A Gram-negative, alkalotolerant bacterium, isolated from the soil continually drained with industrial wastewater and identified as gamma-proteobacteriumby partial 16S rRNA sequence analysis, produced a polyphenol oxidase, which showed laccase but not tyrosinase activity. The organism grew well from pH 6 to 10 and produced laccase maximally at pH 10. The enzyme was stable from pH 3 to 10.6 for at least 24 h and was optimally active at 55 degreesC and pH 6.5 in a 5 min assay.