scholarly journals O-Demethylation and Successive Oxidative Dechlorination of Methoxychlor by Bradyrhizobium sp. Strain 17-4, Isolated from River Sediment

2012 ◽  
Vol 78 (15) ◽  
pp. 5313-5319 ◽  
Author(s):  
Koji Satsuma ◽  
Minoru Masuda ◽  
Kiyoshi Sato
Keyword(s):  
High Performance ◽  
River Sediment ◽  
Degradation Products ◽  
Individual Species ◽  
Rrna Gene ◽  
Metabolic Reaction ◽  
Content Type ◽  
Initial Substrate ◽  
Bradyrhizobium Sp ◽  
Eukaryotic Organisms

ABSTRACTO-Demethylation of insecticide methoxychlor is well known as a phase I metabolic reaction in various eukaryotic organisms. Regarding prokaryotic organisms, however, no individual species involved in such reaction have been specified and characterized so far. Here we successfully isolated a bacterium that mediates oxidative transformation of methoxychlor, includingO-demethylation and dechlorination, from river sediment. The isolate was found to be closely related toBradyrhizobium elkaniiat the 16S rRNA gene sequence level (100% identical). However, based on some differences in the physiological properties of this bacterium, we determined that it was actually a different species,Bradyrhizobiumsp. strain 17-4. The isolate mediatedO-demethylation of methoxychlor to yield a monophenolic derivative [Mono-OH; 1,1,1-trichloro-2-(4-hydroxyphenyl)-2-(4-methoxyphenyl)ethane] as the primary degradation product. The chiral high-performance liquid chromatography (HPLC) analysis revealed that the isolate possesses high enantioselectivity favoring the formation of (S)-Mono-OH (nearly 100%). Accompanied by the sequentialO-demethylation to form the bis-phenolic derivative Bis-OH [1,1,1-trichloro-2,2-bis(4-hydroxyphenyl)ethane], oxidative dechlorination of the side chain proceeded, and monophenolic carboxylic acid accumulated, followed by the formation of multiple unidentified polar degradation products. The breakdown proceeded more rapidly when reductively dechlorinated (dichloro-form) methoxychlor was applied as the initial substrate. The resultant carboxylic acids and polar degradation products are likely further biodegraded by ubiquitous bacteria. The isolate possibly plays an important role for complete degradation (mineralization) of methoxychlor by providing the readily biodegradable substrates.

scholarly journals Spatial and Temporal Variations in Pigment and Species Compositions of Snow Algae on Mt. Tateyama in Toyama Prefecture, Japan

2021 ◽  
Vol 12 ◽  
Author(s):  
Tomomi Nakashima ◽  
Jun Uetake ◽  
Takahiro Segawa ◽  
Lenka Procházková ◽  
Akane Tsushima ◽  
...  
Keyword(s):  
High Performance ◽  
Algal Species ◽  
High Performance Liquid Chromatographic ◽  
Temporal Variations ◽  
Algal Community ◽  
Rrna Gene ◽  
Polar Regions ◽  
Dominant Type ◽  
Content Type ◽  
Snow Algae

Snow algae are photosynthetic microbes that inhabit the melting snow surface in alpine and polar regions. We analyzed the pigment and species composition of colored snow collected on Mt. Tateyama in Japan during the melting seasons of 2015 and 2016. High-performance liquid chromatographic analyses of the pigments extracted from the colored snow showed that their composition varied within the study area and were classified into four types: Type A (astaxanthin-monoester dominant), Type B (medium astaxanthin-monoester content), Type C (abundant primary carotenoids and free-astaxanthin), and Type D (abundant primary carotenoids and astaxanthin diesters). Types A and B were most commonly observed in the study area, whereas Types C and D appeared only at specific sites. Analysis of the 18S ribosomal RNA (18S rRNA) gene revealed six major amplicon sequence variants (ASVs) of snow algae, belonging to the Sanguina, Chloromonas, and Chlainomonas groups. The relative abundance of the algal ASVs showed that Sanguina was dominant (>48%) in both Types A and B, suggesting that the difference in astaxanthin abundance between the two types was caused by the production of pigments in the algal cells. The algal community structures of Types C and D differed from those of Types A and B, indicating that the primary carotenoids and astaxanthin diesters were derived from certain algal species in these types. Therefore, astaxanthin-rich Sanguina algae mostly induced the red snow that appeared widely in this alpine area; however, they were partially dominated by Chloromonas or Chlainomonas algae, causing different pigment compositions.

