MICR 221 Lecture : MICR 221 - Spores and other internal structures.docx

• School: Queen's University
• Department: Microbiology and Immunology
• Course: MICR 221
• Professor: N/ A

Document Summary

Spores restricted almost exclusively to some gram positives. Very resistant to heat, irradiation, chemical disinfectants and desiccation (drying) Viable for hundreds of years or much longer. The shape of the spore, the location and distention (bulging) is diagnostiv. Aid in survival when nutrients or moisture scarce. 15% of the cell dry weight is dipicolinic acid complexed with calcium. Not a contaminant: spore had remained viable trapped for millions of years. Granules of organic or inorganic material that are stockpiled by the cell for future use. Some are enclosed by a single-layered membrane: membranes vary in composition, some made of proteins; others contain lipids. Gas vesicles are aggregates of large numbers of small hollow cylinders floating device that allows cells to reach optimum depth for light, oxygen and nutrients. If they want to move up they make vesicles, if they want to move down the collapse some.