scholarly journals Inhibition of bacteria contaminating alcoholic fermentations by killer yeasts

2010 ◽  
Vol 53 (5) ◽  
pp. 1043-1050 ◽  
Author(s):  
Maria Cristina Meneghin ◽  
Vanda Renata Reis ◽  
Sandra Regina Ceccato-Antonini
Keyword(s):  
Leuconostoc Mesenteroides ◽  
Alcoholic Fermentation ◽  
Pichia Anomala ◽  
Killer Activity ◽  
Candida Sp ◽  
Gram Positive Bacteria ◽  
Crude Toxin ◽  
Yeast Strains ◽  
In Vitro Antibacterial Activity

The aim of this work was to study the in vitro antibacterial activity possessed by killer yeast strains against bacteria contaminating alcoholic fermentation (Bacillus subtilis, Lactobacillus plantarum, Lactobacillus fermentum and Leuconostoc mesenteroides), in cell X cell and cell X crude toxin preparations. The bacteria were not inhibited by any S. cerevisiae killer strains (5 out of 11). The inhibition caused by two crude toxin preparations (Trichosporon figueirae and Candida sp) against L. plantarum was surprisingly high but not in the same extent for B. subtilis, especially with three killer strains (Candida glabrata, Pichia anomala and Candida sp). L. mesenteroides and L. fermentum strains were neither inhibited in cell X cell nor crude toxin X cell tests. The results suggested that killer activity of yeasts might operate over bacteria and it could be used for the biocontrol of contaminating bacteria from alcoholic fermentation if additional tests on toxin application in fermentation shown to be successful. A wider panel of S. cerevisiae killer strains should be used to confirm that they were really unable to control the growth of these Gram-positive bacteria.

scholarly journals In Vitro Activity of S-3578, a New Broad-Spectrum Cephalosporin Active against Methicillin-Resistant Staphylococci

2003 ◽  
Vol 47 (3) ◽  
pp. 923-931 ◽  
Author(s):  
Takaji Fujimura ◽  
Yoshinori Yamano ◽  
Isamu Yoshida ◽  
Jingoro Shimada ◽  
Shogo Kuwahara
Keyword(s):  
Antibacterial Activity ◽  
Population Analysis ◽  
Low Frequency ◽  
Methicillin Resistant ◽  
Gram Positive Bacteria ◽  
Highly Active ◽  
In Vitro Antibacterial Activity ◽  
Mrsa Strains ◽  
Time Kill

ABSTRACT The in vitro antibacterial activity of S-3578, a new parenteral cephalosporin, against clinical isolates was evaluated. The MICs of the drug at which 90% of the isolates were inhibited were 4 μg/ml for methicillin-resistant Staphylococcus aureus (MRSA) and 2 μg/ml for methicillin-resistant Staphylococcus epidermidis, which were fourfold higher than and equal to those of vancomycin, respectively. The anti-MRSA activity of S-3578 was considered to be due to its high affinity for penicillin-binding protein 2a (50% inhibitory concentration, 4.5 μg/ml). In time-kill studies with 10 strains each of MRSA and methicillin-susceptible S. aureus, S-3578 caused more than a 4-log10 decrease of viable cells on the average at twice the MIC after 24 h of exposure, indicating that it had potent bactericidal activity. Furthermore, in population analysis of MRSA strains with heterogeneous or homogeneous resistance to imipenem, no colonies emerged from about 109 cells on agar plates containing twice the MIC of S-3578, suggesting the low frequency of emergence of S-3578-resistant strains from MRSA. S-3578 was also highly active against penicillin-resistant Streptococcus pneumoniae (PRSP), with a MIC90 of 1 μg/ml, which was comparable to that of ceftriaxone. S-3578 also had antibacterial activity against a variety of gram-negative bacteria including Pseudomonas aeruginosa, though its activity was not superior to that of cefepime. In conclusion, S-3578 exhibited a broad antibacterial spectrum and, particularly, had excellent activity against gram-positive bacteria including methicillin-resistant staphylococci and PRSP. Thus, S-3578 was considered to be worthy of further evaluation.