scholarly journals Isolation and Characterization of Methanothermobacter crinale sp. nov., a Novel Hydrogenotrophic Methanogen from the Shengli Oil Field

2011 ◽  
Vol 77 (15) ◽  
pp. 5212-5219 ◽  
Author(s):  
Lei Cheng ◽  
Lirong Dai ◽  
Xia Li ◽  
Hui Zhang ◽  
Yahai Lu
Keyword(s):  
Oil Sands ◽  
Type Strain ◽  
High Performance ◽  
Sequence Similarity ◽  
Oil Field ◽  
Rrna Gene ◽  
Content Type ◽  
Chromatography Analysis ◽  
Hydrogenotrophic Methanogenesis ◽  
Isolation And Characterization

ABSTRACTSyntrophic acetate oxidation coupled with hydrogenotrophic methanogenesis is an alternative methanogenic pathway in certain thermophilic anaerobic environments such as high-temperature oil reservoirs and thermophilic biogas reactors. In these environments, the dominant thermophilic methanogens were generally related to uncultured organisms of the genusMethanothermobacter. Here we isolated two representative strains, Tm2Tand HMD, from the oil sands and oil production water in the Shengli oil field in the People's Republic of China. The type strain, Tm2T, was nonmotile and stained Gram positive. The cells were straight to slightly curved rods (0.3 μm in width and 2.2 to 5.9 μm in length), but some of them possessed a coccal shape connecting with the rods at the ends. Strain Tm2Tgrew with H2-CO2, but acetate is required. Optimum growth of strain Tm2Toccurred in the presence of 0.025 g/liter NaCl at pH 6.9 and a temperature of 65°C. The G+C content of the genomic DNA was 40.1 mol% ± 1.3 mol% (by the thermal denaturation method) or 41.1 mol% (by high-performance liquid chromatography). Analysis of the 16S rRNA gene sequence indicated that Tm2Twas most closely related toMethanothermobacter thermautotrophicusΔHTandMethanothermobacter wolfeiiVKM B-1829T(both with a sequence similarity of 96.4%). Based on these phenotypic and phylogenic characteristics, a novel species was proposed and namedMethanothermobacter crinalesp. nov. The type strain is Tm2T(ACCC 00699T= JCM 17393T).

Kaistia defluvii sp. nov., isolated from river sediment

2012 ◽  
Vol 62 (Pt_12) ◽  
pp. 2878-2882 ◽  
Author(s):  
Long Jin ◽  
Kwang Kyu Kim ◽  
Hyung-Gwan Lee ◽  
Chi-Yong Ahn ◽  
Hee-Mock Oh
Keyword(s):  
Type Species ◽  
Gene Sequence ◽  
River Sediment ◽  
Novel Species ◽  
Rrna Gene ◽  
The Novel ◽  
Content Type ◽  
Link Type ◽  
Gene Sequence Analysis ◽  
Sequence Similarities

A Gram-stain-negative, aerobic, non-motile, rod- and coccus-shaped bacterium, designated strain B6-12T, was isolated from sediment collected from the River Geumho in South Korea. In comparative 16S rRNA gene sequence analysis, the novel strain appeared to be affiliated with the class Alphaproteobacteria and to be most closely related to Kaistia adipata KCTC 12095T, Kaistia dalseonensis DSM 18800T, Kaistia geumhonensis DSM 18799T, Kaistia granuli KCTC 12575T, Kaistia soli KACC 12605T and Kaistia terrae KACC 12910T, with sequence similarities of 96.2–99.1 %. The predominant ubiquinone in the isolate was Q-10, major fatty acids were C18 : 0, C18 : 1ω7c and C19 : 0ω8c cyclo, and genomic DNA G+C content was 63.0 mol%. Based on the phylogenetic and chemotaxonomic evidence and the results of DNA–DNA hybridizations, strain B6-12T represents a novel species in the genus Kaistia , for which the name Kaistia defluvii sp. nov. is proposed. The type strain is B6-12T ( = KCTC 23766T  = JCM 18034T).

