6 research outputs found
Flow Injection System with Fluorimetric Detection for Hydrogen Peroxide Scavenging Activity Evaluation of Several Synthetic Antioxidants
A flow injection analysis (FIA
Degradation of keratin substrates by keratinolytic fungi
Background: The hydrolysis of keratin wastes by microorganisms is
considered a biotechnological alternative for recycling and
valorization through keratinolytic microorganisms. Despite their
resistant structure, keratin wastes can be efficiently degraded by
various microorganisms through the secretion of keratinases,which are
promising enzymes for several applications, including detergents,
fertilizers, and leather and textile industry. In an attempt to isolate
keratinolytic microorganisms that can reach commercial exploitation as
keratinase producers, the current work assesses the dynamics of keratin
biodegradation by several keratinolytic fungal strains isolated from
soil. The activity of fungal strains to degrade keratin substrates was
evaluated by SEM, FTRIR-ATR spectra and TGA analysis. Results: SEM
observations offered relevant information on interactions between
microorganism and structural elements of hair strands. FTIR spectra of
the bands at 1035\u20131075 cm-1 assigned to sulfoxide bond appeared
because of S\u2013S bond breaking, which demonstrated the initiation
of keratin biodegradation. According to TGA, in the second zone of
thermal denaturation, where keratin degradation occurs, the highest
weight loss of 71.10% was obtained for sample incubated with Fusarium
sp. 1A. Conclusions: Among the tested strains, Fusarium sp. 1A was the
most active organism in the degradation process with the strongest
denaturation of polypeptide chains. Because keratinolytic
microorganisms and their enzymes keratinases represent a subject of
scientific and economic interest because of their capability to
hydrolyze keratin, Fusarium sp. 1A was selected for further studies
SCREEN-PRINTED CARBON ELECTRODES MODIFIED WITH PRUSSIAN BLUE AND A NON-CONDUCTING ELECTROPOLYMERIZED FILM FOR SELECTIVE DETERMINATION OF H 2 O 2 IN BEVERAGES
Abstract The development of a highly selective and sensitive sensor for H 2 O 2 in beverages such as natural juices, is described in this work
Peroxynitrite Sensor Based on a Screen Printed Carbon Electrode Modified with a Poly(2,6-dihydroxynaphthalene) Film
For the first time the electropolymerization of 2,6-dihydroxynaphthalene (2,6-DHN) on a screen printed carbon electrode (SPCE) was investigated and evaluated for peroxynitrite (PON) detection. Cyclic voltammetry was used to electrodeposit the poly(2,6-DHN) on the carbon electrode surface. The surface morphology and structure of poly(2,6-DHN) film were investigated by SEM and FTIR analysis, and the electrochemical features by cyclic voltammetry. The poly(2,6-DHN)/SPCE sensor showed excellent electrocatalytic activity for PON oxidation in alkaline solutions at very low potentials (0–100 mV vs. Ag/AgCl pseudoreference). An amperometric FIA (flow injection analysis) system based on the developed sensor was optimized for PON measurements and a linear concentration range from 2 to 300 μM PON, with a LOD of 0.2 μM, was achieved. The optimized sensor inserted in the FIA system exhibited good sensitivity (4.12 nA·μM−1), selectivity, stability and intra-/inter-electrode reproducibility for PON determination
Degradation of keratin substrates by keratinolytic fungi
Background: The hydrolysis of keratin wastes by microorganisms is considered a biotechnological alternative for recycling and valorization through keratinolytic microorganisms. Despite their resistant structure, keratin wastes can be efficiently degraded by various microorganisms through the secretion of keratinases, which are promising enzymes for several applications, including detergents, fertilizers, and leather and textile industry. In an attempt to isolate keratinolytic microorganisms that can reach commercial exploitation as keratinase producers, the current work assesses the dynamics of keratin biodegradation by several keratinolytic fungal strains isolated from soil. The activity of fungal strains to degrade keratin substrates was evaluated by SEM, FTRIR-ATR spectra and TGA analysis.
Results: SEM observations offered relevant information on interactions between microorganism and structural elements of hair strands. FTIR spectra of the bands at 1035–1075 cm-1 assigned to sulfoxide bond appeared because of S–S bond breaking, which demonstrated the initiation of keratin biodegradation. According to TGA, in the second zone of thermal denaturation, where keratin degradation occurs, the highest weight loss of 71.10% was obtained for sample incubated with Fusarium sp. 1A.
Conclusions: Among the tested strains, Fusarium sp. 1A was the most active organism in the degradation process with the strongest denaturation of polypeptide chains. Because keratinolytic microorganisms and their enzymes keratinases represent a subject of scientific and economic interest because of their capability to hydrolyze keratin, Fusarium sp. 1A was selected for further studies