Identification of Inhibitory Compounds in Medicinal Mushrooms against L. monocytogenes and Z. bailii

Extracts from medicinal mushrooms were prepared and tested for anti-microbial activity against food pathogens and food spoilage microorganisms. The inhibitory activity was measured using a disk diffusion assay and with optical density (OD). For OD, 7 fractions were collected using HPLC for 4 (A. blazei Murrill, G. lucidum, G. frondosa, I. obiquus) medicinal mushrooms and 6 fractions from L. edodes and 8 fractions from P. linteus. The results from disk diffusion assay showed that most mushrooms displayed significant inhibition compared to the ethanol. The exceptions were: A. blazei Murrill, I. obliquus, and L. edodes against E. coli O157:H7; I. obliquus against L. monocytogenes V7; I. obliquus against S. cerevisiae Y99; L. edodes against Z. bailii Y03; and I. obliquus against Z. bailii/bisporus Y108. Inhibition was more effective in yeasts than bacteria. The result from Bioscreen C showed that against L. monocytogenes V7, fraction 7 in A. blazei Murrill; fraction 1, 4 and 5 in G. lucidum; fraction 4 in G. frondosa; and fraction 4 and 5 in I. obliquus significantly inhibited the growth compared to ethanol. Against Z. bailii Y03, fraction 7 in A. blazei Murrill; all fractions from G. lucidum, G. frondosa, and P. linteus; fraction 1, 2, 3, and 6 from I. obliquus; and fraction 4 and 6 from L. edodes significantly inhibited growth compare to ethanol. The results indicated that there is significant antimicrobial activity against food pathogens and spoilage organisms in the medicinal mushrooms studied.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Food Science and Technology

Department dc:contributor.department

Food Science and Technology

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2014

Author dc:creator

• Chu, Hyun Sik Stephano

Chair dc:contributor.committeechair

• O'Keefe, Sean F.

Committee members dc:contributor.committeemember

• Kuhn, David D.
• Smith, Stephen A.
• Duncan, Susan E.

• antimicrobial
• medicinal mushrooms
• pathogen
• spoilage

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

vt_gsexam:2073

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/51758