Cultural Characteristics

CULTURAL CHARACTERISTICS

Based upon a broad spectrum of intensive and conclusive research carried out during the past few decades, in fact, have resulted in the accumulation of an array of vital and important ‘additional informations’ with regard to the proper ‘identification of the bacterium’. However, the various cul-tural characteristic features that have been brought to light in different kinds of media are duly observed. Importantly, during the investigative studies one may critically note the following features emerging as very specific colonies upon the solid media, namely :

Shape : irregular, circular, or rhizoid ;

Size : usually expressed in millimeters (mm) ;

Elevation : elevated, convex, concave, umbonate or umbilicate, or effuse ;

Margins : bevelled, or otherwise ;

Surface : wavy, rough, smooth, granular, papillate, or glistening ;

Edges : entire, undulate, crenated, curled, or fimbriate ;

Colour : variation in different colour intensities ;

Structure : transparent, translucent or opaque ;

Consistency : butyrous, membranous, friable or viscid ;

Emulsifiability : good, mediocre, poor, or best ; and

Differentiation : into a central and a peripheral portion.

It is, however, pertinent to state here that there exist a notable variation amongst the stroke culture, such as :

(a) Degree of Growth : These are invariably of three strengths viz., scarce, intermediate, or excessive ;

(b) Nature of Growth : These could be either discrete or confluent, filiform*, spreading, or rhizoid ; and

(c) Physical Characteristics : These essentially include a wide variety of such physical char-acteristic features as : surface, elevation, edges, colour, structure, odour, emulsifiability, consistency, and the overall critical changes observed in the ensuing medium.

It is pertinent to mention at this point in time that in a particular fluid (or liquid) medium one may obviously take cognizance of the following characteristic features, namely :

·        extent of growth,

·        presence of turbidity plus its nature,

·        presence of deposit and its character,

·        nature of surface growth e.g., pellicle* and its observed quality, and

·        ease of disintegration, and colouration.