scholarly journals Mineralization of the Cyclic Nitramine Explosive Hexahydro-1,3,5-Trinitro-1,3,5-Triazine by Gordonia and Williamsia spp

2005 ◽  
Vol 71 (12) ◽  
pp. 8265-8272 ◽  
Author(s):  
Karen T. Thompson ◽  
Fiona H. Crocker ◽  
Herbert L. Fredrickson

ABSTRACT Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a cyclic nitroamine explosive that is a major component in many military high-explosive formulations. In this study, two aerobic bacteria that are capable of using RDX as the sole source of carbon and nitrogen to support their growth were isolated from surface soil. These bacterial strains were identified by their fatty acid profiles and 16S ribosomal gene sequences as Williamsia sp. KTR4 and Gordonia sp. KTR9. The physiology of each strain was characterized with respect to the rates of RDX degradation and [U-14C]RDX mineralization when RDX was supplied as a sole carbon and nitrogen source in the presence and absence of competing carbon and nitrogen sources. Strains KTR4 and KTR9 degraded 180 μM RDX within 72 h when RDX served as the only added carbon and nitrogen source while growing to total protein concentrations of 18.6 and 16.5 μg/ml, respectively. Mineralization of [U-14C]RDX to 14CO2 was 30% by strain KTR4 and 27% by KTR9 when RDX was the only added source of carbon and nitrogen. The addition of (NH4)2SO4 greatly inhibited KTR9's degradation of RDX but had little effect on that of KTR4. These are the first two pure bacterial cultures isolated that are able to use RDX as a sole carbon and nitrogen source. These two genera possess different physiologies with respect to RDX mineralization, and each can serve as a useful microbiological model for the study of RDX biodegradation with regard to physiology, biochemistry, and genetics.

2015 ◽  
Vol 197 (17) ◽  
pp. 2831-2839 ◽  
Author(s):  
Katherine A. Miller ◽  
Robert S. Phillips ◽  
Paul B. Kilgore ◽  
Grady L. Smith ◽  
Timothy R. Hoover

ABSTRACTSalmonella entericserovar Typhimurium, a major cause of food-borne illness, is capable of using a variety of carbon and nitrogen sources. Fructoselysine and glucoselysine are Maillard reaction products formed by the reaction of glucose or fructose, respectively, with the ε-amine group of lysine. We report here thatS. Typhimurium utilizes fructoselysine and glucoselysine as carbon and nitrogen sources via a mannose family phosphotransferase (PTS) encoded bygfrABCD(glucoselysine/fructoselysine PTS components EIIA, EIIB, EIIC, and EIID; locus numbers STM14_5449 to STM14_5454 inS. Typhimurium 14028s). Genes coding for two predicted deglycases within thegfroperon,gfrEandgfrF, were required for growth with glucoselysine and fructoselysine, respectively. GfrF demonstrated fructoselysine-6-phosphate deglycase activity in a coupled enzyme assay. The biochemical and genetic analyses were consistent with a pathway in which fructoselysine and glucoselysine are phosphorylated at the C-6 position of the sugar by the GfrABCD PTS as they are transported across the membrane. The resulting fructoselysine-6-phosphate and glucoselysine-6-phosphate subsequently are cleaved by GfrF and GfrE to form lysine and glucose-6-phosphate or fructose-6-phosphate. Interestingly, althoughS. Typhimurium can use lysine derived from fructoselysine or glucoselysine as a sole nitrogen source, it cannot use exogenous lysine as a nitrogen source to support growth. Expression ofgfrABCDEFwas dependent on the alternative sigma factor RpoN (σ54) and an RpoN-dependent LevR-like activator, which we designated GfrR.IMPORTANCESalmonellaphysiology has been studied intensively, but there is much we do not know regarding the repertoire of nutrients these bacteria are able to use for growth. This study shows that a previously uncharacterized PTS and associated enzymes function together to transport and catabolize fructoselysine and glucoselysine. Knowledge of the range of nutrients thatSalmonellautilizes is important, as it could lead to the development of new strategies for reducing the load ofSalmonellain food animals, thereby mitigating its entry into the human food supply.


