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Active Finishing Agents for Food Bio- Preservation Based on Natural Origin to Prevent Microbial Risks
Published in Mohd Yusuf, Shafat Ahmad Khan, Biomaterials in Food Packaging, 2022
Smrita Singh, Lalit Prasad, Ashutosh Singh Chauhan, Shafat Ahmad Khan
Natamycin is a naturally occurring compound obtained from Streptomyces natalensis comes under GRAS consideration. It is used as a broad-spectrum antifungal in the food industry, and dairy products and beverages. Natamycin shows a high affinity toward ergosterol present in the fungal cell wall. It binds irreversibly to this ergosterol, resulting in the alteration of the permeability of cell wall toward leakage of essential ions and small peptides, thus leading to the cell death [36]. It is not much effective against both Gram-negative and Gram-positive bacteria, as it lacks sterols in its cell wall. A colloidal solution in water is applied either by dipping or spraying on to the food surface. Natamycin is used to control the growth of molds during the fermentation process and it is used as a bio-preservative in beverage products, even it is stable at low temperatures with sufficient effectiveness over a wide range of pH values [37]. Natamycin shows strong inhibitory activity against a number of molds, fungi, and bacteria, such as Penicillium chrysogenum, P. camemberti, P. brevicompactum, P. glabrum, A. niger, A. versicolor, A. flavus, Cunning hamella spp., Fusarium spp., Pseudalles cheriaboydii, Mucorra cemosus, and Eurotium herbariorum. It is also very effective against Cladosporium cladosporiodes, C. tenuissimum, Byssochla mysnivea, Epidermophyton floccosum, Alternaria alternata, Candida albicans, Acremonium spp, Trichophyton spp., Aspergillus carbonarius, P. commune, P. corylophilum, and P. verrucosumetc [38, 39]. Natamycin in combination with nisin [40, 41] is used in polymer packaging films, and it inhibits the growth of Lactobacillus helveticus, Fusarium culmorum, Listeria ivanoviı, and Penicillium expansum. A mixture containing malic acid, nisin, and natamycin, inhibits the growth [42, 43] of several food-spoiling microbes such as Penicillium aeruginosa, P. commune, P. chrysogenum, Y. lipolytica, Penicillium, and L. monocytogenes. Natamycin in combination with chitosan films shows considerable antimicrobial activity against various food-spoiling pathogens and microbes [44]. As an antimicrobial preservative, the property of chitosan has been proposed at less than 6.0 pH to liquid and solid food products [45]. Chitosan shows poor water solubility, therefore, glucosyloxyethylacrylated chitosan, a water-soluble derivative is synthesized by using the Michael reaction of chitosan with glucosyloxyethylacrylate derivative [46].
Expression and characterization of cholesterol oxidase with high thermal and pH stability from Janthinobacterium agaricidamnosum
Published in Preparative Biochemistry & Biotechnology, 2023
Noriyuki Doukyu, Yuuki Ikehata, Taichi Sasaki
Cholesterol oxidase (COXase, EC 1.1.3.6) is an oxidoreductase containing flavin adenine dinucleotide (FAD) as a redox cofactor. It generally catalyzes the oxidation of the OH group at the C3 position, the isomerization of the double bond between the C5 and C6 positions, and the reduction of oxygen to produce cholest-4-en-3-one (C4E3O) and H2O2.[1,2] However, several COXases oxidize cholesterol to produce 6β-hydroperoxycholest-4-en-3-one (6βHC4E3O) instead of C4E3O.[3,4] COXases have been widely employed to quantify cholesterol content in blood serum for clinical diagnoses.[2] COXases can also be used for pest control due to their pesticidal activity against cotton-eating boll weevil larvae[5] and for the biotransformation of various compounds having 3β-hydroxysteroid structures.[6]Chromobacterium sp. DS-1 COXase alleviates oxysterol cytotoxicity in fibroblasts and thus can have therapeutic applications.[7] Overexpression of Streptomyces gilvosporeus COXase, which serves as a positive regulator of gene expression concerning an antifungal antibiotic, enhances the production of the antibiotic natamycin.[8]
Rheological characterization of functional walnut oil-enriched butters stabilized by the various polysaccharides
Published in Journal of Dispersion Science and Technology, 2018
Vahid Mofid, Mohammad Mousavi, Zahra Emam-Djomeh, Seyed Hadi Razavi, Seyed Mohammad Taghi Gharibzahedi, Farid Jahanbakhsh
WO was obtained by pressing Toyserkan cultivar walnuts. WO expression was carried out with a screw press (Model NA 21 T, Zeith, Kerman, Iran), with a 5-mm restriction die and a screw speed of 20 rpm. Fatty acid composition of the used oil after its methyl esterification identified and quantified using a gas chromatography (Varian 3400, Palo Alto, CA, USA). The used oil contained the following fatty acids (mol%): 0.40% C14:0, 8.82% C16:0, 0.15% C16:1, 3.11% C18:0, 25.17% C18:1, 50.18% C18:2, 12.07% C18:3, and 0.13% C20:1.[16] Full-fat butter (82% fat content) was provided by Pegah Co. (Tehran, Iran). Polyglycerol polyricinoleate (PGPR 4175) and distilled monoglycerides (DMG 0291) were purchased from Emulsion-Holland B.V. (Zierikzee, Netherlands). XG and LBG were obtained from Sigma-Aldrich Chemical Co. (St. Louis, MO, USA). MS, citrus PE, Na-alginate (ALG), lactic acid, and natamycin (pimaricin) as an antifungal agent were supplied by Merck Chemical Co. (Darmstadt, Germany).
Synthesis of silver nanoparticles prepared with a dextran-type exopolysaccharide from Weissella cibaria MED17 with antimicrobial functions
Published in Preparative Biochemistry & Biotechnology, 2021
Hümeyra İspirli, Osman Sagdic, Enes Dertli
Same methodology was used to test the antifungal activity of AgNPs-Dex and for this six fungus species Penicillium chrysogenum, Aspergillus niger, Alternaria alternata, Aspergillus parasiticus, Fusarium oxysporum and Botrytis cinerea were targeted and these fungi were grown in PDA agar plates as described previously[16] and the antifungal activity of AgNPs-Dex was determined as described above. The antimicrobial tests were conducted as three independent replicates. Natamycin was applied as a positive control in the antifungal tests.