Degradation of Lignin-Related Compounds by Actinomycetes

Abstract

Evidence for activity against the lignin fraction of straw was produced for a range of actinomycete strains. Decolorization of the polymeric dye Poly R and oxidation of veratryl alcohol, indicators of ligninolytic activity in white rot fungi, and utilization of fractionated Kraft lignin and low-molecular-weight methoxylated aromatic compounds were the criteria used. The relationships between these activities and the solubilization of native lignin are discussed.

Decolorisation of the polymeric dye Poly R by Streptomyces viridosporus T7A

“…These three actinomycetes are the most widely studied lignocellulose-solubilising actinomycetes (MCCARTHY 1987). All 3 strains have been show to be able to utilise KRAFT lignin (BALL et al 1989, GIROUX et al 1988. The decolorisation of Poly R by culture filtrate confirmed that decolorisation was not due merely to biomass uptake suggesting that the dye was being actively degraded.…”

“…Strains and growth conditions : Actinomycete strains were maintained a spore suspensions and hyphal fragments in 20% (v/v) glycerol at -70 "C. Strains were routinely cultured on L-agar plates (HOPWOOD et al 1985), and distilled water suspensions of sporulating growth were used to inoculate shake flasks containing basal salts medium supplemented with Poly R (0.02% w/v; SIGMA Chemical Co.) ( Fig. 1 (BALL et al 1989). In cultures of S. viridosporus examining the inducibility of extracellular decolorising activity, Poly R was replaced by 1 % (w/v) of the appropriate substrate.…”

“…Studies using the white rot fungus Phanerochaete chrysosporium suggested that the ligninolytic degrading activity of the organism was responsible for decolorising the polymeric dye (GLENN and GOLD 1983). Work using actinomycetes and the polymeric dye Poly-R 481 confirmed that lignocellulosesolubilising organisms were also capable of decolorising polymeric dyes (BALL et al 1989). A comparison of the activity of a number of lignocellulose solubilising actinomycetes against lignin and related compounds revealed that although in general there was a poor correlation between Poly R decolorisation and a number of other different assays used regularly as a measure of lignin degradation, a correlation was observed between the ability to decolorise Poly R and the ability to grow on KRAFT lignin (BALL et af.…”

Potentials of Hydrocarbon Utilization by Wood-Digesting Bacteria isolated from the Lagos Lagoon, Nigeria.

“…The culture of each test organism (5.0 mL) from the sets of flasks was harvested every 3 days for determination of biomass. Growth of strains EOB and ROB was monitored by the dry weight method [24] because of their mycelial growth and pellets. Culture was filtered through a pre-weighted Whatman filter paper No 42; it was dried in an oven at 60°C, cooled in a desiccator and weight was recorded.…”

Lignin Degradation: A Review

“…There are many genera of actinomycetes and eubacteria which can degrade extracted lignin and DHP (Buswell and Odier, 1987). Many bacterial strains, especially actinomycetes, can solubilize and modify the lignin structure extensively, but their ability to miner-alize lignin is limited (Buswell and Odier, 1987;Ball et al, 1989;Eriksson et al, 1990;Godden et al, 1992). Actinomycetes degrade lignin as their primary metabolic activity and at high nitrogen levels compared to white-rot fungi, most of which degrade lignin via their secondary metabolism.…”