scholarly journals Characterization of a Major Cluster of nif,fix, and Associated Genes in a Sugarcane Endophyte,Acetobacter diazotrophicus

2000 ◽  
Vol 182 (24) ◽  
pp. 7088-7091 ◽  
Author(s):  
Sunhee Lee ◽  
Alexander Reth ◽  
Dietmar Meletzus ◽  
Myrna Sevilla ◽  
Christina Kennedy
Keyword(s):  
Rhodobacter Capsulatus ◽  
Bacterial Species ◽  
Promoter Sequence ◽  
Gene Products ◽  
Acetobacter Diazotrophicus ◽  
Individual Gene ◽  
Major Cluster ◽  
Transcriptional Units ◽  
The Individual

ABSTRACT A major 30.5-kb cluster of nif and associated genes ofAcetobacter diazotrophicus (syn. Gluconacetobacter diazotrophicus), a nitrogen-fixing endophyte of sugarcane, was sequenced and analyzed. This cluster represents the largest assembly of contiguous nif-fix and associated genes so far characterized in any diazotrophic bacterial species. Northern blots and promoter sequence analysis indicated that the genes are organized into eight transcriptional units. The overall arrangement of genes is most like that of the nif-fix cluster in Azospirillum brasilense, while the individual gene products are more similar to those in species of Rhizobiaceae or in Rhodobacter capsulatus.

Isolation and Characterization of Levoglucosan Metabolizing Bacteria

2021 ◽  
Author(s):  
Ajay S. Arya ◽  
Minh T. H. Hang ◽  
Mark A. Eiteman
Keyword(s):  
Recombinant Expression ◽  
Bacterial Species ◽  
Soluble Carbohydrate ◽  
Rrna Gene ◽  
Gene Products ◽  
16S Rrna Gene Sequences ◽  
E Coli ◽  
Isolation And Characterization ◽  
Charred Wood

Bacteria were isolated from wastewater and soil containing charred wood remnants based on their ability to use levoglucosan as a sole carbon source and on their levoglucosan dehydrogenase (LGDH) activity. On the basis of their 16S rRNA gene sequences, these bacteria represented diverse genera of Microbacterium, Paenibacillus , Shinella , and Klebsiella . Genomic sequencing of the isolates verified that two isolates represented novel species, Paenibacillus athensensis MEC069 T and Shinella sumterensis MEC087 T , while the remaining isolates were closely related to either Microbacterium lacusdiani or Klebsiella pneumoniae . The genetic sequence of LGDH, lgdA , was found in the genomes of these four isolates as well as Pseudarthrobacter phenanthrenivorans Sphe3. The identity of the P. phenanthrenivorans LGDH was experimentally verified following recombinant expression in E. coli . Comparison of the putative genes surrounding lgdA in the isolate genomes indicated that several other gene products facilitate the bacterial catabolism of levoglucosan, including a putative sugar isomerase and several transport proteins. Importance Levoglucosan is the most prevalent soluble carbohydrate remaining after high temperature pyrolysis of lignocellulosic biomass, but it is not fermented by typical production microbes such as Escherichia coli and Saccharomyces cerevisiae . A few fungi metabolize levoglucosan via the enzyme levoglucosan kinase, while several bacteria metabolize levoglucosan via levoglucosan dehydrogenase. This study describes the isolation and characterization of four bacterial species which degrade levoglucosan. Each isolate is shown to contain several genes within an operon involved in levoglucosan degradation, furthering our understanding of bacteria which metabolize levoglucosan.

scholarly journals Genetic Characterization of vanG, a Novel Vancomycin Resistance Locus of Enterococcus faecalis

2000 ◽  
Vol 44 (11) ◽  
pp. 3224-3228 ◽  
Author(s):  
Stuart J. McKessar ◽  
Anne M. Berry ◽  
Jan M. Bell ◽  
John D. Turnidge ◽  
James C. Paton
Keyword(s):  
Enterococcus Faecalis ◽  
Amino Acid Sequence Identity ◽  
Vancomycin Resistance ◽  
Open Reading Frames ◽  
Pcr Analysis ◽  
Resistance Locus ◽  
Gene Products ◽  
The Individual ◽  
Reading Frames

ABSTRACT Enterococcus faecalis strain WCH9 displays a moderate level of resistance to vancomycin (MIC = 16 μg/ml) and full susceptibility to teicoplanin but is negative by PCR analysis using primers specific for all known enterococcal vancomycin resistance genotypes (vanA, vanB,vanC, vanD, and vanE). We have isolated and sequenced a novel putative vancomycin resistance locus (designated vanG), which contains seven open reading frames, from this strain. These are organized differently from those of all the other enterococcal vanloci, and, furthermore, the individual vanG gene products exhibit less than 50% amino acid sequence identity to othervan gene products.

scholarly journals Isolation and Characterization of PHA Producing Bacteria from Sewage Samples of Assam

2019 ◽  
Vol 8 (4) ◽  
pp. 10686-10692
Keyword(s):  
Large Scale ◽  
Raw Materials ◽  
Bacterial Species ◽  
Scale Production ◽  
High Turnover ◽  
Isolation And Characterization ◽  
Naturally Occurring ◽  
Large Scale Production ◽  
The Individual

