Paper Title
Antimicrobial Activity from Rhizome Extracted Zingiber Ottensii Valeton

Abstract
- Zingiber ottensii Valeton is in the Zingiberaceae family which can be found cultivated in Southeast Asia Thailand, Vietnam, Malaysia, and Indonesia. The dark purple of the rhizome of this plant has been used as a Thai traditional herb ingredient in various treatment formulas. This present work reports the in vitro antimicrobial activity of crude metabolites extracted from rhizome Z. ottensii. Fresh rhizome was extracted with organic solvents hexane, isopropanol, dichloromethane, acetonitrile, and methanol respectively. The extracts were obtained and investigated for activities against Bacillus subtilis, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, Vibrio parahaemolyticus and, Candida albicans. Antimicrobial activities of the crude extracts were preliminarily screened by disc diffusion. Minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) were determined by broth microdilution and colorimetric assay (tetrazolium salt). Based on disc diffusion method, S. aureus ATCC25923 E. faecalis ATCC29212, B. subtilis ATCC6633, E. coli ATCC25922, S. typhi (clinical isolate) V. parahaemolyticus5HP, V. parahaemolyticus XN89 and C. albicans ATCC90020 shown susceptibility pattern against crude extracts from dichloromethane, methanol, and isopropanol elicited the highest antimicrobial activity. The MIC values were determined by colorimetric assay due to pigmentations of the acetonitrile rhizome extracts that obscured visual growth turbidity inspection. This study suggested that rhizome extract form Z. ottensii had a potential to inhibit all of the microbial testing agents. Index Terms- Zingiber Ottensii, Rhizome, Antimicrobial Activity, Extracted