Abstract: Boholmycin antibiotic is prepared by fermentation of Streptomyces hygroscopicus H617-25 (ATCC No. 53240) in a nutrient medium preferably comprising glycerol, bacto-liver, cornsteep liquor, ammonium sulfate, sodium chloride and calcium carbonate. The antibiotic and pharmaceutically acceptable salts and hydrates thereof and compositions containing these are effective against Gram-positive, Gram-negative and acid-fast bacteria and against bacterial strains which are resistant to previously known aminoglycoside antibiotics and are useful to treat bacterial infections in mammals.

Abstract: There is described the preparation of novel 2-penem-3-carboxylic acid compounds having the formula ##STR1## and easily cleavable esters and carboxylic acid salts thereof. The compounds of formula I, particularly the dextrorotatory isomers thereof, are potent antibacterial agents or are of use as intermediates in the preparation of such agents.