Colony characteristics of bacteria

Colony characteristics of bacteria

1. بِسْمِ اللهِ الرَّحْمٰنِ الرَّحِيْمِ السَّلاَمُ عَلَيْكُمْ وَرَحْمَةُ اللهِ وَبَرَكَاتُهُ

2. Assignment of Microbiology Assignment Topic : Colony Characteristics Submitted To : Sir Fazal Ilahi Butt Submitted By : Tayyab Roll Number : 869 / 023808 Program : B.S. 4 Years Degree Program Discipline : Zoology Session : 2017-2021 / 7 th Semester Government College Of Science Wahdat Road , Lahore

3. Colony Characteristics Colony: A colony is defined as a visible mass of microorganisms all originating from a single mother cell, therefore a colony constitutes a clone of bacteria all genetically alike.

4. There are many different Characteristics of colony.Som of them are given as:

5. Size: The Colonies range in size from extremely small (pinpoint), measuring only a fraction of millimeter in diameter, to large colonies measuring 5 to 10 millimeter in diameter.

6. Margin: The colony of bacteria may take one of several different patterns. It may be circular, or irregular such as rounded projections,notches,and threadlike or rootlike projections.

7. Surface Texture: The colony surface may be smooth (shiny, gelatinous);rough(dull,granular or matte) or mucoid(slimy or gummy) or wrinkled Streptococcus pneumoniae Smooth Mycobacterium tuberculosis Rough Klebsiella pneumoniae Mucoid

8. Elevation: Depending on the species, colony may be thin to thick and the surface may be flat or it may exhibit varying degrees of convexity.

9. Optical Features: Colonies may be opaque, translucent, or opalescent .   Staphylococci are usually opaque, while many Streptococcus species are translucent .

10. Chromogensis: Some bacterial species produce, and retain water-insoluble pigments intracellularly, thus causing the colonies to become colored (pigmented). Some species which form pigmented colonies are given on next slide.

11. Flectobacillus major Pink Serrotia marcescens Red Chrornobacterium violaceum Violet Staphylococcus aureus Gold Micrococcus luteus Yellow Derxia gummosa Brown Bocteroides meloninogenicus Black

12. Some colonies produce pigments that are water-soluble; these diffuse into the surrounding agar and stain it. For instance, Pseudomonas aeruginosa forms a blue water-soluble pigment called pyocyanin. Some pigments are only sparingly water-soluble and may precipitate in the medium. For example, Pseudomonas chiororaphis forms a pigment called chlororaphin which accumulates in the form of green crystals around the colonies.

13. Reference: Microbilogy by Michael J., Pelczar JR.

14. Thank you