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In this study, carotenoproteins (CPs) were encapsulated in blue crab chitosan-tripolyphosphate and chitosan-protein isolate nanoparticles by ionotropic gelation and complex coacervation, respectively. The success of CPs encapsulation was confirmed by FT-IR spectroscopy, TGA and XRD techniques. Particles size and thermal stability of nanoparticles depend on the encapsulation method. Indeed, a regular distribution and spherical shape, with size range of about 300 nm (ionotropic gelation) – 600 nm (complex coacervation), were observed by SEM analysis. The encapsulation efficiency and loading capacity of CPs were about 74% and 31% for the complex coacervation and 89% and 47% for the ionotropic gelation approaches, respectively. In vitro release studies showed a fast initial release effect, followed by a slow CPs release. The highest amount of released CPs in a shorter time was observed with the ionotropic gelation method. Further, in vitro release kinetics of CPs were found to be medium dependent, where nanoparticles incubated in ethanol displayed higher released CPs amount in a longer release time, compared to nanoparticles immerged in PBS (pH ~ 6.8). These findings suggest that the encapsulation technique obviously affected the particles structure, and the glass transition temperature, and the mass loss of encapsulated materials. The better CPs thermal stabilization was obtained for the ionotropic gelation nanoparticles.

The media containing new complex organic substrates suggested that Mirabilis jalapa tuber powder (MJTP), shrimp wastes powder (SWP) and sardinella peptone could be used as an alternative source of cheaper carbon and nitrogen substrates for production of enzymes by Bacillus mojavensis A21. The use of 40 g/L MJTP as a sole carbon and nitrogen sources resulted in a proteases and α-amylases production of 730 and 3 U/ml, respectively. A two fold higher production of proteases by A21 strain was achieved with 4 g/L of sardinella peptones added in the MJTP medium. More interestingly, SWP supplementation in a medium containing of MJTP resulted in maximum growth and highest α-amylase production.

The co-composting of spent coffee grounds, olive mill wastewater sludge and poultry manure was investigated on a semi-industrial scale. In order to reduce the toxicity of the phenolic fraction and to improve the degree of composting humification, composts were inoculated with the white-rot fungus Trametes versicolor in the early stages of the maturation phase. During composting, a range of physico-chemical parameters (temperature and both organic matter and C/N reduction), total organic carbon, total nitrogen, elemental composition, lignin degradation and spectroscopic characteristics of the humic acids (HAs) were determined; impacts of the composting process on germination index of Hordeum vulgare and Lactuca sativa were assessed. The coffee waste proved to be a highly compostable feedstock, resulting in mature final compost with a germination index of 120% in less than 5 months composting. In addition, inoculation with T. versicolor led to a greater degree of aromatization of HA than in the control pile. Moreover, in the inoculated mixture, lignin degradation was three times greater and HA increased by 30% (P < 0.05), compared to the control pile. In the T. versicolor inoculated mixture, the averages of C and N were significantly enhanced in the HA molecules (P < 0.05), by 26% and 22%, respectively. This improvement in the degree of humification was confirmed by the ratio of optical densities of HA solutions at 465 and 665 nm which was lower for HA from the treated mixture (4.5) than that from the control pile (5.4).

A new low molecular weight (LMW) serine-protease from sardinelle (Sardinella aurita) viscera was purified using ammonium sulphate precipitation and Sephadex G-100 gel filtration, with a 3.82-fold increase in specific activity. The molecular weight of the enzyme was estimated to be 14.2 kDa by SDS-PAGE. The optimum pH and temperature for the enzyme activity were around pH 8.0 and 60 °C, respectively. The purified protease was strongly inhibited by phenylmethylsulphonyl fluoride, a serine-protease inhibitor, and soybean trypsin inhibitor. The N-terminal amino acid sequence of the first 10 amino acids of the purified protease was APVQPCVVVI. This sequence showed low homology with several peptidases, suggesting that the enzyme is a new protease. Interestingly, the protease was found to cleave collagen type I and hydrolyze succinyl-L-Ala-L-Ala-L-Pro-L-Phe-p-nitroanilide (sAAPFpna), an amide substrate of chymotrypsin. Our findings indicate that the S. aurita protease is a new LMW enzyme with collagenolytic activity.

BACKGROUND: The root powder of Periploca laevigata is used for preparing soft drinks and as an aromatic in Tunisia. The infusion or decoction of its root bark has widespread use in folk medicine. The plant is used to treat digestive disorders and hypertensive effects as well as other health problems. RESULTS: The antioxidant activities of extracts of P. laevigata root bark obtained with solvents of different polarity were investigated using assays of 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity, ferric-reducing capacity, β-carotene-bleaching ability, hydroxyl radical-scavenging activity and lipid peroxidation inhibition. The methanol extract, with the highest amount of total phenolics and flavonoids, showed the highest antioxidant activities in all assays, followed by the water extract. Gas chromatography/mass spectrometry was used to determine the composition of the water and methanol extracts. Thirty-four compounds were identified in the methanol extract, with proflavine (516.2 g kg−1 dry matter (DM)) and 4-methoxysalicylaldehyde (198.3 g kg−1 DM) being the most abundant. Sixteen compounds were identified in the water extract, of which 4-hydroxy-3-methoxyphenethylene glycol (351.2 g kg−1 DM) was the main component. CONCLUSION: As far as is known, this is the first report on the chemical composition and biological activities of phenolic extracts from P. laevigata. The results of the study indicate that the root bark of this plant might be a good candidate for further investigation in developing new antioxidants. Copyright © 2009 Society of Chemical Industry