Localization of phytase in Selenomonas ruminantium and Mitsuokella multiacidus by transmission electron microscopy

The localization of phytase (myo-inositol-hexaphosphate phosphohydrolase) i n the ruminal bacteria, Selenomonas ruminantium JY35 and Mitsuokella multia cidus 46/5(2), was determined with transmission electron microscopy. Phosph ate produced from the enzymatic dephosphorylation of the calcium salt of ph ytic acid is precipitated as calcium phosphate. The calcium is then replace d with lead to produce electron-dense lead phosphate. This deposition of le ad phosphate localized phytase in S. ruminantium JY35 and M. multiacidus 46 /5(2) to the outer membrane, and confirmed intracellular expression of the enzyme in Escherichia coli pSrP.2, the recombinant clone which possesses th e gene (phyA) encoding phytase (phyA) in S. ruminantium.