Farnesol stimulates laccase production in Trametes versicolor

Abstract

Farnesol, a quorum-sensing molecule, was used successfully to improve laccase production in submerged cultures of Trametes versicolor. At the optimal farnesol concentration of 60 μM added at the beginning of the culture, the extracellular laccase activity reached 629.3 U L −1 after 6 days of cultivation, which represented a 1.92-fold increase relative to the control without farnesol treatment. The addition of farnesol resulted in an increase in the accumulation of H 2 O 2 and an increased expression of the laccase (lac) gene and the RhoA gene. The RhoA gene correlated with hyperbranched mycelia, which facilitated the secretion of the intracellular laccase. This study provides a basis for understanding the induction mechanism of farnesol for enhancing laccase production.

Farnesol-induced hyperbranched morphology with short hyphae and bulbous tips of Coriolus versicolor

“…Gene rhoA has been identified to be associated with the formation of hyperbranched hyphae of C . versicolor in previous study 26 . But it was not elucidated that how farnesol affected the expression of rhoA gene.…”

“…The results confirmed our previous study that farnesol treatment resulted in a highly branched morphology of C . versicolor 26 .

Figure 1 Morphological changes of C .

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“…In our previous study, we found that 60 μM farnesol stimulated laccase production by inducing a more branched mycelia of C . versicolor , but the induction mechanism was not fully elucidated 26 .…”

β-Carotene from Yeasts Enhances Laccase Production of Pleurotus eryngii var. ferulae in Co-culture

“…Enhancement of fungal laccase production after adding an antioxidant represented a response to oxidative stress, which was caused by oxygen radicals generated by inducers ( Thurston, 1994 ; Wang et al, 2014 ). A higher concentration of intracellular reactive oxygen species (ROS), including superoxide anion (O 2 - ), hydrogen peroxide (H 2 O 2 ) and hydroxyl radical (OH-), has been reported to enhance both laccase production and transcription, depending on the activation of signal transduction and the oxidative stress ( Adekunle et al, 2015 ; Hu et al, 2016 ). H 2 O 2 participated in the activation of the mitogen-activated protein kinase (MAPK) and cyclic adenosine monophosphate (cAMP) pathways ( Calvo et al, 2002 ; Cap et al, 2012 ).…”

“…Besides genetic engineering technology, enhanced laccase production has also been achieved by optimizing the culture medium ( Dekker et al, 2007 ), especially by adding inducers. Some researchers have focused on screening for effective inducers, and laccase production in Trametes versicolor has been effectively improved by farnesol and chitosan ( Adekunle et al, 2015 ; Hu et al, 2016 ). Different inducers enhance laccase production by various mechanisms, including the improvement of silent or poorly expressed laccase isoforms and the response to oxidative stress caused by an inducer ( Hoegger et al, 2006 ; Wang et al, 2014 ).…”