Identification of novel 4-hydroxyphenylpyruvate dioxygenase genes from the deep sea sediment metagenomes
To access the microbial genetic resources of deep-sea sediments by a culture-independent approach,two metagenomic libraries constructed with deep sea sediments DNA were screened for the 4-hydroxyphenylpyruvate dioxygenase(4HPPD)activity and three positive clones were obtained.In vitro transposon mutagenesis and full-length sequencing revealed two novel 4HPPD genes and a novel homogentistic acid(HGA)metabolism gene clus-ter.Three new 4HPPD genes cloned into pMD18-T vector could produce water-soluble brown pigment in Escherichia coli.The pigment was identified to be pyomelanin and associated with HGA.Results show that the metagenomes of deep-sea sediments contain diverse 4HPPD functional genes,which can be used to find new melanin biosysthesis genes.