Diversity of the enzymes from the novel Antarctic psychrotolerant Flavobacterium frigidimaris KUC-1: a possibility of Flavobacterium as a new enzyme source

We isolated a novel species of Flavobacterium from Antarctic seawater named Flavobacterium frigidimaris. The type strain is KUC-1, classified as a psychrotolerant organism based on its growth temperature. Interestingly, F. frigidimaris KUC-1 produces various thermostable enzymes in addition to the cold-active enzymes. We purified from the cell-free extract of F. frigidimaris KUC-1 the following thermostable enzymes: an aspartase (2), an alcohol dehydrogenase (ADH) (3), and an aldehyde dehydrogenase (ALDH) (4); and following the cold-active enzymes: a malate dehydrogenase (MDH), a valine dehydrogenase (ValDH)(5), and a threonine dehydrogenase (ThrDH)(6). Accordingly, Flavobacterium strain is expected to be a good candidate as a source of new type of biocatalysts, which are applicable for various industrial purposes. The thermostable enzyme genes of F. frigidimaris KUC-1 are expected to be useful for investigation of the evolution of Flavobacterium as probes. Running text The phylogenetic tree showed that F. frigidimaris KUC-1 is similar to F. hydatis, F