Deciphering the Amendment-Induced Secretion of Ligninolytic Enzymes by Pleurotus pulmonarius

2021 ◽  
Vol 16 (10) ◽  
pp. 19-26
Author(s):  
G. Thiribhuvanamala ◽  
S. Parthasarathy ◽  
P. Ahiladevi

Pleurotus pulmonarius belonging to the white-rot fungal basidiomycetes group secretes extracellular ligninolytic enzymes for the degradation of agroresidues. The present study was carried out to evaluate the efficacy of different agro-residues for the enhanced production of ligninolytic enzymes and to authenticate their ability by protein analysis. The morphological and molecular sequences of white-rot fungi were characterised. Besides, the efficacy of organic and inorganic amendments in the secretion of ligninolytic enzymes by P. pulmonarius was characterised using SDS-PAGE and native PAGE analysis. The characterised strain of P. pulmonarius secreted enhanced laccase enzyme levels in the liquid medium through supplementation with organic and inorganic amendments. Wheat bran and groundnut cake each @5% enhanced secretions of Laccase, LiP and MnP. Copper sulphate at 150 μM enhanced the laccase enzyme and at 100 μM enhanced the LiP enzyme level by P. pulmonarius. Similarly, supplementation with manganese sulphate at 150 μM enhanced laccase, LiP and MnP enzyme levels compared to control. SDS-PAGE results showed protein banding patterns in the range of 50–85 kDa for the Lac enzyme in samples drawn from wheat bran and groundnut cake-supplemented substrates. Native PAGE results of laccase enzymes also showed that wheat bran (5%) + groundnut cake (5%) + CuSO4 (150 M) + MnSO4 (150 M) induced four laccase isozymes. Supplementing organic and inorganic amendments to the substrates would enhance the secretion of laccase enzyme that would aid in better breakdown of lignin.

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.


2020 ◽  
Author(s):  
RAM SAHAY

Abstract Laccases has been produced by white rot fungi are involved in lignin containing natural substrates wheat-straw, bagasse, saw-dust, corn cob and coir dust particle on the production of laccase enzyme in the aqueous cultivation medium of Gloephyllum stratum MTCC1117. The approach involved concentration of aqueous filtrate by ultrafiltration and anion exchange chromatography on DEAE (diethyl aminoethyl cellulose). From SDS-PAGE analysis the molecular mass of the purified enzyme is 57 kDa. The Km and kcat values of the laccase are found to be 18 μM and 0.34 s-1 using 2,6-dimethoxyphenol as the substrate, giving a kcat/Km value is 1.70 x 103 M-1 s-1. The pH and temperature optimum were 4.5 and 40 °C respectively. The purified enzyme has yellow colour and does not show absorption band around 610 nm found in blue laccases. Moreover the conversion of methylbenzene to benzaldehyde in the lack of mediator molecules, property exhibited by yellow laccases.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2098
Author(s):  
Asiah Sukri ◽  
Raihan Othman ◽  
Firdaus Abd-Wahab ◽  
Noraini M. Noor

The present work describes a self-sustaining bioelectrochemical system that adopts simple cell configurations and operates in uncontrolled ambient surroundings. The microbial fuel cell (MFC) was comprised of white-rot fungus of Phanaerochaete chrysosporium fed with oil palm empty fruit bunch (EFB) as the substrate. This fungal strain degrades lignin by producing ligninolytic enzymes such as laccase, which demonstrates a specific affinity for oxygen as its electron acceptor. By simply pairing zinc and the air electrode in a membraneless, single-chamber, 250-mL enclosure, electricity could be harvested. The microbial zinc/air cell is capable of sustaining a 1 mA discharge current continuously for 44 days (i.e., discharge capacity of 1056 mAh). The role of the metabolic activities of P. chrysosporium on EFB towards the MFC’s performance is supported by linear sweep voltammetry measurement and scanning electron microscopy observations. The ability of the MFC to sustain its discharge for a prolonged duration despite the fungal microbes not being attached to the air electrode is attributed to the formation of a network of filamentous hyphae under the submerged culture. Further, gradual lignin decomposition by fungal inocula ensures a continuous supply of laccase enzyme and radical oxidants to the MFC. These factors promote a self-sustaining MFC devoid of any control features.


