scholarly journals Biodegradation and metabolic pathway of sulfamethoxazole by Sphingobacterium mizutaii

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jinlong Song ◽  
Guijie Hao ◽  
Lu Liu ◽  
Hongyu Zhang ◽  
Dongxue Zhao ◽  
...  

AbstractSulfamethoxazole (SMX) is the most commonly used antibiotic in worldwide for inhibiting aquatic animal diseases. However, the residues of SMX are difficult to eliminate and may enter the food chain, leading to considerable threats on human health. The bacterial strain Sphingobacterium mizutaii LLE5 was isolated from activated sludge. This strain could utilize SMX as its sole carbon source and degrade it efficiently. Under optimal degradation conditions (30.8 °C, pH 7.2, and inoculum amount of 3.5 × 107 cfu/mL), S. mizutaii LLE5 could degrade 93.87% of 50 mg/L SMX within 7 days. Four intermediate products from the degradation of SMX were identified and a possible degradation pathway based on these findings was proposed. Furthermore, S. mizutaii LLE5 could also degrade other sulfonamides. This study is the first report on (1) degradation of SMX and other sulfonamides by S. mizutaii, (2) optimization of biodegradation conditions via response surface methodology, and (3) identification of sulfanilamide, 4-aminothiophenol, 5-amino-3-methylisoxazole, and aniline as metabolites in the degradation pathway of SMX in a microorganism. This strain might be useful for the bioremediation of SMX-contaminated environment.

2021 ◽  
Author(s):  
Jinlong Song ◽  
Guijie Hao ◽  
Lu Liu ◽  
Hongyu Zhang ◽  
Dongxue Zhao ◽  
...  

Abstract Sulfamethoxazole (SMX) is the most commonly used antibiotics in China for inhibiting aquatic animal diseases. However, the residues of SMX are difficult to eliminate and may enter the food chain, leading to considerable threats on human health. The bacterial strain Sphingobacterium mizutaii LLE5 was isolated from activated sludge. This strain could utilize SMX as its sole carbon source and degrade it efficiently. Under optimal degradation conditions (30.8 °C, pH 7.2, and inoculum amount of 3.5 × 107 cfu/mL), S. mizutaii LLE5 could degrade 93.87% of 50 mg/L SMX within 7 days. Four intermediate products from the degradation of SMX were identified: sulfanilamide, 4-aminothiophenol, 5-amino-3-methylisoxazole, and aniline, suggesting a possible degradation pathway based on these findings. This report is the first to confirm that Sphingobacteriumi could degrade SMX. Furthermore, S. mizutaii LLE5 could also degrade other sulfonamides. The degradation efficiencies of strain LLE5 for sulfadiazine, sulfaguanidine, sulfamisoxazole, and sulfadimidine were 59.85%, 51.68%, 46.95%, and 37.42%, respectively.


2009 ◽  
Vol 191 (21) ◽  
pp. 6584-6591 ◽  
Author(s):  
Anna Brzostek ◽  
Jakub Pawelczyk ◽  
Anna Rumijowska-Galewicz ◽  
Bozena Dziadek ◽  
Jaroslaw Dziadek

ABSTRACT It is expected that the obligatory human pathogen Mycobacterium tuberculosis must adapt metabolically to the various nutrients available during its cycle of infection, persistence, and reactivation. Cholesterol, which is an important part of the mammalian cytoplasmic membrane, is a potential energy source. Here, we show that M. tuberculosis grown in medium containing a carbon source other than cholesterol is able to accumulate cholesterol in the free-lipid zone of its cell wall. This cholesterol accumulation decreases the permeability of the cell wall for the primary antituberculosis drug, rifampin, and partially masks the mycobacterial surface antigens. Furthermore, M. tuberculosis was able to grow on mineral medium supplemented with cholesterol as the sole carbon source. Targeted disruption of the Rv3537 (kstD) gene inhibited growth due to inactivation of the cholesterol degradation pathway, as evidenced by accumulation of the intermediate, 9-hydroxy-4-androstene-3,17-dione. Our findings that M. tuberculosis is able to accumulate cholesterol in the presence of alternative nutrients and use it when cholesterol is the sole carbon source in vitro may facilitate future studies into the pathophysiology of this important deadly pathogen.


F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 656 ◽  
Author(s):  
Mautusi Mitra ◽  
Kevin Manoap-Anh-Khoa Nguyen ◽  
Taylor Wayland Box ◽  
Jesse Scott Gilpin ◽  
Seth Ryan Hamby ◽  
...  

