scholarly journals Thermoadaptation-Directed Enzyme Evolution in an Error-Prone Thermophile Derived from Geobacillus kaustophilus HTA426

2014 ◽  
Vol 81 (1) ◽  
pp. 149-158 ◽  
Author(s):  
Hirokazu Suzuki ◽  
Jyumpei Kobayashi ◽  
Keisuke Wada ◽  
Megumi Furukawa ◽  
Katsumi Doi
Keyword(s):  
Bacillus Subtilis ◽  
Parent Strain ◽  
Enzyme Evolution ◽  
Denaturation Temperature ◽  
Content Type ◽  
Practical Applications ◽  
Long Term Storage ◽  
Geobacillus Kaustophilus ◽  
Term Storage

ABSTRACTThermostability is an important property of enzymes utilized for practical applications because it allows long-term storage and use as catalysts. In this study, we constructed an error-prone strain of the thermophileGeobacillus kaustophilusHTA426 and investigated thermoadaptation-directed enzyme evolution using the strain. A mutation frequency assay using the antibiotics rifampin and streptomycin revealed thatG. kaustophilushad substantially higher mutability thanEscherichia coliandBacillus subtilis. The predominant mutations inG. kaustophiluswere A · T→G · C and C · G→T · A transitions, implying that the high mutability ofG. kaustophiluswas attributable in part to high-temperature-associated DNA damage during growth. Among the genes that may be involved in DNA repair inG. kaustophilus, deletions of themutSL,mutY,ung, andmfdgenes markedly enhanced mutability. These genes were subsequently deleted to construct an error-prone thermophile that showed much higher (700- to 9,000-fold) mutability than the parent strain. The error-prone strain was auxotrophic for uracil owing to the fact that the strain was deficient in the intrinsicpyrFgene. Although the strain harboringBacillus subtilispyrFwas also essentially auxotrophic, cells became prototrophic after 2 days of culture under uracil starvation, generatingB. subtilisPyrF variants with an enhanced half-denaturation temperature of >10°C. These data suggest that this error-prone strain is a promising host for thermoadaptation-directed evolution to generate thermostable variants from thermolabile enzymes.

scholarly journals Degradation of chlorobenzene and 2-chlorotoluene by immobilized bacteria strains Comamonas testosterone kt5 and Bacillus subtilis dkt

2019 ◽  
Vol 41 (4) ◽  
Author(s):  
Ha Danh Duc ◽  
Nguyen Thi Oanh
Keyword(s):  
Bacillus Subtilis ◽  
Bacterial Strain ◽  
Immobilized Cells ◽  
Resting Cells ◽  
Long Term Storage ◽  
Degradation Rates ◽  
Contributory Negligence ◽  
Biofilm Bacteria ◽  
Term Storage

Chlorobenzenes and chlorotoluenes have been used to produce a number of industrial products. They are toxic and widely detected in environments due to human contributory negligence. In this article, the mixed culture of a toluenes-degrading bacterial strain, Comamonas testosterone KT5 (a Gram-positive, catalase-positive bacterium) and a chlorobenzenes-degrading bacterial strain, Bacillus subtilis DKT (a Gram-negative soil bacterium) effectively degraded both chemical compounds co-contaminating in liquid media. In addition, the degradations of mixed compounds by biofilm, bacteria immobilized in polyurethane foam (PUF) and alginate were determined. The results showed that the degradation of both compounds by cells in alginate was significantly higher than that by suspended cells. Moreover, cells immobilized in these materials showed lower adverse effects than those of non-immobilized cells for long-term storage. For examples, the degradation rates for chlorobenzine and 2-chlorotoluene by resting cells reduced by 39.5% and 37.3% after storage for 4 months at 4°C, while the degradation rates by immobilized cells decreased by from 16.3% to 19.8% respectively. 

scholarly journals Rediscovering Zygorhizidium affluens Canter: Molecular Taxonomy, Infectious Cycle, and Cryopreservation of a Chytrid Infecting the Bloom-Forming Diatom Asterionella formosa

