Study of angiotensin I-converting enzyme by bacteria found on buckwheat seeds

Bacteria from buckwheat seeds harvested in China were isolated, identified and characterised for their ACE-inhibitory activity. The total bacterial co unt was 3.6x10(6) cfu/g with the Gram-negative bacteria being dominant. Amo ng the Gram-negative bacteria Erwinia ananas was the most numerous, followe d by E. uredovora, Pantoea agglomercans, P. dispersa and E. carotovora. ACE -inhibitory activities were observed in the cell-free extracts of E. ananas M-8, E. uredovora M-11, P. agglomercans M-6 and P. disperser M-36. The hig hest IC50 was observed with E. uredovora M-11 followed by E. ananas M-8 and P. dispersa M-36. A significant reduction in blood pressure was observed i n spontaneously hypertensive rats administered a solution of the lyophilize d cell free extract of E. ananas M-8 in 0.9% saline compared with the contr ol rats (p<0.05).