ABSTRACT
To study the effect and mechanism of the light quality acting on Ganoderma lucidum, and provide a theoretical basis for G. lucidum mycelium cultivation, we focused on growth and endogenous IAA metabolism of G. lucidum mycelium under different light-emitting diode (LED) condition. The growth index, endogenous levels of IAA and Enzymes related to IAA metabolism and Polysaccharides content were investigated in different growth periods. Results showed that blue light irradiation was the best from the viewpoint of steady growth and polysaccharides accumulation, red light irradiation improved endogenous IAA level and promoted growth of mycelium in early stage of cultivation, green light irradiation decreased growth rate and fresh weight of mycelium, but increased drying rate. Enzymes related to IAA metabolism also significantly influenced by light quality. The activity of indole acetic acid oxidase (IAAO), peroxidase (POD) and tryptophan synthetase with blue light irradiation were showed high level in early time, but decreased later, and the IAA content was consistently at lower level than that in other treatments, while mycelium irradiated with yellow light showed the highest activity of both IAAO and tryptophan synthetase, and medium level of IAA content. In conclusion, the light quality affects growth and regulation of the level of endogenous IAA of G. lucidum mycelium.
Subject(s)
Fungal Polysaccharides , Indoleacetic Acids , Metabolism , Light , Peroxidases , Metabolism , Reishi , MetabolismABSTRACT
Objective: To study the effect of light quality on the growth as well as triterpenic acid content and component of Ganoderma lucidum mycelium. Methods: Light-emitting diode (LED) was used as sources of light, the growth index, content and component of triterpenic acids in G. lucidum mycelium cultured under different LED conditions were investigated along with culture time. Results: The growth rate, morphology, biomass, total contents and components of triterpenic acid in G. lucidum mycelium varied under different lights. The mycelium cultured under blue light maintained stable growth during the whole period; Under red light, both growth rate and biomass of mycelium were the highest in early time, subsequently, decreased sharply and grew slowly. Under green light, both growth rate and biomass of mycelium were the lowest in early and medium phases, while increased significantly later, especially dry matter. Triterpenic acids were highly produced on the day 7 of cultivation, while decreased in content and increased in types. Green light and blue light had a distinct advantage of improving the type and content triterpenic acids in G. lucidum. Conclusion: Light quality affects the growth as well as the content and component of triterpenic acids in G. lucidum mycelium, and blue light irradiation is the best for the steady growth and triterpenic acids accumulation.