The growth of microorganisms in an artificial medium is influenced by several physical and chemical factors. For microbiological studies, commercially available ready-made culture media are used in research laboratories. In recent years, several researches have been carried out to formulate alternative and cost effective culture media for the cultivation of common laboratory microorganisms from locally available cheap materials. The financial constraints in research encountered commonly in developing countries like Nigeria warrant that a cheap alternative be sought. Dioscorea dumetorum is one of the six species of yam that are cultivated in Nigeria and is reported to be the most nutritious of commonly consumed yam species with fairly high protein content and a well-balanced amino acid. Proximate analyses of D. dumetorum recorded crude fibre content 62.75%, total ash 3.5%, moisture 4.90%; total carbohydrate 90%. Proximate analyses of Nauclea latifolia included fat 17.73%; total ash 3.5%; carbohydrate 67%, crude protein 6.0%. D.dumetorum and N. latifolia supported fungal growth and can be used as nutrient source in the formulation of microbiological culture media. The results however showed that media formulated with different concentrations of D. dumetorum, and N. latifolia lacked desirable gelling abilities. Therefore their use in culture media preparation depends on the incorporation of a good gelling agent such as Agar Agar. Mannihot esculenta, Afzelia africana, Digitaria exilis and Brachystegia eurycoma were evaluated for their gelling abilities. In as much as these plant products yeilded media with thickened consistency, this thickness was lost after 24hr unlike media containing Agar agar as the gelling agent, which maintained its gelling properties for many days. The media formulated from 200g/L of D. dumetorum; 20 g/L of N. latifolia and 15 g/L of Agar agar supported the luxuriant growth of moulds like Penicillium and Aspergillus and yeasts like C. albicans within 24hr of incubation.
Full conference title:
- ISHAM 19th (2015)