yeast extract 7 5 g l is prepared and has added thereto an extruded starch mixture containing weight ratio of rice bran and corn starch of 1 8 serving as a carbon source resulting in a starting broth haloferax mediterranei is cultivated in a 250 ml culture after 36 hours the culture liquid is inoculated in a 5 l fermentation tank cmbs model cmf 5 firstek taiwan containing 2 5 l starting broth and fermented for 118 hours the 5 l fermentation tank is equipped with a ph regulator suntex pc330 ingold ph electrode which is used to proceed with ph stat feeding control and a do controller responsible for controlling dissolved oxygen during the initial stages of fermentation air is delivered into the tank by an air pump at a flow rate of 6 l min to facilitate growth of bacteria at the beginning of fermentation the ph value decreases due to the carbon source depletion but it can be maintained at 6 8 or above by adding 10n sodium hydroxide once the carbon source is consumed to a low concentration by halobacteria the ph value of the fermentation liquid increases when it rises to 7 0 6 9 7 1 reactive materials are fed to replenish carbon and nitrogen source the feeding reactive materials comprise extruded starch mixture 50 g l and yeast extract 85 g l when the fermentation liquid reaches 4 5 l 2 l is taken out and the remaining fermentation liquid is added with an appropriate amount of salt to maintain salt concentration which.