Production of individual ganoderic acids and expression of biosynthetic genes in liquid static and shaking cultures of Ganoderma lucidum

Abstract

Two-stage culture was efficient in enhancing total ganoderic acid (GA) production by Ganoderma lucidum (Fang and Zhong, Biotechnol Prog 18:51-54, 2002). As different GAs have different bioactivities, it is critical to understand the kinetics of individual GA production during fermentation, but no related information is yet available. To understand the regulation of GA biosynthesis, investigation of the accumulation of intermediate (lanosterol) and by-product (ergosterol) and of the expression of three important biosynthetic genes was also conducted in liquid shaking and static cultures of G. lucidum. The results showed that the content of individual GAs increased rapidly in the liquid static culture, and their maximum value was 6- to 25-fold that of shaking culture while lanosterol content in the former was lower than the latter. The transcript of squalene synthase (SQS), lanosterol synthase and 3-hydroxy-3-methylglutaryl coenzyme A reductase in liquid static culture was 4.3-, 2.1-, and 1.9-fold that of the shaking culture, respectively. Higher GA content in liquid static culture was related to increased transcription of those genes especially SQS. The work is helpful to the production of individual GAs and provided an insight into why the liquid static culture was superior to the shaking culture in view of biosynthetic gene expression.

Enhancement of Ganoderic Acid Accumulation by Overexpression of an N-Terminally Truncated 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Gene in the Basidiomycete Ganoderma lucidum

“…The transcription levels of the hmgr, fps, sqs, and ls genes (which encode the enzymes HMGR, FPS, SQS, and LS, respectively) were analyzed by real-time quantitative RT-PCR (qRT-PCR). The sequences of the primers for the amplification of the 18S rRNA gene, fps, sqs, and ls were described previously (49,52). For hmgr, the primers thmgr-F and thmgr-R (Table 1) were used.…”

“…These observations reinforce the pivotal function of HMGR in the biosynthesis of terpenoids. The G. lucidum HMGR gene was cloned and characterized, and its expression exhibited a positive correlation with triterpenoid content according to reverse transcription-PCR (RT-PCR) data (32,49). However, no direct evidence was found for the regulatory function of HMGR gene in the biosynthesis of triterpenoids in G. lucidum.…”

Enhanced Production of Ganoderic Acids and Cytotoxicity ofGanoderma lucidumUsing Solid-Medium Culture

“…34,35) Xu et al found that growing G. lucidum in static liquid culture rather than shaking liquid culture promoted GA production by 6-fold to 25-fold. 19) In the present study, we cultured G. lucidum strains on solid PDA plates and found that this resulted in higher levels of GAs and better biomass production than submerged liquid PDB culture (Fig. 1).…”

“…Xu et al reported that production of individual GAs (GA-T, -Me, -S, and -Mk) and gene expression of squalene synthase (SQS) and lanosterol synthase (LS) were markedly enhanced by static liquid culture as compared with shaking culture. 19) Both phenobarbital and methyl jasmonate enhanced the production of GAs and upregulated the genes coding for SQS and LS. 46,47) Both squalene synthase and lanosterol synthase play critical roles in the biosynthesis of triterpenoids in plants and fungi.…”

“…Therefore, using submerged culture of fungal mycelium in liquid medium has gained a lot of attention for producing fungal mycelium, GAs, and polysaccharides. [18][19][20] Various environmental and nutritional factors that affect GA production have also been investigated to increase yield. [21][22][23][24] In addition, the fungal mycelium of G. lucidum from submerged liquid culture is used as a functional food to improve immunity, enhance health, protect the liver, and delay senility in Taiwan.…”