Biochemical characterization of two chitinases from Bacillus cereus sensu lato B25 with antifungal activity against Fusarium verticillioides P03

2020 ◽  
Author(s):  
Estefanía Morales-Ruiz ◽  
Ricardo Priego-Rivera ◽  
Alejandro Miguel Figueroa-López ◽  
Jesús Eduardo Cazares-Álvarez ◽  
Ignacio E Maldonado-Mendoza
Keyword(s):  
Bacillus Cereus ◽  
Biochemical Characterization ◽  
Fusarium Verticillioides ◽  
Expression System ◽  
Phytopathogenic Fungi ◽  
Fungal Cell ◽  
Synthetic Pesticides ◽  
Bacillus Cereus Sensu Lato ◽  
Dual Substrate

Abstract Bacterial chitinases are a subject of intense scientific research due to their biotechnological applications, particularly their use as biological pesticides against phytopathogenic fungi as a green alternative to avoid the use of synthetic pesticides. Bacillus cereus sensu lato B25 is a rhizospheric bacterium that is a proven antagonist of Fusarium verticillioides, a major fungal pathogen of maize. This bacterium produces two chitinases that degrade the fungal cell wall and inhibit its growth. In this work, we used a heterologous expression system to purify both enzymes to investigate their biochemical traits in terms of Km, Vmax, optimal pH and temperature. ChiA and ChiB work as exochitinases, but ChiB exhibited a dual substrate activity and it is also an endochitinase. In this work, the direct addition of these chitinases inhibited fungal conidial germination and therefore they may play a major role in the antagonism against F. verticillioides.

Biochemical characterization of a cortexless mutant of a variant of Bacillus cereus

1976 ◽  
Vol 22 (7) ◽  
pp. 1007-1012 ◽  
Author(s):  
Susanne M. Pearce
Keyword(s):  
Cell Wall ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Bacillus Cereus ◽  
Biochemical Characterization ◽  
Diaminopimelic Acid ◽  
Peptidoglycan Synthesis ◽  
Biochemical Lesion ◽  
Do So

Previous studies on this cortexless mutant of Bacillus cereus var. alesti indicated that the forespore membrane was the site of the biochemical lesion. This hypothesis is supported by the results presented here: fatty acid composition of sporulating cells of the mutant is altered, while in vegetative cells it is comparable to the parent; soluble precursors of peptidoglycan synthesis are accumulated in the mutant, at the time of cortex formation; homogenates of the mutant prepared at the time of cortex formation are unable to incorporate tritiated diaminopimelic acid into peptidoglycan, while homogenates of cells forming germ cell wall do so to an extent comparable to that of the parent; lipid-linked intermediates are formed by the mutant as in the parent. Apparently the mutant is unable either to transfer disaccharide penta-peptide units from the carrier lipid to the growing peptidoglycan acceptor, or to transport lipid-linked intermediates across the forespore membrane.

Occurrence of Bacillus cereus and the Bacteriological Quality of Chinese “Take-Out” Foods

1978 ◽  
Vol 41 (6) ◽  
pp. 450-454 ◽  
Author(s):  
D. A. SCHIEMANN
Keyword(s):  
Bacillus Cereus ◽  
Nitrate Reduction ◽  
Biochemical Characterization ◽  
Bacteriological Examination ◽  
Bacteriological Quality ◽  
Litmus Milk ◽  
Aerobic And Anaerobic ◽  
Gelatin Hydrolysis

One hundred sixty-five samples of various foods were collected from 24 different Chinese take-out restaurants for bacteriological examination which included enumeration of Bacillus cereus by three media, MYP, KG and blood agars. Blood agar was less selective but no quantitative differences in recovery were apparent. Twenty-eight samples (15%) yielded B. cereus in excess of 100 per gram, and 20 of these were fried rice (33% positive), which also showed the poorest overall bacteriological quality. Biochemical characterization of 232 isolates of B. cereus showed 96% or more positive for catalase, nitrate reduction, beta-haemolysis, subterminal-ellipsoidal spores, aerobic and anaerobic utilization of glucose, Voges-Proskauer, fermentation of glycerol, gelatin hydrolysis, and alkaline peptonization of litmus milk; and a negative reaction in mannitol. Variable results were obtained for motility, fermentation of sucrose and salicin, and starch hydrolysis. Thirty-three isolates were susceptible to 12 of 19 antibiotics tested, and resistant to colistin. Six (18%) were susceptible to penicillin.

Pathogenicity and characterization of a novel Bacillus cereus sensu lato isolate toxic to the Mediterranean fruit fly Ceratitis capitata Wied.