Fermentation ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 19
Author(s):  
Anastasia Zerva ◽  
Nikolaos Tsafantakis ◽  
Evangelos Topakas

White-rot basidiomycetes are the only microorganisms with the ability to produce both hydrolytic (cellulases and hemicellulases) and oxidative (ligninolytic) enzymes for degrading cellulose/hemicellulose and lignin. In addition, they produce biologically active natural products with important application in cosmetic formulations, either as pure compounds or as standardized extracts. In the present work, three wild strains of Basidiomycetes fungi (Pleurotus citrinopileatus, Abortiporus biennis and Ganoderma resinaceum) from Greek habitats were grown in agro-industrial residues (oil mill wastewater, and corn cob) and evaluated for their anti-tyrosinase and antioxidant activity and for the production of biotechnologically relevant enzymes. P. citrinopileatus showed the most interesting tyrosinase inhibitory activity, while A. biennis showed the highest DPPH(2,2-diphenyl-1-picryl-hydrazyl) scavenging potential. Corn cobs were the most appropriate carbon source for maximizing the inhibitory effect of fungal biomasses on both activities, while the use of oil mill wastewater selectively increased the anti-tyrosinase potential of P. citrinopileatus culture filtrate. All strains were found to be preferential lignin degraders, similarly to most white-rot fungi. Bioinformatic analyses were performed on the proteome of the strains P. citrinopileatus and A. biennis, focusing on CAZymes with biotechnological relevance, and the results were compared with the enzyme activities of culture supernatants. Overall, all three strains showed strong production of oxidative enzymes for biomass conversion applications.


1996 ◽  
Vol 41 (3) ◽  
pp. 264-266 ◽  
Author(s):  
F. Nerud ◽  
Z. Mišurcová

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Hamid Mukhtar ◽  
Ikramul Haq

The present study describes the screening of different agroindustrial byproducts for enhanced production of alkaline protease by a wild and EMS induced mutant strain ofBacillus subtilisIH-72EMS8. During submerged fermentation, different agro-industrial byproducts were tested which include defatted seed meals of rape, guar, sunflower, gluten, cotton, soybean, and gram. In addition to these meals, rice bran, wheat bran, and wheat flour were also evaluated for protease production. Of all the byproducts tested, soybean meal at a concentration of 20 g/L gave maximum production of the enzyme, that is, 5.74  ±  0.26 U/mL from wild and 11.28  ±  0.45 U/mL from mutant strain, during submerged fermentation. Different mesh sizes (coarse, medium, and fine) of the soybean meal were also evaluated, and a finely ground soybean meal (fine mesh) was found to be the best. In addition to the defatted seed meals, their alkali extracts were also tested for the production of alkaline protease byBacillus subtilis, but these were proved nonsignificant for enhanced production of the enzyme. The production of the enzyme was also studied in solid state fermentation, and different agro-industrial byproducts were also evaluated for enzyme production. Wheat bran partially replaced with guar meal was found as the best substrate for maximum enzyme production under solid state fermentation conditions.


Hoehnea ◽  
2016 ◽  
Vol 43 (4) ◽  
pp. 575-581 ◽  
Author(s):  
Thiara Siqueira Bento ◽  
Luce Maria Brandão Torres ◽  
Mauricio Batista Fialho ◽  
Vera Lúcia Ramos Bononi

ABSTRACT White-rot basidiomycetes are able to deteriorate wood products and be pathogenic to living trees, requiring, thus requiring control. The tropical flora is an important source of eco-friendly antifungal compounds; however, the knowledge on how leaf extracts affect the fungal physiology is limited. Therefore, in the present work we investigated the influence of ethanolic leaf extracts of Casearia sylvestris and C. decandra at 0.1 mg mL-1 on the production of ligninolytic enzymes by Trametes villosa, Ganoderma australe and Pycnoporus sanguineus. Overall, the extracts inhibited the mycelial growth and the production of biomass. Additionally, C. sylvestris extract reduced the production of manganese peroxidase and laccase; however, the exposure to C. decandra extract resulted in variable responses. Therefore, enzymes related to lignin degradation are potential targets to control wood decay fungi by plant bioactive compounds, as their ability to colonize the substrate may be impaired.


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