Abstract Detail

Ethnobotany

Reaney, Amber [1], Metzgar, Jordan [2].

Persistence of antimicrobial activity in oyster mushroom herbarium specimens.

Antimicrobial resistance is an increasing concern across many different industries worldwide, including the medical, agricultural and food processing fields. One individual bacterium's mutated genome can cause rapid population allele shift to antimicrobial resistance in as little as 30 minutes. To curtail resistance, multiple broad and narrow spectrum antimicrobials are routinely used during treatment regimes. This dynamic use of antimicrobials necessitates the identification, isolation and testing of new antimicrobial compounds. Most of these compounds are isolates derived from naturally occurring defense mechanisms in plants, bacteria, and fungi. The oyster mushrooms (Pleurotus) are edible higher Basidiomycete fungi that are grown commercially for human consumption worldwide. Recent studies have identified the antimicrobial compound 3-(2-aminophenylthio)-3-hydroxypropanoic acid in extracts from mature tree oyster mushroom fruiting bodies. Our study sought to answer whether long-term preservation methods degraded the antimicrobial properties of the oyster mushroom fruiting body by measuring the zone of inhibition created by both live and preserved oyster mushroom extracts on a lawn of a non-pathogenic, non-antibiotic resistant Escherichia coli. Tree oyster (P. ostreatus), king oyster (P. ernygnii) and Indian oyster (P. pulmonarius) mushrooms were also included in this study to provide cross-species results for comparison in antimicrobial activity. Live samples were grown immediately prior to extraction and preserved material was gathered from Virginia Tech's Massey Herbarium (VPI). Preserved material was originally collected and dried in 1970, 1980, and 1991. Oyster mushroom extracts were created by dissolving mature fruiting bodies in distilled water and centrifuging at 10,000 x g for twenty minutes. Supernatants were concentrated by lyophilization, then 1 mL was placed on a bacterial lawn grown on solid TSA media at room temperature for 48 hours. Zones of inhibition were allowed 48 hours to expand. The zone of inhibition was measured in millimeters from the edge of the extraction supernatants to the edge of the E. coli lawn. We expect the largest zone of inhibitions to be from live oyster species with proportional decreases in zone of inhibitions correlated with age of specimens. Among species, it is predicted the tree oyster mushrooms will have the largest zone of inhibitions, then the Indian and king oysters. Our study is the first to assess the bactericidal potential of Indian and king oysters. Our results will provide an upper bound on the age of appropriate herbarium material for bioprospecting assays, as well as revealing taxonomic variation in antimicrobial effectiveness in the oyster mushroom genus (Pleurotus).

1 - Virginia Tech, Massey Herbarium, 926 W. Campus Drive, Derring 2119, MC 0406, Blacksburg, VA, 24061, United States
2 - 926 W. Campus Dr, MC 0406, Derring Hall 2119, Blacksburg, VA, 24061, United States

Keywords:
Pleurotus
antimicrobial
antibiotic resistance
oyster mushroom.

Presentation Type: Poster
Session: P, Ethnobotany Posters
Location: Arizona Ballroom/Starr Pass
Date: Monday, July 29th, 2019
Time: 5:30 PM This poster will be presented at 6:15 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PET004
Abstract ID:199
Candidate for Awards:Economic Botany Section best poster