scholarly journals Comparison of Fecal Microbiota between German Holstein Dairy Cows with and without Left-Sided Displacement of the Abomasum

2016 ◽  
Vol 54 (4) ◽  
pp. 1140-1143 ◽  
Author(s):  
Eun-Sik Song ◽  
Sang Il Jung ◽  
Hyung-Jin Park ◽  
Kyoung-Won Seo ◽  
Jeong-Hoon Son ◽  
...  
Keyword(s):  
Dairy Cows ◽  
High Performance ◽  
Fecal Microbiota ◽  
Rrna Gene ◽  
Microbial Composition ◽  
16S Rrna Gene Analysis ◽  
Bacterial Composition ◽  
Content Type ◽  
Functional Aspects ◽  
Holstein Dairy Cows

One of the most common diseases in high-performance German Holstein dairy cows is left-sided displacement of the abomasum (LDA). Hypomotility of the abomasum is detrimental during the pathogenesis of LDA. It is known that improper interactions between the gut microbiota and the enteric nervous system contribute to dysfunctions of gastrointestinal motility. Therefore, we hypothesized that the gut microbial composition will be different between German Holstein dairy cows with and without LDA. We used 16S rRNA gene analysis to evaluate whether there are any differences in bacterial composition between German Holstein dairy cows with and without LDA. Even though our data are limited to being used to correlate compositional changes with corresponding functional aspects in the pathogenesis of LDA, results from this study show that the fecal microbial compositions of German Holstein dairy cows with LDA shifted and were less diverse than those in normal cows. In particular,Spirochaeteswere absent in cows with LDA.

scholarly journals Characterization of six clinical isolates of Chimaeribacter gen. nov., a novel genus related to the Yersiniaceae family and the three species Chimaeribacter arupi sp. nov., Chimaeribacter coloradensis sp. nov, and Chimaeribacter californicus sp. nov.

2020 ◽  
Vol 70 (4) ◽  
pp. 2703-2712 ◽  
Author(s):  
Alessandro Rossi ◽  
Mark A. Fisher
Keyword(s):  
Type Strain ◽  
Single Species ◽  
Individual Species ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
Gram Negative ◽  
Novel Genus ◽  
Content Type ◽  
Link Type

Eight genetically related, Gram-negative bacterial strains, isolated from clinical specimens between 2012 and 2016, were submitted to arup Laboratories for species identification. The lack of species- or genus-level matches in curated 16S rRNA gene databases prompted us to undertake the polyphasic characterization of these so far undescribed organisms. Six isolates available for additional testing were oxidase negative, catalase positive, pleomorphic, Gram-negative rods displaying temperature-dependent motility and producing yellow-pigmented colonies with three distinct morphotypes: medium-sized shiny, large mucoid and agar-pitting. Biochemical reactions and sugar fermentation patterns were most similar to members of the genus Serratia . Fatty acid profiles were highly similar across all six organisms, with the major components being: C16 : 0; C17 : 0 cyclo; C14 : 0 3-OH/iso-C16 : 1 I; C18 : 1 ω7c; and C16 : 1 ω7c/C16 : 1 ω6c. Whole-genome comparisons and multi locus sequence analysis (using the coding genes atpD, rpoB, gyrB and infB) suggest that the strains here described constitute three individual species within a novel genus related to the family Yersiniaceae . We propose for this novel taxon the name Chimaeribacter gen. nov., referring to the presentation of multiple characteristics typical of distinct Enterobacterales genera within a single organism. Four isolates are representative of a single species: Chimaeribacter arupi sp. nov (2016-Iso1, 2016-Iso2, type strain 2016-Iso3T=DSM 110101T=ATCC TSD-180T and 2013-Iso5). The remaining two isolates constitute the novel species Chimaeribacter coloradensis sp. nov. (type strain 2016-Iso4T=DSM 110102T=ATCC TSD-182T) and Chimaeribacter californicus sp. nov. (type strain 2015-Iso6T=DSM 110100T=ATCC TSD-181T). Our work provides the first formal characterization of the genus Chimaeribacter and forms the basis to study its taxonomic diversity.

