Molecular and Antibacterial Profile of Edible Oyster Mushrooms Pleurotus sajor-caju

Abstract

Pleurotus varieties cultivated in Mauritius include 3 strains: Pleurotus sajor-caju strain CC114, Pleurotus sajor-caju strain CC200 and Pleurotus sajor-caju strain CC201. In this study the chemical composition, antimicrobial properties and genetic variation of the three Pleurotus strains were explored. Chemical screening of crude extracts of the Pleurotus strains revealed the presence of terpenes, phenols, alkaloids, saponins and hydrolysable tannins. Flavonols were however identified only in Pleurotus strain CC200 extracts and leucoanthocyanins were detected only in the extracts of Pleurotus CC114 strain. Antimicrobial activity was tested against Bacillus subtilis, Escherichia coli and Staphylococcus aureus. Pleurotus sajor-caju strain CC200 had more significant antimicrobial effect than Pleurotus sajor-caju strain CC114 and Pleurotus sajorcaju strain CC201 which both demonstrated nearly similar antimicrobial activity. Genomic DNA extraction was successfully carried out using the Phenol/Chloroform DNA extraction protocol and the DNA was purified using an RNAse treatment. Genetic relatedness among the three strains of Pleurotus sajorcaju was assessed using the RAPD technique. Out of the 50 primers used, maximum polymorphism was observed using 8 Operon primers. Out of the 73 amplification products obtained with all three Pleurotus species, there was 28.8 % polymorphism which was observed. Maximum polymorphism was obtained following amplification using OPL 05. The fact that Pleurotus sajor-caju strain CC200 was least related to Pleurotus sajor-caju strain CC114 and Pleurotus sajor-caju strain CC201 could possibly explain the differences in the bioactivity of these mushrooms.

Keywords: Antimicrobial activity, Flavonoids, Pleurotus, Genetic diversity