Microbial production of isoquinoline from indene

A purified microbial isolate, identified as a strain of Rhodococcus sp., metabolized indene primarily to iso quinoline and lesser amounts of indandiol and indanone. Isoquinoline production was dependent on the presence of microbial culture, indene, and ammonium ions as the source of nitrogen in the molecule. The ability to produce isoquinoline was induced by growth on benzene or naphthalene and by the presence of indene itself. The culture produced compounds tentatively identified as 3-methylisoquinoline and 3-ethylisoquinoline from 2-methylindene and from 2-ethylindene, respectively. Deuterated indene was converted to deuterated isoquinoline, deuterated indanone, and deuterated indandiol. Experiments with [15N]ammonium nitrate and ammonium [15N]nitrate confirmed ammonium as the source of nitrogen in the isoquinoline products.