Investigation of the anti-bacterial properties of mangrove fern, Acrostichum aureum in the Niger Delta, Nigeria

Abstract

Mangroves render several ecosystem services globally, one of which is pharmacological products. This study was done to verify whether Acrostichum aureum, a species of mangrove, common in the Niger Delta has anti-bacterial property. Several leaf samples were plucked from the trees at Eagle Island and placed in a cooler and sent to the lab for further analysis. The leaves were dried and ground into fine powder with manual grinding machine and 100 g of the powdered sample was measured and placed in 1000 ml of each of the extraction solvents (hot water and methanol).  Five different concentrations (32.25 mg/ml, 65.5 mg/ml, 125 mg/l, 250 mg/l and 500 mg/l) were made from each of the extracts using dimethyl sulfoxide (DMSO). Furthermore, bacterial species (Escherichia coli, Salmonella paratyphi, Staphylococcus aureus, and Pseudomonas aeruginosa) were isolated and a stock of each sample was made in agar slant and stored in the refrigerator at 4°C.  Mueller Hinton Sensitivity Agar (MHA) medium was prepared in agar and triplicate discs of each of the concentrations made from the two extracts were placed on the medium (MHA). The zone of inhibition in diameter in all plates was measured and analyzed statistically using R statistics. The result revealed that there is a significant difference in the growth of the microbes on the different concentrations of A. aureum (F4, 100 = 4.02, P = 0.01). A. aureum had higher effect on E. coli and S. aureus. Similarly, the higher the concentrations of the extracts the more effective it is in controlling the bacteria.  Finally, the study revealed that A. aureum has antibacterial properties that can be employed in drug production to treat common diseases prevalent in the region.   Key words: Antibiotics, bacteria, Niger Delta, mangrove, microbial species, medicinal products.