Microbial metabolism of quinoline and related compounds. IV. Degradation of isoquinoline by Alcaligenes faecalis Pa and Pseudomonas diminuta 7

From sewage and soil isoquinoline-degrading organisms were enriched. Two strains could be isolated which were able to utilize isoquinoline as sole carbon source. The bacteria were tentatively identified as Alcaligenes faecalis and Pseudomonas diminuta with respect to their morphological and physiological characters. When growing on isoquinoline both strains excrete a metabolite into the medium which was identified as 1-oxo-1,2-dihydroisoquinoline. Alcaligenes faecalis was cultivated in continuous culture on 1-oxo-1,2-dihydroisoquinoline to improve growth on isoquinoline and degradative activity.     

Microbial metabolism of quinoline and related compounds. II. Degradation of quinoline by Pseudomonas fluorescens 3, Pseudomonas putida 86 and Rhodococcus spec. B1

Quinoline catabolism was investigated with different bacterial strains, able to use quinoline as sole source of carbon, nitrogen and energy. Some degradation products of quinoline were isolated from the culture fluids and identified. With Pseudomonas fluorescens and Pseudomonas putida we found 2-oxo-1,2-dihydroquinoline, 8-hydroxy-2-oxo-1,2-dihydroquinoline, 8-hydroxycoumarin and 2,3-dihydroxyphenylpropionic acid as intermediates. With a Rhodococcus strain 2-oxo-1,2-dihydroquinoline, 6-hydroxy-2-oxo-1,2-dihydroquinoline, a red meta-cleavage product and a blue fluorescent compound were isolated. The red compound was identified as 5-hydroxy-6-(3-carboxy-3-oxopropenyl)-1H-2-pyridone. From this the blue fluorescent azacoumarin 2H-pyrano-2-one-[3,2b]-5H-6-pyridone is formed by chemical decomposition. Therefore it can be considered a by-product of quinoline-degradation in Rhodococcus spec. With the present results two different degradation pathways for quinoline in different microorganisms are proposed.     

Microbial metabolism of quinoline and related compounds. V. Degradation of 1H-4-oxoquinoline by Pseudomonas putida 33/1

A bacterial strain was isolated with the ability to use 1H-4-oxoquinoline as the sole source of carbon, nitrogen and energy. On the basis of its physiological properties, this isolate was classified as Pseudomonas putida. 1H-3-Hydroxy-4-oxoquinoline, N-formylanthranilic acid, anthranilic acid and catechol were identified as intermediates in the degradation pathway. The latter was further degraded by ortho-cleavage. The enzymatic conversion of 1H-4-oxoquinoline into 1H-3-hydroxy-4-oxoquinoline requires oxygen and NADH. Experiments with 18O2 showed that the oxygen consumed in this enzymatic reaction is derived from the atmosphere.     

Microbial metabolism of quinoline and related compounds. III. Degradation of 3-chloroquinoline-8-carboxylic acid by Pseudomonas spec. EK III

Bacteria have been isolated with the ability to use 3-chloroquinoline-8-carboxylic acid as sole source of carbon and energy. According to their physiological properties, these bacteria have been classified as Pseudomonas spec. Two metabolites of the degradation pathway have been isolated and identified. The first metabolite was 3-(3-carboxy-3-oxopropenyl)-2-hydroxy-5-chloropyridine, the meta-cleavage product of 3-chloro-7,8-dihydroxyquinoline. The second metabolite, 5-chloro-2-hydroxynicotinic acid, was not further metabolized by this organisms.     

Microbial metabolism of quinoline and related compounds. VIII. Xanthine dehydrogenase from a quinoline utilizing Pseudomonas putida strain.

