Phytase activity as a novel metabolic feature in Bifidobacterium.

Phytase activity has been detected for the first time in Bifidobacterium spp. These bacteria were able to dephosphorylate phytic acid (myo-inositol hexaphosphate, IP(6)) and generate several myo-inositol phosphate intermediates (IP(3)-IP(5)). B. globosum and B. pseudocatenulatum were optimally active at neutral-alkaline pH and B. adolescentis, B. angulatum and B. longum at acid pH. B. pseudocatenulatum showed the highest levels of phytase activity. This species produced maximum activity in the exponential phase of growth and when fructo-oligosaccharides were used as carbon source in the culture medium. The potential role of phytase activity from Bifidobacterium spp. in the reduction of the antinutritional properties of IP(6) is discussed.