Isolation, Culture and Characterization of Hirsutella sinensis Mycelium from Caterpillar Fungus Fruiting Body

Abstract

The caterpillar fungus Ophiocordyceps sinensis (previously called Cordyceps sinensis) has been used for centuries in Asia as a tonic to improve health and longevity. Recent studies show that O. sinensis produces a wide range of biological effects on cells, laboratory animals and humans, including anti-fatigue, anti-infection, anti-inflammatory, antioxidant, and anti-tumor activities. In view of the rarity of O. sinensis fruiting bodies in nature, cultivation of its anamorph mycelium represents a useful alternative for large-scale production. However, O. sinensis fruiting bodies harvested in nature harbor several fungal contaminants, a phenomenon that led to the isolation and characterization of a large number of incorrect mycelium strains. We report here the isolation of a mycelium from a fruiting body of O. sinensis and we identify the isolate as O. sinensis’ anamorph (also called Hirsutella sinensis) based on multi-locus sequence typing of several fungal genes (ITS, nrSSU, nrLSU, RPB1, RPB2, MCM7, β-tubulin, TEF-1α, and ATP6). The main characteristics of the isolated mycelium, including its optimal growth at low temperature (16°C) and its biochemical composition, are similar to that of O. sinensis fruiting bodies, indicating that the mycelium strain characterized here may be used as a substitute for the rare and expensive O. sinensis fruiting bodies found in nature.

Gut commensal Parabacteroides goldsteinii plays a predominant role in the anti-obesity effects of polysaccharides isolated from Hirsutella sinensis

“…H. sinensis strain CGB 999335 was isolated and cultured as described previously 36. HSM consisted of <10% crude fibre; >3% polysaccharides; crude proteins at 42.8 g/100 g; crude fat at 8.2 g/100 g; carbohydrates at 31.9 g/100 g; amino acids at 7.8 g/100 g and sodium at 242.7 mg/100 g. Calories were measured at 373 kcal per 100 g. HSM water extract and polysaccharide fractions were prepared as described earlier for G. lucidum 33…”

Uncovering fungal community composition in natural habitat of Ophiocordyceps sinensis using high-throughput sequencing and culture-dependent approaches

“…O. sinensis and its soil microhabitat represent the potential source to explore microbial biosynthetic diversity and evolutionarily ancient examples of symbiosis, for some of O. sinensis associated fungi produce similar bioactive metabolites [ 6 , 37 , 38 ]. In microecosystem, polyketide synthase and nonribosomal peptide synthetase, the large multidomain and multifunctional megaenzymes involved in biosynthesis of secondary metabolites, evolve rapidly through horizontal transfer from bacteria to fungi, particularly, between fungi, which contribute to produce vast numbers of novel metabolites [ 39 ].…”

Diversity and Co-Occurrence Patterns of microbial Communities in the Fertilized Eggs of Thitarodes Insect, the Implication on the Occurrence of Chinese cordyceps

“…Currently, at least 37 genera and 90 fungal species related to the anamorphs of O. sinensis have been isolated [19][20]. Among these fungi, Hirsutella sinensis is the most widely accepted anamorph [21]. However, the H. sinensis strain isolated from the stroma of Chinese cordyceps could not induce the germination of stroma on healthy Thitarodes larvae in the laboratory [22].…”