Abstract: Process for producing a copolyester of desired quality at low cost with high productivity, preferably a process for producing P(3HB-co-3HH) of 4 mol % or more 3HH content with a productivity as high as 40 g/L or more. In particular, a process for producing a copolyester of 3HB and 3HH comprising culturing a microorganism with the use of, as a carbon source, a fat or oil containing lauric acid as a constituent fatty acid under such conditions that phosphorus as a source of nutrition is limited.

Abstract: Process for producing a copolyester of desired quality at low cost with high productivity, preferably a process for producing P(3HB-co-3HH) of 4 mol % or more 3HH content with a productivity as high as 40 g/L or more. In particular, a process for producing a copolyester of 3HB and 3HH comprising culturing a microorganism with the use of, as a carbon source, a fat or oil containing lauric acid as a constituent fatty acid under such conditions that phosphorus as a source of nutrition is limited.

Abstract: The object of the present invention is to develop a technology to optionally control a composition of a biodegradable copolyester with maintaining low cost and high productivity. The present invention consists in a culture method in producing a copolyester by a microorganism, which comprises controlling a specific substrate feed rate of an oil or fat to be used as a carbon source at a constant value throughout the whole culture period, or a method, which comprises applying a different specific substrate feed rate of an oil or fat used as a carbon source between a cell growth phase and a polyester accumulation phase in a culture and controlling the rate at a constant value during the respective phases. Furthermore, the present invention also consists in a culture method, which comprises controlling the composition of the produced copolyester by selecting the species and/or the control value for the specific substrate feed rate.

Abstract: A process of an interesterification reaction of fats, wherein a fatty acid moiety of a glyceride is substituted by other fatty acid moiety, and the reaction is accelerated by a catalyst and is continued constantly at a high rate for a long time. The process uses a dry cell for a catalyst. The dry cell is prepared from a lipase-containing microorganism by cultivating it to increase a lipase content and drying it to control water content.

Abstract: A process for removing an organic compound having a high boiling point from a floatable polymer containing the organic compound, which comprises contacting a slurry of the polymer with a non-condensable gas at a high temperature by strongly agitating with an agitator at an impeller Reynolds number of not less than 10.sup.5. According to the process, the organic compound having a high boiling point can be readily removed down to not more than 10 ppm.