2015 ◽  
Vol 126 ◽  
pp. 71-77 ◽  
Author(s):  
Luca Ruiu ◽  
Giovanni Falchi ◽  
Ignazio Floris ◽  
Maria Giovanna Marche ◽  
Maria Elena Mura ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Ceratitis Capitata ◽  
Fruit Fly ◽  
Mediterranean Fruit Fly ◽  
The Mediterranean ◽  
Bacillus Cereus Sensu Lato

scholarly journals Overproduction and Biochemical Characterization of the Chryseobacterium meningosepticum BlaB Metallo-β-Lactamase

2002 ◽  
Vol 46 (6) ◽  
pp. 1921-1927 ◽  
Author(s):  
Sandrine Vessillier ◽  
Jean-Denis Docquier ◽  
Sandrine Rival ◽  
Jean-Marie Frere ◽  
Moreno Galleni ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Ion Exchange ◽  
Kinetic Parameters ◽  
Culture Supernatant ◽  
Biochemical Characterization ◽  
Expression System ◽  
T7 Promoter ◽  
Hydrolysis Of

ABSTRACT The BlaB metallo-β-lactamase of Chryseobacterium meningosepticum CCUG4310 was overproduced in Escherichia coli by means of a T7 promoter-based expression system. The overproducing system, scaled up in a 15-liter fermentor, yielded approximately 10 mg of BlaB protein per liter, mostly released in the culture supernatant. The enzyme was purified by two ion-exchange chromatographic steps with an overall yield of 66%. Analysis of the kinetic parameters revealed efficient activities (k cat/Km ratios of >106 M−1 s−1) toward most penam and carbapenem compounds, with the exception of the 6-α-methoxypenam derivative temocillin and of biapenem, which were poorer substrates. Hydrolysis of cephalosporins was overall less efficient, with a remarkable variability that was largely due to variable affinities of the BlaB enzyme for different compounds. BlaB was also able to hydrolyze serine-β-lactamase inhibitors, including β-iodopenicillanate, sulbactam and, although less efficiently, tazobactam.

scholarly journals Genomic characterization of the Bacillus cereus sensu lato species: Backdrop to the evolution of Bacillus anthracis

2012 ◽  
Vol 22 (8) ◽  
pp. 1512-1524 ◽  
Author(s):  
M. E. Zwick ◽  
S. J. Joseph ◽  
X. Didelot ◽  
P. E. Chen ◽  
K. A. Bishop-Lilly ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Bacillus Anthracis ◽  
Genomic Characterization ◽  
Bacillus Cereus Sensu Lato

scholarly journals Biochemical Characterization of a Group-5 Soluble Diiron Monooxygenase Hydroxylase and Related Chaperonin-like Component

2020 ◽  
Author(s):  
Chihiro Inoue ◽  
Yoshitaka Abe ◽  
Nobutaka Fujieda
Keyword(s):  
Biochemical Characterization ◽  
Quaternary Structure ◽  
Expression System ◽  
Functional Expression ◽  
Size Exclusion ◽  
Native Page ◽  
Dinuclear Iron ◽  
Exclusion Chromatography ◽  
Group 5

<p>Recently, the functional expression of group-5 hydroxylase component (MimA and MimC) in <i>Escherichia coli </i>along with its related chaperonin-like component (MimG) was reported by Furuya and Kino. In this study, we report the purification via a heterologous expression system and the biochemical characterization of MimAC, the complex of MimA and MimC and MimG to understand their exact roles. MimAC and MimG were fused with His-tags and purified using affinity chromatography in a homogenous state on SDS-PAGE. Blue native PAGE demonstrated that the quaternary structure of MimG was almost identical to that of chaperonin GroEL, indicating that its function was also similar to GroEL. Size-exclusion chromatography and ICP-AES analysis demonstrated that MimAC was assembled in the dimer of two sort of subunits and exhibited two iron atoms and at least one zinc atom per two subunits. This result indicated that MimAC possessed a dinuclear iron center, similar to other soluble diiron monooxygenase hydroxylases.</p>

scholarly journals Heterologous Expression and Biochemical Characterization of the Human Zinc Transporter 1 (ZnT1) and Its Soluble C-Terminal Domain

2021 ◽  
Vol 9 ◽  
Author(s):  
Camila A. Cotrim ◽  
Russell J. Jarrott ◽  
Andrew E. Whitten ◽  
Hassanul G. Choudhury ◽  
David Drew ◽  
...  
Keyword(s):  
Heterologous Expression ◽  
Biochemical Characterization ◽  
Expression System ◽  
Zinc Transporter ◽  
X Ray ◽  
Terminal Domain ◽  
X Ray Scattering ◽  
Cholesteryl Hemisuccinate ◽  
Soluble C

Human zinc transporter 1 (hZnT1) belongs to the cation diffusion facilitator (CDF) family. It plays a major role in transporting zinc (Zn2+) from the cytoplasm across the plasma membrane and into the extracellular space thereby protecting cells from Zn2+ toxicity. Through homology with other CDF family members, ZnT1 is predicted to contain a transmembrane region and a soluble C-terminal domain though little is known about its biochemistry. Here, we demonstrate that human ZnT1 and a variant can be produced by heterologous expression in Saccharomyces cerevisiae cells and purified in the presence of detergent and cholesteryl hemisuccinate. We show that the purified hZnT1 variant has Zn2+/H+ antiporter activity. Furthermore, we expressed, purified and characterized the soluble C-terminal domain of hZnT1 (hZnT1-CTD) in a bacterial expression system. We found that the hZnT1-CTD melting temperature increases at acidic pH, thus, we used an acetate buffer at pH 4.5 for purifications and concentration of the protein up to 12 mg/mL. Small-angle X-ray scattering analysis of hZnT1-CTD is consistent with the formation of a dimer in solution with a V-shaped core.

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