Isolation and cultivation of a novel microorganism producing a maltopentaose-forming enzyme

Summary A novel microorganism producing a maltopentaose-forming enzyme was screened from a soil sample. The enzyme produced by the bacteria formed maltopentaose from starch during the first stage of the reaction. The bacterium was characterized asPseudomonas sp. (KO-8940) on the basis of its morphological, physiological and biological properties. Culture conditions for enzyme production were investigated and established. The medium was composed of beef extract 0.8%, ammonium sulphate 1.0% and maltose 0.8% in tap water. Optimum conditions for bacterial growth were: initial pH 8.0, temperature 45°C, and 3 days cultivation with a rotary shaker (200 rpm). The broth supernatant obtained contained the maltopentaose-forming crude enzyme, with which 40% of starch was converted to maltopentaose.