Abstract: A method for producing L-allysine acetal represented by general formula (II), comprising reacting D,L-allysinamide acetal represented by general formula (I) with cells of microorganism or treated cell product having an activity of stereoselectively hydrolyzing L-allysinamide acetal, wherein R1 and R2, which may be the same or different, each independently represent a lower alkyl group, or R1 and R2 are combined to form an alkylene group represented by [CH2]n, and n is 2 to 3. D,L-allysinamide acetal represented by general formula (I) is also in the scope of the invention. According to the present invention, L-allysine acetal useful as a raw material for medicine can be produced in a smaller number of steps at low costs.

Abstract: Disclosed is a process for accumulating a poly-3-hydroxy butyric acid in bacterial cells by continuously fermenting a methanol-assimilating bacterium having a capability of producing a poly-3-hydroxy butyric acid, in a single fermentation vessel by using methanol as carbon source at a limited feeding rate of nitrogen, phosphorus, or potassium such that the retention time for the fermentation is more than 10 hours.

Abstract: Disclosed is a process for the preparation of a copolymer, which comprises propagating cells of a bacterium having a capacity of producing poly-3-hydroxybutyrate mainly at a former stage, synthesizing and accumulating in the cells a copolymer comprising D-3-hydroxybutyrate and D-3-hydroxyvalerate by contacting the bacterium with a mixture of a carbon source utilizable by the bacterium and a primary alcohol having 3 to 7 carbon atoms, or with a primary alcohol having 3 to 7 carbon atoms, at a latter stage, and recovering the copolymer from the cells. According to this process, a copolymer comprising D-3-hydroxybutyrate and D-3-hydroxyvalerate can be manufactured in a large quantity at a low cost.