Pessione E, Giunta C
Dipartimento di Biologia Animale, Università di Torino, Italy.
Microbios. 1997;89(359):105-17.
The metabolic potentialities of an Acinetobacter radioresistens strain, isolated from the soil adjacent to an activated sludge plant, were investigated. Among 26 aromatic substrates tested, only phenol, benzoate and catechol were metabolized. Since this strain possessed abundant plasmid DNA, the antibiotic and heavy metal resistance was examined, and the bacterial cells proved to be sensitive to all metals (Ni, Tl, Pb, Cd, Ag, Co, Zn) and antibiotics tested except for Fosfomycin and chloramphenicol. The degradation kinetics for phenol and benzoate as the sole carbon/energy source (pH 7, 30 degrees C) displayed different trends, confirmed by the bacterial growth curve. Crude extracts from phenol-grown cultures showed both phenol hydroxylating activity and catechol dioxygenating activity. Phenol hydroxylase possessed a reductase component able to reduce nitroblue tetrazolium (NBT) and cytochrome C, thus exhibiting differences from previously reported monocomponent phenol hydroxylases from the same genus. Catechol dioxygenase is an intradiol-cleaving enzyme recognizing also substituted catechols.
对从活性污泥厂附近土壤中分离出的一株抗辐射不动杆菌的代谢潜力进行了研究。在测试的26种芳香族底物中，只有苯酚、苯甲酸盐和儿茶酚能够被代谢。由于该菌株拥有丰富的质粒DNA，因此对其抗生素和重金属抗性进行了检测，结果表明，除磷霉素和氯霉素外，该细菌细胞对所有测试的金属（镍、铊、铅、镉、银、钴、锌）和抗生素均敏感。以苯酚和苯甲酸盐作为唯一碳源/能源（pH 7，30℃）时的降解动力学呈现出不同趋势，这一点通过细菌生长曲线得到了证实。苯酚培养物的粗提物同时具有苯酚羟化活性和儿茶酚双加氧活性。苯酚羟化酶拥有一个能够还原氮蓝四唑（NBT）和细胞色素C的还原酶组分，因此与该属之前报道的单组分苯酚羟化酶存在差异。儿茶酚双加氧酶是一种识别取代儿茶酚的间位裂解酶。
