Bistage control of pH for improving exopolysaccharide production from mycelia of Ganoderma lucidum in an air-lift fermentor

Evaluation of polysaccharides content in fruit bodies and their antimicrobial activity of four Ganoderma lucidum (W Curt.: Fr.) P. Karst. strains cultivated on different wood type substrates

“…Baabitskaia et al [28] maintain that polysaccharide production by G. lucidum depends on such conditions as the initial pH of the substrate, C:N ratio and incubation temperature. The influence of substrate pH on polysaccharide production by G. lucidum was also reported by Kim et al [29] and Lee et al [30]. According to Prosiński [31], wood of various tree species differs with regard to the content of cellulose, lignin, hemicellulose, sugars, protein as well as other substances and shows differences in pH.…”

Effect of Different Substrates on the Production of Ganoderma lucidum (Curt.:Fr.) Karst.

“…This method of production has also several disadvantages, including the long time required to cultivate the fruiting body of Ganoderma lucidum, the difficulty of controlling the quality of the product, and the ease with which the culture is affected by the environmental changes. Recently, submerged fermentation technology for mycelial cultures of G. lucidum has been developed which none of the weaknesses has stated above (Yang and Lieu, 1998;Lee et al, 1999). The historical method of cultivation of medicinal mushrooms, and still practiced mainly in Asia, is on logs of broad leaved hardwood trees.…”

Efficient Production of Exopolysaccharide by Submerged Fermentation of Hypsizygus marmoreus Using a Two-stage pH Control Strategy

“…2 indicates that the pH in the culture broth was critical in the fermentation of H. marmoreus, and the cell growth could be prolonged and the polysaccharide production could be improved by controlling the pH in the culture broth. Previous researches have shown that high pH was favorable for some polysaccharide production, such as pullulan 20 , Ganoderma polysaccharide 21 . Similarly, EPS of H. marmoreus was biosynthesized in higher pH level.…”

“…Mycelial growth and metabolism can be significant-* ly affected by media composition and other chemical and physical factors in submerged culture, and pH is one of the vital parameters because it can influence the solubility of salts, the ionic state of substrates, cell membrane function, and metabolite biosynthesis 19 . Various pH conditions were studied and two-stage pH strategy had been utilized to enhance the mycelial growth and product biosynthesis in some fungi fermentation 14,15,[19][20][21] . The polysaccharide productivity of Auricularia auricula increased by 93.3 % when culture pH was controlled at 5.0 in the first 48 h and then switched to 5.5 compared with that of non-pH control 15 .…”

“…Investigation suggested that lower pH supported cell growth of Auerobasidium pullulans while higher pH stimulated pullulan synthesis, and maximum pullulan production could be conducted when two-stage pH strategy was performed 20 . Tang et al suggested that the pH-shift from 3.0 to 4.5 on day 4 was beneficial to the intracellular polysaccharide production in the cultivation of G. lucidum CGMCC 5.616, and Lee et al reported that the pH-shift from 3.0 to 6.0 on day 2 was best for extracellular polysaccharide biosynthesis in the fermentation of G. lucidum ASI 7004 14,21 . In this work, the effect of various pH on polysaccharide production of H. marmoreus was systematically investigated.…”