2018 ◽  
Vol 84 (23) ◽  
Author(s):  
Cecilia Rad-Menéndez ◽  
Mélanie Gerphagnon ◽  
Andrea Garvetto ◽  
Paola Arce ◽  
Yacine Badis ◽  
...  
Keyword(s):  
Molecular Taxonomy ◽  
Cost Effective ◽  
Trophic Levels ◽  
Content Type ◽  
Long Term Storage ◽  
Asterionella Formosa ◽  
Infectious Cycle ◽  
Cryopreservation Method ◽  
Term Storage

ABSTRACT Parasitic Chytridiomycota (chytrids) are ecologically significant in various aquatic ecosystems, notably through their roles in controlling bloom-forming phytoplankton populations and in facilitating the transfer of nutrients from inedible algae to higher trophic levels. The diversity and study of these obligate parasites, while critical to understand the interactions between pathogens and their hosts in the environment, have been hindered by challenges inherent to their isolation and stable long-term maintenance under laboratory conditions. Here, we isolated an obligate chytrid parasite (CCAP 4086/1) on the freshwater bloom-forming diatom Asterionella formosa and characterized its infectious cycle under controlled conditions. Phylogenetic analyses based on 18S, 5.8S, and 28S ribosomal DNAs (rDNAs) revealed that this strain belongs to the recently described clade SW-I within the Lobulomycetales. All morphological features observed agree with the description of the known Asterionella parasite Zygorhizidium affluens Canter. We thus provide a phylogenetic placement for this chytrid and present a robust and simple assay that assesses both the infection success and the viability of the host. We also validate a cryopreservation method for stable and cost-effective long-term storage and demonstrate its recovery after thawing. All the above-mentioned tools establish a new gold standard for the isolation and long-term preservation of parasitic aquatic chytrids, thus opening new perspectives to investigate the diversity of these organisms and their physiology in a controlled laboratory environment. IMPORTANCE Despite their ecological relevance, parasitic aquatic chytrids are understudied, especially due to the challenges associated with their isolation and maintenance in culture. Here we isolated and established a culture of a chytrid parasite infecting the bloom-forming freshwater diatom Asterionella formosa. The chytrid morphology suggests that it corresponds to the Asterionella parasite known as Zygorhizidium affluens. The phylogenetic reconstruction in the present study supports the hypothesis that our Z. affluens isolate belongs to the order Lobulomycetales and clusters within the novel clade SW-I. We also validate a cryopreservation method for stable and cost-effective long-term storage of parasitic chytrids of phytoplankton. The establishment of a monoclonal pathosystem in culture and its successful cryopreservation opens the way to further investigate this ecologically relevant parasitic interaction.

scholarly journals The Effect of Endophytic Bacteria Bacillus subtilis and Salicylic Acid on Some Resistance and Quality Traits of Stored Solanum tuberosum L. Tubers Infected with Fusarium Dry Rot

Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 738 ◽  
Author(s):  
Oksana Lastochkina ◽  
Liudmila Pusenkova ◽  
Darya Garshina ◽  
Ruslan Yuldashev ◽  
Irina Shpirnaya ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Salicylic Acid ◽  
Solanum Tuberosum ◽  
Solanum Tuberosum L ◽  
Quality Traits ◽  
Dry Rot ◽  
Long Term Storage ◽  
Fusarium Dry Rot ◽  
Term Storage

The effect of endophytic Bacillus subtilis (strains 10-4, 26D) and their compositions with salicylic acid (SA) on some resistance and quality traits of stored potatoes infected with Fusarium dry rot were studied. The experiments were carried out on hydroponically grown Solanum tuberosum L. tubers that were infected before storage with Fusarium oxysporum and coated with B. subtilis 10-4, 26D with and without exogenous SA, and then stored for six months. It has been shown that 10-4, 26D, 10-4 + SA, and 26D + SA reduced in different levels (up to 30–50%) the incidence of F. oxysporum-caused dry rot (with the highest effect for 10-4 + SA). SA notably enhanced the positive effect of 10-4, while for 26D, such an effect was not observed. All of the tested treatments increased amylase (AMY) and AMY inhibitors activity in infected tubers, while decreased Fusarium-induced protease activity (except in the case of 10-4 + SA, which promoted a slight increase) was revealed. 10-4, 26D, and their compositions with SA decreased (in different degrees) the pathogen-caused lipid peroxidation, proline, and reducing sugars accumulation in potatoes after long-term storage. It was also discovered 10-4 and 26D, regardless of SA presence, decrease pathogen-induced glycoalkaloids α-Solanine and α-Chaconine accumulation and preserved increased levels of starch and total dry matter in infected stored potatoes. The findings indicate endophytic B. subtilis and its compositions with SA is a promising eco-friendly and bio-safe approach to cope with postharvest decays of potato during long-term storage; however, when developing preparations-compositions it should take into account the strain-dependent manner of B. subtilis action together with SA.