Synthesis and Antimicrobial Evaluation of 1,3,4-Oxadiazole bearing Schiff Base Moiety

2020 ◽  
Vol 5 (1) ◽  
pp. 1-5
Author(s):  
K. Kapadiya ◽  
G. Dubal ◽  
Y. Bhola ◽  
P. Dholaria
Keyword(s):  
Streptococcus Pyogenes ◽  
Nmr Spectra ◽  
Gram Negative Bacteria ◽  
13C Nmr Spectra ◽  
Aspergillus Clavatus ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
In Vitro Antibacterial Activity ◽  
Antimicrobial Evaluation

A new series of 4-((5-(2-chlorophenyl)-1,3,4-oxadiazol-2-yl)methoxy)-N-(benzylidene derivatives)benzenamine (5a-k) have been synthesized and were screened for their in vitro antibacterial activity against Gram-positive bacteria (Pseudomonas aeruginosa, Streptococcus pyogenes), Gram-negative bacteria (Escherichia coli, Staphylococcus aureus) and antifungal activity (Candida albicans, Aspergillus niger, Aspergillus clavatus). Synthesized compounds were characterized by IR, mass (MS), 1H NMR and 13C NMR spectra. The synthesized compounds 5b, 5c, 5g and 5i showed potency in terms of antimicrobial activity against tested microorganisms.

scholarly journals Antimicrobial activity of DU-6681a, a parent compound of novel oral carbapenem DZ-2640.

1997 ◽  
Vol 41 (6) ◽  
pp. 1260-1268 ◽  
Author(s):  
M Tanaka ◽  
M Hohmura ◽  
T Nishi ◽  
K Sato ◽  
I Hayakawa
Keyword(s):  
Parent Compound ◽  
Inoculum Size ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Alkaline Conditions ◽  
In Vitro Antibacterial Activity ◽  
Acidic Conditions ◽  
Kill Curve ◽  
Time Kill

The in vitro antibacterial activity of DU-6681a, a parent compound of DZ-2640, against gram-positive and -negative bacteria was compared with those of penems and cephalosporins currently available. MICs at which 90% of the isolates are inhibited (MIC90s) of the compound for clinical isolates of methicillin-susceptible and -resistant Staphylococcus aureus and Staphylococcus epidermidis, including methicillin-susceptible and -resistant strains, were 0.10, 25, and 12.5 microg/ml, respectively. DU-6681a inhibited the growth of all strains of Streptococcus pyogenes and of penicillin-susceptible and -insusceptible Streptococcus pneumoniae at 0.006, 0.025, and 0.20 microg/ml, respectively, and MIC90s of the compound were 6.25 and >100 microg/ml for Enterococcus faecalis and Enterococcus faecium, respectively. MIC90s of DU-6681a were 0.20, 0.10, and 0.025 microg/ml for Haemophilus influenzae, Moraxella catarrhalis, and Neisseria gonorrhoeae, respectively. For Pseudomonas aeruginosa, the MIC50 and MIC90 of DU-6681a were 25 and 50 microg/ml, respectively. DU-6681a activity was not affected by different media, varied inoculum size (10(4) to 10(7) CFU), or the addition of human serum but was decreased under acidic conditions against gram-negative bacteria, under alkaline conditions against gram-positive bacteria, and in human urine, as was the activity of the other antibiotics tested. The frequency of spontaneous resistance to DU-6681a was less than or equal to those of the reference compounds. Time-kill curve studies demonstrated the bactericidal action of DU-6681a against S. aureus, S. pneumoniae, Escherichia coli, and H. influenzae.

scholarly journals Microwave and Conventional Study of Coumarin-Oxadiazole Adducts and their Anti-Microbial Evaluation

Folia Medica ◽  
2021 ◽  
Vol 63 (1) ◽  
pp. 105-112
Author(s):  
Khushal Kapadiya ◽  
Piyush Dholaria
Keyword(s):  
Microwave Synthesis ◽  
Industrial Applications ◽  
Spectroscopic Techniques ◽  
Reference Drug ◽  
Gram Positive Bacteria ◽  
In Vitro Antibacterial Activity ◽  
Greener Synthesis ◽  
Conventional Study ◽  
Synthesis Approach

