Bacteria Morphology, Colony Morphology, and Reproduction - PDF

USING BACTERIA MORPHOLOGY CHARACTERISTICS TO STUDY BACTERIAL DIVERSITY UNIT 5 -  Bacteria…? ← Leptospira, causes serious disease in livestock Bacteria are often viewed as the cause of diseases in humans and animals. So...

USING BACTERIA MORPHOLOGY CHARACTERISTICS TO STUDY BACTERIAL DIVERSITY UNIT 5 -  Bacteria…? ← Leptospira, causes serious disease in livestock Bacteria are often viewed as the cause of diseases in humans and animals. Some bacteria are useful, for example certain bacteria aids in digestion. Bacteria make up the base of the food web in many environments. Bacteria are of such immense importance because of their extreme flexibility, capacity for rapid growth and reproduction, and great age. They can be photosynthetic, using light, or chemosynthetic, using inorganic chemicals as the source of energy, but most are heterotrophic, absorbing nutrients from the environment.  Bacterial Structure Biochemical processes that normally occur in a chloroplast or mitochondria of eukaryotes will take place in the inner membrane of prokaryotes. Bacterial DNA is circular and is located in the cytoplasm. It is not separated from the rest of the bacteria interior but the bacterial DNA is known as the nucleoid. Scattered within bacteria’s inner membrane are numerous small loops of DNA known as plasmids.  Bacterial Structure Some bacteria have flagella with a different microtubule structure than the flagella of eukaryotes.. Ribosomes are the structures in cells where proteins are assembled. Bacterial ribosomes have different sized ribosomal subunits than do eukaryotes.  Bacteria Have One of Three Cellular Shapes Rods (bacilli) Sphere or Coccoid-Shaped Spirilla Microbe Colony Morphology The information to the right is another set of information that you will use to try to identify the microbial life you have found and cultured. Each colony represents a single microbe that you had placed there. It replicated and has become a huge colony of identical clones (for the most part). The shape of that colony helps us to determine what we are looking at.  Reproduction Prokaryotic cell division is binary fission. – Single DNA molecule that first replicates. – Attaches each copy to a different part of the cell membrane. – Cell begins to pull apart. – Following cytokinesis, there are then two cells of identical genetic composition.  Now…On to our experiment... Purpose: Identify varieties of bacterial colonies and investigate bacterial species diversity, by isolating, culturing, and analyzing bacterial colonies, or species, that inhabit: Hypothesis: Air Knowing that bacteria can Pond Water thrive in almost anywhere on Raw Chicken our planet, we reason that all of Washed/Unwashed hands the environments tested will Keyboard grow bacterial species. Soil Sample  Inoculation Methods For chicken, soil, pond water, and keyboard samples, streak the plate using the streak plate method to isolate bacterial colonies. Leave agar plate open for air sample. For the unwashed hand gently press thumb against agar. Take washed hand and gently press thumb against agar. Label the petri as to location and your name and period Wrap in Parafilm and incubate the Figure 1. Streak Plate Method. (a) Streak the plate back and forth cultures for 48 hours at 22 C. across top half of plate. (b) Rotate plate a quarter turn counter Observe and Interpret Data clockwise and streak top right quarter of plate. (c) Rotate plate a quarter turn counter clockwise and streak top right quarter of plate again. Examine the morphology for each type of colony Describe each in detail Organize your data - see next slide  Example of results and how to record them Results: Soil SIZE SHAPE MARGIN SURFACE COLOR 1 4 mm Irregular Lobate Wavy Yellow/white 2 2 3 mm Irregular Lobate Wrinkled Brown/yellow 3 3 5 mm Filamentous Filamentous Wrinkled Green/white 1