Phytate degradation by human gut isolated Bifidobacterium pseudocatenulatum

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• 作者：Monika Haros ; Nils-Gunnar Carlsson ; Annette Almgren ; Marie Larsson-Alminger ; Ann-Sofie S ; berg ; Thomas Andlid
• 关键词：Bifidobacterium ; Phytate-degrading activity ; myo-inositol phosphates ; Acid and bile tolerance ; Adhesion
• 刊名：International Journal of Food Microbiology
• 出版年：2009
• 出版时间：30 September 2009
• 年：2009
• 卷：135
• 期：1
• 页码：7-14
• 全文大小：677 K

文摘

The growing awareness of the relationship between diet and health has led to an increasing demand for food products that support health above and beyond providing basic nutrition. Probiotics are live organisms present in foods, which yield health benefits related to their interactions with the gastrointestinal tract. Phytases are a subgroup of phosphatases that catalyse the desphosphorylation of phytate, which reduces its negative impact on mineral bioavailability, and generates lower inositol phosphates. The aims of this investigation were to (i) study the ability of the probiotic candidate Bifidobacterium pseudocatenulatum to degrade phytate in synthetic medium, to (ii) identify the lower inositol phosphates generated, to (iii) study its survival under conditions mimicking gastrointestinal passage and finally to (iv) assess adhesion of the bacteria to Caco-2 cells. The first steps of InsPb>6b> degradation by B. pseudocatenulatum phytate-degrading enzyme/s were preferentially initiated at the DL-6-position and 5-position of the myo-inositol ring. It suggests that the main InsPb>6b> degradation pathway by B. pseudocatenulatum by sequential removal of phosphate groups was D/L-Ins(1,2,3,4,5)Pb>5b> or D/L-Ins(1,2,3,4,6)Pb>5b>; D/L-Ins(1,2,3,4)Pb>4b>; to finally Ins(1,2,3)Pb>3b> and D/L-Ins(1,2,4)Pb>3b>/D/L-Ins(1,3,4)Pb>3b>. This human strain also showed a notable tolerance to bile as well as a selective adhesion capacity (adhesion to control surfaces was zero), to human intestinal Caco-2 cells comparable to the commercial probiotic B. lactis. The phytate-degrading activity constitutes a novel metabolic trait which could contribute to the improvement of mineral absorption in the intestine as a nutritional probiotic feature with potential trophic effect in human gut.