2019 ◽  
Vol 4 (1) ◽  
pp. 33-44 ◽  
Author(s):  
S. N. Zheleznova

The diatom Cylindrotheca closterium (Ehrenberg) Reimann et Levin is characterized by high productivity (up to 1.5 g·l-1·day-1) and the ability to accumulate a valuable carotenoid fucoxanthin (up to 2 % of dry weight). In the development of biotechnology based on microalgae, the key issue is the creation of concentrated nutrient medium. Nitrogen is one of the most important components in the nutrient medium that significantly affects the production characteristics of all microalgae. The aim of this study is to compare the production characteristics of C. closterium in an intensive storage culture using different forms of nitrogen in the medium. In the first experiment, nitrate and sodium nitrite, urea, and nitrogen in the form of ammonium were used as a source of nitrogen. The amount of nitrates, nitrites, ammonium, and urea in the medium was calculated from the nitrogen content of the RS nutrient medium, with a nitrogen to phosphorus ratio of 15 : 1. In the second experiment, amino acids were used as a nitrogen source – arginine, asparagine, cysteine. The possibility of using the microalgae C. closterium for the growth of various organic sources of nitrogen (urea, cysteine, asparagine) was shown. Productive characteristics in the intensive storage culture of C. closterium using urea, cysteine, and asparagine as the sole source of nitrogen in the RS nutrient medium were determined. It is shown that when urea was used, the productivity reached its maximum values and amounted to 1.5 g·l-1·day-1. Thus, the expediency of using urea in the medium for obtaining the maximum yield of biomass was shown. The use of cysteine in the stationary phase of growth to achieve a long stationary phase with minimal concentrations of the nitrogen source in the nutrient medium is also advisable. It was found that C. closterium was able to grow and vegetate at sufficiently high concentrations of nitrite, and the addition of nitrogen in ammonium form to the nutrient medium during the active growth of C. closterium led to inhibition of all metabolic processes and to the death of the culture.


2021 ◽  
Vol 36 ◽  
pp. 05003
Author(s):  
Nguyen Van Zhang ◽  
Nguyen Thi Thu ◽  
Vu Thi Linh ◽  
V.V. Pylnev ◽  
M.I. Popchenko

This work presents the experimental study results of the influence of the culture medium on the ability to IAA synthesis of three endophytic strains TH10R, TH11T, and TH13T from roots of Ipomoea pes-caprae. Three investigated strains give the highest IAA concentration after 96 h of cultivation. A significant increase in IAA biosynthesis was obtained by cultivating the TH10R strain in a medium containing lactose or starch as a carbon source and NH4Cl or KNO3 as a nitrogen source. The TH11T strain produces the maximum amount of IAA, using glucose or xylose and KNO3 or NH4NO3 as carbon and nitrogen sources, respectively. Sucrose is a suitable carbon source for the TH13T strain; on a sucrose-containing medium, the TH13T strain produces the highest IAA amount. The most active strain is TH10R, identified as Bacillus mycoides and named Bacillus mycoides TH10R.


2000 ◽  
Vol 66 (8) ◽  
pp. 3134-3141 ◽  
Author(s):  
Edward Topp ◽  
Walter M. Mulbry ◽  
Hong Zhu ◽  
Sarah M. Nour ◽  
Diane Cuppels

ABSTRACT Atrazine, a herbicide widely used in corn production, is a frequently detected groundwater contaminant. Nine gram-positive bacterial strains able to use this herbicide as a sole source of nitrogen were isolated from four farms in central Canada. The strains were divided into two groups based on repetitive extragenic palindromic (rep)-PCR genomic fingerprinting with ERIC and BOXA1R primers. Based on 16S ribosomal DNA sequence analysis, both groups were identified as Nocardioides sp. strains. None of the isolates mineralized [ring-U-14C]atrazine. There was no hybridization to genomic DNA from these strains usingatzABC cloned from Pseudomonas sp. strain ADP or trzA cloned from Rhodococcus corallinus. S-Triazine degradation was studied in detail inNocardioides sp. strain C190. Oxygen was not required for atrazine degradation by whole cells or cell extracts. Based on high-pressure liquid chromatography and mass spectrometric analyses of products formed from atrazine in incubations of whole cells with H2 18O, sequential hydrolytic reactions converted atrazine to hydroxyatrazine and then to the end productN-ethylammelide. Isopropylamine, the putative product of the second hydrolytic reaction, supported growth as the sole carbon and nitrogen source. The triazine hydrolase from strain C190 was isolated and purified and found to have a Km for atrazine of 25 μM and a V max of 31 μmol/min/mg of protein. The subunit molecular mass of the protein was 52 kDa. Atrazine hydrolysis was not inhibited by 500 μM EDTA but was inhibited by 100 μM Mg, Cu, Co, or Zn. Whole cells and purified triazine hydrolase converted a range of chlorine or methylthio-substituted herbicides to the corresponding hydroxy derivatives. In summary, an atrazine-metabolizingNocardioides sp. widely distributed in agricultural soils degrades a range of s-triazine herbicides by means of a novel s-triazine hydrolase.


