GROWTH AND PLASMID-ENCODED NAPHTHALENE CATABOLISM OF PSEUDOMONAS-PUTIDA IN BATCH CULTURE

The growth characteristics of Pseudomonas putida plasmid-harbouring st rains which catabolize naphthalene via various pathways in batch cultu re with naphthalene as the sole source of carbon and energy have been investigated. The strains under study were constructed using the host strain P. putida BS394 which contained various naphthalene degradation plasmids. The highest specific growth rate was ensured by the plasmid s that control naphthalene catabolism through the meta-pathway of cate chol oxidation. The strains metabolizing catechol via the ortho-pathwa y grew at a lower rate. The lowest growth rate was observed with strai n BS291 harbouring plasmid pBS4 which controls naphthalene catabolism via the gentisic acid pathway. Various pathways of naphthalene catabol ism appear to allow these strains to grow at various rates which shoul d be taken into account when constructing efficient degraders of polyc yclic aromatic compounds.