Abstract: The biodegradable composition comprises at least poly(beta-hydroxybutyric acid) or a biodegradable copolymer thereof and a stereospecifically regular block copolymer having the structure units of formula (I): ##STR1## where R1 is a hydrocarbon group having 1 to 14 carbon atoms, optionally including double bonds, oxygen atoms or both of them; and m and n are respectively an integer ranging from 300 to 5,000, or having the structure units of formula (II): ##STR2## where R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are either a hydrogen atom or a methyl group; and m and n are respectively an integer ranging from 300 to 5,000.

Abstract: A deodorant composition comprising a phenolic compound and an enzyme oxidizing said phenolic compound is disclosed. The deodorant composition is useful to remove environmental smells such as bad breath, the smell in refrigerator, smells derived from pets and domestic animals, smells in factories, the stench of factory effluent, and other smells that are offensive to people.

Abstract: The block copolymer of polyesters and polycarbonates comprises at least one of each of the constituting units of (I) and (II) having the general formulae: ##STR1## where the sign * indicates an asymmetric carbon atom; R.sub.1, R.sup.2, R.sup.3 and R.sup.4 are either a hydrogen atom or a methyl group; m and n are respective a natural numbers ranging from 300 to 5000: The block copolymer is obtained by successive ring-opening and copolymerization of optically active .beta.-butyrolactones and cyclic carbonates in the presence of a catalyst.The block polymer obtained has high molecular weight and high melting temperature, and can thus be used as a high strength material for practical use and which has bio-degradable and hydrolyzable nature.