摘要:
New antibiotics, SF-2050 substance and SF-2050B substance are produced by cultivating a microorganism Streptomyces sp. SF-2050 now deposited under FERM-P 4358 and under ATCC. 31450 in a liquid culture medium under aerobic conditions, and these antibiotics may be isolated from the fermentation broth and useful as an antibacterial agent. These antibiotics have an activity inhibitory to .beta.-lactamase.