Find and describe your two isolated colonies. * If you did not get isolated colonies find a classmate that has them and really look at the colonies and describe theirs. With a partner Gram stain from an isolated colony of the bigger flatter type. What species is this bigger flatter colony?_______________________ One partner should the domed (younger) colonies One partner should the flatter (older) colonies Fig. 8-7 Photomicrograph of Gram (+) Bacillus megaterium from an older colony. Note the endospores and that the stain looks somewhat uneven due to the endospores and the degradation of the peptidoglycan of the cell wall following the sporulation. The arrow points to a cell with spores. Photo by Josefina Villalobos, Bio 2192 student Spring, 2018. Based on the results of the Gram stain, address the following: Draw (do not photograph) the cells you see. Make notes about the uneven staining and note any endospores you see. Younger colonies will be more strongly purple, older will stain more unevenly and have endospores. Check out your classmate’s Gram stains, too. THESE FEATURES CAN HELP with identification on your unknown project. Cells from younger colonies Cells from the older colonies Name the cell shape. Determine cell size. They are really large.
Find and describe your two isolated colonies. * If you did not get isolated colonies find a classmate that has them and really look at the colonies and describe theirs. With a partner Gram stain from an isolated colony of the bigger flatter type. What species is this bigger flatter colony?_______________________ One partner should the domed (younger) colonies One partner should the flatter (older) colonies Fig. 8-7 Photomicrograph of Gram (+) Bacillus megaterium from an older colony. Note the endospores and that the stain looks somewhat uneven due to the endospores and the degradation of the peptidoglycan of the cell wall following the sporulation. The arrow points to a cell with spores. Photo by Josefina Villalobos, Bio 2192 student Spring, 2018. Based on the results of the Gram stain, address the following: Draw (do not photograph) the cells you see. Make notes about the uneven staining and note any endospores you see. Younger colonies will be more strongly purple, older will stain more unevenly and have endospores. Check out your classmate’s Gram stains, too. THESE FEATURES CAN HELP with identification on your unknown project. Cells from younger colonies Cells from the older colonies Name the cell shape. Determine cell size. They are really large.
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