| Cultural characteristic of bacteria is one of the important aspect applied in identification of bacteria. Cultural characteristics describe various features of growth of bacteria on medium. |
| Growth on solid media |
| Size – in mm Shape – Round, irregular, rhizoid, spindle Elevation – Flat, raised, convex, umbonate Surface – Smooth, rough, papillate, ringed, fried egg, medusa head Margins – Entire, wavy, lobate, erose, curled,filamentous Opacity – Opaque, translucent, transparent Consistancy – Butyrous, friable, viscid Emulsifiability – Easy, difficult, forms homogenous or granular suspension. |
| Growth on slant |
| Amount – Scanty, moderate, abundant Form – Spreading, filiform, rhizoid |
| Growth in stab |
| Amount – Scanty, moderate, abundant Form – Papillate, filiform, beaded, arborescent Surface growth– Absent, present, colouration Liquification – forming layer, like cup, like turnip, like funnel, tubular |
| Growth in liquid media |
| Amount – Scanty, moderate, abundant Surface growth– Absent,present, ring, pellicle (thin, thick, smooth, granular) Deposit -Absent,present(slight, moderate, abundant, powdery, viscid) Turbidity – Absent,present Odour – Absent,present |
| Exercise Q1.Describe the colony characteristics of Escherichia coli on MacConkey’s agar medium. Q2.Describe cultural characters of Staphylococcus aureus in Nutrient Broth. |