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

Bilal Adil,Maolan He,Peng Qin,Qiang Chen,Muhammad Arshad,Xiumei Yu,Xiaoqiong Chen,Muhammad Ahsan Asghar,Ke Zhao,Yuetong Wu,Xiaoping Zhang,Yanhong Yan,Yunfu Gu,Quanju Xiang,Menggen Ma

doi:10.1186/s13568-020-00985-w

Bilal Adil, Maolan He + Show 13 more

Open Access

https://doi.org/10.1186/s13568-020-00985-w

Copy DOI

Abstract

Lentinan is a Lentinus edodes secondary metabolite that can regulate human immune function, but yields are low. Here, the effects of Ca2+ and Na+ on L. edodes lentinan content were investigated. Metal ion concentrations and induction times were optimized according to mycelial biomass, and intracellular polysaccharide (IPS), extracellular polysaccharide (EPS), and total polysaccharide (TPS) content. The activities and gene expression of phospho-glucose isomerase (PGI), phosphoglucomutase (PGM), and UDP-glcpyrophosphorylase (UGP) were also measured. Ca2+ and Na+ concentration and induction time affected biomass, IPS, and EPS concentrations. Na+ increased EPS, IPS and TPS, while Ca2+ increased biomass, IPS, and TPS. During fermentation, mycelial biomass varied greatly under Ca2+ induction, while IPS, EPS and TPS varied greatly under Na+ induction. PGM and UGP activities increased in the presence of Na+, while PGI increased with Ca2+. Compared to control samples, pgi and pgm expression under Na+ was greater at days 45 and 60, respectively, while under Ca2+, ugp expression was greater at day 45. IPS content correlated significantly with enzyme activity, while EPS correlated with PGM activity. Our data contributes to better understanding how Na+ and Ca2+ affect mycelial growth and secondary metabolite production, and of polysaccharide biosynthesis mechanisms of L. edodes.

Highlights

Most commercial mushroom species belong to the Basidiomycota and are absorptive, obtaining external nutrients for the growth of vegetative mycelium (Taylor and Ellison 2010)
Determination of the optimum metal ion concentration and induction time Significant differences in mycelial biomass of L. edodes were observed in samples incubated with metal ion to that of control samples (Fig. 2)
Samples incubated with metal ions had significantly different biomass yields during different periods of culture

Summary

Introduction

Most commercial mushroom species belong to the Basidiomycota and are absorptive, obtaining external nutrients for the growth of vegetative mycelium (Taylor and Ellison 2010). Mushrooms have high nutritional value, including high protein, fiber, and essential amino acids, and low fat content (Carneiro et al 2013). Growth and secondary metabolite production are affected by many factors, including temperature, pH, and culture conditions (Fan et al 2007). 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). Metal ions including Fe2+, Zn2+, Ca2+, Mg2+ and Cu2+ could inhibit mycelium growth of Tricholoma mongolicum, but promoted polysaccharide production (Min et al 2011). Production of secondary metabolites can be improved by optimizing conditions, such as by adding metal ions

Methods

Results

Conclusion