin as substrate, ChiA-Nh30 demonstrated a higher degree of catalytic efficiency than the commercially available Chitodextrinase®. In addition, ChiA-Nh30 could be immobilized by applying encapsulation and encapsulation-adsorption techniques. The kaolin and charcoal used acted as excellent binders, resulting in improved ChiA-Nh30 stability. For the immobilized ChiA-Nh30, the yield of N -acetyl- d -glucosamine monomers released from 20% ( w / v ) blue swimming crab residues increased by 3.1 (kaolin) and 2.65 (charcoal) times, respectively.