The medium-term prospects for long-term storage systems

2017 ◽  
Vol 35 (1) ◽  
pp. 11-31 ◽  
Author(s):  
David Stuart Holmes Rosenthal
Keyword(s):  
Digital Media ◽  
Media Industry ◽  
Medium Term ◽  
Bulk Storage ◽  
Content Type ◽  
Long Term Storage ◽  
Storage Media ◽  
Technology Changes ◽  
Term Storage

Purpose Increasingly, the content that libraries collect is no longer on paper, a long-lived, medium whose technology changes very slowly and with which they have centuries of experience. Instead, it is stored on relatively short-lived digital media whose technology appears to change rapidly and with which they have little history. The paper aims to discuss this issue. Design/methodology/approach The storage media industry is highly competitive and is currently evolving rapidly as flash, a solid state medium, displaces spinning disk from many applications. Long-term archival storage is a small part of the total storage market. It typically re-uses media and systems intended for more general bulk storage. Findings What are the medium-term prospects for change in this market? Originality/value Much of this material has appeared in blog posts and talks aimed at storage experts, such as the recent DARPA workshop on future of storage. It is presented here for a librarian audience with the necessary additional exposition and background.

Clinical results of lyophilized human cadaver dura transplantation

1971 ◽  
Vol 34 (6) ◽  
pp. 770-773 ◽  
Author(s):  
William M. Abbott ◽  
Emmett L. Dupree
Keyword(s):  
Clinical Results ◽  
Complication Rates ◽  
Human Cadaver ◽  
Content Type ◽  
Dural Closure ◽  
Long Term Storage ◽  
Freeze Dried ◽  
Neurosurgical Patients ◽  
Term Storage

✓ The clinical results of lyophilized human cadaver dura transplantation in 170 neurosurgical patients show that it is a safe and effective material for dural closure. It is associated with low complication rates and minimal cortical scarring and adhesions. The successful results have been attributed to the minimal foreign body reaction stimulated by freeze-dried tissue. These factors plus its capacity for safe and convenient long-term storage at room temperature make lyophilization the method of choice for preserving dura mater.

Modelling of Moisture Movement in Wood during Outdoor Storage

2001 ◽  
Vol 6 (2) ◽  
pp. 3-14 ◽  
Author(s):  
R. Baronas ◽  
F. Ivanauskas ◽  
I. Juodeikienė ◽  
A. Kajalavičius
Keyword(s):  
Experimental Data ◽  
Finite Difference ◽  
Climatic Conditions ◽  
Two Dimensional ◽  
Moisture Movement ◽  
Finite Difference Technique ◽  
Long Term Storage ◽  
Space Formulation ◽  
Term Storage

A model of moisture movement in wood is presented in this paper in a two-dimensional-in-space formulation. The finite-difference technique has been used in order to obtain the solution of the problem. The model was applied to predict the moisture content in sawn boards from pine during long term storage under outdoor climatic conditions. The satisfactory agreement between the numerical solution and experimental data was obtained.

Trehalose: a cryoprotectant that enhances recovery and preserves function of human pancreatic islets after long-term storage

Diabetes ◽  
1997 ◽  
Vol 46 (3) ◽  
pp. 519-523 ◽  
Author(s):  
G. M. Beattie ◽  
J. H. Crowe ◽  
A. D. Lopez ◽  
V. Cirulli ◽  
C. Ricordi ◽  
...  
Keyword(s):  
Pancreatic Islets ◽  
Human Pancreatic Islets ◽  
Long Term Storage ◽  
Term Storage
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