A mycelium with polyelectrolyte complex-bunched hyphae: several important factors affecting on the fermentation performance at a very high cell density.
We have reported in the previous paper (Colloids Surf. B (2006) in press) a marked increase in the rate of gluconic acid production at a very high cell concentration (40 g/l) of filamentous fungus (Aspergillus niger IFO 31012) which was immobilized with polyelectrolyte complex consisting of potassium poly(vinyl alcohol) sulfate and trimethylammonium glycol chitosan iodide [6-O-(2-hydroxyethyl)-2-(trimethylammonio)-chitosan iodide]. The present study was carried out to look at what factors play a crucial role in this enhancement. We measured viscosity of broth, mass-transfer coefficient (k(L)a) for oxygen and diffusion coefficient of glucose (substrate). It has become apparent that there is only a difference in the diffusion coefficient of glucose between the free and immobilized cells. Therefore, we believe that the diffusion limitation by substrates as a problem in submerged mycelial processes is improved by immobilization based on polyelectrolyte complexes.
Mizunuma
Takato
T
Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan.
Kokufuta
Etsuo
E
Sato
Seigo
S
D001234:Aspergillus niger / Q000378:metabolism; D018914:Cells, Immobilized; D004058:Diffusion; D004573:Electrolytes / Q000737:chemistry*; D005285:Fermentation / Q000502:physiology*; D005947:Glucose / Q000378:metabolism; D025301:Hyphae / Q000737:chemistry*; D025282:Mycelium / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011142:Polyvinyl Alcohol / Q000737:chemistry; D014783:Viscosity
D004573:Electrolytes; D011108:Polymers; D011142:Polyvinyl Alcohol; D005947:Glucose; D010100:Oxygen