▁M . ▁b ark eri ▁could ▁even ▁surv ive ▁on ▁Mars . ▁ ▁M eth anos arc ina ▁grow ▁in ▁colon ies ▁and ▁show ▁primitive ▁cell ular ▁different iation . ▁ ▁In ▁ 2 0 0 2 , ▁the ▁am ino ▁acid ▁p yr ro ly s ine ▁was ▁discovered ▁in ▁M . ▁b ark eri ▁by ▁Ohio ▁State ▁University ▁research ers . ▁▁ ▁Ear lier ▁research ▁by ▁the ▁team ▁had ▁shown ▁that ▁a ▁gene ▁in ▁M . ▁b ark eri ▁had ▁an ▁in - frame ▁am ber ▁( U AG ) ▁cod on ▁that ▁did ▁not ▁signal ▁the ▁end ▁of ▁a ▁protein , ▁as ▁would ▁normally ▁be ▁expected . ▁ ▁This ▁behavior ▁suggested ▁the ▁possibility ▁of ▁an ▁unknown ▁am ino ▁acid ▁which ▁was ▁confirmed ▁over ▁several ▁years ▁by ▁s lic ing ▁the ▁protein ▁into ▁pe pt ides ▁and ▁sequ encing ▁them . ▁ ▁P yr ro ly s ine ▁was ▁the ▁first ▁gen et ically - encoded ▁am ino ▁acid ▁discovered ▁since ▁ 1 9 8 6 , ▁and ▁ 2 2 nd ▁overall . ▁ ▁It ▁has ▁subsequently ▁been ▁found ▁throughout ▁the ▁family ▁M eth anos arc in aceae ▁as ▁well ▁as ▁in ▁a ▁single ▁b acter ium , ▁Des ul fit ob acter ium ▁ha fn ien se . ▁ ▁Both ▁M . ▁ac et iv or ans ▁and ▁M . ▁ma ze i ▁have ▁exception ally ▁large ▁genom es . ▁As ▁of ▁August ▁ 2 0 0 8 , ▁ ▁M . ▁ac et iv or ans ▁possessed ▁the