title: Antimicrobial properties of black grape (Vitis vinifera L.) peel extracts against antibiotic-resistant pathogenic bacteria and toxin producing molds.
abstract: OBJECTIVE
  Black grape peel possesses a substantial amount of polyphenolic antimicrobial compounds that can be used for controlling the growth of pathogenic microorganisms. The purpose of this study was to assess antibacterial and antifungal activity of black grape peel extracts against antibiotic-resistant pathogenic bacteria and toxin producing molds, respectively.
  
  
  METHODS
  Peel of grape was subjected to polyphenolic extraction using different solvents viz., water, ethanol, acetone, and methanol. Antibiotic-resistant strains of Staphylococcus aureus, Enterococcus faecalis, Enterobacter aerogenes, Salmonella typhimurium, and Escherichia coli were screened for the antibacterial activity of different grape extracts. Antibacterial activity was analyzed using agar well diffusion method. Penicillium chrysogenum, Penicillium expansum, Aspergillus niger and Aspergillus versicolor were screened for the antifungal activity. Antifungal activity was determined by counting nongerminated spores in the presence of peel extracts.
  
  
  RESULTS
  As compared to other solvent extracts, methanol extracts possessed high antibacterial and antifungal activity. S. typhimurium and E. coli showed complete resistance against antibacterial action at screened concentrations of grape peel extracts. Maximum zone of inhibition was found in case of S. aureus, i.e., 22 mm followed by E. faecalis and E. aerogenes, i.e., 18 and 21 mm, respectively, at 1080 mg tannic acid equivalent (TAE)/ml. The maximum and minimum percent of growth inhibition was shown by P. expansum and A. niger as 73% and 15% at 1080 TAE/ml concentration of grape peel extract, respectively.
  
  
  CONCLUSIONS
  Except S. typhimurium and E. coli, growth of all bacterial and mold species were found to be significantly (P < 0.05) inhibited by all the solvent extracts.
authors.affiliation: Dairy Chemistry Division, National Dairy Research Institute, Karnal, Haryana, India.
authors.forename: Devbrat
authors.initials: D
authors.lastname: Yadav
authors.affiliation: Centre of Food Science and Technology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
authors.forename: Arvind
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Dairy Chemistry Division, National Dairy Research Institute, Karnal, Haryana, India.
authors.forename: Pramod
authors.initials: P
authors.lastname: Kumar
authors.affiliation: Dairy Technology Division, SRS, National Dairy Research Institute, Bengaluru, Karnataka, India.
authors.forename: Diwaker
authors.initials: D
authors.lastname: Mishra
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000935:Antifungal Agents / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D015169:Colony Count, Microbial; D052978:Disk Diffusion Antimicrobial Tests; D055808:Drug Discovery; D024881:Drug Resistance, Bacterial; D005638:Fruit / Q000737:chemistry* / Q000191:economics; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000254:growth & development; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000254:growth & development; D007194:India; D000432:Methanol / Q000737:chemistry; D008826:Microbial Sensitivity Tests; D003904:Mitosporic Fungi / Q000187:drug effects / Q000254:growth & development / Q000502:physiology; D019441:Plant Epidermis / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D012997:Solvents / Q000737:chemistry; D013172:Spores, Fungal / Q000187:drug effects / Q000254:growth & development; D027843:Vitis / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D010936:Plant Extracts; D012997:Solvents; D000432:Methanol
keywords: Antibacterial activity; Vitis vinifera L; antifungal activity; polyphenolic compounds; zone of inhibition