2002 ◽  
Vol 48 (12) ◽  
pp. 1089-1098 ◽  
Author(s):  
David M Stamper ◽  
Mark Radosevich ◽  
Kevin B Hallberg ◽  
Samuel J Traina ◽  
Olli H Tuovinen

The purpose of this study was to characterize the phylogenetic and phenotypic traits of M91-3, a soil bacterium capable of mineralizing atrazine (2-chloro-4-N-isopropyl-6-N-ethyl-s-triazine). The isolate was identified as Ralstonia basilensis based on 99.5% homology of the 16S rRNA sequence and various chemotaxonomic data. The isolate used atrazine as the sole source of energy, carbon, and nitrogen. It could also use several other s-triazines as nitrogen sources. Ralstonia basilensis M91-3 was capable of denitrification, which was confirmed by gas chromatographic analysis of nitrous oxide under acetylene blockage conditions.Key words: atrazine biodegradation, denitrification, herbicide degrader, Ralstonia basilensis, triazine degradation.


2000 ◽  
Vol 20 (3) ◽  
pp. 892-899 ◽  
Author(s):  
Hoching L. Huang ◽  
Marjorie C. Brandriss

ABSTRACT The proline utilization pathway in Saccharomyces cerevisiae is regulated by the Put3p transcriptional activator in response to the presence of the inducer proline and the quality of the nitrogen source in the growth medium. Put3p is constitutively bound to the promoters of its target genes, PUT1 andPUT2, under all conditions studied but activates transcription to the maximum extent only in the absence of rich nitrogen sources and in the presence of proline (i.e., when proline serves as the sole source of nitrogen). Changes in target gene expression therefore occur through changes in the activity of the DNA-bound regulator. In this report, we demonstrate by phosphatase treatment of immunoprecipitates of extracts metabolically labeled with32P or 35S that Put3p is a phosphoprotein. Examination of Put3p isolated from cells grown on a variety of nitrogen sources showed that it was differentially phosphorylated as a function of the quality of the nitrogen source: the poorer the nitrogen source, the slower the gel migration of the phosphoforms. The presence of the inducer does not detectably alter the phosphorylation profile. Activator-defective and activator-constitutive Put3p mutants have been analyzed. One activator-defective mutant appears to be phosphorylated in a pattern similar to that of the wild type, thus separating its ability to be phosphorylated from its ability to activate transcription. Three activator-constitutive mutant proteins from cells grown on an ammonia-containing medium have a phosphorylation profile similar to that of the wild-type protein in cells grown on proline. These results demonstrate a correlation between the phosphorylation status of Put3p and its ability to activate its target genes and suggest that there are two signals, proline induction and quality of nitrogen source, impinging on Put3p that act synergistically for maximum expression of the proline utilization pathway.


2019 ◽  
Vol 113 (3) ◽  
pp. 437-445
Author(s):  
Tomas Linder

Abstract The effect of nitrogen source on the inhibitory properties of glycine and its N-methylated derivatives N-methylglycine (sarcosine), N,N-dimethylglycine, N,N,N-trimethylglycine (glycine betaine) on yeast growth was investigated. On solid minimal medium, all four glycine species completely or partially inhibited growth of Kluyveromyces lactis, Komagataella pastoris, Ogataea arabinofermentans, Spathaspora passalidarum and Yamadazyma tenuis at concentrations 5–10 mM when 10 mM NH4Cl was the sole source of nitrogen. If NH4Cl was substituted by sodium L-glutamate as the sole source of nitrogen, obvious growth inhibition by glycine and its N-methylated derivatives was generally not observed in any of these species. No obvious growth inhibition by any of the glycine species at a concentration of 10 mM was observed in Cyberlindnera jadinii, Lipomyces starkeyi, Lodderomyces elongisporus, Scheffersomyces stipitis or Yarrowia lipolytica on solid minimal medium irrespective of whether the nitrogen source was NH4Cl or sodium L-glutamate. Growth inhibition assays of K. pastoris in liquid minimal medium supplemented with increasing concentrations of N,N-dimethylglycine demonstrated inhibitory effects for nine tested nitrogen sources. In most cases, N,N-dimethylglycine supplementation caused a decrease in growth efficiency that appeared to be proportional to the concentration of N,N-dimethylglycine. The biological relevance of these results is discussed.


