Transformation and electrophoretic karyotyping of Coniochaeta ligniaria NRRL30616

Coniochaeta ligniaria NRRL30616 is an ascomycete that grows with yeast-like appearance in liquid culture. The strain has potential utility for conversion of fibrous biomass to fuels or chemicals. Furans and other inhibitory compounds in lignocellulosic biomass are metabolized by NRRL30616, facilitating subsequent microbial fermentation of biomass sugars. This study undertook initial characterization of the genetic system of C. ligniaria NRRL30616. Transformation using hygromycin as a dominant selectable marker was achieved using protoplasts generated by incubating cells in 1% (v/v) β-mercaptoethanol, followed by cell wall-digesting enzymes. Thirteen chromosomes with an estimated total size of 30.1 Mb were detected in C. ligniaria. The GC content of chromosomal DNA and of coding regions from cDNA sequences were 49.2 and 51.9%, respectively. This study is the first report of genome size, electrophoretic karyotype, and transformation system for a member of the Coniochaetales.