Biology-Elective 1 Biotechnology Practice The following is the experimental process of making fruit wine and fruit vinegar and the fermentation device of fruit wine and fruit vinegar designed by a classmate. solution; (1) The experimental process of making fruit wine and fruit vinegar is: Selecting grapes → washing → juicing → alcohol fermentation → acetic acid fermentation → acetic acid. < P > (2) Yeast is the strain for fruit wine fermentation, and Acetobacter is the strain for fruit vinegar fermentation; Because the optimum growth temperature of acetic acid bacteria is 3-35℃, which is higher than that of yeast alcohol fermentation; Acetobacter is an aerobic bacterium, and oxygen must be sufficient to ferment to produce acetic acid. Therefore, when fruit wine is converted into vinegar, it is necessary to raise the temperature and introduce oxygen. < P > (3) Alcohol fermentation uses anaerobic respiration of yeast, and Acetobacter is an aerobic bacterium, so the aeration port in the device in Figure 2 should be closed during alcohol fermentation and opened during acetic fermentation; Yeast breathes to produce carbon dioxide, so the exhaust port should be open during alcohol fermentation. In order to prevent other microorganisms in the air from entering the fermentation device (to prevent microbial pollution in the air), the exhaust port should be connected with the bottle body through a long and curved hose

(4) Under acidic conditions, the reaction between potassium dichromate and alcohol is grayish green, so it can be used to detect whether alcohol is produced in the fermentation process.

(5) In the natural fermentation process of wine, wild yeast attached to grape skin plays a major role. Sterilization will kill the yeast attached to the grape skin, so the fermentation can't be carried out, so the grapes can't be sterilized.

So the answer is:

(1) acetic acid fermentation

(2) yeast? Acetobacter oxygen temperature 3-35℃ Acetobacter is aerobic bacteria, and only when there is enough oxygen can it carry out vigorous life activities; The optimum growth temperature of acetic acid bacteria is 3-35℃

(3) Alcohol-fermented yeast breathes carbon dioxide anaerobically to prevent other microorganisms in the air from entering the fermentation device (to prevent microbial pollution in the air)

(4) Potassium dichromate? Gray-green

(5) is not necessary. In the natural fermentation process of wine, the wild yeast attached to grape skin plays a major role. Sterilization will kill the yeast attached to grape skin, making fermentation impossible.