Biomedical potential of chitosan-silver nanoparticles with special reference to antioxidant, antibacterial, hemolytic and in vivo cutaneous wound healing effects.

The aim of the present study was to prepare chitosan-PVA-silver nanoparticles (CS-AgNPs) through green method. Chitosan and PVA polymers acted as stabilizing agents. DLS and TEM analyses showed that CS-AgNPs were homogeneously dispersed in matrix with an average size of 190-200 nm.

Chitin extraction from blue crab (Portunus segnis) and shrimp (Penaeus kerathurus) shells using digestive alkaline proteases from P. segnis viscera.

Since chitin is closely associated with proteins, deproteinization is a crucial step in the process of extracting chitin. Thus, this research aimed to extract chitin from Portunus segnis and Penaeus kerathurus shells by means of crude digestive alkaline proteases from the viscera of P. segnis, regarding deproteinization step, as an alternative to chemical treatment.

Alkaline proteases from a newly isolated Micromonospora chaiyaphumensis S103: Characterization and application as a detergent additive and for chitin extraction from shrimp shell waste.

The present study was undertaken to characterize the extracellular thermostable serine alkaline proteases from newly actinomycete strain Micromonospora chaiyaphumensis S103 and to describe their evaluation in commercial detergents and shrimp waste deproteinization. This proteolytic crude extract was active and stable in alkaline solution. It was extremely stable in the pH range of 5.

Structural analysis, and antioxidant and antibacterial properties of chitosan-poly (vinyl alcohol) biodegradable films.

The development and characterization of biodegradable blend films based on chitosan and poly (vinyl alcohol) for possible use in a variety of biological activities are reported. Fourier transform infrared spectroscopy (FTIR) spectra of chitosan-poly (vinyl alcohol) (Ch/PVA) films showed characteristics peaks shifting to a lower frequency range due to hydrogen bonding between -OH of PVA and -NH2 of chitosan. The chitosan and PVA polymers presented good compatibility.

Optimization of proteins and minerals removal from shrimp shells to produce highly acetylated chitin.

Chitin and derivatives used for biomedical or pharmaceutical applications require a high level of purity and quality that are difficult to achieve. In this study, we propose to optimize the extraction of chitin in order to obtain pure product keeping a structure as close as possible to the native form. Thus, demineralization step was firstly optimized using response surface methodology.

Digestive alkaline proteases from thornback ray (Raja clavata): Characteristics and applications.

This study describes the characterization of a crude protease extract from thornback ray (Raja clavata) and its evaluation in liquid detergent and in deproteinizattion of shrimp waste. At least five clear caseinolytic proteases bands were observed in a zymogram. The crude protease showed optimum activity at pH 8.

Characterization and In Vitro Evaluation of Cytotoxicity, Antimicrobial and Antioxidant Activities of Chitosans Extracted from Three Different Marine Sources.

Chitins in the α and β isomorphs were extracted from three Tunisian marine sources shrimp (Penaeus kerathurus) waste, crab (Carcinus mediterraneus) shells and cuttlefish (Sepia officinalis) bones. The obtained chitins were transformed into chitosans, the acid-soluble form of chitin. Chitosans were characterized and their biological activities were compared.

Chitin extraction from crab shells by Bacillus bacteria. Biological activities of fermented crab supernatants.

Crab shells waste were fermented using six protease-producing Bacillus species (Bacillus subtilis A26, Bacillus mojavensis A21, Bacillus pumilus A1, Bacillus amyloliquefaciens An6, Bacillus licheniformis NH1 and Bacillus cereus BG1) for the production of chitin and fermented-crab supernatants (FCSs). In medium containing only crab shells, the highest demineralization DM was obtained with B. licheniformis NH1 (83±0.

Chitin extraction from shrimp shell using enzymatic treatment. Antitumor, antioxidant and antimicrobial activities of chitosan.

Chitin was recovered through enzymatic deproteinization of the shrimp processing by-products. Different microbial and fish viscera proteases were tested for their deproteinization efficiency. High levels of protein removal of about 77±3% and 78±2% were recorded using Bacillus mojavensis A21 and Balistes capriscus proteases, respectively, after 3h of hydrolysis at 45°C using an enzyme/substrate ratio of 20U/mg.

Structural differences between chitin and chitosan extracted from three different marine sources.

Three marine sources of chitin from Tunisia were investigated. Structural differences between α-chitin from shrimp (Penaeus kerathurus) waste, crab (Carcinus mediterraneus) shells, and β-chitin from cuttlefish (Sepia officinalis) bones were studied by the (13)C NMR, FTIR, and XRD diffractograms. The (13)C NMR analysis showed a splitting of the C3 and C5 carbon signals for α-chitin, while that of β-chitin was merged into a single resonance.

Optimization of chitin extraction from shrimp waste with Bacillus pumilus A1 using response surface methodology.

Chitin extraction from shrimp shells by biological treatment, using the Bacilli Bacillus pumilus A1, is a non-polluting method and offers the opportunity to preserve the exceptional qualities of chitin and its derivatives. However, the major disadvantage of the fermentative way is the low efficiency of demineralization and deproteinization. The aim of this study is to improve the yield of extraction which depends on many factors, such as the medium composition and the physical parameters.

Chitin extraction from shrimp shell waste using Bacillus bacteria.

The ability of six protease-producing Bacillus species (Bacillus pumilus A1, Bacillus mojavencis A21, Bacillus licheniformis RP1, Bacillus cereus SV1, Bacillus amyloliquefaciens An6 and Bacillus subtilis A26) to ferment media containing only shrimp shell waste, for chitin extraction, was investigated. More than 80% deproteinization was attained by all the strains tested. However, demineralization rates not exceeding 67% were registered.