Search

Marine bioactive peptides (MBPs) are widely applied in functional foods and medicine industries. Several studies indicate that MBP consumption may play a vital role in the body's health due to their biological properties such as antioxidant, anti-inflammatory, and ACE-inhibitory activities. However, the majority of MBPs have numerous limitations, including bitter taste, stability, and unfavorable bioactivity. Recently, chemical and physical modifications have been commonly used to solve these limitations. Modification of MBPs, which involves using novel techniques, was discussed in this review. This review displayed that MBP properties, including biological activity, stability, and taste properties, were improved after modification mainly by encapsulation and chemical reaction. In particular, the results showed that the biological properties (antioxidant, anti-inflammatory, ACE-inhibitory, and antimicrobial activities) of the modified MBPs were higher than unmodified ones. In addition, the taste of MBPs, especially volatile flavor, was also enhanced after modification. Furthermore, modified MBPs may have to remain stable during food processing, storage, and in the host mouth and stomach for absorption in the small intestine. Therefore, modification of MBPs is an effective approach to protect and improve MBP properties. Finally, food matrix interactions and in vivo studies of modified MBPs are needed in the future. [ABSTRACT FROM AUTHOR]

The objective of this work was to examined the effect of short-chain xylooligosaccharides (XOS) as sweeteners on the foaming properties and physicochemical and rheological properties of hen egg white protein (EWP) under neutral conditions. The foaming properties, and solubility were determined by spectrometric methods, zeta potential was detected by zetasizer nano instrument, viscosity, rheological behaviors, and coagulation temperature are assessed by dynamic rheometer and protein structure were measured by Fourier transform infrared spectroscopy (FTIR). The foaming properties of the EWP-XOS complex were higher than those of EWP alone due to changes in the molecular structure of the protein. In addition, this study also showed that the physicochemical and rheological properties related to the foaming properties of EWP, including the solubility, zeta potential, viscosity, and elastic behavior, were increased by XOS addition. Furthermore, XOS supplementation increased the coagulation temperature of EWP due to improvements in the thermal stability of the protein. Alterations in the above properties may be due to EWP and XOS interactions via glycosylation, which were confirmed by FTIR analysis. The present study suggested that XOS enhanced the foam properties of EWP and therefore improved its application as a functional ingredient in foam-type food manufacturing or functional foods. [ABSTRACT FROM AUTHOR]

Candida species are the most common causative agents responsible for the majority of morbidity as well as mortality rates due to invasive fungal infections worldwide. In this study, a green approach was developed to control the pathogenic Candida spp. isolated from clinical samples, and prior data collections, ethics approval was obtained. Sixty candida isolates were obtained from the different device-associated infections and identified as Candida albicans, Candida tropicalis, Candida krusei, Candida parapsilosis, and Candida glabrata with prevalence rates 41.6, 38.3, 8.3, 6.6, and 5%, respectively. On the other hand, silver nanoparticles (Ag-NPs) were extra-cellular synthesized by biomass filtrate of previously identified Penicillium chrysogenum strain F9. The physico-chemical characterizations of biosynthesized Ag-NPs were assessed by using UV-Vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) patterns, transmission electron microscope (TEM), dynamic light scattering (DIS), and zeta potential (ζ) analysis. Data revealed successful synthesis of crystallographic spherical Ag-NPs with average size 18 to 60 nm at maximum absorption peak 415 nm. FT-IR analysis confirmed the presence of functional groups related to reduction, capping, and stabilizing Ag-NPs. The DLS analysis showed that NPs were homogenous and stable with poly-dispersity index (PDI) and ζ value 0.008 and − 21 mV, respectively. Susceptibility pattern analysis revealed that sixty Candida isolates (100%) were susceptible to Ag-NPs as compared to 25 isolates (41.6%), and 30 isolates (50%) were susceptible to fluconazole and amphotericin B, respectively. Interestingly, 30 Candida isolates (50%) were resistant to amphotericin B, which are more than those recorded for fluconazole (17 isolates with percent 28.3%), while 18 candida isolates (30%) were susceptible dose-dependent to fluconazole. The recorded minimum inhibitory concentration 50/90 (MIC50/90) was 62.5/125, 16/64, and 1/4 for Ag-NPs, fluconazole, and amphotericin B, respectively. However, green synthesized Ag-NPs can be used to overcome the resistance pattern of Candida spp., and recommended as an anti-candida agent. [ABSTRACT FROM AUTHOR]

