The Role of Enzymes and Mediators in White-Rot Fungal Degradation of Lignocellulose

Author(s):  
Kaichang Li
Keyword(s):  
2018 ◽  
Vol 69 (1) ◽  
pp. 38-44
Author(s):  
Nicoleta Mirela Marin ◽  
Olga Tiron ◽  
Luoana Florentina Pascu ◽  
Mihaela Costache ◽  
Mihai Nita Lazar ◽  
...  

This study investigates the synergistic effects of ion exchange and biodegradation methods to remove the Acid Blue 193 also called Gryfalan Navy Blue RL (GNB) dye from wastewater. Ion exchange studies were performed using a strongly basic anion exchange resin Amberlite IRA 400. The equilibrium was characterized by a kinetic and thermodynamic points of view, establishing that the sorption of the GNB dye was subject to the Freundlich isotherm model with R2 = 0.8710. Experimental results showed that the activated resin can removed up to 93.4% when the concentration of dye solution is 5.62�10-2 mM. The biodegradation of the GNB was induced by laccase, an enzyme isolated from white-rot fungus. It was also analyzed the role of pH and dye concentration on GNB biodegradation, so 5�10-2 mM dye had a maximum discoloration efficiency of 82.9% at pH of 4. The laccase showed a very fast and robust activity reaching in a few minutes a Km value of 2.2�10-1mM. In addition, increasing the GNB concentration up to 8�10-1 mM did not triggered a substrat inhibition effect on the laccase activity. Overall, in this study we proposed a mixt physicochemical and biological approach to enhance the GNB removal and biodegradability from the wastewaters and subsequently the environment.


2019 ◽  
Vol 68 ◽  
pp. 37-48 ◽  
Author(s):  
Kazumu Kuramitsu ◽  
Teruhito Ishihara ◽  
Aki Sugita ◽  
Thitaree Yooboon ◽  
Barry Lustig ◽  
...  

Woodwasps (Hymenoptera: Siricidae) are saproxylic insects and a common forest pest. Siricid woodwasps are classified into two subfamilies: Siricinae and Tremecinae. All known symbiotic fungi of Siricinae are in the genusAmylostereumBoidin while some species of Tremecinae have been observed to have a relationship with the fungusCerrenaunicolor(Bull.) Murrill. Previous studies about the host searching behavior of woodwasps and their parasitoids have focused primarily on the subfamily Siricinae.We analyzed the role ofC.unicolorvolatiles on the host searching behavior ofTremexapicalisMatsumura (Hymenoptera: Siricidae: Tremecinae) and its parasitoid Ibalia (Tremibalia) japonica Matsumura (Hymenoptera: Ibaliidae). The results of an olfactory response experiment indicated that the females ofT.apicalisand its parasitoid find their respective hosts using volatiles fromC.unicolor. Using DNA barcode, we identified basidiocarps on the trees infested withT.apicalis.The basidiocarps were all white-rot fungi that cause sapwood decay, includingC.unicolor. Two additional species that we identified belonged to genera closely related toC.unicolor.Woodwasp species are known to carry symbiotic fungi in a pair of specialized sacs called mycangia. Notably we found that mycangia-like structures were absent in the abdomens ofT.apicalisfemales. To the best of our knowledge,Xerisspectrum(Linnaeus) (Hymenoptera: Siricidae) is the only reported example of woodwasp species that do not contain symbiotic fungi in their bodies.Our results suggested that: (1)T.apicalisfemales search for host wood that is already infected with sapwood decaying fungus using volatile compounds; (2)T.apicalis’ female parasitoid also uses volatile compounds from fungus to locate wood that is infested with its potential host.


Holzforschung ◽  
1999 ◽  
Vol 53 (3) ◽  
pp. 247-252 ◽  
Author(s):  
M.J. Martínez-Inigo ◽  
P. Immerzeel ◽  
A. Gutierrez ◽  
J.C. del Río ◽  
R. Sierra-Alvarez

