Abstract: L-2-Amino-4-methylphosphinobutyric acid (L-MPGA) which is useful as bactericide and herbicide can be prepared by optical resolution of its racemic mixture, D,L-MPGA with the action of a microbial acylase. The process comprises providing D,L-MPGA in the form of its N-acyl derivative, reacting N-acyl-D,L-MPGA in an aqueous medium with a microbial acylase having an optically specific hydrolytic activity, whereby selectively eliminating the acyl group of N-acyl-L-MPGA to give a mixture of L-MPGA and N-acyl-D-MPGA and isolating L-MPGA from the mixture. The acylase is produced by cultivating a microbial strain belonging to the genus Pseudomonas, Streptomyces or Aspergillus, particularly Pseudomonas maltophilia BN-233, Streptomyces violascens SF 2072, Streptomyces diastatochromogenes SF 2073, Aspergillus sp. KS-101 or Aspergillus sp. KS-102.

Abstract: Compounds are provided having the general formula I: ##STR1## wherein X represents an hydroxyl group, an acetoxy group or a thiosulfuric acid residue. The formula I compounds are prepared from compounds of the general formula II: ##STR2## wherein R.sub.1 represents hydrogen, a lower alkanoyl group, an arylalkanoyl group, an alkoxycarbonyl group, a lower haloalkoxycarbonyl group, a substituted or unsubstituted aroyl group, a N-arylcarbamoyl group of a substituted or unsubstituted aryl group; R.sub.2 either represents hydrogen or, together with the ##STR3## group, represents a phthalimido group; and X represents an hydroxyl group, an acetoxy group or a thiosulfuric acid residue, or their metal salts or their salts with organic bases, by causing the culture of a cephalosporin C acylase-producing strain of a microorganism, especially a mold, fungus, or the secondary preparation therefrom, to act on the latter compounds II in the presence of an aqueous medium.

Abstract: A new antibiotic designated BN-130 substance is now provided, which has antibacterial activity against gram-negative and gram-positive bacteria as well as acid-fast bacteria. BN-130 substance is produced by cultivating a strain of Pseudomanas stutzeri under aerobic conditions.

Abstract: A BN-109 substance producing strain of the genus Bacillus is cultivated under an aerobic condition to produce and accumulate BN-109 substance in a culture medium. The BN-109 substance is isolated from the culture broth and purified, and proved to be a novel antibiotic. The BN-109 is effective in the treatment and prevention of swine scours.