scholarly journals Carbon and sulphur utilization during growth of Pseudomonas fluorescens on potassium d-glucose 6-O-sulphate as the sole sulphur source

1971 ◽  
Vol 122 (3) ◽  
pp. 277-283 ◽  
Author(s):  
J. W. Fitzgerald ◽  
K. S. Dodgson

Pseudomonas fluorescens N.C.I.B. 8248, cultured on potassium d-glucose 6[35S]-O-sulphate as the sole sulphur source, liberated the 6-O-sulphate ester of d-gluconate into the culture medium. Extracts of bacteria grown under this cultural condition oxidized d-glucose 6-O-sulphate to yield the gluconate ester. Results suggest the involvement of a glucose dehydrogenase-like enzyme. The gluconate ester was apparently not oxidized further to any significant extent; however, it served as substrate for a desulphating enzyme found in extracts. Growth on d-glucose 6-O-sulphate as the sole source of sulphur was not associated with the appearance of a true glycosulphatase. Collectively, these results suggest that d-gluconate 6-O-sulphate, rather than the glucose ester, supplied the necessary sulphur for growth. Oxidative activities toward d-glucose 6-O-sulphate, d-glucose, d-gluconate 6-O-sulphate and d-gluconate found in extracts of P. fluorescens adapted to grow on d-glucose 6-O-sulphate as the sole source of carbon and sulphur are presented for comparative purposes.

1971 ◽  
Vol 121 (3) ◽  
pp. 521-528 ◽  
Author(s):  
J. W. Fitzgerald ◽  
K. S. Dodgson

Pseudomonas fluorescens N.C.I.B. 8248 was adapted to grow on potassium d-glucose 6-O-sulphate as the sole carbon and sulphur source. Adapted bacteria grew optimally at 37°C on 1.6% (w/v) sulphate ester and growth coincided with the disappearance of the ester from the culture medium at a rate of 2.4mg/h per ml. Three sulphated compounds were detected in the culture fluid at the termination of growth. One of these was present in traces only and has not been identified. The second was present in somewhat greater amounts and was identified as the 6-O-sulphate ester of d-gluconate, and the major metabolite was identified as d-glycerate 3-O-sulphate. Sulphur utilization by the organism was not associated with the appearance of a glycosulphatase enzyme in the cells. However, a novel enzyme system (or systems) was present that liberated inorganic 35SO42− ions from dipotassium d-gluconate 6[35S]-O-sulphate and from dipotassium dl-glycerate 3[35S]-O-sulphate. Activity towards the latter substrate could not be detected when the adapted or parent Pseudomonas strain was cultured on d-glucose and potassium sulphate as respective carbon and sulphur sources. Some properties of the enzyme acting on the glycerate ester are recorded.


2002 ◽  
Vol 45 (12) ◽  
pp. 175-179 ◽  
Author(s):  
J.H. Shi ◽  
Y. Suzuki ◽  
B.-D. Lee ◽  
S. Nakai ◽  
M. Hosomi

We cultivated hundreds of sediment, soil, and manure samples taken from rivers and farms in a medium containing ethynylestradiol (EE2) as the sole source of carbon, so that microorganisms in the samples would acclimatize to the presence of EE2. Finally, we isolated an EE2-degrading microorganism, designated as strain HNS-1, from a cowshed sample. Based on its partial nucleotide sequence (563 bp) of the 28S rRNA gene, strain HNS-1 was identified as Fusarium proliferatum. Over 15 days, F. proliferatum strain HNS-1 removed 97% of EE2 at an initial concentration of 25 mg.L−1, with a first-order rate constant of 0.6 d−1. Unknown products of EE2 degradation, which may be more polar compounds that have a phenolic group, remained in the culture medium.


1990 ◽  
Vol 45 (4) ◽  
pp. 552-556 ◽  
Author(s):  
K. Taraz ◽  
E. M. Schaffner ◽  
H. Budzikiewicz ◽  
H. Korth ◽  
G. Pulverer

In addition to phenazine, phenazine-1-carboxylic acid, phenazine-1,6-dicarboxylic acid and 2,9-dihydroxyphenazine-1-carboxylic acid a new compound, viz. 2,3,9-trihydroxyphenazine-1-carboxylic acid could be isolated from the culture medium of Pseudomonas fluorescens grown under iron deficiency with beryllium added to the culture medium. Its structure elucidation is described.


