Oxygen mass transfer for an immobilised biofilm of Phanerochaete chrysosporium in a membrane gradostat reactor

Abstract

A novel system, the membrane gradostat reactor (MGR), designed for the continuous production of secondary metabolites, has been shown to have higher production per reactor volume than batch culture systems. The MGR system mimics the natural environment in which wild occurring microorganism biofilms flourish. The biofilms are immobilised on the external surface of an ultrafiltration membrane where substrate distribution gradients are established across the biofilm. The hypothesis that, dissolved oxygen (DO) mass transfer parameters obtained in submerged pellets can be used to describe and model DO mass transfer parameters in the MGR, was refuted. Phanerochaete chrysosporium biofilms, immobilised on ultrafiltration capillary membranes in the MGR systems were used to quantify DO distribution using a Clark-type microsensor. The DO penetration depth decreased with increasing biofilm thickness, which resulted in the formation of anaerobic zones in the biofilms. Oxygen flux values of 0.27 to 0.7 g/(m².h) were obtained during the MGR operation. The consumption of oxygen and the Monod saturation constants used in the modelling of oxygen distribution in immobilised biofilms were in the range of 894.53 to 2739.70 g/(m³.h) and 0.041 to 0.999 g/m³, respectively

Mathematical modeling of Fe(II), Cu(II), Ni(II) and Zn(II) removal in a horizontal rotating tubular bioreactor

“…Langmuir and Freundlich isotherm was also used for the description of metal ions adsorption process inside microbial biofilm on the inner surface of HRTB. In the integral bioprocess model it is assumed that inside microbial biofilm attached on the inner surface of HRTB concentration profiles have concave forms what is in agreement with literature data [48,49]. Different order of polynomial equation could be selected for description of these concentration profiles.…”

“…Different order of polynomial equation could be selected for description of these concentration profiles. Similar to the continuously stirred biofilm reactors [49], second-order polynomial equation was chosen although in the literature third-order polynomial equations were also used [48]. Values of adjustable parameters for Langmiur and Freundlich isotherms for the adsorption process inside microbial biofilm in the HRTB are also presented in Table 4.…”

Biosorption of Mn (II), Co (II) and Cr (VI) in a horizontal rotating tubular bioreactor: experiments and evaluation of the integral bioprocess model

“…In the integral bioprocess model it is assumed that inside the microbial biofilm attached on the inner surface of the HRTB concentration profiles have concave forms, in agreement with literature data (Wik et al, 2005;Ntwampe et al, 2008). Values of adjustable parameters of Freundlich isotherm for the adsorption process inside the microbial biofilm in the HRTB are also presented in Table 9.…”

Effect of a perfluorocarbon‐Pluronic F 68‐based emulsion on a Phanerochaete chrysosporium biofilm immobilised in a membrane gradostat bioreactor

“…Younger biofilms showed greater DO transfer, while in older biofilms, the transfer of DO was limited. [13] Active biomass near the membrane surface area, where metabolic activity was presumed high due to nutrient availability, was growing under anoxic conditions. As P. chrysosporium can survive transient anoxic conditions by producing ethanol, the amount of alcohol produced was determined to be increasing with an increase in biofilm and anaerobic zone thickness.…”