SummaryThe fungal degradation of lipophilic extractives in sapwood and heartwood from Scots pine (Pinus sylvestris) was studied. In sapwood, the white rot fungi,Bjerkanderasp. andFunalia trogii, removed higher amounts of extractives than the sapstain strains,Ophiostoma ainoaeandCeratocystis allantospora. Triglycerides, long chain fatty acids, steryl esters and waxes in pine sapwood were almost completely degraded by all the fungi. Sterols and resin acids were also extensively degraded by the white rot strains; however, these components were not or only poorly removed by the sapstain fungi. The removal of total extractives by all the fungal strains was higher in sapwood as compared to heartwood. The highly concentrated extractive fraction in pine heartwood mainly consists of resin acids. As observed in sapwood, sapstain were also poorly effective in the degradation of the resin acids present in heartwood. The fungal degradation of heartwood extractives was not only limited by the degradative ability of the various test microorganisms, but also by the inhibitory effect exerted by the extractive fraction. The white rot fungusF. trogiiwas particularly inhibited on heartwood.Bjerkanderasp. showed a higher tolerance to toxic extractives and was the most efficient fungus in degrading extractive constituents in both Scots pine heartwood and sapwood. Therefore,Bjerkanderasp. strain BOS55 should be considered as a potential agent for pitch control in pulp and paper manufacture.


SpringerPlus ◽  
2016 ◽  
Vol 5 (1) ◽  
Author(s):  
Prashant D. Kunjadia ◽  
Gaurav V. Sanghvi ◽  
Anju P. Kunjadia ◽  
Pratap N. Mukhopadhyay ◽  
Gaurav S. Dave

2021 ◽  
Vol 37 (4) ◽  
pp. 365-374
Author(s):  
Rupeet Gill ◽  
Prabhjodh S. Sandhu ◽  
Sanjula Sharma ◽  
Pankaj Sharma

White rot or stem rot caused by Sclerotinia sclerotiorum is one of the most destructive fungal diseases that have become a serious threat to the successful cultivation of oilseed Brassicas. The study was designed with an aim to investigate the association between the pathogenic aggressiveness and pathogenicity determinants of this pathogen specifically in Brassica for the first time. For this, a total of 58 isolates of S. sclerotiorum from different geographical regions were collected and purified. These isolates were inoculated on a Brassica juncea cv. RL-1359 and they exhibited high level of variation in their disease progression. The isolates were grouped and then 24 isolates were selected for the biochemical analysis of pathogenicity determinants. The isolates varied significantly with respect to their total organic acids, oxalic acid production and pectin methyl esterase and polygalacturonase activity. The oxalic acid production corresponded to the disease progression of the isolates; the isolates with higher oxalic acid production were the more aggressive ones and vice-versa. This is, in our knowledge, the first study to establish a correlation between oxalic acid production and pathogenic aggressiveness of S. sclerotiorum on B. juncea. However, the pectinases’ enzyme activity did not follow the trend as of disease progression. These suggest an indispensable role of oxalic acid in pathogenicity of the fungus and the potential to be used as biochemical marker for preliminary assessment of pathogenic aggressiveness of various isolates before incorporating them in a breeding program.


2019 ◽  
Vol 359 ◽  
pp. 1427-1435 ◽  
Author(s):  
I.A. Vasiliadou ◽  
R. Molina ◽  
M.I. Pariente ◽  
K.C. Christoforidis ◽  
F. Martinez ◽  
...  

2001 ◽  
Vol 28 (4-5) ◽  
pp. 301-307 ◽  
Author(s):  
Kaichang Li ◽  
Peter S Horanyi ◽  
Robert Collins ◽  
Robert S Phillips ◽  
Karl-Erik L Eriksson

2020 ◽  
Vol 5 (10) ◽  
Author(s):  
Amit Kumar ◽  
Mukesh Yadav ◽  
Workinesh Tiruneh

AbstractMicrobial enzymes are green and clean alternatives for several processes in the pulp and paper industry. Enzyme treatment decreases the energy requirement and minimizes the wood losses during drum debarking. Lipophilic wood extractives are known as pitch. Pitch deposition adversely affects the pulp quality and increases equipment maintenance and operating costs during paper manufacturing. Several chemical additives have been used to remove pitch deposits. Natural seasoning of wood is used to minimize pitch content in wood, but it has some disadvantages including yield losses and decreased brightness. Controlled seasoning with white-rot fungi or albino strains of sapstain fungi is an effective tool for degradation and removal of wood extractives. Enzymes including lipase, laccase, sterol esterase, and lipooxygenase have also been used to minimize pitch-related problems. Enzymatic retting has been proved an eco-friendly and economical solution for chemical degumming and traditional retting.


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