1991 ◽  
Vol 46 (5-6) ◽  
pp. 398-406 ◽  
Author(s):  
H. Schäfer ◽  
K. Taraz ◽  
H. Budzikiewicz

Pseudomonas strains of the so-called fluorescent group usually produce several pyoverdins which differ only in the nature of a dicarboxylic acid bound amidically to the chromophor. For the pyoverdins isolated from the culture medium of Pseudomonas fluorescens 12 it is shown that succinic acid is an artefact formed by hydrolysis of succinic amide, and that a-ketoglutaric acid is transformed enzymatically to glutamic acid. This process is reversed after the phase of exponential growth of the bacteria. The ratio C4- vs. C5 -acids changes with the culture time and with increasing Fe3+ content of the medium in favor of the latter


1999 ◽  
Vol 62 (5) ◽  
pp. 543-546 ◽  
Author(s):  
J. FERNÁNDEZ ◽  
A. F. MOHEDANO ◽  
P. GAYA ◽  
M. MEDINA ◽  
M. NUÑEZ

Three proteinases were isolated from culture medium of Pseudomonas fluorescens INIA 745 and purified to homogeneity by a combination of Phenyl-Sepharose, DEAE-Sepharose, and Sephadex G-100 chromatography. Optimal temperature for enzymatic activity was 45°C for all three proteinases. The pH optimum of proteinases I and II was found to be 7.0, while that of proteinase III was 8.0. Divalent metal ions like Cu2+, Co2+, Zn2+, Fe2+, and Hg2+ were inhibitory to proteinase activity while Ca2+, Mg2+, and Mn2+ had little or no inhibitory effect. The three enzymes were strongly inhibited by EDTA and 1,10-phenantroline and partially by cysteine. The three enzymes are metalloproteinases since they were inhibited by chelators and reactivated by Co2+, Mn2+, Cu2+, and Zn2+. The Km values of proteinases I, II, and III for casein were calculated to be 3.2, 2.6, and 5.2 mg/ml, respectively. Proteinases II and III rapidly degraded β-casein, with preference to αs1-casein, whereas proteinase I hydrolyzed both casein fractions at a slow rate.


2002 ◽  
Vol 184 (3) ◽  
pp. 672-678 ◽  
Author(s):  
Johannes P. van Dijken ◽  
Arjen van Tuijl ◽  
Marijke A. H. Luttik ◽  
Wouter J. Middelhoven ◽  
Jack T. Pronk

ABSTRACT Under anaerobic conditions, the yeast Saccharomyces bulderi rapidly ferments δ-gluconolactone to ethanol and carbon dioxide. We propose that a novel pathway for δ-gluconolactone fermentation operates in this yeast. In this pathway, δ-gluconolactone is first reduced to glucose via an NADPH-dependent glucose dehydrogenase (EC 1.1.1.47). After phosphorylation, half of the glucose is metabolized via the pentose phosphate pathway, yielding the NADPH required for the glucose-dehydrogenase reaction. The remaining half of the glucose is dissimilated via glycolysis. Involvement of this novel pathway in δ-gluconolactone fermentation in S. bulderi is supported by several experimental observations. (i) Fermentation of δ-gluconolactone and gluconate occurred only at low pH values, at which a substantial fraction of the substrate is present as δ-gluconolactone. Unlike gluconate, the latter compound is a substrate for glucose dehydrogenase. (ii) High activities of an NADP+-dependent glucose dehydrogenase were detected in cell extracts of anaerobic, δ-gluconolactone-grown cultures, but activity of this enzyme was not detected in glucose-grown cells. Gluconate kinase activity in cell extracts was negligible. (iii) During anaerobic growth on δ-gluconolactone, CO2 production exceeded ethanol production by 35%, indicating that pyruvate decarboxylation was not the sole source of CO2. (iv) Levels of the pentose phosphate pathway enzymes were 10-fold higher in δ-gluconolactone-grown anaerobic cultures than in glucose-grown cultures, consistent with the proposed involvement of this pathway as a primary dissimilatory route in δ-gluconolactone metabolism.


2005 ◽  
Vol 71 (10) ◽  
pp. 6235-6240 ◽  
Author(s):  
Juan Pablo Busalmen ◽  
Susana R. de Sánchez

ABSTRACT The effect of surface electrochemical polarization on the growth of cells of Pseudomonas fluorescens (ATCC 17552) on gold electrodes has been examined. Potentials positive or negative to the potential of zero charge (PZC) of gold were applied, and these resulted in changes in cell morphology, size at cell division, time to division, and biofilm structure. At −0.2 V (Ag/AgCl-3 M NaCl), cells elongated at a rate of up to 0.19 μm min−1, rendering daughter cells that reached up to 3.8 μm immediately after division. The doubling time for the entire population, estimated from the increment in the fraction of surface covered by bacteria, was 82 ± 7 min. Eight-hour-old biofilms at −0.2 V were composed of large cells distributed in expanded mushroom-like microcolonies that protruded several micrometers in the solution. A different behavior was observed under positive polarization. At an applied potential of 0.5 V, the doubling time of the population was 103 ± 8 min, cells elongated at a lower rate (up to 0.08 μm min−1), rendering shorter daughters (2.5 ± 0.5 μm) after division, although the duplication times were virtually the same at all potentials. Biofilms grown under this positive potential were composed of short cells distributed in a large number of compact microcolonies. These were flatter than those grown at −0.2 V or at the PZC and were pyramidal in shape. Polarization effects on cell growth and biofilm structure resembled those previously reported as produced by changes in the nutritional level of the culture medium.


