scholarly journals Can (We Make) Bacillus thuringiensis Crystallize More Than Its Toxins?

Toxins ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 441
Author(s):  
Guillaume Tetreau
Keyword(s):  
Bacillus Thuringiensis ◽  
Structural Biology ◽  
Medical Applications ◽  
Long Term Stability ◽  
Natural Crystal ◽  
Bt Protein ◽  
Aqueous Environments ◽  
Bacterium Bacillus ◽  
Scientific Fields

The development of finely tuned and reliable crystallization processes to obtain crystalline formulations of proteins has received growing interest from different scientific fields, including toxinology and structural biology, as well as from industry, notably for biotechnological and medical applications. As a natural crystal-making bacterium, Bacillus thuringiensis (Bt) has evolved through millions of years to produce hundreds of highly structurally diverse pesticidal proteins as micrometer-sized crystals. The long-term stability of Bt protein crystals in aqueous environments and their specific and controlled dissolution are characteristics that are particularly sought after. In this article, I explore whether the crystallization machinery of Bt can be hijacked as a means to produce (micro)crystalline formulations of proteins for three different applications: (i) to develop new bioinsecticidal formulations based on rationally improved crystalline toxins, (ii) to functionalize crystals with specific characteristics for biotechnological and medical applications, and (iii) to produce microcrystals of custom proteins for structural biology. By developing the needs of these different fields to figure out if and how Bt could meet each specific requirement, I discuss the already published and/or patented attempts and provide guidelines for future investigations in some underexplored yet promising domains.

scholarly journals How Does Bacillus thuringiensis Crystallize Such a Large Diversity of Toxins?

Toxins ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 443
Author(s):  
Guillaume Tetreau
Keyword(s):  
Bacillus Thuringiensis ◽  
Structural Biology ◽  
Structural Information ◽  
Future Evolution ◽  
Mechanisms Of Toxicity ◽  
Bt Toxin ◽  
Natural Crystal ◽  
Biological Insecticide ◽  
Key Drivers

Bacillus thuringiensis (Bt) is a natural crystal-making bacterium. Bt diversified into many subspecies that have evolved to produce crystals of hundreds of pesticidal proteins with radically different structures. Their crystalline form ensures stability and controlled release of these major virulence factors. They are responsible for the toxicity and host specificity of Bt, explaining its worldwide use as a biological insecticide. Most research has been devoted to understanding the mechanisms of toxicity of these toxins while the features driving their crystallization have long remained elusive, essentially due to technical limitations. The evolution of methods in structural biology, pushing back the limits of the resolution attainable, now allows access to be gained to structural information hidden within natural crystals of such toxins. In this review, I present the main parameters that have been identified as key drivers of toxin crystallization in Bt, notably in the light of recent discoveries driven by structural biology studies. Then, I develop how the future evolution of structural biology will hopefully unveil new mechanisms of Bt toxin crystallization, opening the door to their hijacking with the aim of developing a versatile in vivo crystallization platform of high academic and industrial interest.

Evaluation of The Long-Term Stability of Passive Corrosion On The Drip Shield and Waste Package Under Yucca Mountain Conditions

2002 ◽  
Vol 713 ◽  
Author(s):  
D.W. Shoesmith
Keyword(s):  
Environmental Conditions ◽  
Yucca Mountain ◽  
Localized Corrosion ◽  
Waste Package ◽  
Long Term Stability ◽  
Alloy 22 ◽  
Aqueous Environments ◽  
Engineered Barriers ◽  
Titanium Grade

ABSTRACTPossible long term corrosion scenarios for the engineered barriers proposed for the Yucca Mountain (Nevada, USA) repository are reviewed.Introduction:The materials proposed for the engineered barriers in the Yucca Mountain repository (Nevada, USA), Alloy-22 for the waste packages (WP) and titanium Grade-7 (Ti-7) for the drip shield (DS), appear unlikely to suffer localized corrosion (LC) and have very low passive corrosion (PC) rates (1–3). Since environmental conditions will become more benign as temperatures decline and aqueous environments become more dilute (4), this leads to the prediction of exceedingly long waste package lifetimes. In this review, possible corrosion scenarios are discussed in the context of the anticipated evolution in the repository environment.

Dissolution kinetics of synthetic LaPO4-monazite in acidic media

MRS Advances ◽  
2018 ◽  
Vol 3 (21) ◽  
pp. 1133-1137 ◽  
Author(s):  
Yulia Arinicheva ◽  
Stefan Neumeier ◽  
Felix Brandt ◽  
Dirk Bosbach ◽  
Guido Deissmann
Keyword(s):  
Single Phase ◽  
Dissolution Kinetics ◽  
Dissolution Process ◽  
Temperature Range ◽  
Long Term Stability ◽  
Aqueous Environments ◽  
Fundamental Understanding ◽  
Acidic Conditions ◽  
Kinetics Of

Single-phase monazite-type ceramics are discussed as waste forms for the safe disposal of surplus plutonium or separated minor actinides. To derive a fundamental understanding of the long-term stability of these materials under repository relevant conditions, the dissolution kinetics of synthetic lanthanum monazite (LaPO4) were studied in dynamic dissolution experiments in the temperature range from 50 to 90°C under acidic conditions. The surface area normalised dissolution rates increased with temperature from 3.2·10-5 g m-2 d-1 at 50°C to 1.8·10-4 g m-2 d-1 at 90°C. The apparent activation energy Ea of the dissolution process was determined to be about 44 kJ mol-1, indicating a predominantly surface reaction controlled dissolution process in this temperature range. From thermodynamic considerations it can be inferred that the dissolution of the LaPO4 ceramics is governed by the dissolution of a thin layer of La-rhabdophane (LaPO4 · 0.667H2O) forming at the monazite surface in low temperature aqueous environments.