The Influence of Some Factors on Spirolactone Stability in Solution

2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Daniela Lucia Muntean ◽  
Silvia Imre ◽  
Cosmina Voda
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Uv Irradiation ◽  
High Performance ◽  
Degradation Products ◽  
Simultaneous Action ◽  
Ethanolic Solution ◽  
Degradation Processes ◽  
Stable Solutions ◽  
Preformulation Study

The influence of some factors on spironolactone stability in solution was studied, by applying high-performance liquid chromatography, as a part of a pharmaceutical preformulation study in order to obtain a spironolactone solution for alopecia treatment. Solutions of 1 mg/ml spironolactone in aqueous ethanolic solution 1 : 1 and in 20 mM cyclodextrines solutions (b-, hydroxi-b- and methyl-b-cyclodextrine) was used, maintained at 8 and 22 �C, protected from light and after UV irradiation at 254 nm. The main degradation products were 7a-thiospirolactone and canrenone. The most stable solutions were the alcoholic ones and with methyl-beta-cyclodextrine, but the simultaneous action of temperature and UV irradiation allowed degradation processes after one hour of exposure, more aggressive in the presence of methyl-beta-cyclodextrine. In conclusion, for alopecia treatment with spironolactone a 1 mg/mL ethanolic solution could be used and it is recommendable the protection of treated zone.

Recent Applications of High Performance Thin Layer Chromatography and Derivative Spectrophotometry in Pharmaceutical Analysis

2020 ◽  
Vol 16 (6) ◽  
pp. 671-689
Author(s):  
Marcin Gackowski ◽  
Marcin Koba ◽  
Katarzyna Mądra-Gackowska ◽  
Piotr Kośliński ◽  
Stefan Kruszewski
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Pharmaceutical Analysis ◽  
High Performance ◽  
Degradation Products ◽  
Derivative Spectrophotometry ◽  
Accuracy And Precision ◽  
Post Marketing ◽  
Layer Chromatography

At present, no one can imagine drug development, marketing and post-marketing without rigorous quality control at each stage. Only modern, selective, accurate and precise analytical methods for determination of active compounds, their degradation products and stability studies are able to assure the appropriate amount and purity of drugs administered every day to millions of patients all over the world. For routine control of drugs simple, economic, rapid and reliable methods are desirable. The major focus of current scrutiny is placed on high-performance thin layer chromatography and derivative spectrophotometry methods, which fulfill routine drug estimation’s expectations [1-4]. The present paper reveals state-of-the-art and possible applications of those methods in pharmaceutical analysis between 2010 and 2018. The review shows advantages of high-performance thin layer chromatography and derivative spectrophotometry, including accuracy and precision comparable to more expensive and time-consuming methods as well as additional fields of possible applications, which contribute to resolving many analytical problems in everyday laboratory practice.

ICH/FDA Guidelines-Compliant Validated Stability-Indicating HPLC-UV Method for the Determination of Axitinib in Bulk and Dosage Forms

2020 ◽  
Vol 16 (8) ◽  
pp. 1106-1112
Author(s):  
Ibrahim A. Darwish ◽  
Nasr Y. Khalil ◽  
Mohammad AlZeer
Keyword(s):  
High Performance ◽  
Kinase Inhibitor ◽  
Degradation Products ◽  
Internal Standard ◽  
Dosage Forms ◽  
Uv Detector ◽  
Stability Indicating ◽  
Therapeutic Benefits ◽  
Relative Standard