The xanthine dehydrogenase from Pseudomonas putida 86 was purified 68-fold to homogeneity with 47% recovery. SDS-polyacrylamide gel electrophoresis of the enzyme revealed two protein bands corresponding to an Mr of 87,000 and 52,000. The Mr of the native enzyme was calculated to 550,000 by gel chromatography. The enzyme contained 4 atoms of molybdenum, 16 atoms of iron, 16 atoms of acidlabile sulphur and 4 molecules of FAD. Due to the composition of the cofactors the xanthine dehydrogenase belongs to the class of molybdo-iron/sulphur-flavoproteins. Form A, an oxidation product of the molybdenum cofactor, was identified. Methanol and cyanide were effective inhibitors.     

Microbial metabolism of quinoline and related compounds. XI. Degradation of quinoline-4-carboxylic acid by Microbacterium sp. H2, Agrobacterium sp. 1B and Pimelobacter simplex 4B and 5B.

From soil enrichment cultures four strains, using quinoline-4-carboxylic acid as sole source of energy and carbon, have been isolated. According to their physiological properties these bacteria have been identified as Microbacterium sp. designated H2, as Agrobacterium sp. designated 1b and Pimelobacter simplex designated 4B and 5B. Metabolites of the degradation pathway of quinoline-4-carboxylic acid have been isolated and identified. With Pimelobacter simplex 4B and 5B 2-oxo-1,2-dihydroquinoline-4-carboxylic acid and 8-hydroxycoumarin-4-carboxylic acid were isolated. The Agrobacterium strain accumulated 2-oxo-1,2-dihydroquinoline-4-carboxylic acid and 2-oxo-1,2,3,4-tetrahydroquinoline-4-carboxylic acid in the media during growth; with Microbacterium sp. H2 we only found 8-hydroxycoumarin-4-carboxylic acid. With mutants of Microbacterium sp. H2 which were induced with N-methyl-N'-nitro-N-nitrosoguanidine we found 2-oxo-1,2-dihydroquinoline-4-carboxylic acid, 8-hydroxy-coumarin-4-carboxylic acid and 2,3-dihydroxyphenyl-succinic acid.     

节杆菌(Arthrobacter sp.)降解阿魏酸的效能

[背景]蓄积在土壤中的阿魏酸类化感自毒物质对农作物生长产生危害,利用有益微生物分解该类物质是一项有效的治理措施.[目的]从自然界土壤分离获得能高效降解阿魏酸的菌株,并评估典型环境因子对降解效能的影响,以期为该菌在阿魏酸类自毒物质降解领域中的应用提供理论依据.[方法]采用一次性投加高浓度化合物的驯化方法分离筛选得到能有效...     

Microbial metabolism of quinoline and related compounds. IX. Degradation of 6-hydroxyquinoline and quinoline by Pseudomonas diminuta 31/1 Fa1 and Bacillus circulans 31/2 A1

Two strains, using 6-hydroxyquinoline as sole source of energy, carbon and nitrogen, have been isolated. These bacteria, designated 31/1 Fa1 and 31/2 A1, are also able to degrade quinoline. According to their physiological properties strain 31/1 Fa1 has been identified as Pseudomonas diminuta and strain 31/2 A1 as Bacillus circulans. 6-Hydroxy-2-oxo-1,2-dihydroquinoline was found as intermediate in the degradation of 6-hydroxyquinoline and quinoline. 2-Oxo-1,2-dihydroquinoline was the first metabolite in the degradation of quinoline.     

Microbial transformation of quinoline by a Pseudomonas sp.

A Pseudomonas sp. isolated from sewage by enrichment culture on quinoline metabolized this substrate by a novel pathway involving 8-hydroxycoumarin. During early growth of the organism on quinoline, 2-hydroxyquinoline accumulated as the intermediate; 8-hydroxycoumarin accumulated as the major metabolite on further incubation. 2,8-Dihydroxyquinoline and 2,3-dihydroxyphenylpropionic acid were identified as the other intermediates. Inhibition of quinoline metabolism by 1 mM sodium arsenite led to the accumulation of pyruvate, whereas inhibition by 5 mM arsenite resulted in the accumulation of 2-hydroxyquinoline as the major metabolite and 2,8-dihydroxyquinoline as the minor metabolite. Coumarin was not utilized as a growth substrate by this bacterium, but quinoline-grown cells converted it to 2-hydroxyphenylpropionic acid, which was not further metabolized. Quinoline, 2-hydroxyquinoline, 8-hydroxycoumarin, and 2,3-dihydroxyphenylpropionic acid were rapidly oxidized by quinoline-adapted cells, whereas 2,8-dihydroxyquinoline was oxidized very slowly. Quinoline catabolism in this Pseudomonas sp. is therefore initiated by hydroxylation(s) of the molecule followed by cleavage of the pyridine ring to yield 8-hydroxycoumarin, which is further metabolized via 2,3-dihydroxyphenylpropionic acid.     