In this study, metabolites involved in the free-biomass filtrates for three endophytic actinomycetes of Streptomyces capillispiralis Ca-1, Streptomyces zaomyceticus Oc-5, and Streptomyces pseudogriseolus Acv-11 were used as biocatalysts for green synthesis of silver nanoparticles (Ag-NPs). Characterization of biosynthesized Ag-NPs was accomplished using UV-Vis spectroscopy, X-ray diffraction patterns (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM-EDX), transmission electron microscopy (TEM), and particle size analyzer. The biosynthesized Ag-NPs showed maximum surface plasmon resonance (SPR) at 440 for strain Ca-1 and 450 for both strains of OC-5 and Acv-11. Nanoparticle spherical shape was recorded with size ranging from 23.77 to 63.14 nm, 11.32 to 36.72 nm, and 11.70 to 44.73 nm for Ca-1, Oc-5, and Acv-11, respectively. SEM-EDX analysis exhibited the weight percentages of 17.3, 22.3, and 48.7% for Ag-NPs synthesized by strains Ca-1, Oc-5 and Acv-11, respectively. The activities of biosynthesized Ag-NPs were concentration dependent and the obtained results confirmed the efficacy of Ag-NPs as antimicrobial agents against Gram-positive and Gram-negative bacteria as well unicellular and multicellular fungi. The MIC for Gram-positive bacteria, Gram-negative bacteria (E. coli), and eukaryotic microorganisms was 0.25 mM with clear zone ranging from 10.3 to 14.6 mm, while MIC for Pseudomonas aeruginosa was 1.0 mM for Ag-NPs synthesized by strain Ca-1 and 0.25 mM for those synthesized by strains Oc-5 and Acv-11. Moreover, Ag-NPs exhibited antimicrobial activity against four plant pathogenic fungi represented by Alternaria alternata, Fusarium oxysporum, Pythium ultimum, and Aspergillus niger at 2.0, 1.5, 1.0, and 0.5 mM of Ag-NPs with different degree. In vitro assessment of the antioxidant efficacy of biosynthesized Ag-NPs was achieved by scavenging assay of H2O2, reducing power of Fe3+, or total antioxidant assay. The results showed that antioxidant activities of Ag-NPs were concentration dependent with the highest activity at Ag-NP concentration of 2.0 mM. Furthermore, the biosynthesized NPs have prospective bioinsecticidal activity against Culex pipiens and Musca domestica. Green synthesis of NPs could be quite potential for the development of new bioactive compounds used in different biomedical applications. [ABSTRACT FROM AUTHOR]

In this study, two endophytic actinomycetes isolates Oc-5 and Acv-11, were isolated from healthy leaves of medicinal plant Oxalis corniculata L. These isolates were identified as Streptomyces zaomyceticus Oc-5 and Streptomyces pseudogriseolus Acv-11 using 16S rRNA gene sequence. Biomass extract of these strains were used as a greener attempt for synthesis of copper oxide nanoparticles (CuO-NPs). The synthesized NPs were characterized by UV–Vis spectroscopy, Fourier transform infra-red (FT-IR) spectroscopy, X-ray diffraction (XRD)‚ transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and X-ray photoelectron spectroscopy (XPS). Green synthesized NPs showed surface plasmon resonance (SPR) absorption band at 400 nm, crystalline nature, spherical-shaped with an average size of 78 nm and 80.0 nm for CuO-NPs synthesized using strain Oc-5 and Acv-11, respectively. The bioactivities of CuO-NPs were evaluated. Results revealed that CuO-NPs exhibited promising antimicrobial activity against prokaryotic and eukaryotic microbial cells (Gram positive bacteria, Gram negative bacteria, unicellular and multicellular fungi). In addition, it showed antimicrobial potential against phyto-pathogenic fungal strains Fusarium oxysporum, Pythium ultimum, Aspergillus niger and Alternaria alternata. We further explored the in vitro antioxidant activity and cytotoxicity for biosynthesized CuO-NPs. The results revealed that‚ scavenging and total antioxidant activity for NPs synthesized using Streptomyces pseudogriseolus Acv-11 was better than those synthesized by Streptomyces zaomyceticus Oc-5. Also, the morphological changes and cell viability for Vero and Caco-2 cell line due to NPs treatments were assessed using MTT assay method. Furthermore, Larvicidal efficacy against Musca domestica and Culex pipiens was evaluated. The results obtained in this study clearly showed that biosynthesized CuO-NPs exhibited effective bioactivity and, therefore, provide a base for the development of versatile biotechnological applications soon. [ABSTRACT FROM AUTHOR]