Medium composition effects on growth kinetic of cordyceps militaris cells using agar plate method

Abstract

Mushroom Cordyceps, as one of the most well known funguses with numerous bioactive compounds possess therapeutic actions; many years used as medicinal food particularly in China and Japan. Interestingly, the long history of mushroom as a therapeutic agent is not far from its role as a food component among Asian people specifically in Traditional Chinese Medicine (TCM). It has been cultivated naturally or in artificial media. Fungal mycelia contain adenosine, cordycepin, and polysaccharides, which are responsible for its biological activities. Cordycepin is the best-known and most potent mushroom-derived substances possessing anticancer, antitumor, antiviral, antihypertensive, immune response stimulating effects, blood lipid lowering effects and several other immunomodulating activities. Therefore, it can be a potential alternative or supplement to chemotherapy in order to treat or accelerate the treatment efficiency on the different types of human related cancer diseases. However, high quality and large-scale production of bioactive products from mushroom Cordyceps are the issues need to be investigated. Thus, optimization of cultural conditions such as medium composition and also the type of components used in medium are two essential factors, which are so effective on the acceleration of the product formation by the cells. In this study, optimized solid state cultivation of fungal mycelia cells using modified potato dextrose agar (PDA) medium culture supplemented with specific amount of malt extract (ME) together with yeast extract (YE) was investigated. The mycelial growth diameter was monitored during 21 days of cultivation time using two series of experiments including 2, 4, 6 and 8 g of ME and 6 g of ME with 0, 2, 4 and 6 g/L of YE in the PDA medium culture, respectively. Results illustrated the highest mycelial growth diameter around 7.5 cm using medium composed of PDA supplemented with 6 g/L ME and 4 g/L. Further investigations are now undertaken in our laboratories to clarify the effects of the new medium presented here on the bioactive metabolite formation (e.g. cordycepin).