Background: Chlamydomonas reinhardtii, a green micro-alga can be grown at the lab heterotrophically or photo-heterotrophically in Tris-Phosphate-Acetate (TAP) medium which contains acetate as the sole carbon source. When grown in TAP medium, Chlamydomonas can utilize the exogenous acetate in the medium for gluconeogenesis using the glyoxylate cycle, which is also present in many bacteria and higher plants. A novel bacterial strain, LMJ, was isolated from a contaminated TAP medium plate of Chlamydomonas. We present our work on the isolation and physiological and biochemical characterizations of LMJ. Methods: Several microbiological tests were conducted to characterize LMJ, including its sensitivity to four antibiotics. We amplified and sequenced partially the 16S rRNA gene of LMJ. We tested if LMJ can utilize cyclic alkanes, aromatic hydrocarbons, poly-hydroxyalkanoates, and fresh and combusted car motor oil as the sole carbon source on Tris-Phosphate (TP) agar medium plates for growth. Results: LMJ is a gram-negative rod, oxidase-positive, mesophilic, non-enteric, pigmented, salt-sensitive bacterium. LMJ can ferment glucose, is starch hydrolysis-negative, and is very sensitive to penicillin and chloramphenicol. Preliminary spectrophotometric analyses indicate LMJ produces pyomelanin. NCBI-BLAST analyses of the partial 16S rRNA gene sequence of LMJ showed that it matched to that of an uncultured bacterium clone LIB091_C05_1243. The nearest genus relative of LMJ is an Acidovorax sp. strain. LMJ was able to use alkane hydrocarbons, fresh and combusted car motor oil, poly-hydroxybutyrate, phenanthrene, naphthalene, benzoic acid and phenyl acetate as the sole carbon source for growth on TP-agar medium plates. Conclusions: LMJ has 99.14% sequence identity with the Acidovorax sp. strain A16OP12 whose genome has not been sequenced yet. LMJ’s ability to use chemicals that are common environmental pollutants makes it a promising candidate for further investigation for its use in bioremediation and, provides us with an incentive to sequence its genome.


1971 ◽  
Vol 122 (4) ◽  
pp. 519-526 ◽  
Author(s):  
J. K. Gaunt ◽  
W. C. Evans

1. A pseudomonad capable of utilizing the herbicide 4-chloro-2-methylphenoxyacetate as a sole carbon source was isolated from soil and cultured in liquid medium. 2. Analysis of induction patterns of 4-chloro-2-methylphenoxyacetate-grown cells suggests that 5-chloro-o-cresol and 5-chloro-3-methylcatechol are early intermediates in the oxidation of 4-chloro-2-methylphenoxyacetate. Cells were not adapted to oxidize 4-chloro-6-hydroxy-2-methylphenoxyacetate. 3. In culture, 4-chloro-2-methylphenoxyacetate rapidly disappeared and the chlorine in the molecule was quantitatively released as Cl− ion. 4. A lactone (γ-carboxymethylene-α-methyl-Δαβ-butenolide) was isolated from cultures and established as an intermediate. 5. The following metabolic pathway is suggested: 4-chloro-2-methylphenoxyacetate → 5-chloro-o-cresol → 5-chloro-3-methylcatechol → cis–cis-γ-chloro-α-methylmuconate → γ-carboxymethylene-α-methyl-Δαβ-butenolide → γ-hydroxy-α-methylmuconate. 6. The tentative identification of 5-chloro-o-cresol, a γ-chloro-α-methylmuconate and γ-hydroxy-α-methylmuconate in culture extracts supports this scheme. However, the catechol was never observed to accumulate in cultures. 7. The detection of 4-chloro-6-hydroxy-2-methylphenoxyacetate, 2-methyl-phenoxyacetate, a dehalogenated cresol and oxalate in culture extracts is discussed in relation to the proposed metabolic pathway.


2016 ◽  
Vol 73 (12) ◽  
pp. 2896-2903 ◽  
Author(s):  
Lin Wang ◽  
Xiaolin Zhang ◽  
Yongmei Li

Abstract A novel bacterial strain Klebsiella sp. Y1 was isolated from the soil of a constructed wetland, and it was identified based on the 16S rDNA sequence analysis. The co-metabolic degradation of nicosulfuron with glucose by Klebsiella sp. Y1 was investigated. The response surface methodology analysis indicated that the optimal pH and temperature were 7.0 and 35 °C, respectively, for the degradation of nicosulfuron. Under the optimal conditions, the degradation of nicosulfuron fitted Haldane kinetics model well. The removal of nicosulfuron was triggered by the acidification of glucose, which accelerated the hydrolysis of nicosulfuron. Then, the C–N bond of the sulfonylurea bridge was attacked and cleaved. Finally, the detected intermediate 2-amino-4,6-dimethoxypyrimidine was further biodegraded.