1994 ◽  
Vol 40 (9) ◽  
pp. 787-790 ◽  
Author(s):  
Ramaraj Boopathy ◽  
John Manning ◽  
Carlo Montemagno ◽  
Kris Rimkus

The metabolism of trinitrobenzene by a Pseudomonas consortium was studied. The Pseudomonas consortium used trinitrobenzene as a sole source of nitrogen, but not as a sole source of carbon. Trinitrobenzene was metabolized within 60 h of incubation. The main intermediates produced were dinitroaniline, 1,5-dinitrobenzene, nitroaniline, 5-nitrobenzene, and ammonia. The ammonia concentration in the culture medium increased during the course of incubation. Nearly stoichiometric amounts of 1,5-dinitrobenzene and 5-nitrobenzene were produced by the consortium. During trinitrobenzene metabolism by this bacterial consortium, the trinitrobenzene was first reduced to an amino compound, dinitroaniline. This intermediate was reductively deaminated with the release of ammonia into the culture medium and production of 1,5-dinitrobenzene. By the same mechanism, 1,5-dinitrobenzene was further converted to 5-nitrobenzene, which was not metabolized further, even after 60 days of incubation. This pathway is believed to be novel in that an aerobic bacterial consortium uses the nitroaromatic compound as its nitrogen source but leaves the ring intact. The bacterial consortium studied could be used in a syntrophic culture system with other 5-nitrobenzene-degrading bacteria to remove trinitrobenzene completely from soil and water at contaminated sites.Key words: trinitrobenzene, aniline, nitrobenzene, biodegradation, transformation.


2019 ◽  
Vol 58 (5) ◽  
pp. 1-23
Author(s):  
Anton Z. Mindubaev ◽  
◽  
Elena K. Badeeva ◽  
Salima T. Minzanova ◽  
Lubov G. Mironova ◽  
...  

The biodegradation of white phosphorus is undoubtedly an amazing illustration of the adaptability of living organisms to adverse environmental factors. In addition, it is a potential basis for the creation of new, breakthrough methods for detoxifying substances of the first class danger. However, establishing the fact of biological destruction is only half the battle. It is essential to optimize the growth conditions of microbial cultures and P4 biodegradation for industrial cultivation. The presented study compared the growth of Aspergillus niger strain AM1 in culture media varying in composition but containing P4 as the sole source of phosphorus. Of the ten media, two in which Aspergillus grew the fastest were selected. These media were concluded to be optimal for growth. Comparing the compositions of the media and the growth rate of Aspergillus in them, we found a key component that is a favorable factor for the growth of AM1 and the biodegradation of white phosphorus. This component was sodium nitrate (NaNO3). It has also been shown that copper sulphate (CuSO4) has no effect on the growth of Aspergillus in media with white phosphorus, regardless of the composition of these media. This result is in harmony with our previous findings. Furthermore, in the present work, attempts to increase the concentration of white phosphorus in the culture medium to values above 1% are described for the first time. For this purpose, we added the following solvents to the culture media: dimethyl sulfoxide (DMSO) and diesel, in which white phosphorus dissolves relatively well. Apparently, the presence of these substances adversely affects the growth of Aspergill. Therefore, the problem of further increasing the concentration of P4 remains an unanswered.


2020 ◽  
Author(s):  
Bo Zhang ◽  
Hui Zhao ◽  
Xiaogang Wu ◽  
Li-Qun Zhang

Abstract The polyketide antibiotic 2,4-diacetylphloroglucinol (2,4-DAPG), produced by Pseudomonas fluorescens 2P24, is positively regulated by the GacS-GacA two-component system. Here we reported on the characterization of DsbA1 (disulfide oxidoreductase) as novel regulator of biocontrol activity in P. fluorescens . Our data showed that mutation of dsbA1 caused the accumulation of 2,4-DAPG in a GacA-independent manner. Further analysis indicated that DsbA1 interacts with membrane-bound glucose dehydrogenase Gcd, which positively regulates the production of 2,4-DAPG. Mutation of cysteine (C)-235, C275, and C578 of Gcd, significantly reduced the interaction with DsbA1, enhanced the activity of Gcd and increased 2,4-DAPG production. Taken together, our results suggest that DsbA1 regulates the 2,4-DAPG concentration via fine-tuning the function of Gcd in P. fluorescens 2P24.


Sign in / Sign up

Export Citation Format

Share Document