Methane fermentation of Japanese cedar wood pretreated with a white rot fungus, Ceriporiopsis subvermispora

2006 ◽  
Vol 123 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Rudianto Amirta ◽  
Toshiaki Tanabe ◽  
Takahito Watanabe ◽  
Yoichi Honda ◽  
Masaaki Kuwahara ◽  
...  
Holzforschung ◽  
2008 ◽  
Vol 62 (4) ◽  
Author(s):  
Marcos Paulo Vicentim ◽  
André Ferraz

Abstract The effect of different culture conditions have been evaluated concerning the extracellular enzyme activities of the white-rot fungus Ceriporiopsis subvermispora growing on Eucalyptus grandis wood. The consequence of the varied fungal pretreatment on a subsequent chemithermomechanical pulping (CTMP) was addressed. In all cultures, manganese peroxidase (MnP) and xylanase were the predominant extracellular enzymes. The biopulping efficiency was evaluated based on the amount of fiber bundles obtained after the first fiberizing step and the fibrillation levels of refined pulps. It was found that the MnP levels in the cultures correlated positively with the biopulping benefits. On the other hand, xylanase and total oxalate levels did not vary significantly. Accordingly, it was not possible to determine whether MnP accomplishes the effect alone or depends on synergic action of other extracellular agents. Pulp strength and fiber size distribution were also evaluated. The average fiber length of CTMP pulps prepared from untreated wood chips was 623 μm. Analogous values were observed for most of the biopulps; however, significant amounts of shorter fibers were found in the biopulp prepared from wood chips biotreated in cultures supplemented with glucose plus corn-steep liquor. Despite evidence of reduced average fiber length, biopulps prepared from these wood chips presented the highest improvement in tensile indexes (+28% at 23° Schopper-Riegler).


Holzforschung ◽  
2008 ◽  
Vol 62 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Fernando Masarin ◽  
André Ferraz

Abstract In biopulping, efficient wood colonization by a selected white-rot fungus depends on previous wood chip decontamination to avoid the growth of primary molds. Although simple to perform in the laboratory, in large-scale biopulping trials, complete wood decontamination is difficult to achieve. Furthermore, the use of fungal growth promoters such as corn steep liquor enhances the risk of culture contamination. This paper evaluates the ability of the biopulping fungus Ceriporiopsis subvermispora to compete with indigenous fungi in cultures of fresh or poorly decontaminated Eucalyptus grandis wood chips. While cultures containing autoclaved wood chips were completely free of contaminants, primary molds grew rapidly when non-autoclaved wood chips were used, resulting in heavily contaminated cultures, regardless of the C. subvermispora inoculum/wood ratio evaluated (5, 50 and 3000 mg mycelium kg−1 wood). Studies on benomyl-amended medium suggested that the fungi involved competed by consumption of the easily available nutrient sources, with C. subvermispora less successful than the contaminant fungi. The use of acid-washed wood chips decreased the level of such contaminant fungi, but production of manganese peroxidase and xylanases was also decreased under these conditions. Nevertheless, chemithermomechanical pulping of acid-washed samples biotreated under non-aseptic conditions gave similar fibrillation improvements compared to samples subjected to the standard biodegradation process using autoclaved wood chips.


2013 ◽  
Vol 12 (2) ◽  
pp. 120-128 ◽  
Author(s):  
Daniela Chmelová ◽  
Miroslav Ondrejovič

Abstract The aim of this study was to set parameters of repeated-batch cultivation of Ceriporiopsis subvermispora for laccase production and evaluate the efficiency of this type of cultivation for production of selected enzyme. The suitable conditions for repeated-batch cultivation were designed on the base of study of batch cultivation of white-rot fungus C. subvermispora. C. subvermispora was cultivated in media with different concentration of casein hydrolysate as nitrogen source and glucose as carbon source. A suitable concentration of casein hydrolysate to stimulate the laccase production was 1.5 and 2.5 g/L. Laccase production was started at certain critical concentration of glucose (5 g/L). In order to improve laccase production by repeated-batch cultivation of C. subvermispora, glucose was tested in concentration 10 g/L and casein hydrolysate in concentration 1.5 g/L. During a repeated-batch cultivation was measured increase laccase activities from 177.8 to 266 U/L. It was also observed, the cultivation time needed to reach maximum laccase production was shortened to 10 days.