2019 ◽  
Author(s):  
Peng Lu ◽  
Ai-min Liu ◽  
Hong-ming Liu ◽  
Jian-zhong Wang

Abstract The bactrial strain Cupriavidus sp. DT-1 can degrade 3,5,6-trichloro-2-pyridinol (TCP) and transform it into 2-hydroxypyridine (2-HP). This is a unique degradation pathway of TCP but incomplete. In the present study, strain DT-1 could degrade 2-HP at a high concentration 500 mg/L and use it as sole carbon source for growth. Three metabolites (nicotine blue, maleamic acid and fumaric acid) were detected in the medium and the complete degradation pathway of TCP was derived. Inoculation of TCP-contaminated soils with strain DT-1 resulted in a degradation rate 94.4% and 86.7% as compared to 20.4% and 28.4% in uninoculated soils, respectively. Fluorescent marker gene gfp was introduced into strain DT-1 and a new strain DT-1- gfp was created, viability test showed the strain could survive well in soils for more than 35 d. This finding suggests that strain DT-1 has potential for use in bioremediation of TCP-contaminated environments.


2008 ◽  
Vol 74 (6) ◽  
pp. 1717-1725 ◽  
Author(s):  
Sabina Chalabaev ◽  
Evelyne Turlin ◽  
Sylvie Bay ◽  
Christelle Ganneau ◽  
Emma Brito-Fravallo ◽  
...  

ABSTRACT Photorhabdus luminescens, an entomopathogenic bacterium and nematode symbiont, has homologues of the Hca and Mhp enzymes. In Escherichia coli, these enzymes catalyze the degradation of the aromatic compounds 3-phenylpropionate (3PP) and cinnamic acid (CA) and allow the use of 3PP as sole carbon source. P. luminescens is not able to use 3PP and CA as sole carbon sources but can degrade them. Hca dioxygenase is involved in this degradation pathway. P. luminescens synthesizes CA from phenylalanine via a phenylalanine ammonia-lyase (PAL) and degrades it via the not-yet-characterized biosynthetic pathway of 3,5-dihydroxy-4-isopropylstilbene (ST) antibiotic. CA induces its own synthesis by enhancing the expression of the stlA gene that codes for PAL. P. luminescens bacteria release endogenous CA into the medium at the end of exponential growth and then consume it. Hca dioxygenase is involved in the consumption of endogenous CA but is not required for ST production. This suggests that CA is consumed via at least two separate pathways in P. luminescens: the biosynthesis of ST and a pathway involving the Hca and Mhp enzymes.


Genetics ◽  
1997 ◽  
Vol 146 (4) ◽  
pp. 1211-1220 ◽  
Author(s):  
Trevor C Charles ◽  
Guo-qin Cai ◽  
Punita Aneja

Chromosomal and megaplasmid loci that affect the poly-3-hydroxybutyrate (PHB) degradation pathway in Rhizobium meliloti were identified. A clone that restores the ability of certain R. meliloti mutants with defined deletions in megaplasmid pRmeSU47b to use 3-hydroxybutyrate or acetoacetate as the sole carbon source was isolated from a cosmid library of R. meliloti genomic DNA. Tn5 insertion mutagenesis, followed by merodiploid complementation analysis, demonstrated that the locus consists of at least four transcriptional units, bhbA-D. We also identified loci involved in 3-hydroxybutyrate and/or acetoacetate utilization by screening for mutants that had lost the ability to use 3-hydroxybutyrate as the sole carbon source while retaining the ability to use acetate (thus ensuring an intact glyoxylate cycle and gluconeogenic pathway). These mutants fell into four classes, as determined by replicon mobilization experiments and genetic linkage in phage transduction; one class corresponded to the bhb locus on pRmeSU47b, two classes mapped to different regions on the chromosome and the fourth, bdhA, represented by a single mutant, mapped to another pRmeSU47b locus, near bacA. The bdhA mutant is deficient in 3-hydroxybutrate dehydrogenase activity.


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