scholarly journals Separation, purification and properties of β-lactamase I and β-lactamase II from Bacillus cereus 569/H/9

1974 ◽  
Vol 143 (1) ◽  
pp. 115-127 ◽  
Author(s):  
Richard B. Davies ◽  
E. P. Abraham ◽  
J. Melling
Keyword(s):  
Molecular Weight ◽  
Bacillus Cereus ◽  
Large Scale ◽  
Cysteine Residue ◽  
Peptide Fragment ◽  
Tryptic Digest ◽  
Purification And Properties ◽  
Carbohydrate Complex ◽  
Entire Sequence ◽  
Main Components

1. A procedure was devised which is suitable for the isolation of β-lactamase I and β-lactamase II from Bacillus cereus 569/H/9 on a large scale. After adsorption on to Celite both enzymes were eluted in good yield and separated by chromatography on Sephadex CM-50. 2. β-Lactamase I was separated into three main components by isoelectric focusing and into two components by chromatography. 3. The Zn2+-requiring β-lactamase II obtained by this procedure had a lower molecular weight (22000) than β-lactamase I (28000) and also differed from the latter in containing one cysteine residue. 4. The β-lactamase II contained no carbohydrate, but showed the thermostability of the enzyme isolated earlier as a protein–carbohydrate complex. 5. Amino acid analyses and tryptic-digest ‘maps’ indicate that some degree of homology between β-lactamase I and β-lactamase II is possible, but that β-lactamase I is not composed of the entire sequence of β-lactamase II together with an additional peptide fragment. 6. A 6-methylpenicillin and a 7-methylcephalosporin showed much lower affinities for both enzymes than did penicillins and cephalosporins themselves.

scholarly journals Purification and properties of two extracellular β-lactamases from Bacillus cereus 569/H

1970 ◽  
Vol 118 (3) ◽  
pp. 457-465 ◽  
Author(s):  
S. Kuwabara
Keyword(s):  
Molecular Weight ◽  
Bacillus Cereus ◽  
Zinc Sulphate ◽  
Deae Cellulose ◽  
Casein Hydrolysate ◽  
Crystalline Form ◽  
Casamino Acid ◽  
Fractional Precipitation ◽  
Purification And Properties ◽  
Rapid Production

1. When Bacillus cereus 569/H was grown in a casamino acid (casein-hydrolysate) medium containing zinc sulphate rapid production of extracellular β-lactamase II preceded that of β-lactamase I. 2. β-Lactamase I was separated from β-lactamase II by fractional precipitation with ammonium sulphate. 3. β-Lactamase I was purified by a process involving chromatography on Celite and DEAE-cellulose and β-lactamase II by chromatography on DEAE-cellulose after denaturation of β-lactamase I by heat. Both enzymes were obtained in crystalline form. 4. β-Lactamase II prepared in this way appeared to have a higher molecular weight than β-lactamase I and required Zn2+ as a cofactor for both cephalosporinase and penicillinase activities.

A ribosomal-bound aminopeptidase in Escherichia coli B: purification and properties

1970 ◽  
Vol 48 (11) ◽  
pp. 1181-1188 ◽  
Author(s):  
A. J. Dick ◽  
A. T. Matheson ◽  
J. H. Wang
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Large Scale ◽  
The Other ◽  
Stable Form ◽  
Peptidase Activity ◽  
Purification And Properties ◽  
Pancreatic Rnase ◽  
High Concentrations ◽  
Escherichia Coli B

Two procedures have been developed for the large-scale purification from Escherichia coli B of a ribosomal-bound aminopeptidase in a stable form: one involving the digestion of the ribosome with pancreatic RNase and the other the selective removal of the aminopeptidase from the ribosomal surface with NH4Cl. The enzyme, as isolated from the ribosome, is a polymeric protein composed of monomeric units with a molecular weight of approximately 60 000 Daltons. The purified enzyme is activated by β-mercaptoethanol or dithiothreitol, although at high concentrations dithiothreitol inhibits peptidase activity. Propylene glycol also inhibits the enzyme. The enzyme is stable at 70° in the presence of free SH groups.

