Laccase production by free and immobilized mycelia of Peniophora cinerea and Trametes versicolor: a comparative study

Abstract

The production of laccase by immobilized mycelia of Peniophora cinerea and Trametes versicolor was studied. In an initial stage, experimental assays were performed in Erlenmeyer flasks using free and immobilized mycelium, and the performance of the fungal strains to produce the enzyme was compared. Both fungi adhered into the support material (a synthetic fiber), growing not only on the surface but also in the interspaces of the fibers. Immobilization of P. cinerea provided a 35-fold increase in laccase production when compared to the production obtained by using free mycelium. On the other hand, immobilization of T. versicolor caused a decrease in laccase activity. A comparison between the strains revealed that immobilized P. cinerea (3,500 U/L) surpassed the enzyme production by free T. versicolor (800 U/L). When the conditions that gave the best laccase production to each fungus were employed in a stirred tank bioreactor, very low laccase production was observed for both the cases, suggesting that shear stress and mycelia damage caused by the agitation impellers negatively affected the enzyme production.

Recent Developments in the Immobilization of Laccase on Carbonaceous Supports for Environmental Applications - A Critical Review

“…Under submerged fermentation conditions, the availability and transfer of oxygen is essential for fungal growth. As mentioned earlier, mycelial uncontrolled expansion can limit oxygen transfer (Krull et al, 2013;Silvério et al, 2013). To promote oxygen transfer, it is important that the culture must remain continuously under shaking conditions.…”

“…However, SmF can be limited by uncontrolled mycelial growth resulting in an overabundant biomass. Expansion of biomass can increase broth viscosity and limit mass and oxygen transfer, thereby reducing metabolic rate and enzyme secretion ( Krull et al, 2013 ; Silvério et al, 2013 ).…”

Development of a Novel Spawn (Block Spawn) of an Edible Mushroom, Pleurotus ostreatus, in Liquid Culture and its Cultivation Evaluation

“…Despite corncob and sugarcane bagasse having been utilized as supports for immobilization of several white-rot fungi [37,38], their use as supports for immobilization of P. ostreatus mycelia has yet not been reported. A significantly higher mycelial growth capacity was observed for the loofah sponge and PUF supports than for the corncob and sugarcane bagasse supports, which was mainly due to the high adsorption surface area caused by high pore volume in the former two supports [36,39]. However, the higher adsorbed biomass did not lead to faster mycelial colonization, indicating that the mycelial colonization of block spawns mainly depends on their surface mycelia.…”

Purification and Characterization of Two Novel Laccases from Peniophora lycii

“…Currently, only 11 published articles can be found about laccases from fungi of the Peniophora genus [18][19][20][21][22][23][24][25][26][27][28]. Worse than that, almost all these works are strictly technically oriented and use only crude laccase preparations: only in three works [20,22,28] laccases were purified; only in four works [20,21,25,26] used fungi were identified to the species level; only in two works [21,29] fungi were properly genetically barcoded; and only in three works [25,28,29] either full or partial sequences of used laccases were obtained. This situation enormously complicates any comparative studies and raises serious reproducibility issues.…”