title: Utilization of quinate and p-hydroxybenzoate by actinomycetes: key enzymes and taxonomic relevance.
abstract: 474 strains of the actinomycete genera Streptomyces (including species of the former genera Chainia and Streptoverticillium), Pseudonocardia and Micromonospora were examined for their ability to degrade quinate (Q) and p-hydroxybenzoate (pHB); selected strains were also tested for their capacity to catabolize benzoate (B). Whereas in the case of Q (5-10 g/l of a mineral salts agar medium) the growth response signalizes assimilation, pHB has to be supplied in lower concentration (routinely 0.3 g/l together with small amounts of peptone and yeast extract in liquid broth), and its degradation has to be determined spectrophotometrically. 27% of the streptomycete strains were able to grow with Q, and 57% with pHB. The three strains of "Chainia" that were tested metabolized Q and pHB, but none of the fourty species of "Streptoverticillium" showed this ability. 80% of the 30 strains of Psn. autotrophica grew with Q, and 100% degraded pHB and B. Two of the five Micromonospora strains gave a positive response with pHB, but not with Q.-Toluene treated cells (preincubated with Q, pHB or B, respectively) gave a positive Rothera reaction with protocatechuate or catechol respectively, thus demonstrating that these organisms employed the beta-ketoadipate pathway (orthofission) for the degradation of Q, pHB and B. The assay of five relevant enzymes in cell-free extracts of nine selected organisms showed that in nocardioform actinomycetes (Pseudonocardia, Rhodococcus) all enzymes of the protocatechuate branch of the ketoadipate pathway seem to be induced by beta-ketoadipate as demonstrated here for protocatechuate-3,4-dioxygenase. In contrast, in Streptomyces this enzyme appears to be induced by its substrate, protocatechuate, whereas the regulation of the other enzymes of this pathway remains to be elucidated.
authors.affiliation: Institut für Mikrobiologie und Genetik der Technischen Universität Darmstadt, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Grund
authors.forename: H J
authors.initials: HJ
authors.lastname: Kutzner
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D000192:Actinomycetales / Q000145:classification / Q000201:enzymology / Q000378:metabolism; D001565:Benzoates / Q000378:metabolism; D001673:Biodegradation, Environmental; D002396:Catechols / Q000378:metabolism; D010226:Parabens / Q000378:metabolism*; D011520:Protocatechuate-3,4-Dioxygenase / Q000378:metabolism; D011801:Quinic Acid / Q000378:metabolism*; D012765:Shikimic Acid / Q000378:metabolism; D012988:Soil Microbiology; D013302:Streptomyces / Q000145:classification* / Q000201:enzymology* / Q000378:metabolism
chemical_list: D001565:Benzoates; D002396:Catechols; D010226:Parabens; D011801:Quinic Acid; D015084:2,4-Dichlorophenoxyacetic Acid; D012765:Shikimic Acid; D011520:Protocatechuate-3,4-Dioxygenase; C038193:4-hydroxybenzoic acid; C034221:catechol; C004764:4-(2,4-dichlorophenoxy)butyric acid