SOVIET SCIENTIFIC PERSONAL REPRESSIVE STATE APPARATUS AS AN OBJECT OF HISTORICAL SCIENCE OF SCIENCE STUDIES

2020 ◽  
pp. 27-35
Author(s):  
Alexander Allakhverdyan
Keyword(s):  
Science Policy ◽  
Large Scale ◽  
Science Studies ◽  
Soviet Science ◽  
State Repression ◽  
Developed Country ◽  
Systemic Analysis ◽  
State Apparatus ◽  
Dramatic Practice ◽  
Main Components

Numerous studies by Russian scientists and historians of science are devoted to the state science policy in the USSR and its well-known achievements, but not enough attention is paid to the negative, socially repressed aspects of the Soviet science policy. Repressions became one of the main components of the state's scientific and personnel policy in the Stalinist era. The systemic analysis of the development of Soviet science declared in the scientific literature, limited only by its indisputably outstanding achievements, without under-standing the origins, causes and mechanisms of the repressed state apparatus that operated in the same period, sharply reduces the overall picture of the reliability of the study of Soviet science. The purpose of the study is to comprehend the diverse and dramatic practice of state repression in the system of Soviet science, because in the world history of science no other developed country has experienced such large-scale and tragic events in the functioning of the scientific society.

Reuse of Wastewaters in Agriculture by Means of Sprinkler Irrigation on a Farmland Area of 3000 ha – Large Scale Experience in Germany

1986 ◽  
Vol 18 (9) ◽  
pp. 163-173
Author(s):  
R. Boll ◽  
R. Kayser
Keyword(s):  
Large Scale ◽  
Treatment Process ◽  
Treatment Plant ◽  
Sprinkler Irrigation ◽  
Paper Briefly ◽  
Treatment Results ◽  
Sewage Farm ◽  
Western Germany ◽  
Pre Treatment ◽  
Main Components

The Braunschweig wastewater land treatment system as the largest in Western Germany serves a population of about 270.000 and has an annual flow of around 22 Mio m3. The whole treatment process consists of three main components : a pre-treatment plant as an activated sludge process, a sprinkler irrigation area of 3.000 ha of farmland and an old sewage farm of 200 ha with surface flooding. This paper briefly summarizes the experiences with management and operation of the system, the treatment results with reference to environmental impact, development of agriculture and some financial aspects.

scholarly journals Development and Characterization of Two Types of Surface Displayed Levansucrases for Levan Biosynthesis

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 757
Author(s):  
Huiyi Shang ◽  
Danni Yang ◽  
Dairong Qiao ◽  
Hui Xu ◽  
Yi Cao
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Weight ◽  
Large Scale ◽  
Surface Display ◽  
Yeast Surface Display ◽  
Fusion Partner ◽  
Whole Cell ◽  
Food Industries ◽  
Yeast Surface ◽  
The Stability

Levan has wide applications in chemical, cosmetic, pharmaceutical and food industries. The free levansucrase is usually used in the biosynthesis of levan, but the poor reusability and low stability of free levansucrase have limited its large-scale use. To address this problem, the surface-displayed levansucrase in Saccharomyces cerevisiae were generated and evaluated in this study. The levansucrase from Zymomonas mobilis was displayed on the cell surface of Saccharomyces cerevisiae EBY100 using a various yeast surface display platform. The N-terminal fusion partner is based on a-agglutinin, and the C-terminal one is Flo1p. The yield of levan produced by these two whole-cell biocatalysts reaches 26 g/L and 34 g/L in 24 h, respectively. Meanwhile, the stability of the surface-displayed levansucrases is significantly enhanced. After six reuses, these two biocatalysts retained over 50% and 60% of their initial activities, respectively. Furthermore, the molecular weight and polydispersity test of the products suggested that the whole-cell biocatalyst of levansucrase displayed by Flo1p has more potentials in the production of levan with low molecular weight which is critical in certain applications. In conclusion, our method not only enable the possibility to reuse the enzyme, but also improves the stability of the enzyme.

scholarly journals Characterization of Polycaprolactone Nanohydroxyapatite Composites with Tunable Degradability Suitable for Indirect Printing

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 295
Author(s):  
Stephanie E. Doyle ◽  
Lauren Henry ◽  
Ellen McGennisken ◽  
Carmine Onofrillo ◽  
Claudia Di Bella ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Large Scale ◽  
Three Dimensional ◽  
Cell Number ◽  
Compressive Modulus ◽  
Degradation Rates ◽  
Scaffold Materials ◽  
Natural Tissue ◽  
Complete Regeneration

Degradable bone implants are designed to foster the complete regeneration of natural tissue after large-scale loss trauma. Polycaprolactone (PCL) and hydroxyapatite (HA) composites are promising scaffold materials with superior mechanical and osteoinductive properties compared to the single materials. However, producing three-dimensional (3D) structures with high HA content as well as tuneable degradability remains a challenge. To address this issue and create homogeneously distributed PCL-nanoHA (nHA) scaffolds with tuneable degradation rates through both PCL molecular weight and nHA concentration, we conducted a detailed characterisation and comparison of a range of PCL-nHA composites across three molecular weight PCLs (14, 45, and 80 kDa) and with nHA content up to 30% w/w. In general, the addition of nHA results in an increase of viscosity for the PCL-nHA composites but has little effect on their compressive modulus. Importantly, we observe that the addition of nHA increases the rate of degradation compared to PCL alone. We show that the 45 and 80 kDa PCL-nHA groups can be fabricated via indirect 3D printing and have homogenously distributed nHA even after fabrication. Finally, the cytocompatibility of the composite materials is evaluated for the 45 and 80 kDa groups, with the results showing no significant change in cell number compared to the control. In conclusion, our analyses unveil several features that are crucial for processing the composite material into a tissue engineered implant.