Background: Axitinib (AXT) is a member of the new generation of the kinase inhibitor indicated for the treatment of advanced renal cell carcinoma. Its therapeutic benefits depend on assuring the good-quality of its dosage forms in terms of content and stability of the pharmaceutically active ingredient. Objective: This study was devoted to the development of a simple, sensitive and accurate stabilityindicating high-performance liquid chromatographic method with ultraviolet detection (HPLC-UV) for the determination of AXT in its bulk and dosage forms. Methods: Waters HPLC system was used. The chromatographic separation of AXT, internal standard (olaparib), and degradation products were performed on the Nucleosil CN column (250 × 4.6 mm, 5 μm). The mobile phase consisted of water:acetonitrile:methanol (40:40:20, v/v/v) with a flow rate of 1 ml/min, and the UV detector was set at 225 nm. AXT was subjected to different accelerated stress conditions and the degradation products, when any, were completely resolved from the intact AXT. Results: The method was linear (r = 0.9998) in the concentration range of 5-50 μg/ml. The limits of detection and quantitation were 0.85 and 2.57 μg/ml, respectively. The accuracy of the method, measured as recovery, was in the range of 98.0-103.6% with relative standard deviations in the range of 0.06-3.43%. The results of stability testing revealed that AXT was mostly stable in neutral and oxidative conditions; however, it was unstable in alkaline and acidic conditions. The kinetics of degradation were studied, and the kinetic rate constants were determined. The proposed method was successfully applied for the determination of AXT in bulk drug and dosage forms. Conclusions: A stability-indicating HPLC-UV method was developed and validated for assessing AXT stability in its bulk and dosage forms. The method met the regulatory requirements of the International Conference on Harmonization (ICH) and the Food and Drug Administration (FDA). The results demonstrated that the method would have great value when applied in quality control and stability studies for AXT.

Validated Stability Indicating HPTLC Method for the Estimation of Amoxapine in Different Stress Conditions

2019 ◽  
Vol 15 (3) ◽  
pp. 273-279
Author(s):  
Shweta G. Rangari ◽  
Nishikant A. Raut ◽  
Pradip W. Dhore
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Degradation Products ◽  
Analysis Data ◽  
Peak Height ◽  
Good Resolution ◽  
Stability Indicating ◽  
Limit Of Quantitation ◽  
Wide Range ◽  
Hptlc Method

Background:The unstable and/or toxic degradation products may form due to degradation of drug which results into loss of therapeutic activity and lead to life threatening condition. Hence, it is important to establish the stability characteristics of drug in various conditions such as in temperature, light, oxidising agent and susceptibility across a wide range of pH values.Introduction:The aim of the proposed study was to develop simple, sensitive and economic stability indicating high performance thin layer chromatography (HPTLC) method for the quantification of Amoxapine in the presence of degradation products.Methods:Amoxapine and its degraded products were separated on precoated silica gel 60F254 TLC plates by using mobile phase comprising of methanol: toluene: ammonium acetate (6:3:1, v/v/v). The densitometric evaluation was carried out at 320 nm in reflectance/absorbance mode. The degradation products obtained as per ICH guidelines under acidic, basic and oxidative conditions have different Rf values 0.12, 0.26 and 0.6 indicating good resolution from each other and pure drug with Rf: 0.47. Amoxapine was found to be stable under neutral, thermal and photo conditions.Results:The method was validated as per ICH Q2 (R1) guidelines in terms of accuracy, precision, ruggedness, robustness and linearity. A good linear relationship between concentration and response (peak area and peak height) over the range of 80 ng/spot to 720 ng/spot was observed from regression analysis data showing correlation coefficient 0.991 and 0.994 for area and height, respectively. The limit of detection (LOD) and limit of quantitation (LOQ) for area were found to be 1.176 ng/mL and 3.565 ng/mL, whereas for height, 50.063 ng/mL and 151.707 ng/mL respectively.Conclusion:The statistical analysis confirmed the accuracy, precision and selectivity of the proposed method which can be effectively used for the analysis of amoxapine in the presence of degradation products.

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