2020 ◽  
Author(s):  
Alex R Gonzalez ◽  
Gino R Corsini ◽  
Sergio Lobos ◽  
Daniela Seelenfreund ◽  
Mario Tello

Abstract Background: Ceriporiopsis subvermispora is a white-rot fungus that displays a high specificity towards lignin mineralization when colonizing dead wood or lignocellulosic compounds. The lignocellulose degrading system from C. subvermispora is formed by genes that encode cellulose hydrolytic enzymes, manganese peroxidases, and laccases that catalyze the efficient depolymerization and mineralization of lignin in the presence of Mn3+ through the formation of lipoperoxides from unsaturated lipid acids. This highly specific lignin-degrading system is unique among white-rot fungi. Methods: In order to determine if this metabolic specialization has modified codon usage of the ligninolytic system, leading to an increased adaptation to the fungal translational machine, we analyzed the adaptation to host codon usage (CAI), tRNA pool (tAI, and AAtAI), codon pair bias (CPB) and the number of effective codons (Nc). These indexes were correlated with gene expression of C. subvermispora, as evaluated by microarray in the presence of two carbon sources, glucose and Aspen wood.Results: General gene expression of C. subvermispora was not correlated with the CAI, tAI, AAtAI, CBP or Nc indexes used to evaluate adaptation to codon bias or the tRNA pool, neither in the presence of glucose or Aspen wood. However, in media containing Aspen wood, the induction of expression of lignin-degrading genes showed a strong correlation with all the former indexes. Lignin-degrading genes, defined as genes whose expression increases at least two-fold in Aspen wood, showed significantly (p<0.001) higher values of CAI, AAtAI, CPB, tAI and lower values of Nc with respect to non-induced genes. Among ligninolytic genes, cellulose-binding proteins and manganese peroxidases presented the highest adaptation values. We also identified an expansion of genes encoding glycine and glutamic acid tRNAs.Conclusions: Our results suggest that the metabolic specialization to use wood as the sole carbon source has introduced a bias in the codon usage of genes involved in lignocellulose degradation. This bias reduces codon diversity and increases codon usage adaptation to the tRNA pool available in C. subvermispora. To our knowledge, this is the first study showing that codon usage is modified to improve the translation efficiency of a group of genes involved in a particular metabolic pathway.


2018 ◽  
Vol 280 ◽  
pp. S88-S89
Author(s):  
Gordana Selo ◽  
Mirela Planinic ◽  
Marina Tisma ◽  
Darijo Sibalic ◽  
Ana Bucic Kojic

Holzforschung ◽  
2001 ◽  
Vol 55 (1) ◽  
pp. 42-46
Author(s):  
G. Idárraga ◽  
J. Ramos ◽  
R.A. Young ◽  
F. Denes ◽  
V. Zuñiga

Summary The effect of biological pretreatment of sisal with several white rot fungi on the energy consumption in refining and on the mechanical properties of the pulps was evaluated in this investigation. Improvements were realized in all the mechanical properties (22–66 %) and a reduction in the energy consumption of > 39% was realized for the treated pulps with the different fungi. The best strength improvement and energy reduction results overall were obtained with the white-rot fungus, Ceriporiopsis subvermispora. The incubation time was optimized for this fungus with the optimum mechanical properties obtained with a two week treatment time.


2005 ◽  
Vol 71 (7) ◽  
pp. 3608-3616 ◽  
Author(s):  
Marta R. Escutia ◽  
Laura Bowater ◽  
Anne Edwards ◽  
Andrew R. Bottrill ◽  
Matthew R. Burrell ◽  
...  

ABSTRACT Oxalate oxidase is thought to be involved in the production of hydrogen peroxide for lignin degradation by the dikaryotic white rot fungus Ceriporiopsis subvermispora. This enzyme was purified, and after digestion with trypsin, peptide fragments of the enzyme were sequenced using quadrupole time-of-flight mass spectrometry. Starting with degenerate primers based on the peptide sequences, two genes encoding isoforms of the enzyme were cloned, sequenced, and shown to be allelic. Both genes contained 14 introns. The sequences of the isoforms revealed that they were both bicupins that unexpectedly shared the greatest similarity to microbial bicupin oxalate decarboxylases rather than monocupin plant oxalate oxidases (also known as germins). We have shown that both fungal isoforms, one of which was heterologously expressed in Escherichia coli, are indeed oxalate oxidases that possess ≤0.2% oxalate decarboxylase activity and that the organism is capable of rapidly degrading exogenously supplied oxalate. They are therefore the first bicupin oxalate oxidases to have been described. Heterologous expression of active enzyme was dependent on the addition of manganese salts to the growth medium. Molecular modeling provides new and independent evidence for the identity of the catalytic site and the key amino acid involved in defining the reaction specificities of oxalate oxidases and oxalate decarboxylases.


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