Related Experiment Video

Updated: Aug 15, 2026

Using the Overlay Assay to Qualitatively Measure Bacterial Production of and Sensitivity to Pneumococcal Bacteriocins
06:05

Using the Overlay Assay to Qualitatively Measure Bacterial Production of and Sensitivity to Pneumococcal Bacteriocins

Published on: September 30, 2014

[Properties of bacteriocins of Morganella morganii]

D Sakowska, A Jerzmanowski

    Medycyna Doswiadczalna I Mikrobiologia
    |January 1, 1989
    PubMed

    Insights

    Two bacteriocins from Morganella morganii exhibit distinct properties. Bacteriocin "115" is heat-stable, while "137" is heat-sensitive, with both affected by freezing and pH, showing narrow-spectrum activity.

    Area of Science:

    • Microbiology
    • Biochemistry

    Background:

    • Bacteriocins are ribosomally synthesized antimicrobial peptides with diverse biological activities.
    • Morganella morganii is an opportunistic pathogen, and understanding its bacteriocins can offer insights into antimicrobial strategies.

    Purpose of the Study:

    • To characterize the physical and chemical properties of bacteriocins produced by Morganella morganii strains.
    • To compare the stability, activity spectrum, and diffusion capabilities of two distinct bacteriocins.

    Main Methods:

    • Bacteriocin production was induced using mitomycin C in Morganella morganii strains.
    • Investigated effects of temperature, pH, freezing/thawing, and enzymatic digestion (trypsin, papain, lysozyme).
    • Assessed antimicrobial activity range and agar diffusion properties.

    Main Results:

    • Bacteriocin "115" demonstrated thermostability and sensitivity to proteases, diffusing in 1.5% agar.
    • Bacteriocin "137" was thermolabile, resistant to proteases, and did not diffuse in 1.5% agar.
    • Both bacteriocins lost activity upon freezing/thawing, were resistant to lysozyme, and exhibited optimal activity at neutral to alkaline pH.

    Conclusions:

    • Morganella morganii produces bacteriocins with differing physicochemical characteristics, impacting their potential applications.
    • The narrow spectrum of activity suggests potential for targeted antimicrobial use against susceptible Morganella strains.
    • Understanding these bacteriocin properties is crucial for developing novel therapeutic or control strategies.

    More Related Videos

    A Method to Assess Bacteriocin Effects on the Gut Microbiota of Mice07:54

    A Method to Assess Bacteriocin Effects on the Gut Microbiota of Mice

    Published on: July 25, 2017

    Evaluation of Antimicrobial Activities of Nanoparticles and Nanostructured Surfaces In Vitro11:52

    Evaluation of Antimicrobial Activities of Nanoparticles and Nanostructured Surfaces In Vitro

    Published on: April 21, 2023

    Related Concept Videos

    Biological Methods for Microbial Control01:28

    Biological Methods for Microbial Control

    Biological agents offer an effective means of controlling microbial growth by leveraging natural processes like predation, competition, and the secretion of antimicrobial substances.Predatory bacteria such as Bdellovibrio species target and kill pathogens like Salmonella and E. coli. They are widely used in poultry farms to control infections. Myxococcus species help combat plant-pathogenic fungi. These naturally occurring predators serve as eco-friendly alternatives to chemical pesticides and...
    Bacterial Phylum Actinobacteria01:30

    Bacterial Phylum Actinobacteria

    Coryneform bacteria are gram-positive, aerobic, nonmotile rods that exhibit irregular, club-shaped, or V-shaped arrangements. Their V-shape results from snapping division, where the inner cell wall layer forms the cross-wall, while the outer layer remains intact until it ruptures on one side, causing the daughter cells to bend away.The primary genera are Corynebacterium and Arthrobacter. Corynebacterium includes diverse species, ranging from saprophytes to pathogens like Corynebacterium...
    Other Unique Bacteria01:18

    Other Unique Bacteria

    Magnetic bacteria exhibit a directed movement called magnetotaxis, driven by structures called magnetosomes. These magnetosomes consist of chains of magnetic particles made of either magnetite (Fe₃O₄) or greigite (Fe₃S₄) and are organized in a linear conformation by a protein scaffold within invaginations of the cell membrane. The bacteria align along the north–south magnetic field lines, much like a compass needle. They are typically microaerophilic or anaerobic and are commonly found near the...
    Inhibitors of Gram-positive Cell Wall Synthesis01:23

    Inhibitors of Gram-positive Cell Wall Synthesis

    Bacterial cell walls are typically rigid structures composed mainly of peptidoglycan, a mesh-like polymer that provides mechanical strength and maintains cell shape. The synthesis of peptidoglycan is a crucial process in bacterial growth and serves as a primary target for many antibiotics.Mechanism of Action of Beta-Lactam AntibioticsBeta-lactam antibiotics, such as penicillin, inhibit peptidoglycan synthesis in actively growing cells. These antibiotics share a characteristic four-membered...
    Inhibitors of Bacterial Protein Synthesis01:25

    Inhibitors of Bacterial Protein Synthesis

    Aminoglycosides constitute a highly potent class of bactericidal antibiotics that exert their antimicrobial effects by targeting the bacterial ribosome, specifically disrupting protein synthesis. These polycationic molecules consist of amino-modified sugars linked via glycosidic bonds to an aminocyclitol core such as 2-deoxystreptamine or streptamine. Their strong positive charges facilitate tight binding to the negatively charged phosphate backbone of ribosomal RNA (rRNA), primarily at the 16S...
    Clinical Significance of Antibiotic Resistance01:25

    Clinical Significance of Antibiotic Resistance

    Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...