title: Antimicrobial activities of the rhizome extract of Zingiber zerumbet Linn.
abstract: OBJECTIVE
  To investigate antimicrobial effects of ethanolic extract of Zingiber zerumbet (Z. zerumbet) (L.) Smith and its chloroform and petroleum ether soluble fractions against pathogenic bacteria and fungi.
  
  
  METHODS
  The fresh rhizomes of Zingiber zerumbet were extracted in cold with ethanol (4.0 L) after concentration. The crude ethanol extract was fractionated by petroleum ether and chloroform to form a suspension of ethanol extract (15.0 g), petroleum ether fraction (6.6 g) and chloroform soluble fraction (5.0 g). The crude ethanol extract and its petroleum ether and chloroform fractions were evaluated for antibacterial and antifungal activity against thirteen pathogenic bacteria and three fungi by the disc diffusion method. Commercially available kanamycin (30 µg/disc) was used as standard disc and blank discs impregnated with the respective solvents were used as negative control.
  
  
  RESULTS
  At a concentration of 400 µg/disc, all the samples showed mild to moderate antibacterial and antifungal activity and produced the zone of inhibition ranging from 6 mm to 10 mm. Among the tested samples, the crude ethanol extract showed the highest activity against Vibrio parahemolyticus (V. parahemolyticus). The minimum inhibitory concentration (MIC) of the crude ethanol extract and its fractions were within the value of 128-256 µg/mL against two Gram positive and four Gram negative bacteria and all the samples showed the lowest MIC value against V. parahemolyticus (128 µg/mL).
  
  
  CONCLUSIONS
  It can be concluded that, potent antibacterial and antifungal phytochemicals are present in ethanol extract of Z. zerumbet (L).
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Rajshahi, Rajshahi-6205, Bangladesh.
authors.forename: Golam
authors.initials: G
authors.lastname: Kader
authors.forename: Farjana
authors.initials: F
authors.lastname: Nikkon
authors.forename: Mohammad Abdur
authors.initials: MA
authors.lastname: Rashid
authors.forename: Tanzima
authors.initials: T
authors.lastname: Yeasmin
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D000431:Ethanol; D005658:Fungi / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D027343:Rhizome / Q000737:chemistry*; D030521:Zingiberaceae / Q000737:chemistry*
chemical_list: D000890:Anti-Infective Agents; D010936:Plant Extracts; D000431:Ethanol
keywords: Antibacterial; Antifungal; Antifungal activity; Antimicrobial activity; Disc diffusion method; Minimum inhibitory concentration (MIC); Pathogenic bacteria; Phytochemicals; Rhizome; Soluble fraction; Zingiber zerumbet (L.) Smith