11 December

Tuesday 11 December, we have a group quizzes on the microbial metabolism and nutritional. Then, we proceed to the microbial growth topic. There are two type of requirement for growth which is physical requirement and chemical requirement. The physical requirement is light, temperature, pH, water activity and osmotic pressure. The chemical requirement is water,  carbon, oxygen, nitrogen, phosphorus and sulfur, special growth factor and trace element . The bacteria cannot survive in the temperature that below than their optimum temperature or the bacteria will lower down their activity in this condition. For pH factor, we have acidophile at pH range 0-6, neutrophile pH at range 6-7.5, alkaliphiles pH at range 8-11. In chemical growth, water factor importance is for dissolve nutrient and cellular functions. In oxygen factor, there are 5 types which is obligate, facultative anaerobe, obligate anaerobe, aerotolerant anaerobes and microaerophiles. Trace element need in small amout but without them enzyme cannot function. In special growth factors we are introduce on the watermelon snow by the dr. I get exited to know about this. When we step on it, the white snow turn pinkish-red. Not only the colour, but it also smells like a watermelon. The reason why it turns res is because we actually step on algae.