Modeling of growth and laccase production by Pycnoporus sanguineus

Abstract

Production of extracellular laccase by the white-rot fungus Pycnoporus sanguineus was examined in batch submerged cultures in shake flasks, baffled shake flasks and a stirred tank bioreactor. The biomass growth in the various culture systems closely followed a logistic growth model. The production of laccase followed a Luedeking-Piret model. A modified Luedeking-Piret model incorporating logistic growth effectively described the consumption of glucose. Biomass productivity, enzyme productivity and substrate consumption were enhanced in baffled shake flasks relative to the cases for the conventional shake flasks. This was associated with improved oxygen transfer in the presence of the baffles. The best results were obtained in the stirred tank bioreactor. At 28 °C, pH 4.5, an agitation speed of 600 rpm and a dissolved oxygen concentration of ~25 % of air saturation, the laccase productivity in the bioreactor exceeded 19 U L(-1 )days(-1), or 1.5-fold better than the best case for the baffled shake flask. The final concentration of the enzyme was about 325 U L(-1).

Production of a biofunctional titanium surface using plasma electrolytic oxidation and glow-discharge plasma for biomedical applications

“…According to Galhaup et al (2002), their synthesis starts when the glucose is nearly absent from the medium, below a certain critical level. In the exponential growth of the microorganism, during the consumption of glucose, the metabolism of the fungus is intensified and coincides with a decrease of the dissolved oxygen (DO) concentration in the medium (Bettin et al, 2011;Saat et al, 2014). In our experiments, the DO concentration sharply decreased during the initial day, while the glucose was being consumed (Fig.…”

“…Agitation and aeration rates are considered as important parameters for the production of laccases in ST bioreactors (Saat et al, 2014). According to McNeil and Harvey (2008), both aeration and agitation rates in ST bioreactors supply the fermentation system with oxygen and provides the mixture of the moist.…”

“…Many terrestrial fungal strains have been reported as good laccases producers at bioreactor scale, including Trametes pubescens, Pycnoporus sanguineus, and Pleurotus sp. (Galhaup et al, 2002;Bettin et al, 2011;Saat et al, 2014). However, studies related to the production of these enzymes by marine-derived fungi are still scarce.…”

Artificial neural network‐genetic algorithm (ANN‐GA) based medium optimization for the production of human interferon gamma (hIFN‐γ) in Kluyveromyces lactis cell factory

“…The kinetics of the IFN‐γ production was proposed by the Luedeking‐Piret equation, which states that the product formation rate depends upon the instantaneous biomass concentration (X in g/L) and the growth rate (dX/dt) in a linear fashion. α and β in the equation represent the growth and non‐growth associated constants, respectively, values for which are dependent on the fermentation conditions, as follows: …”

Simultaneous Biological Pretreatment and Saccharification of Rice Straw by Ligninolytic Enzymes from Panus neostrigosus I9 and Commercial Cellulase

“…neostrigosus I9 is a fast-growing white rot fungus when cultivated in submerged culture, especially in tomato juice medium. When the agitation rate is above the optimal rate, and fungal growth is inhibited due to insufficient mixing and hydrodynamic shear stress [37,38]. Although P. neostrigosus I9 could be tolerated at a high agitation speed when compared to the other white rot fungi (Table 8), the positive correlation turns into a negative one when the rotation rate exceeds 750 rpm, indicating that increasing the agitation speed does not promote enzyme formation [26] (Figure S1).…”