title: Significance of bed porosity, bran and specific surface area in solid-state cultivation of Aspergillus oryzae.
abstract: In this paper, the effects of bed porosity, bran and specific surface area on the oxygen uptake rate and alpha-amylase production during growth of Aspergillus oryzae on wheat grain and wheat-flour substrate are reported. The high oxygen uptake rate found during cultivation of A. oryzae on wheat-flour substrate was not reached on wheat grain. This is mainly due to the bran of the wheat grain. Using wheat-flour substrates, it was shown that extra bed porosity increased the alpha-amylase production and oxygen uptake rates. Furthermore, the peak oxygen uptake rate decreased with increasing surface area-volume ratio of the substrate particles, while the alpha-amylase production and the cumulative oxygen uptake per gram of initial substrate dry matter increased. The present work does not support a direct correlation between aerial mycelia and enzyme production. There is, however, a correlation between the alpha-amylase yield and the cumulative oxygen uptake (not the uptake rate). This implies that aerial mycelia could accelerate alpha-amylase production even if they do not increase the yield.
authors.affiliation: Wageningen Centre for Food Sciences, P.O. Box 557, 6700 AN Wageningen, The Netherlands. Yovita.Rahardjo@wur.nl
authors.forename: Yovita S P
authors.initials: YS
authors.lastname: Rahardjo
authors.forename: Fenna
authors.initials: F
authors.lastname: Jolink
authors.forename: Sebastiaan
authors.initials: S
authors.lastname: Haemers
authors.forename: Johannes
authors.initials: J
authors.lastname: Tramper
authors.forename: Arjen
authors.initials: A
authors.lastname: Rinzema
mesh_terms: D001236:Aspergillus oryzae / Q000378:metabolism*; D018533:Biomass; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods; D018929:Cell Culture Techniques / Q000379:methods*; D049109:Cell Proliferation; D003198:Computer Simulation; D005285:Fermentation; D005433:Flour; D010100:Oxygen / Q000378:metabolism; D016062:Porosity; D013379:Substrate Specificity; D013997:Time Factors; D014908:Triticum; D000516:alpha-Amylases / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism
chemical_list: D000516:alpha-Amylases; D010100:Oxygen