Design and characterization of ultrastable, biopassive and lubricious cyclic poly(2-alkyl-2-oxazoline) brushes

2018 ◽  
Vol 9 (19) ◽  
pp. 2580-2589 ◽  
Author(s):  
Wenqing Yan ◽  
Mohammad Divandari ◽  
Jan-Georg Rosenboom ◽  
Shivaprakash N. Ramakrishna ◽  
Lucca Trachsel ◽  
...  
Keyword(s):  
Term Stability ◽  
Long Term Stability ◽  
Bilayer Films ◽  
Aqueous Environments

Bilayer films featuring cyclic, poly(2-alkyl-2-oxazoline) brush interfaces display excellent biopassivity, lubrication and long-term stability in chemically harsh aqueous environments.

Stability and Change in Emotional Intelligence: Exploring the Transition to Young Adulthood

2005 ◽  
Vol 26 (2) ◽  
pp. 100-106 ◽  
Author(s):  
James D.A. Parker ◽  
Donald H. Saklofske ◽  
Laura M. Wood ◽  
Jennifer M. Eastabrook ◽  
Robyn N. Taylor
Keyword(s):  
High School ◽  
Emotional Intelligence ◽  
Postsecondary Education ◽  
Life Transition ◽  
Full Time ◽  
Major Life ◽  
Long Term Stability ◽  
Time Period ◽  
Transition From High School

Abstract. The concept of emotional intelligence (EI) has attracted growing interest from researchers working in various fields. The present study examined the long-term stability (32 months) of EI-related abilities over the course of a major life transition (the transition from high school to university). During the first week of full-time study, a large group of undergraduates completed the EQ-i:Short; 32 months later a random subset of these students (N = 238), who had started their postsecondary education within 24 months of graduating from high school, completed the measures for a second time. The study found EI scores to be relatively stable over the 32-month time period. EI scores were also found to be significantly higher at Time 2; the overall pattern of change in EI-levels was more than can be attributed to the increased age of the participants.

Multi-Center Calibration of the Second Reference Material for Thromboplastin, Rabbit, Plain, Coded CRM 149R

1991 ◽  
Vol 65 (03) ◽  
pp. 263-267 ◽  
Author(s):  
A M H P van den Besselaar ◽  
R M Bertina
Keyword(s):  
Reference Material ◽  
Standard Error ◽  
Standard Errors ◽  
Sensitivity Index ◽  
Long Term Stability ◽  
Significant Bias ◽  
The Mean ◽  
The Relationship ◽  
International Sensitivity Index

SummaryIn a collaborative trial of eleven laboratories which was performed mainly within the framework of the European Community Bureau of Reference (BCR), a second reference material for thromboplastin, rabbit, plain, was calibrated against its predecessor RBT/79. This second reference material (coded CRM 149R) has a mean International Sensitivity Index (ISI) of 1.343 with a standard error of the mean of 0.035. The standard error of the ISI was determined by combination of the standard errors of the ISI of RBT/79 and the slope of the calibration line in this trial.The BCR reference material for thromboplastin, human, plain (coded BCT/099) was also included in this trial for assessment of the long-term stability of the relationship with RBT/79. The results indicated that this relationship has not changed over a period of 8 years. The interlaboratory variation of the slope of the relationship between CRM 149R and RBT/79 was significantly lower than the variation of the slope of the relationship between BCT/099 and RBT/79. In addition to the manual technique, a semi-automatic coagulometer according to Schnitger & Gross was used to determine prothrombin times with CRM 149R. The mean ISI of CRM 149R was not affected by replacement of the manual technique by this particular coagulometer.Two lyophilized plasmas were included in this trial. The mean slope of relationship between RBT/79 and CRM 149R based on the two lyophilized plasmas was the same as the corresponding slope based on fresh plasmas. Tlowever, the mean slope of relationship between RBT/79 and BCT/099 based on the two lyophilized plasmas was 4.9% higher than the mean slope based on fresh plasmas. Thus, the use of these lyophilized plasmas induced a small but significant bias in the slope of relationship between these thromboplastins of different species.

The Stability of the WHO Reference Thromboplastin NIBS & C 67/40

1979 ◽  
Vol 42 (04) ◽  
pp. 1135-1140 ◽  
Author(s):  
G I C Ingram
Keyword(s):  
Human Brain ◽  
Collaborative Study ◽  
Calibration Constant ◽  
Long Term Stability ◽  
Freeze Dried ◽  
Show Evidence ◽  
Human Material ◽  
Reference Preparation ◽  
The Stability

SummaryThe International Reference Preparation of human brain thromboplastin coded 67/40 has been thought to show evidence of instability. The evidence is discussed and is not thought to be strong; but it is suggested that it would be wise to replace 67/40 with a new preparation of human brain, both for this reason and because 67/40 is in a form (like Thrombotest) in which few workers seem to use human brain. A �plain� preparation would be more appropriate; and a freeze-dried sample of BCT is recommended as the successor preparation. The opportunity should be taken also to replace the corresponding ox and rabbit preparations. In the collaborative study which would be required it would then be desirable to test in parallel the three old and the three new preparations. The relative sensitivities of the old preparations could be compared with those found in earlier studies to obtain further evidence on the stability of 67/40; if stability were confirmed, the new preparations should be calibrated against it, but if not, the new human material should receive a calibration constant of 1.0 and the new ox and rabbit materials calibrated against that.The types of evidence available for monitoring the long-term stability of a thromboplastin are discussed.

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