Some microbes has the ability of secrete certain vitamines etal. in large amount during the metabolism, thus can be used as vitamine-producing bacterial strains Normally, lactic bacteria needs vitamines as growth factor, many microbes and their auxotroph mutant strains need nitrogenous base Some natural material contains rich growth factors therefore can act as growth factor source such as yeast extract, cornsteep liquor(玉米浆, liver infusion(肝浸液), malt extract(麦 芽汁)etal
Normally, lactic bacteria needs vitamines as growth factor, many microbes and their auxotroph mutant strains need nitrogenous base. Some natural material contains rich growth factors therefore can act as growth factor source such as yeast extract, cornsteep liquor(玉米浆),liver infusion(肝浸液), malt extract (麦 芽汁) etal. Some microbes has the ability of secrete certain vitamines etal. in large amount during the metabolism, thus can be used as vitamine-producing bacterial strains
Mineralsalts Mineral salts or inorganic salts(无机盐或矿质元素) supply the im portant elements except the carbon source and nitrogen source macroelements大量元素103104mouL Mineral salts microelements微量元素106~108mo∥L As far as the macroelement is concerned, when a medium is prepared, above all we usually select K,HPO4 and MgSO4, for they can provide four elements that the microbes need in the greatest amount at the same time Normally enough trace elements are present in the water
Mineral salts Mineral salts or inorganic salts(无机盐或矿质元素) supply the important elements except the carbon source and nitrogen source. macroelements大量元素 10-3~10-4 mol/L Mineral salts microelements微量元素 10-6~10-8 mol/L As far as the macroelement is concerned, when a medium is prepared ,above all we usually select K2HPO4 and MgSO4 , for they can provide four elements that the microbes need in the greatest amount at the same time. Normally enough trace elements are present in the water