Microbial metabolism of quinoline and related compounds. VII. Quinoline oxidoreductase from Pseudomonas putida: a molybdenum-containing enzyme

The quinoline oxidoreductase from Pseudomonas putida was purified 50-fold to homogeneity with 21% recovery, using ammonium sulfate precipitation, hydrophobic interaction-, anion exchange-, and gel chromatography. The Mr of the native enzyme was calculated to be 300,000 by gel filtration. SDS-polyacrylamide gel electrophoresis of the enzyme revealed three protein bands corresponding to Mr 85,000, 30,000 and 20,000. The enzyme contained 8 atoms of iron, 8 atoms of acid-labile sulfide, 2 molecules of FAD, and the molybdenum cofactor, molybdopterin. Besides quinoline, the quinoline oxidoreductase also catalysed the conversion of 5-, 6-, 7- and 8-hydroxyquinoline and 8-chloroquinoline to the corresponding 2-oxo compounds. The incorporated oxygen atom was derived from water. Cyanide and methanol were effective inhibitors.     

Degradation of 4-Chlorobenzoic Acid by Arthrobacter sp

A mixed population, enriched and established in a defined medium, from a sewage sludge inoculum was capable of complete mineralization of 4-chlorobenzoate. An organism, identified as Arthrobacter sp., was isolated from the consortium and shown to be capable of utilizing 4-chlorobenzoate as the sole carbon and energy source in pure culture. This organism (strain TM-1), dehalogenated 4-chlorobenzoate as the initial step in the degradative pathway. The product, 4-hydroxybenzoate, was further metabolized via protocatechuate. The ability of strain TM-1 to degrade 4-chlorobenzoate in liquid medium at 25°C was improved by the use of continuous culture and repeated sequential subculturing. Other chlorinated benzoates and the parent compound benzoate did not support growth of strain TM-1. An active cell extract was prepared and shown to dehalogenate 4-chloro-, 4-fluoro-, and 4-bromobenzoate. Dehalogenase activity had an optimum pH of 6.8 and an optimum temperature of 20°C and was inhibited by dissolved oxygen and stimulated by manganese (Mn²⁺). Strain improvement resulted in an increase in the specific activity of the cell extract from 0.09 to 0.85 nmol of 4-hydroxybenzoate per min per mg of protein and a decrease in the doubling time of the organism from 50 to 1.6 h.     

Microbial transformation of quinoline by a Pseudomonas sp

A Pseudomonas sp. isolated from sewage by enrichment culture on quinoline metabolized this substrate by a novel pathway involving 8-hydroxycoumarin. During early growth of the organism on quinoline, 2-hydroxyquinoline accumulated as the intermediate; 8-hydroxycoumarin accumulated as the major metabolite on further incubation. 2,8-Dihydroxyquinoline and 2,3-dihydroxyphenylpropionic acid were identified as the other intermediates. Inhibition of quinoline metabolism by 1 mM sodium arsenite led to the accumulation of pyruvate, whereas inhibition by 5 mM arsenite resulted in the accumulation of 2-hydroxyquinoline as the major metabolite and 2,8-dihydroxyquinoline as the minor metabolite. Coumarin was not utilized as a growth substrate by this bacterium, but quinoline-grown cells converted it to 2-hydroxyphenylpropionic acid, which was not further metabolized. Quinoline, 2-hydroxyquinoline, 8-hydroxycoumarin, and 2,3-dihydroxyphenylpropionic acid were rapidly oxidized by quinoline-adapted cells, whereas 2,8-dihydroxyquinoline was oxidized very slowly. Quinoline catabolism in this Pseudomonas sp. is therefore initiated by hydroxylation(s) of the molecule followed by cleavage of the pyridine ring to yield 8-hydroxycoumarin, which is further metabolized via 2,3-dihydroxyphenylpropionic acid.     

