Problem of oxygen transfer during degradation of lignin by Phanerochaete chrysosporium

Overview of parameters influencing biomass and bioreactor performance used for extracellular ligninase production from Phanerochaete chrysosporium

“…Proposed solutions for improvement of gaseous oxygen transport were: 1) to limit the biofilm thickness and 2) to increase pressure in the bioreactors where the biofilms are immobilised. In addition, when the biofilm thickness was restricted to the determined limiting thickness, the P. chrysosporium mycelial mats grown in air degraded lignin at the same rate comparable to that measured in 100% O 2 (Leisola et al, 1983). This means that the use of fixed-film bioreactors in which sufficient biofilm thickness is required to establish the areas with limited nutrients, the transport of DO will be limited.…”

“…DO penetration in pellets equilibrated in air-saturated culture fluid was ~400 µm (Michel et al, 1992). Oxygen limitation was also shown to be the main reason for slow, incomplete degradation of lignin in non-agitated cultures (Leisola et al, 1983). As DO transfer is limited to a depth of less than 1000 µm, oxygen limitation can result in the production of ethanol (Kenealy and Dietrich, 2004).…”

“…It was shown that DO limitation was the main reason for slow and incomplete lignin degradation (Kirk et al, 1978). When a DO Clarktype microsensor was used to quantify the DO in mycelial mats, the DO penetration depth was less than 1000 µm even under cultures incubated under 100% O 2 at 1 atm (Leisola et al, 1983). DO penetration in pellets equilibrated in air-saturated culture fluid was ~400 µm (Michel et al, 1992).…”

Effect of Oxygen on Upgradation of Wheat Straw withPleurotus sajor cajuat High Partial Pressure of Carbondioxide

“…Lower concentrations of these compounds may stimulate the growth of fungi (Glasare, 1970). The volatile and gaseous metabolites produced during fungal metabolism which influence the solid state fermentation (Leisola et al, 1983;Zadrazil and Kamra, 1989) were daily washed out in our experiments from the flasks with gassing.…”

Solid state fermentation of waste pomace from olive processing

“…These results are expected on the grounds that lignin degradation is an oxidative process and that oxygen plays an important role in the regulation of ligninolytic activity; 14,23 the rate of oxygen transfer into the culture is more important than the concentration of oxygen in the atmosphere. 24 The effect on lignin degradation of the addition of 0.25%, 0.5% and 0.75% ammonium sulfate as an additional source of nitrogen after 40 days is shown in Fig 3, and it is clear that the addition was inhibitory. 25, 26 Jeffries et al 27 also found that lignin degradation is stimulated by nitrogen limitation, and that scarcity increases both the extent and selectivity of deligni®cation.…”