Introduction: Nowadays, researchers are progressively concentrated to generate economical, affordable and also greener synthesis approach for the synthesis of various heterocycles. On look at the beauty of coumarin molecules and oxazoles, it seems to be lead  molecules in the anti-microbial area.  Aim: With the target to identify efficient molecules, we studied 2-oxo-2H-chromen-4-yl-2-((5-substituted aryl-1,3,4-oxadiazol-2-yl) thio)acetate derivatives using two synthetic protocol/methods, i.e. conventional synthesis and microwave-based synthesis. Materials and methods: Two simultaneous methods, i.e. conventional and microwave synthesis have been used for the synthe-sis of 2-oxo-2H-chromen-4-yl-2-((5-substituted aryl-1,3,4-oxadiazol-2-yl)thio)acetate (6a-l) derivatives. The desired molecules were synthesized by conventional and microwave synthesis and a comparative study was carried out to identify an easy route for industrial applications. The confirmations of the compounds were carried out by spectroscopic techniques such as IR, 1H NMR, 13C NMR, mass spectra and elemental analysis.  Results: All synthesized compounds were evaluated for their in-vitro antibacterial activity against gram-positive bacteria (Staphylococcus aureus, Staphylococcus pyogenes), gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa), and antifungal activity (Candida albicans, Aspergillus niger).  Conclusions: All conventional synthesis of final coumarin derivatives were completed within 4-6 h. While that of microwave-based reaction took comparatively more reaction time. Surprisingly, the compounds 6f and 6g could not be synthesized by microwave radiation even after 32 minutes of irradiation. As to the medicinal application part, microbial evaluation of synthesized analogues showed that the compounds 6b, 6e, 6d, and 6j were found more potent in comparison to the reference drug. 

scholarly journals Synthesis and Characterization of Some New Pyrazoline and Isoxazoline Derivatives as Antibacterial Agents

2016 ◽  
Vol 13 (3) ◽  
pp. 568-577
Author(s):  
Baghdad Science Journal
Keyword(s):  
Sodium Hydroxide ◽  
Antibacterial Agents ◽  
Amine Hydrochloride ◽  
Gram Negative Bacteria ◽  
Gram Positive Bacteria ◽  
In Vitro Antibacterial Activity ◽  
Derivatives Of ◽  
Number Of Bacteria

In this paper some chalcones (C1-C8) are prepared based on the reaction of one mole of substituted acetophenone with one mole of substituted benzaldehydes in the presence of (40%) sodium hydroxide as a base. Pyrazolines (P1–P8) are prepared from the reaction of chalcones (C1-C8) with hydrazine hydrate. Isoxazoline (I1-I8) is prepared from the reaction of chalcones (C1-C8) with hydroxyl amine hydrochloride in the presence of (10%) sodium hydroxide as a base. These compounds are characterized by using various physical and spectral methods. The compounds are screened for their in vitro antibacterial activity using gram-positive bacteria and gram-negative bacteria. Several derivatives of pyrazolines and isoxazolines are produced well to moderate activities against number of bacteria.

scholarly journals Synthesis, Anti-microbial, Flameretardance and Anti-corrosive Activity of Some New Heterocycles Incorporating Coumarin moiety

2020 ◽  
pp. 23-37
Author(s):  
S. M. Mohamed ◽  
Nadia T. A. Dawoud ◽  
N. Abd El-Khalik ◽  
Wafaa. M. Mazen ◽  
Z. I. El Bailey
Keyword(s):  
Heterocyclic Compounds ◽  
Gram Negative Bacteria ◽  
Coumarin Derivatives ◽  
Flame Resistance ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
In Vitro Antibacterial Activity ◽  
Flame Retardant Properties ◽  
Corrosive Activity

In the present study a series of novel heterocyclic compounds (2-16) incorporating coumarin moiety was synthesized. The newly synthesized compounds were elucidated on the basis of elemental analysis, spectral data, were tested for in-vitro antibacterial activity against Staphylococcus aureus, Bacillus subtilis (Gram-positive bacteria), Salmonella typhimurium, Escherichia coli (Gram-negative bacteria) and Candida albicans, Aspergillus fumigatus (fungi). Coumarin derivatives (1,6,16) were chosen to evaluate the anti-corrosion, flame retardant properties. The results clearly showed that, the incorporation of coumarin derivatives into epoxy coating have led to improve the flame residency, corrosion resistance, and mechanical properties of investigated coating and confirmed that these new developed varnishes have an excellent properties as flame resistance and anticorrosive for mild steel.

scholarly journals Synthesis and biological evaluation of pyrazole analogues linked with 1,2,3-triazole and 4-thiazolidinone as antimicrobial agents

