ENH 222 Lecture Notes - Lecture 4: Facultative Anaerobic Organism, Superoxide Dismutase, Osmotic Pressure

• School: Ryerson University
• Department: Environmental Health
• Course: ENH 222
• Professor: Jordan Tustin

Document Summary

Psychrophiles (cold loving) sensitive to temps over 20, optimal growth at 15 (found in. Psychrotrophs rate of growth best b/w 0 & 30, best at 22. Refrigeration slows down microbial growth and spoilage. Mesophiles (middle loving) rate of growth best b/w 25 & 40, best at 37. Bacillus cereus multiples in rice b/w 15 & 43. Most common group of microbes commonly associated with food spoilage. Thermophiles (heat loving) rate of growth best b/w 50 & 60, best at 62. Adapted to live in sunlit soil, compost piles, hot springs. Elevated food storage temp may cause endospores to germinate and grow spoilage. Clostridium spp. toxins cause food poisoning by intoxication, food does not taste bad. Most live in volcanic or ocean vents ph. Most bacteria grow at neutral ph b/w 6. 5 - 7. 5. Molds and yeasts grow b/w ph 5 & 6. Very few bacteria grow in ph < 4.