Physiology Properties And Studies On The Freeze-dried Processing Of Lactobacillus Acidophilus

As one kind of probiotic bacteria,Lactobacillus acidophilus has its important function on the host for its health benefit and prophylaxis disease,and it has become a hot subject in the field of dairy science.This text has the researches on the proliferative substrate,physiological characteristic and freeze-drying technology of the Lactobacillus acidophilus.To assure a high amount of the living bacterium,this text has the research on the proliferative substrate of the Lactobacillus acidophilus.As it shown that,the best growth substrate of the aidophile Bacillus lactis is:peptone 1.0%,glucose 1.0%,soybean oligosaccharide 1.5%,yeast extract paste 1.0%,tomato juice 12.0%,Tween 80 0.1%,K₂HPO₄ 0.1%.After 16h cultivating in the best substrate,the highest amount of the living bacterium, 2.2×10¹²cfu/ml,can be gotten.The premise of the exerting of the curative and health protection effect of the probiotics is to get a certain amount in the intestinal tract,therefore,this text has the research on the physiological characteristic,as it shown that,the Lactobacillus acidophilus has a very obvious acid resistant and bilesalt ability.When the bilesalt's concentration gets to 0.3%,the pH is 2.0. The livability reaches to the 62.2%,the acidophile Bacillus lactis has a obvious osmotic pressure ability.The max tolerance of the Nacl is 9%.The Lactobacillus acidophilus has an obvious anti-effect on the Staphylococcus aureus and the Escherichia coli.The inhibition zone are 15mm and 14mm.The Lactobacillus acidophilus has certain but different tolerance on gentamycin,ampicillin and chloramphenicol.This text has the research on the freeze-drying technology of the Lactobacillus acidophilus.As it shown that,the best centrifugal condition is:revolving speed 4000r/min, time 5min.Before the freeze-drying,the best protectant combination is:skim milk 10%, Tween80 0.3%,glycerol 2.0%,monosodium glutamate 2.0%.The proportion of the thalli and the protectant has an effect on the livability.The best proportion is protectant:thalli=4:2.In the processing of the freeze-drying,the thickness of the thalli,the prefreeze temperature and the prefreeze time are the important elements that affect the result of the freeze-drying.The best condition confirmed bv the experiment is:the thickness of the thalli 7mm.the prefreeze temperature -30℃,the prefreeze time 7h.The best water content of the thalli is 3.0%.The guidelines of the bacterium powder of the Lactobacillus acidophilus is determined. As it shown that:the best fermente time of the bacterium powder of the Lactobacillus acidophilus is 12h,rate of retention N=78.5%,curding time is 5h,reserve the Lactobacillus acidophilus in the refrigerator at 4℃,sampling at a certain time to get the amount of the living bacterium and calculate the livability.When the reserve time reaches 18 months,determined the amount of the living bacterium is 10⁷cfu/g,can meet the condition that ensure it to have the probiological effect.Therefore,the reservation time is determined at 18 months.