Mechanisms of Polyhydroxyalkanoate Biosynthesis

1 Conditions that Promote the Biosynthesis and Accumuiation of Poiyhydroxyaikanoates in Microorganisms 

Early studies revealed that the rate of PHA accumulation can be increased by increasing the ratio of the carbon to nitrogen source [99]. Eventually it became evident that PHA accumulation usually occurs when cell growth is impaired due to depletion of an essential nutrient such as sulfate, ammonium, phosphate, potassium, iron, magnesium or O2 [1, 100, 103]. Suzuki and co-workers [103] studied 51 methylotrophs for their ability to produce P(3HB) from methanol. Similar nutrient limitations were found to stimulate the formation of P(3HB). However, a kinetic study of the production of P(3HB) by a fed-batch culture of Protomonas extorquens 

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