Evaluation of the white-rot fungi Ganoderma australe and Ceriporiopsis subvermispora in biotechnological applications

Abstract

Ganoderma australe is a white-rot fungus that causes a selective wood biodelignification in some hardwoods found in the Chilean rainforest. Ceriporiopsis subvermispora is also a lignin-degrading fungus used in several biopulping studies. The enzymatic system responsible for lignin degradation in wood can also be used to degrade recalcitrant organic pollutants in liquid effluents. In this work, two strains of G. australe and one strain of C. subvermipora were comparatively evaluated in the biodegradation of ABTS and the dye Poly R-478 in liquid medium, and in the pretreatment of Eucalyptus globulus wood chips for further kraft biopulping. Laccase was detected in liquid and wood cultures with G. australe. Ceriporiopsis subvermispora produce laccase and manganese peroxidase when grown in liquid medium and only manganese peroxidase was detected during wood decay. ABTS was totally depleted by all strains after 8 days of incubation while Poly R-478 was degraded up to 40% with G. australe strains and up to 62% by C. subvermispora after 22 days of incubation. Eucalyptus globulus wood chips decayed for 15 days presented 1-6% of lignin loss and less than 2% of glucan loss. Kraft pulps with kappa number 15 were produced from biotreated wood chips with 2% less active alkali, with up to 3% increase in pulp yield and up to 20% less hexenuronic acids than pulps from undecayed control. Results showed that G. australe strains evaluated were not as efficient as C. subvermispora for dye and wood biodegradation, but could be used as a feasible alternative in biotechnological processes such as bioremediation and biopulping.

Determination of Differences in Anatomical and Chemical Characteristics of Tension and Opposite Wood of 8-Year Old Eucalyptus Globulus

“…Extractive free milled wood samples were characterized for glucan and lignin content by the procedure described by Mendonça et al (2008). Samples (300 mg) were weighed in a test tube and 3 mL of 72% H 2 SO 4 (w/w) added.…”

Chemical characteristics and Kraft pulping of tension wood from Eucalyptus globulus labill

“…Samples were characterized for glucans and lignin content by the acid hydrolysis with 72% H2SO4 following the procedure detailed by Mendonça et al (2008). The carbohydrates present in hemicelluloses were quantified by acid methanolysis followed by gas chromatography analysis according to Sundberg et al (1996).…”

An exploratory evaluation of the pulpability of Brachystegia spiciformis and Pericopsis angolensis from the angolan miombo woodlands

“…Two grams of milled wood samples were extracted with 90% acetone for 16 h. Samples were characterized for lignin by acid hydrolysis following the methodology described by Mendonça et al (2008). In a test tube were weighed 300 mg of sample and added 3 mL of 72% (w w -1 ) H 2 SO 4 .…”