Influence of fermentation conditions on polysaccharide production and the activities of enzymes involved in the polysaccharide synthesis of Cordyceps militaris

Abstract

The influence of different fermentation conditions on intracellular polysaccharide (IPS) production and activities of the phosphoglucomutase (PGM), UDPG-pyrophosphorylase (UGP), phosphoglucose isomerase (PGI), UDPG-dehydrogenase (UGD), and glucokinase (GK) implicated in metabolite synthesis in Cordyceps militaris was evaluated. The highest IPS production (327.57 ± 6.27 mg/100 mL) was obtained when the strain was grown in the optimal medium containing glucose (40 g · L(-1)), beef extract (10 g · L(-1)), and CaCO3 (0.5 g · L(-1)), and the initial pH and temperature were 7 and 25 °C, respectively. The activities of PGM, UGP, and PGI were proved to be influenced by the fermentation conditions. A strong correlation between the activities of these enzymes and the production of IPS was found. The transcription level of the pgm gene (encoding PGM) was 1.049 times and 1.467 times compared to the ugp gene and pgi gene (encoding UGP and PGI), respectively, in the optimal culture medium. This result indicated that PGM might be the highly key enzyme to regulate the biosynthesis of IPS of C. militaris in a liquid-submerged culture. Our study might be helpful for further research on the pathway of polysaccharide biosynthesis aimed to improve the IPS production of C. militaris.

Effect of sodium and calcium on polysaccharide production and the activities of enzymes involved in the polysaccharide synthesis of Lentinus edodes

“…In this study, Ca 2+ addition enhanced PGI and PGM enzyme activity, whereas Na + increased UGP activity. The results from (Zhu et al 2016) showed that higher activities of PGM, UGP, and PGI were desirable for the rate of IPS biosynthesis in C. militaris. The activities of a-PGM and UDPase were highly correlated with the amount of polysaccharide produced in S. thermophilus and A. pullulans (Degeest and De Vuyst 2000;Pan et al 2013).…”

“…These three enzymes play key roles in pathways of metabolite synthesis. Higher activities of PGM, UGP, and PGI were desirable for the biosynthetic rate of IPS in Cordyceps militaris (C. militaris), which is a member of Ascomycota (Zhu et al 2016). The activities of PGM and UGP highly correlated with the amount of polysaccharide produced in Streptococcus thermophilus (S. thermophilus) and Aureobasidium pullulans (A. pullulans) (Degeest and De Vuyst 2000;Pan et al 2013).…”

“…Growth and secondary metabolite production are affected by many factors, including temperature, pH, and culture conditions (Fan et al 2007). In one study, cell growth and intracellular polysaccharide (IPS) accumulation of Phellinus linteus (P. linteus) decreased when NaCl was added to the culture (Zhu et al 2016). When 2.0 g/L of ascorbic acid was added to the culture broth of Hericium erinaceus, melanism was eliminated and mycelial growth was promoted (Lee et al 2010).…”

Effects of superfine grinding on the properties and qualities of Cordyceps militaris and its spent substrate

“…Cordyceps militaris (CM), a traditonal Chinese edible and medicinal mushroom, usually called Bei Dong Chong Xia Cao and Yong Chong Cao, belonging to the phylum of Ascomycota and class of Pyrenomycetes, has been proved having similar pharmacological effect to Cordyceps sinensis (Yue, Ye, Zhou, Sun, & Lin, ; Zhu et al, ). CM has been used as a medicine for over hundreds years in many Asian countries especially in China for containing abundant special natural components with biological and pharmacological activities, such as cordycepin (3′‐deoxyadenosine), adenosine, cordycepic acid, SOD enzyme, and cordyceps polysaccharides (CP) (Cui, ).…”

Influence of culture conditions on extracellular polysaccharide production and the activities of enzymes involved in the polysaccharide synthesis of Nostoc flagelliforme

“…17,[20][21][22][23][24][25] Most of cyanobacteria have efficient carbon concentration mechanisms (CCM) which could transport and accumulate inorganic carbon actively (Ci; HCO 3 glucose pyrophosphorylase and UDP-glucose dehydrogenase, were relatively conserved, which played important roles in EPS production. [32][33][34][35][36][37][38][39][40][41] Based on previous reports, [42][43][44] and KEGG pathway, a simplied biosynthesis pathway for biosynthesis of cyanobacterial EPS was summarized ( Fig. 1).…”