▁of ▁research ers . ▁ ▁The ▁most ▁extens ively ▁studied ▁ 2 - py rid one ▁de gr ader ▁is ▁the ▁gram ▁positive ▁b acter ium ▁Ar th rob acter ▁cry stal lo po iet es , ▁a ▁member ▁of ▁the ▁ph yl um ▁Act in ob acter ia ▁which ▁includes ▁numerous ▁related ▁organ isms ▁that ▁have ▁been ▁shown ▁to ▁deg rade ▁py rid ine ▁or ▁one ▁or ▁more ▁alk yl -, ▁car box yl -, ▁or ▁hydro x yl - subst it uted ▁py rid ines . ▁▁ 2 - Py rid one ▁de grad ation ▁is ▁commonly ▁initi ated ▁by ▁mon o - ox y gen ase ▁attack , ▁resulting ▁in ▁a ▁di ol , ▁such ▁as ▁ 2 , 5 - d ih ydro x yp y rid ine , ▁which ▁is ▁met abol ized ▁via ▁the ▁male am ate ▁path way . ▁ ▁F ission ▁of ▁the ▁ring ▁proceed s ▁via ▁action ▁of ▁ 2 , 5 - d ih ydro x yp y rid ine ▁mon o ox y gen ase , ▁which ▁is ▁also ▁involved ▁in ▁met abol ism ▁of ▁nic ot in ic ▁acid ▁via ▁the ▁male am ate ▁path way . ▁ ▁In ▁the ▁case ▁of ▁Ar th rob acter ▁cry stal lo po iet es , ▁at ▁least ▁part ▁of ▁the ▁de grad ative ▁path way ▁is ▁pl as mid - bor ne . ▁ ▁Py rid ine ▁di ols ▁under go ▁chemical ▁transformation ▁in ▁solution ▁to ▁form ▁intens ely ▁colored ▁p ig ments