scholarly journals Mechanism of Laccase Induction via Emodin in Trametes versicolor

Author(s):  
Lin Wang ◽  
Xuecai Luo ◽  
Yu Pan ◽  
Zai Zheng ◽  
Ruochun Yin ◽  
...  

Secondary metabolites of traditional Chinese herbs can prominently stimulate the production of laccase from white rot fungi during submerged fermentation. However, the molecular mechanism through which these natural products induce the production of laccase remains unknown. In this study, the Chinese herbal medicine Polygonum cuspidatum was used to induce laccase production in Trametes versicolor, and the best inducer was identified in emodin, even under conditions of 1000-L, large-scale fermentation. Proteomics analysis identified a selection of proteins that were differentially expressed in the presence of emodin, indicating that emodin may affect the expression of laccase genes through three mechanisms: reducing bioenergy productivity, the aryl hydrocarbon receptor (AHR)/xenobiotic response element (XRE) pathway, and the nuclear erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway. Combined with protoplast flow cytometry and fluorescence, it is revealed that emodin might reduce the synthesis of ATP by lowering the mitochondrial membrane potential, leading to the subsequent responses.

Ecocycles ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 25-31
Author(s):  
Hayet Djelal ◽  
Paola Estrada Martinez ◽  
Djouza Haddouche ◽  
Malika Chabani

Doxycycline, an antibiotic, is largely used in human and veterinary medicine. The conventional treatment with activated sludge is not very efficient. Laccase appeared to be the main enzyme secreted essentially by white rot fungi as Trametes versicolor and Phlebia fascicularia on the degradation of xenobiotic compounds from the pharmaceutical industry. The main purpose of this study was to enhance the biodegradation of doxycycline through activated sludge combined with addition of glucose as a carbon co-substrate to improve the growth of the microbial population present in the activated sludge, phenol as a laccase mediator, copper as a cofactor and inductor for laccase production. The enhancement of the biodegradation of doxycycline was 50, 90, 68 and 83% greater respectively with the addition of glucose, copper, phenol and with a mixture of the compounds after 14 days of treatment at 25°C. Compared with the biotic control (activated sludge alone), a 30% increase for the test with the addition of phenol was observed.


Processes ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 648
Author(s):  
Luong N. Nguyen ◽  
Minh T. Vu ◽  
Md Abu Hasan Johir ◽  
Nirenkumar Pathak ◽  
Jakub Zdarta ◽  
...  

Laccase enzyme from white-rot fungi is a potential biocatalyst for the oxidation of emerging contaminants (ECs), such as pesticides, pharmaceuticals and steroid hormones. This study aims to develop a three-step platform to treat ECs: (i) enzyme production, (ii) enzyme concentration and (iii) enzyme application. In the first step, solid culture and liquid culture were compared. The solid culture produced significantly more laccase than the liquid culture (447 vs. 74 µM/min after eight days), demonstrating that white rot fungi thrived on a solid medium. In the second step, the enzyme was concentrated 6.6 times using an ultrafiltration (UF) process, resulting in laccase activity of 2980 µM/min. No enzymatic loss due to filtration and membrane adsorption was observed, suggesting the feasibility of the UF membrane for enzyme concentration. In the third step, concentrated crude enzyme was applied in an enzymatic membrane reactor (EMR) to remove a diverse set of ECs (31 compounds in six groups). The EMR effectively removed of steroid hormones, phytoestrogen, ultraviolet (UV) filters and industrial chemical (above 90%). However, it had low removal of pesticides and pharmaceuticals.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
K. Y. Usha ◽  
K. Praveen ◽  
B. Rajasekhar Reddy

The white rot fungi Stereum ostrea displayed a wide diversity in their response to supplemented inducers, surfactants, and copper sulphate in solid state fermentation. Among the inducers tested, 0.02% veratryl alcohol increased the ligninolytic enzyme production to a significant extent. The addition of copper sulphate at 300 μM concentration has a positive effect on laccase production increasing its activity by 2 times compared to control. Among the surfactants, Tween 20, Tween 80, and Triton X 100, tested in the studies, Tween 80 stimulated the production of ligninolytic enzymes. Biosorption of dyes was carried out by using two lignocellulosic wastes, rice bran and wheat bran, in 50 ppm of remazol brilliant blue and remazol brilliant violet 5R dyes. These dye adsorbed lignocelluloses were then utilized for the production of ligninolytic enzymes in solid state mode. The two dye adsorbed lignocelluloses enhanced the production of laccase and manganese peroxidase but not lignin peroxidase.


2019 ◽  
Vol 20 (24) ◽  
pp. 6131 ◽  
Author(s):  
Yafang Wang ◽  
Fugui Jiang ◽  
Haijian Cheng ◽  
Xiuwen Tan ◽  
Yifan Liu ◽  
...  

Oxidative stress can damage intestinal epithelial cell integrity and function, causing gastrointestinal disorders. Astragaloside IV (ASIV) exhibits a variety of biological and pharmacological properties, including anti-inflammatory and antioxidant effects. The purpose of this research was to investigate the cytoprotective action of ASIV and its mechanisms in calf small intestine epithelial cells with hydrogen peroxide (H2O2)-induced oxidative stress. ASIV pretreatment not only increased cell survival, but it also decreased reactive oxygen species generation and apoptosis, enhanced superoxide dismutase, catalase, and glutathione peroxidase levels, and it reduced malondialdehyde formation. Furthermore, pretreatment with ASIV elevated the mRNA and protein levels of nuclear factor erythroid 2-related factor 2 (NFE2L2), heme oxygenase-1 (HMOX1), and NAD(P)H quinone dehydrogenase 1 (NQO1). The NFE2L2 inhibitor ML385 inhibited NFE2L2 expression and then blocked HMOX1 and NQO1 expression. These results demonstrate that ASIV treatment effectively protects against H2O2-induced oxidative damage in calf small intestine epithelial cells through the activation of the NFE2L2-antioxidant response element signaling pathway.


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