Functional design of glycan-conjugated molecules using a chemoenzymatic approach

2021 ◽  
Author(s):  
Makoto Ogata
Keyword(s):  
Molecular Weight ◽  
Large Scale ◽  
Biological Activities ◽  
Natural Compounds ◽  
Low Molecular Weight ◽  
Functional Design ◽  
Enzymatic Method ◽  
Conjugated Molecules ◽  
Design Synthesis ◽  
And Function

Abstract Carbohydrates play important and diverse roles in the fundamental processes of life. We have established a method for accurately and a large scale synthesis of functional carbohydrates with diverse properties using a unique enzymatic method. Furthermore, various artificial glycan-conjugated molecules have been developed by adding these synthetic carbohydrates to macromolecules and to middle and low molecular weight molecules with different properties. These glycan-conjugated molecules have biological activities comparable to or higher than those of natural compounds, and present unique functions. In this review, several synthetic glycan-conjugated molecules are taken as examples to show design, synthesis and function.

Poly(ethyleneimine)-Mediated Large-Scale Transient Gene Expression: Influence of Molecular Weight, Polydispersity and N -Propionyl Groups

2012 ◽  
Vol 12 (5) ◽  
pp. 628-636 ◽  
Author(s):  
Zuzana Kadlecova ◽  
Sophie Nallet ◽  
David L. Hacker ◽  
Lucia Baldi ◽  
Harm-Anton Klok ◽  
...  
Keyword(s):  
Gene Expression ◽  
Molecular Weight ◽  
Large Scale ◽  
Transient Gene Expression

scholarly journals Potentiating Effect of Mandelate and Lactate on Chemically Induced Germination in Members of Bacillus cereus Sensu Lato

2017 ◽  
Vol 83 (24) ◽  
Author(s):  
Alistair H. Bishop
Keyword(s):  
Bacillus Cereus ◽  
Large Scale ◽  
Germination Rate ◽  
Dependent Manner ◽  
Clostridium Sporogenes ◽  
Specific Chemical ◽  
Content Type ◽  
Ph Range ◽  
Significant Discovery ◽  
The Impact

ABSTRACT Endospores of the genus Bacillus can be triggered to germinate by a limited number of chemicals. Mandelate had powerful additive effects on the levels and rates of germination produced in non-heat-shocked spores of Bacillus anthracis strain Sterne, Bacillus cereus, and Bacillus thuringiensis when combined with l-alanine and inosine. Mandelate had no germinant effect on its own but was active with these germinants in a dose-dependent manner at concentrations higher than 0.5 mM. The maximum rate and extent of germination were produced in B. anthracis by 100 mM l-alanine with 10 mM inosine; this was equaled by just 25% of these germinants when supplemented with 10 mM mandelate. Half the maximal germination rate was produced by 40% of the optimum germinant concentrations or 15% of them when supplemented with 0.8 mM mandelate. Germination rates in B. thuringiensis were highest around neutrality, but the potentiating effect of mandelate was maintained over a wider pH range than was germination with l-alanine and inosine alone. For all species, lactate also promoted germination in the presence of l-alanine and inosine; this was further increased by mandelate. Ammonium ions also enhanced l-alanine- and inosine-induced germination but only when mandelate was present. In spite of the structural similarities, mandelate did not compete with phenylalanine as a germinant. Mandelate appeared to bind to spores while enhancing germination. There was no effect when mandelate was used in conjunction with nonnutrient germinants. No effect was produced with spores of Bacillus subtilis, Clostridium sporogenes, or C. difficile. IMPORTANCE The number of chemicals that can induce germination in the species related to Bacillus cereus has been defined for many years, and they conform to specific chemical types. Although not a germinant itself, mandelate has a structure that is different from these germination-active compounds, and its addition to this list represents a significant discovery in the fundamental biology of spore germination. This novel activity may also have important applied relevance given the impact of spores of B. cereus in foodborne disease and B. anthracis as a threat agent. The destruction of spores of B. anthracis, for example, particularly over large outdoor areas, poses significant scientific and logistical problems. The addition of mandelate and lactate to the established mixtures of l-alanine and inosine would decrease the amount of the established germinants required and increase the speed and level of germination achieved. The large-scale application of “germinate to decontaminate” strategy may thus become more practicable.

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