[Transfer and expression of tyrosinase gene of Pseudomonas maltophilia in Pseudomonas pseudoalcaligenes].

Pseudomonas pseudoalcaligenes is a notably killing maggots bacterium, which was isolated from natural dead maggots in the manure pits in the countryside of Yancheng. It easily die from effect of ultra-violet ray when it is exposed in the sun. Antiradiation effect of melanin is quite strong. Mel gene of P. maltophilia AT18 has been introduced into P. pseudoalcaligenes, and enabled it the ability of producing melanin steadily. Southern hybridization studies confirmed that the small fragment cloned in the P. pseudoalcaligenes comes from P. maltophilia DNA. SDS-PAGE analysis also revealed that an additional protein of 18 kD, which was equal to the size of the putative tyrosinase according to mel fragment, was exressed in the P. pseudoalcaligenes recombinant carrying the mel gene, The results of assay show that antiradiation effect of recombinant is quites strong, the effect time of killing maggats is longer than the recipient, the recombinant can't infect animals and fowls.