Open AccessAnaerobic degradation of 3‐hydroxybenzoate by a newly isolated nitrate‐reducing bacterium
Author(s) -
Heising Silke,
Brune Andreas,
Schink Bernhard
Publication year - 1991
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1991.tb04608.x
Subject(s) - nitrite , hydroxybenzoate , nitrate , chemistry , bacteria , biochemistry , biodegradation , anaerobic exercise , strain (injury) , energy source , nuclear chemistry , organic chemistry , biology , physiology , coal , anatomy , genetics
A gram‐negative nitrate‐reducing bacterium, strain Asl‐3, was isolated from activated sludge with nitrate and 3‐hydroxybenzoate as sole source of carbon and energy. The new isolate was faculaatively anaerobic, catalase‐ and oxidase‐positive and polarly monotrichously flagellated. In addition to nitrate, nitrite, N 2 O, and O 2 served as electron acceptors. Growth with 3‐hydroxybenzoate and nitrate was biphasic: nitrate was completely reduced to nitrite before nitrite reduction to N 2 started. Benzoate, 3‐hydroxybenzoate, 4‐hydroxybenzoate, protocatechuate or phenyl‐acetate served as electron and carbon source under aerobic and anaerobic conditions. During growth with excess carbon source, poly‐ β ‐hydroxybutyrate was formed. These characteristics allow the affiliation of strain Asl‐3 with the family Pseudomonadaceae. Analogous to the pathway of 4‐hydroxybenzoate degradation in other bacteria, the initial step in anaerobic 3‐hydroxybenzoate degradation by this organism was activation to 3‐hydroxy‐benzoyl‐CoA in an ATP‐consuming reaction. Cell extracts of 3‐hydroxybenzoate‐grown cells exhibited 3‐hydroxybenzoyl‐CoA synthetase activity of 190 nmol min −1 mg protein −1 as well as benzoyl‐CoA synthetase activity of 86 nmol min −1 mg protein −1 . A reductive dehydroxylation of 3‐hydroxybenzoyl‐CoA could not be demonstrated due to rapid hydrolysis of chemically synthesized 3‐hydroxybenzoyl‐CoA by cell extracts.