Morphological Observations and Fatty Acid Composition of Indoor-Cultivated Cordyceps sinensis at a High-Altitude Laboratory on Sejila Mountain, Tibet

Abstract

Cordyceps sinensis, a caterpillar entomopathogenic fungus-host larva complex, is a rare medicinal herb found in the Qinghai-Tibetan Plateau and its surrounding high-altitude areas. The alternation of generations in the life cycle, whatever the fungus or its host insect, requires special growth conditions. However, it is difficult to simulate the growth conditions of C. sinensis, which hinders its artificial cultivation. In this work, the life cycle from the host larva to C. sinensis was observed in an indoor-cultivation laboratory at 4,200 m a.s.l. on Sejila Mountain, Tibet. Comparative examinations between indoor-cultivated and wild C. sinensis demonstrated that the indoor-cultivated C. sinensis preferred to germinate multiple long, slim stromata at diverse positions on dead larvae, including but not limited to their heads. Their fatty acid composition shows a significant difference in the levels of polyunsaturated fatty acids (PUFAs). In indoor-cultivated C. sinensis, PUFAs constituted 24.59% and 49.43%, respectively, of neutral and polar lipids; meanwhile, in wild C. sinensis, PUFAs represented 34.34% and 61.25% of neutral and polar lipids, respectively. These observations and fatty acid data suggest that environmental factors, particularly temperature, soil pressure and light intensity, strongly affect the growth of C. sinensis. Our new findings may provide important information for improving techniques for the large-scale artificial cultivation of C. sinensis.

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

“…Network analysis was applied to investigate these potential microbial interactions in the complex microbial communities [26]. Chinese cordyceps is essentially the outcome of the competition of the entomogenous fungus (H. sinensis) and the other microbial inhabitants in the host insects [13]. Thus, the microbial interactions would in uence the infection, colonization, and growth of H. sinensis, which ultimately related with the occurrence of Chinese cordyceps.…”

“…Besides O. sinensis, our previous study also revealed that several physicochemical factors, the soil bacterial and fungal structure, and the network of these factors, are closely related with the occurrence of Chinese cordyceps, manifesting that the soil ecological environment is important for the occurrence of Chinese cordyceps [12]. Observation on the indoor cultivated Thitarodes larva revealed that, although collected from the same sampling site, the fates of these wild larvae varied greatly and a proportion of these larvae eventually formed Chinese cordyceps [13]. Thus, we proposed that, besides external soil factors, the internal factors of the Thitarodes host (such as the entophytic microbes and immune system of Thitarodes) may also contribute to occurrence of Chinese cordyceps.…”

Medicinal Value of Cordyceps sinensis

“…Indoor CS development from the host larva was observed in a High-Altitude Laboratory on Sejila Mountain, Tibet by LianXian Guo and his group [21], the soil used initially to keep larva was from natural habitat sampled from Sejila Mountain only. Their findings regarded that low temperature incubation increases the level of unsaturated fatty acid content and could promote infection by Hirstutella sinensis which is a responsible fungal to form this organism.…”

Stable Carbon Isotope Composition of the Lipids in Natural <em>Cordyceps sinensis</em> from Major Habitats in China and Its Substitutes

“…This abnormity may be reasonably explained as follows. To adapt the inclement environments, C. sinensis requires the plentiful polar lipids enriched in polyunsaturated fatty acids, in particular C18:2 for the larger proportion of cellular and subcellular biomembranes [15,34]. We had revealed that the absolute amount of total fatty acids and relative content of C18:2 in polar lipids from C. sinensis were evidently higher than those from its host larva, implying that C. sinensis assimilated polar lipids much more than those in the host larva and had transformed more C18:1 to C18:2 except a direct uptake of C18:2 from the parasitized larva.…”