Use of Mangifera indica Mesocarp Extract As Alternative Growth Medium for Bacteria and Fungi

Abstract

Commercially available growth medium contains a complete set of nutrients and growth factors needed to cultivate bacteria and fungi. The mango fruit contains carbohydrates, proteins, several vitamins and a number of growth factors making it a potential candidate in the development of alternative culture medium. This study aims to determine the growth of bacteria, yeast and mold on various mango agar preparations. The mesocarp of yellow ripe mangoes was osterized and filtered to obtain the extract. The pH of the mango mesocarp extract was neutralized. Three kinds of mango agar preparations were made, a mango mesocarp only (Mangifera indica Agar or MIA), mango mesocarp with beef extract (MIAB) and mango mesocarp with yeast extract (MIAY). Comparison of population densities was done by viable cell count using Miles and Mizra Method. Cultural and morphological characteristics were observed using Nutrient agar (NA) as standard medium of reference after 24 hours of incubation at 37°C. These were done for Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Saccharomyces cerevisiae. Cultural characteristics of Rhizopus oryzae was compared using Potato Dextrose agar (PDA) as standard medium of reference. The colonies of the three bacteria grown in NA were larger than those grown in MIA, MIAY and MIAB. But after 2-3 days of further incubation, bacterial colonies attain the same size as those grown in NA. R. oryzae had the same cultural characteristics when grown in PDA, MIA, MIAB and MIAY. The cells of B. cereus and E. coli in MIA, MIAY and MIAB appeared short and plump under oil immersion objective unlike those grown in NA which was long and thin. The bacterial cells in MIA, MIAY and MIAB had a longer period of adjustment. The cells of S. aureus appeared the same in NA, MIA, MIAB and MIAY. The cells of S. cerevisiae appeared largest in MIA and smallest in NA. The average population density of B. cereus, S. aureus, E. coli and S. cerevisiae in NA, MIA, MIAB and MIAY varies depending on the medium used. We therefore conclude that mango mesocarp extract maybe used as an alternative growth medium for the cultivation of bacteria, yeast and mold but only when supplemented with yeast extract or beef extract.