Liquid fermentation of Ophiocordyceps sinensis for bulk mycelium production
Alppi, Meeri (2026-03-05)
Liquid fermentation of Ophiocordyceps sinensis for bulk mycelium production
(05.03.2026)
Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty.
avoin
Julkaisun pysyvä osoite on:
https://urn.fi/URN:NBN:fi-fe2026031821339
https://urn.fi/URN:NBN:fi-fe2026031821339
Tiivistelmä
Ophiocordyceps sinensis, a parasitic caterpillar fungus, is a highly valued filamentous fungus containing several bioactive compounds. Those contribute to several bioactivities such as antioxidant, antitumor and anti-inflammation activities. These properties make Ophiocordyceps sinensis an area of interest in the nutraceutical industry.
Being an endangered species with high market demand, in vitro cultivation is studied to provide a renewable and stable source of the species. But its complex parasite-insect host relationship makes the artificial cultivation of the species challenging. Liquid fermentation produces mycelium, which contains bioactive compounds although in different concentrations than wild Ophiocordyceps sinensis.
The aim of this study is to utilize liquid fermentation to cultivate Ophiocordyceps sinensis, identify and optimize the key variables that affect growth to reach mycelium and bioactive compound levels that meet the industrial requirements. Different culture conditions (inoculation density, pH, duration, light and medium composition) are tested to find the ideal growth conditions. After cultivation, the mycelium is harvested by filtration and dried. Bioactive compounds are analyzed from dried mycelium with liquid chromatography and mass spectrometry. Dry weight and bioactive compound content of the mycelium are used to evaluate the differences between treatments.
The experiment showed that medium component concentration (glucose and yeast) had significant effect on the mycelium formation. The highest mycelium dry weight reached was 14.9±1.2 g/L after a 4-day culture, which is in the biomass range generally reported in literature (10-20 g/L). Significant effects were also detected from pH, duration and light experiments, but those did not result in as high biomass amounts as increased glucose and yeast concentrations did.
The dried mycelium contains bioactive compounds; such as adenosine, D-mannitol, ergosterol, ergothioneine and cordycepin; which are typical for Ophiocordyceps sinensis, but at lower concentrations than previously reported in literature. Only one tested treatment reached adenosine levels previously reported in the literature. Overall, the content of bioactive compounds was higher in treatments where biomass formation was lower, so compromises need to be made between the need for high biomass and bioactive compound formation. Based on the results cultivating the fungus in pH 4 instead of 6 would result in similar biomass formation but alter morphology, resulting in higher content of bioactive compounds in the mycelium.
Due to variation in growth and limited resources available (all the necessary variables could not be tested) optimization did not get as far as hoped for. A lot of testing and optimizing need to be done in the future to get the liquid fermentation process scaled into industrial scale.
Being an endangered species with high market demand, in vitro cultivation is studied to provide a renewable and stable source of the species. But its complex parasite-insect host relationship makes the artificial cultivation of the species challenging. Liquid fermentation produces mycelium, which contains bioactive compounds although in different concentrations than wild Ophiocordyceps sinensis.
The aim of this study is to utilize liquid fermentation to cultivate Ophiocordyceps sinensis, identify and optimize the key variables that affect growth to reach mycelium and bioactive compound levels that meet the industrial requirements. Different culture conditions (inoculation density, pH, duration, light and medium composition) are tested to find the ideal growth conditions. After cultivation, the mycelium is harvested by filtration and dried. Bioactive compounds are analyzed from dried mycelium with liquid chromatography and mass spectrometry. Dry weight and bioactive compound content of the mycelium are used to evaluate the differences between treatments.
The experiment showed that medium component concentration (glucose and yeast) had significant effect on the mycelium formation. The highest mycelium dry weight reached was 14.9±1.2 g/L after a 4-day culture, which is in the biomass range generally reported in literature (10-20 g/L). Significant effects were also detected from pH, duration and light experiments, but those did not result in as high biomass amounts as increased glucose and yeast concentrations did.
The dried mycelium contains bioactive compounds; such as adenosine, D-mannitol, ergosterol, ergothioneine and cordycepin; which are typical for Ophiocordyceps sinensis, but at lower concentrations than previously reported in literature. Only one tested treatment reached adenosine levels previously reported in the literature. Overall, the content of bioactive compounds was higher in treatments where biomass formation was lower, so compromises need to be made between the need for high biomass and bioactive compound formation. Based on the results cultivating the fungus in pH 4 instead of 6 would result in similar biomass formation but alter morphology, resulting in higher content of bioactive compounds in the mycelium.
Due to variation in growth and limited resources available (all the necessary variables could not be tested) optimization did not get as far as hoped for. A lot of testing and optimizing need to be done in the future to get the liquid fermentation process scaled into industrial scale.