Because tetracycline 's secreted by a soil bacterium , streptomyces .
因为四环素是由土壤中的一种细菌链霉菌分泌而成。
Female beewolf digger wasps cultivate symbiotic streptomyces bacteria in unique antennal glands and secrete them into their larval brood cells .
雌性狼蜂掘土蜂在其独特的触角腺里培育共生链霉菌,并将它们分泌到其幼虫的巢房中。
Researchers now believe that the ancient brewmasters learned to purposely make their beer medicinal , by lacing it with grain contaminated with antibiotic-producing streptomyces bacteria .
A team at the university of warwick employed genome mining ( analysis of controlled genetic tweaks ) to isolate a previously unknown signaling chemical in streptomyces bacteria that causes the bugs to produce natural antibiotics .