Polyphenol oxidase and laccase are known as enzymes that oxidize polyphenols. Various studies have been made on the use of polyphenol-oxidizing enzymes. For example, WO 94-29510 reports the delignination in the field of paper and pulp; and WO 91-05839, EP 91619032, DE 4008894 and JP-A 64-60693 report the use of the enzymes for bleaching in laundry washing.
However, the only known microbial sources for polyphenol oxidase and laccabe are mold fungi such as Basidiomycetes and Deuteromycetes., and it is generally difficult to cultivate large amounts of such fungi and, in addition, the rate of growth of the cells during cultivation is not high. Improving the enzyme yield by mutation or by use of genetic engineering technology is more difficult with these fungi than with bacteria, since the fungi have complicated life cycles and have complicated gene structures comprising introns, etc. For these reasons, it is difficult to stably and inexpensively obtain large amounts of polyphenol oxidases from such fungi, and bacteria-derived polyphenol oxidases are desired in order to apply them to practical use.
It is the object of the present invention to provide a polyphenol oxidase to be produced by bacteria, the bacteria that produce the enzyme and the use of the enzyme, thus providing a novel enzyme source of polyphenol oxidase for use in the oxidation of colored substances and oxidation of polyphenol-containing substances and also for use in cleaning.