1981 ◽  
Vol 27 (7) ◽  
pp. 685-691 ◽  
Author(s):  
E. A. Barnett ◽  
W. A. Ayers

Three of five isolates of Sporidesmium sclerotivorum, a mycoparasite of Sclerotinia spp., grew well on an agar medium containing mineral salts, glucose, thiamine, and glutamine or Casamino acids as the nitrogen source. The nitrogen requirement for two of the isolates was satisfied by NH4Cl, Casamino acids, or glutamine. Glutamine was the best single nitrogen source. Only one isolate, CS-1, was used in further nutritional studies. The optimum concentration of glutamine for growth was 5 g/L. Glucose, mannose, mannitol, and cellobiose were excellent carbon sources. A glucose concentration of 20 g/L was optimum. Mannitol supported greater growth than glucose with Casamino acids as the nitrogen source but glucose was the superior carbon source with glutamine as the nitrogen source. Greatest growth was achieved with a combination of these carbon and nitrogen sources. Sporidesmium sclerotivorum, isolate CS-1, required thiamine for growth and sporulation. Biotin stimulated growth. The fungus developed maximally within the range of pH 5.0–5.5 and growth was greatly reduced at a pH below 4.0 or above 6.0. Control of acidity by the periodic addition of NaOH solution permitted substantially increased growth. The optimum temperature for growth was 22.5–25.0 °C but production of macroconidia was greatest at 15–20 °C.


2021 ◽  
Vol 12 (1S) ◽  
pp. 31-39
Author(s):  
Nur Dinie Zailan ◽  
Nurul Asma Hasliza Zulkifly ◽  
Afnani Alwi ◽  
Siti Noor Syuhada Muhammad Amin ◽  
Nadiawati Alias

Efficient strategies for phytase production gained increasing importance as more applications require high amounts of phytase for the market. Four phytase-producing bacterial strains isolated from Malaysia’s hot springs were used in this study to determine the effect of nitrogen sources on phytase production. All of the strains were screened out by applying halozone method which shows all of the strains were definitely positive phytase producer. Phytase Screening Medium (PSM) with soybean extract as substrate was used as a cultivation medium. Optimised condition with 1.0 % (w/v) of glucose (as carbon source), pH 5.5 and 37°C temperature was applied. Yeast extract and peptone were used to identify optimum nitrogen source in maximum phytase production. Quantitative analysis observed were optical density, colony forming unit, pH values and phytase activity to identify the effect of nitrogen source in phytase production. The finding was bacterial strain L3 as the best producer in producing maximum phytase (0.2162 U/mL) with optimised condition using yeast extract as nitrogen source. Findings in this study proved that yeast extract act as the optimum nitrogen source which contribute to maximum phytase production as supported by previous studies. This study can provide an efficient strategy to produce maximum phytase as few studies stated that phytase is an application tool in functional food production that consists of myo-inositol phosphates that is believed to have important pharmacological effects.


Author(s):  
Duc Danh Ha

Aniline is a toxic aromatic compound causing environmental pollution, especially water problems, which harmfully affect to human and aquatic species. Seven bacterial strains were isolated from the sewerage of biological and chemical laboratories using aniline as a sole carbon and nitrogen source. Among them, Pseudomonas moraviensis AN-5 showed the highest efficiency. The aniline-degrading P. moraviensis AN-5 utilized aniline completely after 3 days at concentrations ≤ 4.0 mM. The addition of yeast extract and succinate stimulated the growth and aniline degradation of the strain. The investigation of aniline degraration pathway of P. moraviensis AN-5 showed that aniline was degraded by AN-5 via the ortho-clevage pathway.


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