Microbial metabolism of quinoline and related compounds. XII. Isolation and characterization of the quinoline oxidoreductase from Rhodococcus spec. B1 compared with the quinoline oxidoreductase from Pseudomonas putida 86.

Quinoline oxidoreductase from Rhodococcus spec. B1 was purified 39-fold to apparent homogeneity in a 5-step procedure with a recovery of 26%. The Mr of the native enzyme as determined by gel chromatography was 300,000. SDS polyacrylamide gel electrophoresis of the enzyme revealed 3 protein bands corresponding to Mr 82,000, 32,000, and 18,000. The enzyme contains 1.3 atoms of molybdenum, 8 atoms of iron, 8 atoms of acid-labile sulphur, 2 molecules of FAD and 2 molecules of molybdopterin cytosine dinucleotide. Cyanide, 4-hydroxymercuribenzoate and methanol were effective as inhibitors. The amino-terminal protein sequences of the 3 subunits of quinoline oxidoreductase from Rhodococcus B1 compared to those of quinoline oxidoreductase from Pseudomonas putida 86 revealed no difference among 71 amino acids examined.     

Degradation of a Sodium Acrylate Oligomer by an Arthrobacter sp

Arthrobacter sp. strain NO-18 was first isolated from soil as a bacterium which could degrade the sodium acrylate oligomer and utilize it as the sole source of carbon. When 0.2% (wt/wt) oligomer was added to the culture medium, the acrylate oligomer was found to be degraded by 70 to 80% in 2 weeks, using gel permeation chromatography. To determine the maximum molecular weight for biodegradation, the degradation test was done with the hexamer, heptamer, and octamer, which were separated from the oligomer mixture by fractional gel permeation chromatography. The hexamer and heptamer were consumed to the extents of 58 and 36%, respectively, in 2 weeks, but the octamer was not degraded. Oligomers with three different terminal groups were synthesized to examine the effect of the different terminal groups on biodegradation, but few differences were found. Arthrobacter sp. NO-18 assimilated acrylic acid, propionic acid, glutaric acid, 2-methylglutaric acid, and 1,3,5-pentanetricarboxylic acid. Degradation of the acrylic unit structure by this strain is discussed.     

Degradation of 4-Chlorobenzoate by Facultatively Alkalophilic Arthrobacter sp. Strain SB8

A facultative alkalophile capable of utilizing 4-chlorobenzoate (4-CBA), strain SB8, was isolated from soil with an alkaline medium (pH 10.0) containing the haloaromatic compound as the carbon source. The strain, identified as an Arthrobacter sp., showed rather extensive 4-CBA-degrading ability. 4-CBA utilization by the strain was possible in the alkaline medium containing up to 10 g of the compound per liter. The 4-CBA-dechlorinating activity of resting cells was almost completely uninhibited by substrate concentrations up to 150 mM. The bacterium dehalogenated 4-CBA in the initial stage of the degradation and metabolized the compound via 4-hydroxybenzoate and protocatechuate. O₂ was needed for 4-CBA dechlorination by resting cells but not by cell extracts. O₂ was inhibitory to the 4-CBA dechlorination activity of cell extracts. These facts suggest dechlorination of 4-CBA by halide hydrolysis and an energy requirement for the transport of 4-CBA into cells.     

Microbial metabolism of quinoline and related compounds. X. The molybdopterin cofactors of quinoline oxidoreductases from Pseudomonas putida 86 and Rhodococcus spec. B1 and of xanthine dehydrogenase from Pseudomonas putida 86.

