Synthesis of Nm-PHB (nanomelanin-polyhydroxy butyrate) nanocomposite film and its protective effect against biofilm-forming multi drug resistant Staphylococcus aureus

• Published in: Scientific reports 2017-08, Vol.7 (1), p.9167-9167, Article 9167
• Main Authors: Kiran, George Seghal, Jackson, Stephen A., Priyadharsini, Sethu, Dobson, Alan D. W., Selvin, Joseph
• Format: Article
• Language: English
• Subjects: 631/326; 631/326/2522; Antimicrobial activity; Antioxidants; Biofilms; Cosmetics; Fabrication; Food; Food contamination; Food packaging; Glycerol; Gram-negative bacteria; Humanities and Social Sciences; Melanin; multidisciplinary; Multidrug resistance; Nanocomposites; Oxidation; Packaging materials; Science; Science (multidisciplinary); Sonication
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-08816-y

Melanin is a dark brown ubiquitous photosynthetic pigment which have many varied and ever expanding applications in fabrication of radio-protective materials, food packaging, cosmetics and in medicine. In this study, melanin production in a Pseudomonas sp. which was isolated from the marine sponge Tetyrina citirna was optimized employing one-factor at a time experiments and characterized for chemical nature and stability. Following sonication nucleated nanomelanin (Nm) particles were formed and evaluated for antibacterial and antioxidant properties. Nanocomposite film was fabricated using combinations (% w/v) of polyhydroxy butyrate-nanomelanin (PHB:Nm) blended with 1% glycerol. The Nm was found to be spherical in shape with a diameter of 100–140 nm and showed strong antimicrobial activity against both Gram positive and Gram negative bacteria. The Nm-PHB nanocomposite film was homogeneous, smooth, without any cracks, and flexible. XRD and DSC data indicated that the film was crystalline in nature, and was thermostable up to 281.87 °C. This study represents the first report on the synthesis of Nm and fabrication of Nm-PHB nanocomposite film which show strong protective effect against multidrug resistant Staphyloccoccus aureus . Thus this Nm-PHB nanocomposite film may find utility as packaging material for food products by protecting the food products from oxidation and bacterial contamination.