Optimization of exopolysaccharides production from a novel strain of Ganoderma lucidum CAU5501 in submerged culture

Abstract

This study aimed at optimizing the medium of a new Ganoderma lucidum strain CAU5501 to enhance the yield of exopolysaccharides (EPS) and mycelial growth. Firstly, the suitable level of glucose, magnesium, phosphate and C/N ratio was determined by single factor experiment. Subsequently, the optimum concentrations of these medium components were investigated using the orthogonal matrix method. The results indicated that the higher levels of EPS were correlated with the level of cell growth when glucose concentration was studied (data no show). The optimum medium for EPS yield was found to be 70 g/l glucose, 5 C/N ratio, 2.5 g/l KH2PO4, 0.75 g/l MgSO4·7H2O, and for mycelial growth was 50 g/l glucose, 5 C/N ratio, 1.5 g/l KH2PO4, 0.5 g/l MgSO4·7H2O. When cultivated in the obtained optimal media in 3 L shake flask, compared to the basal medium, the EPS yield increased markedly from 1.003 to 1.723 g/l, and the mycelium formation was also markedly improved from 2.028 to 7.235 g/l. Results obtained in this study are beneficial to further study for enhancing the production of Ganoderma lucidum polysaccharides in large scale commercialized production.

Screening of endophytic sources of exopolysaccharides: Preliminary characterization of crude exopolysaccharide produced by submerged culture of Diaporthe sp. JF766998 under different cultivation time

“…In laboratory, the fungal EPS production has many advantages compared to polysaccharides extracted from fruiting bodies: easy isolation and purification avoiding the use of harsh extraction steps, minor production cost and huge production in short time [13] , [14] . One homogeneous system that provides a source of EPS is the submerged culture [15] , in which filamentous fungi exhibit different morphological growth forms ranging from dispersed mycelial filaments to pellets (densely interwoven mycelial masses) [16] .…”

Statistical optimization of culture conditions for enhanced mycelial biomass production using Ganoderma lucidum

“…Different studies have reported the use of diverse factors and their combinations for the statistical optimization of biomass of G. lucidum [4,6,10,11,17,19,20]. Hence, it is not justified to exactly compare the biomass obtained in the present study with those obtained in other studies.…”

“…The growth of mycelia has been found to be related with various environmental factors such as pH and temperature and the nutrients that are available to it. In general, culture conditions are optimized using a one factor-at-a-time approach, i.e., varying one factor while keeping all the others constant [4][5][6]. However, this method does not allow testing two factors simultaneously which when interacted together could improve the production.…”

Differences in Production, Composition, and Antioxidant Activities of Exopolymeric Substances (EPS) Obtained from Cultures of Endophytic Fusarium culmorum Strains with Different Effects on Cereals

“…In other studies, the C:N ratio of 5 was optimal for EPS synthesis, as observed in the culture of Ganoderma lucidum [79] or exceeded this value, as in the culture of Lactobacillus fermentum in a medium with the C:N ratio of 6.3 [80]. On the other hand, a C:N ratio of 20 was reported to be optimal for EPS production in active sludge [81].…”