1. Basic information
Lactobacillus acidophilus (Lactobacillus acidophilus, referred to as bacterium A) belongs to the genus Lactobacillus in the Lactobacillus family. It is a Gram-positive bacterium with a slender rod shape, no flagella, non-motile, anaerobic or facultative anaerobic; it Glucose, fructose, lactose and sucrose can be used for homofermentation to produce DL lactic acid.
2. Size and Colony Morphology
(1). Size Under the electron microscope, the cell size is generally 0.6-0.9×1.5-6.0 μm, arranged in singles, pairs or 2-3 short chains, and the cells are usually slender and rod-shaped, without flagella, without Movement, as shown in the figure:
(2). Colony morphology: On MRS medium, the colonies formed are smaller, have smooth edges, convex surfaces, are smooth, shiny and shiny, and the colonies are opaque and do not produce pigments.
3. Suitable for growth environment
(1). The optimum growth temperature is 35°C-38°C, no growth below 20°C, the maximum growth temperature is 43°C-48°C, and the heat resistance is poor; the optimum pH is 5.5-6.0, and the initial growth pH is 5.0-7.0, Strong acid resistance, can grow and reproduce in an environment where other lactic acid bacteria cannot grow. Lactobacillus acidophilus has a particularly strong acid and bile salt resistance. When the bile salt concentration is 0.3% and the pH value is 2.0, the survival rate reaches 62.2%; Lactobacillus acidophilus has obvious resistance to osmotic pressure, and the highest concentration of NaCI that it can tolerate is 9%; Lactobacillus acidophilus has obvious inhibitory effect on Staphylococcus aureus and Escherichia coli, and the diameters of the inhibition zone are 15mm and 14mm; Lactobacillus acidophilus has certain tolerance to gentamicin, ampicillin and chloramphenicol, but the degree of tolerance is different.
(2). The growth and reproduction of Lactobacillus acidophilus requires certain vitamins and other growth factors. It grows slowly when cultured at the optimal growth temperature and has a long production cycle. The acid production rate in milk is low, mainly due to its incomplete proteolytic enzyme system. , redox potential and trace elements. Adding substances that reduce redox potential (such as ascorbic acid, cysteine, etc.) Growth of Lactobacilli.
4.Growth characteristics
(1). Culture characteristics: cultured in the laboratory, can be cultivated with MRS medium;
(2). Biochemical characteristics: the growth and reproduction of Lactobacillus acidophilus requires certain growth factors such as vitamins and folic acid, and the culture at the optimum growth temperature grows slowly and the production cycle is long; the protein decomposition ability is weak, and the rate of acid production in milk is low. It is due to its incomplete proteolytic enzyme system, redox potential and trace elements. Adding substances that lower the redox potential and growth-promoting substances in milk can promote the growth of Lactobacillus acidophilus.
Product Name
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Lactobacillus Acidophilus
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Appearance
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White Powder
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Grade
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Food grade
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Test methold
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HPLC
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Odor
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Characteristic
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MOQ
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1KG
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Storage conditions
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Store in cool & dry place, Keep away from strong light and heat.
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