Institut für Allgemeine Botanik, Abteilung Mikrobiologie, Ohnhorststrasse 18, and Institut für Organische Chemie, Martin-Luther-King-Platz 4, Universität Hamburg, D-2000 Hamburg, Federal Republic of Germany.
Appl Environ Microbiol. 1990 Apr;56(4):1148-56. doi: 10.1128/aem.56.4.1148-1156.1990.
A Pseudomonas sp. strain, HH69, and a mixed culture, designated HH27, were isolated by selective enrichment from soil samples. The pure strain and the mixed culture grew aerobically on dibenzofuran as the sole source of carbon and energy. Degradation proceeded via salicylic acid which was branched into the gentisic acid and the catechol pathway. Both salicylic acid and gentisic acid accumulated in the culture medium of strain HH69. The acids were slowly metabolized after growth ceased. The enzymes responsible for their metabolism showed relatively low activities. Besides the above-mentioned acids, 2-hydroxyacetophenone, benzopyran-4-one (chromone), several 2-substituted chroman-4-ones, and traces of the four isomeric monohydroxydiben-zofurans were identified in the culture medium. 2,2',3-Trihydroxybiphenyl was isolated from the medium of a dibenzofuran-converting mutant derived from parent strain HH69, which can no longer grow on dibenzofuran. This gives evidence for a novel type of dioxygenases responsible for the attack on the biarylether structure of the dibenzofuran molecule. A meta-fission mechanism for cleavage of the dihydroxylated aromatic nucleus of 2,2',3-trihydroxybiphenyl is suggested as the next enzymatic step in the degradative pathway.
一株假单胞菌 HH69 菌株和一种混合培养物 HH27 通过从土壤样品中进行选择性富集分离出来。纯菌株和混合培养物可以在二苯并呋喃作为唯一碳源和能源的条件下进行好氧生长。降解通过水杨酸进行，水杨酸分叉为龙胆酸和儿茶酚途径。在 HH69 菌株的培养液中积累了水杨酸和龙胆酸。生长停止后，这些酸会缓慢代谢。负责其代谢的酶的活性相对较低。除了上述酸外，在培养基中还鉴定出了 2-羟基苯乙酮、苯并吡喃-4-酮（色酮）、几种 2-取代色烷-4-酮以及痕量的四种同分异构单羟基二苯并呋喃。从二苯并呋喃转化突变体的培养基中分离出了 2,2',3-三羟基联苯，该突变体不能再在二苯并呋喃上生长。这为负责二苯并呋喃分子的联苯醚结构攻击的新型双加氧酶提供了证据。建议 2,2',3-三羟基联苯的二羟基芳核的间分裂机制是降解途径中的下一步酶促步骤。
