Class Three February 7-9 Culture Characteristics Microbiology Class Three February 7-9 Culture Characteristics

Class schedule( Part One) Check results from week 2. Record results in templates. Organisms studied – week 2 S. marcescens B. subtilis M. luteus E. coli

Culture characteristics Use supplement and handout to observe the growth of the four organisms in the slant, deep, broth, and on the plate. Do the organisms look like one of the examples on your sheet? Try to record their appearance on your templates

Culture observations on the agar plate Color production( chromogenesis). An example of this is the pink color of Serratia Growth pattern and characteristics Amount of growth( scant or heavy)

Comparison of E. coli and Micrococcus luteus

Colony morphology

Colony morphology

Margin of the colonies

Elevation

Broth culture( refer to supplement) Cloudy Turbid( Flocculent) Sediment formation Pellicle formation

Slants Is there growth in the bottom ? Is there growth on the slant itself What are the growth characteristics on the slant? Key words Aerobic Anaerobic Facultative

Isolation of Pure culture Observe your dilution streak of your mixed culture On the bottom of your Petri dish circle colonies of two organisms Example ML/SM mixture – circle yellow and pink cultures With your inoculating loop lift cells from circled colonies and streak on new plate or inoculate a slant per detailed instructions in class

Part One – Completion of week 2 work When you have finished observing all of your cultures Place all tubes in rack in hazardous waste Place all plates in cans in hazardous waste Wipe down desk top

New work( supply table) Eight Organisms for Study/Table 8 Plates 8 Deeps( if available) 8 Slants 8 Broths

Preparation Label all tubes and plates carefully Assign each member of the group 2 organisms Transfer the organisms to the culture media using aseptic techniques used in weeks one and two

Organisms for study Gram negative organisms PA - Pseudomonas aeruginosa PV- Proteus vulgaris EC- Escherichia coli EA- Enterobacter aerogenes Gram Positive Organisms BS - Bacillus subtilis SA - Staphylococcus aureus SE - Staphylococcus epidermidis SS- Streptococcus salivarius

Review for Quiz One Aseptic techniques Culture transfer techniques Media Safety precautions Microscope identification