Physiological characterization and sequence analysis of a syringate-consuming Actinobacterium

• Hardwood lignin is made of up to 75% syringyl-units and the bioconversion of syringate and syringaldehyde is therefore of considerable interest for biological valorization of lignin. In the current study, we have isolated a syringate-consuming bacterium identified as Microbacterium sp. RG1 and characterized its growth on several lignin model compounds. Growth was observed on syringate, 3-O-methylgallate, vanillate, 4-hydroxybenzoate, ferulate and p-coumarate. Toxic aromatic aldehydes such as vanillin and syringaldehyde were converted to their respective alcohols/acids which were eventually consumed with a maximum specific uptake rate of 0.02 and 0.1 mmol (g CDW h) −1 respectively. The isolate was further subjected to whole genome sequencing and putative genes related to the metabolism of syringyl-compounds were mapped for the first time in a Gram-positive bacterium. These findings will be of high significance when designing future host microorganisms and bioprocesses for the efficient valorization of pre-treated lignin feedstocks.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Industriell bioteknik -- Bioprocessteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Industrial Biotechnology -- Bioprocess Technology (hsv//eng)

Keyword

Gram-positive

Lignin bioconversion

Microbacterium

Syringaldehyde

Syringate demethylase

Publication and Content Type

art (subject category)

ref (subject category)