PLASMID PROFILE OF ERWINIA-HERBICOLA ATCC-21998

Extra-chromosomal genome study of Erwinia herbicola ATCC 21998 was car ried out. Two plasmids (pVQ1, pVQ2: mol. wt 7.4 and 8.0 kb respectivel y) were identified. One of the plasmids (pVQ2) was cured off and a res triction endonuclease map of the other plasmid (pVQ1) is established. E. herbicola ATCC 21998 being a keto-acid producing bacteria like Gluc onobacter oxydans ATCC 9937 converts glucose to 2,5-diketo gluconic ac id by a membrane-bound direct glucose dehydrogenase system, Plasmid me diation of direct glucose oxidation in G. oxydans ATCC 9937 (refs 1, 2 ) prompted us to study the presence of glucose dehydrogenase gene on t he plasmid of E. herbicola. Based on DNA/DNA hybridization it is sugge sted that glucose dehydrogenase gene is encoded in 4.3 kb Sac I fragme nt of plasmid pVQ1.