The bis(carboxamidomethyl) derivatives of the molybdenum cofactors in three eubacterial molybdo-iron/sulphur-flavoproteins were examined. The quinoline oxidoreductases from Pseudomonas putida 86 and Rhodococcus spec. B1 contain molybdopterin cytosine dinucleotide. In xanthine dehydrogenase from Pseudomonas putida 86, however, only molybdopterin was found. The bis(carboxamidomethyl) derivatives of all three enzymes were treated with nucleotide pyrophosphatase, but only those of the quinoline oxidoreductases were cleaved into [bis(carboxamidomethyl)]molybdopterin and CMP, whereas that of xanthine dehydrogenase remained unchanged. Dephosphorylation by alkaline phosphatase yielded dephospho-[bis(carboxamidomethyl)]molybdopterin and cytidine from the cleaved molybdopterin cytosine dinucleotide. The bis(carboxamidomethyl) derivative from xanthine dehydrogenase was converted to dephospho-[bis(carboxamidomethyl)]molybdopterin by alkaline phosphatase. Acid hydrolysis of the purified enzymes and analysis of the hydrolysate by HPLC confirmed that compared with the xanthine dehydrogenase both quinoline oxidoreductases contain CMP.     

Oxidative Degradation of 4-Hydroxyacetophenone in Arthrobacter sp. TGJ4

The 4-hydroxyacetophenone assimilating bacterium Arthrobacter sp. TGJ4 was isolated from a soil sample. The resting cell reaction suggested that the strain cleaved 4-hydroxyacetophenone and its 3-methoxy derivative to the corresponding carboxylic acids and formaldehyde. Some properties of the enzyme catalyzing the cleavage reaction were examined.     

Microbial oxidation of dehydroepiandrosterone and related compounds.

The oxidation of dehydroepiandrosterone (DHEA), 4-androstene-3, 17-dione, and estrone with Streptomyces roseochromogenes NRRL B-1233 was studied. The oxidation products were isolated and identified as as 16alpha-hydroxy-DHEA, 16alpha-hydroxy-4-androstene-3,17-dione and 16alpha-hydroxyestrone. The yields of these three products were 85%, 41% and 18%, respectively. This indicates the substrate stereospecificity of 16alpha-hydroxylase of the organism. An interrelationship between cell growth and the formation of 16alpha-hydroxylated steroid was observed in any case. For formation of 16alpha-hydroxy-DHEA, 16alpha-hydroxylase showed good activity at DHEA concentration of 3.47 x 10(-4)M. In the case of DHEA, 16alpha-hydroxy-4-androstene-3,17-dione and 5-androstene-3beta, 16alpha, 17beta-triol were obtained after the yield of 16alpha-hydroxy-DHEA reached the maximum yield for about 30 hr. The oxidation pathway of DHEA is discussed.     

Plant compounds that induce polychlorinated biphenyl biodegradation by Arthrobacter sp. strain B1B.

Plant compounds that induced Arthrobacter sp. strain B1B to cometabolize polychlorinated biphenyls (PCBs) were identified by a screening assay based on the formation of a 4,4'-dichlorobiphenyl ring fission product. A chemical component of spearmint (Mentha spicata), l-carvone, induced Arthrobacter sp. strain B1B to cometabolize Aroclor 1242, resulting in significant degradation of 26 peaks in the mixture, including selected tetra- and pentachlorobiphenyls. Evidence for PCB biodegradation included peak disappearance, formation of a phenylhexdienoate ring fission product, and chlorobenzoate accumulation in the culture supernatant. Carvone was not utilized as a growth substrate and was toxic at concentrations of greater than 500 mg liter-1. Several compounds structurally related to l-carvone, including limonene, p-cymene, and isoprene, also induced cometabolism of PCBs by Arthrobacter sp. strain B1B. A structure-activity analysis showed that chemicals with an unsaturated p-menthane structural motif promoted the strongest cometabolism activity. These data suggest that certain plant-derived terpenoids may be useful for promoting enhanced rates of PCB biodegradation by soil bacteria.