MORPHOLOGY OF MICROORGANISMS

Morphology
relates to the ‘science dealing with the structures and forms of organisms’. In
reality, the ‘
morphology of the bacterium’ exclusively trusts confidently upon a number of factors,
namely :
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the strain under investigation,
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nature of the culture medium,
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temperature and time of incubation,
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age of the culture, and
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the number of ‘subculture’ it has been subjected to.
Importantly, the various characteristic features that may be observed from such meticulous
investigational studies are : shape, size, arrangement, motility, flagella, spores, and capsules.
The
variants observed in the above cited physical characteristic features may be stated as under :
Shape :
spherical, rod shaped, comma shaped, spiral shaped, filamentous.
Axis of organism :
straight, curved.
Length and breadth :
mostly variable.
Sides of organism :
convex, concave, parallel, irregular.
Ends of organism :
tapering, rounded, straight.
Shape :
club shaped, giant forms, navicular, swollen, shadow shaped.
Arrangement
: in pairs, in tetrads, packs of eight, in chains (short or long) e.g., cocci ; in short
and long chains at random
e.g., bacilli ; in single or in ‘S’ or in spiral forms .e.g., vibrios.
Motility :
non-motile, sluggishly motile, actively motile or may show darting motility.
Forms :
atrichate (i.e., without flagella) ; monotrichate ; lophotrichate ; amphitrichate ; peritrichate ;
Spores :
oval, spherical, ellipsoidal, having same width or wider than the prevailing bacillary
body ; equatorial, subterminal or terminal.
Capsules :
may or may not be present.
Techniques used :
Electron microscopy ; phase-contrast microscopy ; background illumination ;and hanging drop preparations.