No abstract

A Gram-positive bacterium which was isolated from a Finnish soil and identified as a Nocardia sp., was able to decompose lignin and to assimilate lignin degradation products as a carbon source. It could release 14CO2 from 14C-labelled methoxyl groups, side chains or ring carbons of coniferyl alcohol dehydropolymers (DHP) and from specifically 14C-labelled lignin of plant material. Furthermore, it could release 14CO2 from phenolcarboxylic and cinnamic acids and alcohols labelled in the OCH3, COOH groups, side chain or aromatic ring carbons.

No abstract

Several Nocardia and Pseudomonas spp., as well as some unidentified bacteria, isolated from lake water containing high loads of waste lignin, were tested for their capacity to release 14CO2 from specifically 14C-labelled dehydropolymer of coniferyl alcohol (DHP) or corn stalk lignins. The bacteria were selected according to their ability to degrade phenolic compounds. However, only some of them could release significant amounts of 14CO2 from the labelled lignin. The tested Nocardia spp. were more active than the Pseudomonas spp. and the unidentified bacteria. The most active strains belonged to N. autotrophica. These strains released CO2 significantly from the methoxyl group and transformed the other carbons from the phenylpropane skeleton of lignin also into CO2. Other less demethylating strains also released little CO2 from the other carbons of the lignin molecule. From corn stalk materials which were specifically labelled in the lignin part, only small amounts of labelled CO2 were released.

No abstract