Nutritional Requirements for Mycelial Growth of <i>Ophiocordyceps sinensis</i> on Agar Media

Abstract

Ophiocordyceps sinensis has been used as one of the most valuable traditional Chinese Medication. This fungus parasitizes larva of Hepialus armoricanus , and converts each larva into a sclerotium form, in which the fruit body grows. Due to the geographical limitation, where O. sinensis can only be found in Himalayas region, the natural resources are limited and very expensive. This research aims to compare the growth-rate of O. sinensis mycelia with different ingredients mix with agar media using one-factor-at-a-time method. This research demonstrated the mycelial growth-rate with different carbon sources, including monosaccharide (Fructose, Glucose), disaccharide (Maltose, Sucrose), and polysaccharide (Dextrin, Malt extract), complex organic nitrogen sources, including beef extract, yeast extract, whey protein, and soy protein, and eight different carbon to nitrogen ratios. The objective of this research is to find out the suitable carbon and organic complex nitrogen sources and ratio for the O. sinensis solid cultivation. As results, O. sinensis grew best with disaccharides comparing to the other types of carbon sources. Furthermore, O. sinensis preferred whey protein in contrast to other organic complex nitrogen sources. As for the carbon to nitrogen ratios, an optimal ratio of 18:1 was observed. Based on those experiments, carbon source shows a greater influence for the mycelial growth. Hence many different types of grains and cereals would be great candidates as the main ingredients for the O. sinensis solid cultivation.