The Journal of Phytopharmacology, 2017;6(2):115-125 DOI:10.31254/phyto.2017.6209

Research Article

Evaluation of the mycochemical composition and antimicrobial potency of wild macrofungus, Rigidoporus microporus (Sw).

Falade O.E.¹ , Oyetayo V.O.¹ , Samuel I. Awala¹

Falade O.E.,Oyetayo V.O.,Samuel I. Awala

1. Department of Microbiology, Federal University of Technology, P M B 704, Akure, Nigeria

*Author to whom correspondence should be addressed.

Received: 25th April, 2017 / Accepted: 22nd May, 2017

Abstract

This study examined the myochemical and antimicrobial properties of extracts obtained from Rigidoporus microporus (Sw), a wild, non- edible mushroom. Methanol and acetone extracts of R. microporus were screened qualitatively and quantitatively. Also the antimicrobial effect of the crude and partially purified fractions of the extracts of R. microporus was evaluated on clinical and referenced microbial cultures. The probable mechanism of action of the extract was assessed by measuring the amount of sodium and potassium ions leaked from the bacterial and fungal cells. In addition, the chemical compositions of mushroom extracts were analyzed using GC-MS and fragmentation analyses. Results of the phytochemical analysis revealed the presence of tannins, saponins, terpenoids, flavonoids, steroids and cardiac glycosides in the extracts with values ranging between 2.692 to 23.435 mg/g. Among the phytochemicals, terpenoids (23.65 mg/g) and cardiac glycosides (22.57 mg/g) were the most abundant while flavonoid (2.54 mg/g) was the least abundant in the mushroom extracts. The extracts produced varying antimicrobial activities with zones of inhibition ranging from 4.03 to 18.00mm. The methanol extract displayed better antimicrobial activities. Pseudomonas aeruginosa ATCC 29853 and Aspergillus fumigatus were the most susceptible bacterial (16.77mm) and fungal isolate (18.00mm) respectively. Lesser minimum inhibitory concentration values were expressed by the extracts against the fungal isolates (6.25 mg/mL). The partially purified fractions of Rigidoporus microporus extracts exhibited better antimicrobial activities against the selected test organisms with zones of inhibition ranging from 10.17mm to 32.32mm. Candida albicans had the highest leakage of sodium (390 mg/L) and potassium (455 mg/L) when exposed to the mushroom extracts, whereas Pseudomonas aeruginosa (80mg/L) and Klebsiella pnuemoniae (225 mg/L) produced the least amount of leaked sodium and potassium ion respectively. The bioactive compounds found in the extracts were hexadecane, n-hexadecanoic acid, pentadecanoic acid, octadecane, hexadecanoic acid, n-octadecenoic acid, di-n-octyl phthalate (1, 2- benzenedicarboxylic acid, dioctyl ester) and n-decanoic acid. These findings has shown that Rigidoporus microporus (Sw) collected from Ondo State, Nigeria could be considered a potential source of natural antimicrobials and could be exploited in the pharmaceutical industry.