Morphological and rheological properties of the three different species of basidiomycetes Phellinus in submerged cultures

• Published in: Journal of applied microbiology Vol. 96; no. 6; pp. 1296 - 1305
• Main Authors: Hwang, H.J., Kim, S.W., Xu, C.P., Choi, J.W., Yun, J.W.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.06.2004; Blackwell Science; Oxford University Press
• Subjects: Basidiomycetes; Basidiomycota - metabolism; Basidiomycota - physiology; Basidiomycota - ultrastructure; Biological and medical sciences; Biomass; Bioreactors; exopolysaccharide; Fermentation; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; Microbiology; morphology; mycelial biomass; Phellinus; Phellinus linteus; Phellinus species; Polysaccharides - biosynthesis; Rheology; Species Specificity; submerged culture; Applied microbiology; Rheology; Basidiomycetes; Biomass; Extracellular; mycelial biomass; Fungi; Phellinus; exopolysaccharide; Phellinus species; Submerged culture; Morphology; Polysaccharide; Thallophyta; Rheological properties
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1111/j.1365-2672.2004.02271.x

Aims:  The objective of this work was to investigate the morphological and rheological properties in submerged culture of the three different basidiomycetes Phellinus (P. baumii, P. gilvus and P. linteus) that produce pharmacologically important exopolysaccharides (EPS). Methods and Results:  In flask cultures, pH proved to be a critical factor affecting mycelial growth, morphological change and EPS production. The macroscopic morphologies observed under different pHs in flask cultures were also comparable: i.e. starfish‐like pellets with a lesser extent of free mycelium appeared in P. baumii, whereas smooth pellets with higher amounts of free mycelium were observed in P. gilvus and P. linteus. The pelleted fermentations were further characterized in a 5‐l stirred‐tank fermenter by image analysis with respect to mean diameter, core area and pellet circularity. Phellinus baumii showed the largest pellet size (5·2 mm in diameter), whereas P. linteus had extremely small and spherical pellets. The culture broth of P. baumii and P. gilvus yielded extremely high apparent viscosities, ranging from 5 to 7 Pa s. Conclusions:  Three important species of Phellinus showed significantly different morphological and rheological properties. The morphological variation of the three Phellinus species was closely linked to EPS productivity and the apparent viscosity of the whole broth. Significance and Impact of the Study:  The morphological change in the three species of Phellinus was a good indicator for identifying cell activity for EPS production. Our finding may be beneficial for further optimization of other fungal fermentation processes for large‐scale production of EPS.