Isolation and characterization of a fungus Aspergillus sp. strain F-3 capable of degrading alkali lignin

Abstract

A fungus strain F-3 was selected from fungal strains isolated from forest soil in Dalian of China. It was identified as one Aspergillus sp. stain F-3 with its morphologic, cultural characteristics and high homology to the genus of rDNA sequence. The budges or thickened node-like structures are peculiar structures of hyphae of the strain. The fungus degraded 65% of alkali lignin (2,000 mg l(-1)) after day 8 of incubation at 30°C at pH 7. The removal of colority was up to 100% at 8 days. The biodegradation of lignin by Aspergillus sp. F-3 favored initial pH 7.0. Excess acid or alkali conditions were not propitious to lignin decomposing. Addition of ammonium L: -tartrate or glucose delayed or repressed biodegradation activities. During lignin degradation, manganese peroxidase (28.2 U l(-1)) and laccase (3.5 U l(-1))activities were detected after day 7 of incubation. GC-MS analysis of biodegraded products showed strain F-3 could convert alkali lignin into small molecules or other utilizable products. Strain F-3 may co-culture with white rot fungus and decompose alkali lignin effectively.

A dye-decolorizing peroxidase from Bacillus subtilis exhibiting substrate-dependent optimum temperature for dyes and β-ether lignin dimer

“…Until now, the lignin-degrading peroxidase such as LiP has been widely assayed with VA as the substrate 8 22 23 24 . In order to screen Bacillus species secreting the lignin-degrading biocatalyst, VA oxidation test was conducted using cell-free supernatant after two days cultivation of four Bacillus species ( B. subtilis KCTC 2023, B. subtilis ATCC6051, B. licheniformis ATCC14580 and B. amyloliquefacience subsp.…”

Characterization of lignin-degrading enzymes (LDEs) from a dimorphic novel fungus and identification of products of enzymatic breakdown of lignin

“…Literature survey shows that in general, fungi require a minimum of 2–4 weeks for growth and production of extracellular lignin-degrading enzymes. They also prefer lower pH (4–7) and temperature for lignin decomposition activity (Yang et al 2011 ). No single organism has been reported to produce all three enzymes, and, in equal proportions (Li et al 2001 ).…”

Isolation of Bacillus sp. strains capable of decomposing alkali lignin and their application in combination with lactic acid bacteria for enhancing cellulase performance

“…After sterilization, flasks were inoculated with 2% inoculum. Flasks were then incubated at 37ºC for 48 h.2.5 Enzyme activityLignin peroxidase (LiP, EC1.11.1.14) and manganese peroxidase (EC1.11.1.1) activity were determined as described byYang et al (2011).Laccase activity was determined in both culture fluid and using a crude intracellular enzyme. Laccase activity was measured in 1mL reaction measurements containing 75 mM catechol as the substrate in 50 mM sodium phosphate buffer, pH 5 and 200 μL of culture fluid.…”