2022 ◽  
Vol 11 (1) ◽  
pp. 139-146 ◽  
Author(s):  
Nagaraj Adki ◽  
Neelofer Rana ◽  
Ramesh Naik Palthya
Keyword(s):  
Antimicrobial Agents ◽  
Micrococcus Luteus ◽  
Trichophyton Mentagrophytes ◽  
Biological Evaluation ◽  
Significant Activity ◽  
Standard Drug ◽  
Gram Positive Bacteria ◽  
Highly Active ◽  
In Vitro Antibacterial Activity

A new series of 2-[3-(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)-1-phenyl-1H-4-pyrazolyl]-3-aryl-1,3-thiazolan-4-one 5(a-i) have been designed, synthesized and evaluated for their in vitro antibacterial activity against Gram positive bacteria viz. Bacillus subtilis (ATCC 6633), Staphylococcus aureus (ATCC 6538p), Micrococcus luteus (IFC 12708) and Gram negative bacteria viz. Proteus vulgaris (ATCC 3851), Salmonella typhimurium (ATCC 14028), Escherichia coli (ATCC 25922) the antifungal activity against Candida albicans (ATCC 10231), Aspergillus fumigatus (HIC 6094), Trichophyton rubrum (IFO 9185), Trichophyton mentagrophytes (IFO 40996). Antibacterial evaluation indicates that compounds containing 4-methoxyphenyl 5c, 4-fluorophenyl 5d and 2,5-difluorophenyl 5h groups on thiazolidinone ring showed significant activity equal to that of standard drug. The antifungal evaluation shows that compound 5c is highly active against A. fumigatus, compound 5d and 5h were also active against C. albicans and A. fumigatus.

scholarly journals In vitro Antibacterial Activity of Mentha spicata Essential Oil against Some Pathogenic Bacteria

2021 ◽  
Vol 11 (1) ◽  
pp. 13-15
Author(s):  
Sara I. Othman ◽  
Fouad H. Kamel
Keyword(s):  
Pathogenic Bacteria ◽  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
Mentha Spicata ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Aerial Parts ◽  
In Vitro Antibacterial Activity ◽  
Pharmaceutical Industries

Mentha spicata (M. spicata) is within family Lamiaceae that spreads mainly in the temperate and subtemperate zones of the world. It is considered as a good source of essential oils (EOs), which is widely used in food production and pharmaceutical industries. The aim of the current study is to evaluate antibacterial activities associated with the EO of M. spicata cultivated in Iraq-Erbil city. The aerial parts of M. spicata were subjected to hydro distillation to extract the oil. Antimicrobial potential was tested against many microorganisms, signifying Gram-negative and Gram-positive bacteria. EO of M. spicata demonstrated antimicrobial activities with best susceptibility observed for Gram-negative bacteria toward the oil. The results suggest that EO of M. spicata may have potential value as antibacterial activities.

scholarly journals Synthesis, Characterization and Antibacterial Evaluation of Mn (II), Co (II) and Cu (II) Complexes of Schiff Base Derived from 3-aminophenol and Benzaldehyde

2020 ◽  
pp. 39-44
Author(s):  
Usman Abubakar Adamu ◽  
Buhari Magaji ◽  
Muhammad Nazifi Ibrahim ◽  
Mukhtar Muhammad Sani
Keyword(s):  
Schiff Base ◽  
Bidentate Ligand ◽  
Bacterial Strains ◽  
Gram Positive Bacteria ◽  
Infrared Spectral ◽  
In Vitro Antibacterial Activity ◽  
Spectrum Activity ◽  
Metal Ligand ◽  
Broad Spectrum Activity

Schiff base was prepared by the condensation of 3-aminophenol and benzaldehyde in a 1:1 ratio and its complexes of Mn(II), Co(II) and Cu(II) were synthesized in a 1:2 ratio (Metal: Ligand) and the Schiff base and the complexes were characterized by using the different techniques. The infrared spectral data revealed that the Schiff base behaved as a bidentate ligand and the molar conductivity value indicated that the complexes were non-electrolytes. Furthermore, the in vitro antibacterial activity of the Schiff base and its complexes was evaluated against one gram-negative and one gram-positive bacteria to indicate that Mn (II) complex demonstrated a good broad-spectrum activity against all the tested bacterial strains.

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