Polyhydroxyalkanoate (Pha) Is A Family Of Naturally Occurring Polymers Which Is Reportedly Produced By More Than 75 Genera Of Gram-Positive And Gram-Negative Bacteria. Although The Industrial Production Of This Bioplastic Commenced Decades Ago, Its Large Scale Production Is Still Debilitated By Factors Such As Rate Of Production By The Bacteria And The Raw Materials For Its Production, Which Finally Elevates The Production Cost. The Present Thrust In This Area Is To Isolate Bacterial Species Which Have A High Turnover Of Pha With Minor Expenditure. Sewage And Sewage Sludge Samples Are Rich Sources Of Microflora Which Offer A Nutrient Limited Habitat To The Individual Organisms. Under These Conditions Of Stress, Native Organisms Develop A Metabolomics Which Efficiently Convert Vital Nutrients Into Essential Macromolecules, And In This Case A Storage Polymer Of Industrial Significance I.E. Pha. In This Pilot Study An Attempt Was Made To Isolate Indigenous Bacterial With Ability To Produce The Polymer.

Separation and Characterization of Standard Propoxyphene Diastereomers and Their Determination in Pharmaceutical and Illicit Preparations

1981 ◽  
Vol 64 (4) ◽  
pp. 875-883
Author(s):  
Shiv K Soni ◽  
Daniel Van Gelder
Keyword(s):  
High Pressure ◽  
Optical Isomers ◽  
Gold Chloride ◽  
Melting Points ◽  
Eutectic Melting ◽  
Racemic Mixtures ◽  
The Individual ◽  
Isomeric Mixtures ◽  
Asymmetric Carbon

Abstract Due to the existence of 2 asymmetric carbon atoms in: the propoxyphene molecule, there are 4 diastereomers: alpha dextro, alpha levo, beta dextro, and beta levo. Only α-d-propoxyphene is included under the federal Controlled Substances Act. Baseline separations of propoxyphene from various incipients (aspirin, caffeine, phenacetin, and acetaminophen) present in pharmaceutical and illicit preparations, and between the alpha and beta diastereomers, were achieved by high pressure liquid chromatography. The column eluant was collected and propoxyphene was extracted. The optical isomers were differentiated and characterized by melting points and by chemical microcrystalline tests. Using hot stage thermomicroscopy, the eutectic melting points of binary isomeric mixtures of propoxyphene bases and salts were found to be depressed about 10° and 15-30°C, respectively, below the individual isomer melting points. The characteristic microcrystals formed with the alpha racemic mixtures by using a glycerin-aqueous gold chloride reagent were not produced by the beta racemic mixtures.

scholarly journals Does higher education properly prepare graduates for the growing artificial intelligence market? Gaps identification using text mining

2021 ◽  
pp. 1-13
Author(s):  
Lamiae Benhayoun ◽  
Daniel Lang
Keyword(s):  
Artificial Intelligence ◽  
Natural Language Processing ◽  
Text Mining ◽  
Natural Language ◽  
Language Processing ◽  
Academic Training ◽  
Market Requirements ◽  
Job Advertisements ◽  
The Individual

BACKGROUND: The renewed advent of Artificial Intelligence (AI) is inducing profound changes in the classic categories of technology professions and is creating the need for new specific skills. OBJECTIVE: Identify the gaps in terms of skills between academic training on AI in French engineering and Business Schools, and the requirements of the labour market. METHOD: Extraction of AI training contents from the schools’ websites and scraping of a job advertisements’ website. Then, analysis based on a text mining approach with a Python code for Natural Language Processing. RESULTS: Categorization of occupations related to AI. Characterization of three classes of skills for the AI market: Technical, Soft and Interdisciplinary. Skills’ gaps concern some professional certifications and the mastery of specific tools, research abilities, and awareness of ethical and regulatory dimensions of AI. CONCLUSIONS: A deep analysis using algorithms for Natural Language Processing. Results that provide a better understanding of the AI capability components at the individual and the organizational levels. A study that can help shape educational programs to respond to the AI market requirements.

scholarly journals Material Geometry of Binary Composites

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 892
Author(s):  
Marcelo Epstein
Keyword(s):  
Continuum Mechanics ◽  
Mathematical Framework ◽  
Double Groupoid ◽  
The Individual ◽  
Elastic Composites

The constitutive characterization of the uniformity and homogeneity of binary elastic composites is presented in terms of a combination of the material groupoids of the individual constituents. The incorporation of these two groupoids within a single double groupoid is proposed as a viable mathematical framework for a unified formulation of this and similar kinds of problems in continuum mechanics.

scholarly journals Physical and genetic characterization of the melibiose operon and identification of the gene products in Escherichia coli.

1984 ◽  
Vol 259 (3) ◽  
pp. 1807-1812 ◽  
Author(s):  
M Hanatani ◽  
H Yazyu ◽  
S Shiota-Niiya ◽  
Y Moriyama ◽  
H Kanazawa ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genetic Characterization ◽  
Gene Products
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