Lactic Acid Bacteria (LAB)

Question 1

shape and gram

Answer 1

positive, rods and cocci

Question 2

catalase test

Answer 2

most -ive

Question 3

4 other facts

Answer 3

most: non motile, aerotolerant anaerobes, mesophiles/thermophiles, acid tolerant

Question 4

they are fastidious meaning. eg?

Answer 4

need many growth factors eg Leuconostoc

Question 5

fermentation

Answer 5

most only catabolize sugars including lactose,some are homofermentative lactate fermenters or heterofementative lactate fermenters

Question 6

Application food production

Answer 6

fermentation of food to preserve food, acidic waste products inhibit growth of pathogens and spoilage of organism

Question 7

food production yogourt

Answer 7

2 species of thermophilic LAB added to warm milk and grow, ferment lactose producing acidic waste which denatures milk proteins causing milk to thicken, other waste produce the flavour

Question 8

Application prebiotics

Answer 8

are oats and lentils that contain soluble fibres that are metabolized by bacteria in large intestine

Question 9

Application probiotics

Answer 9

foods like yogurt that contain live bacteria and have health benefits