Screening, selection and characterization of phytic acid degrading lactic acid bacteria from chicken intestine Ponnala Raghavendra, Prakash M. Halami ⁎ Food Microbiology Department, Central Food Technological Research Institute, Mysore 570020, India abstract article info Article history: Received 30 January 2009 Received in revised form 5 May 2009 Accepted 6 May 2009 Keywords: Lactic acid bacteria Phytic acid Phytase Acid phosphatase Pediococcus pentosaceus This study was undertaken to screen and select potent phytate degrading lactic acid bacteria and to evaluate their additional characteristic features. Forty lactic acid bacterial strains were isolated from different sources and screened for their ability to degrade myo-inositol hexaphosphate or IP 6 by cobalt chloride staining (plate assay) method, using calcium or sodium salt of phytic acid as substrate. All the forty isolates were able to degrade calcium phytate. However, only two Pediococcus pentosaceus strains (CFR R38 and CFR R35) were found to degrade sodium phytate. These strains showed phytase activity of 213 and 89 U at 50 °C, respectively and poor acid phosphatase activity. These strains were further evaluated for additional characteristic features. At pH 2, P. pentosaceus strains CFR R38 and CFR R35 showed 50.7 and 48.5 percentage survivability after 2 h of incubation respectively and they could also withstand 0.3% ox-bile. These cultures exhibited 54.6 and 44.8% of hydrophobicity to xylene, antibacterial activity against food borne pathogens and possessed β-galactosidase activity. The resistance pattern to several antibiotics was also analyzed. The present study indicates that these strains, having phytate degrading ability and other characteristic features can be exploited as starter cultures in fermented foods to improve the mineral bioavailability. © 2009 Elsevier B.V. All rights reserved. 1. Introduction Cereals, legumes, nuts, seeds and tubers are rich sources of phosphorus in the form of phytic acid (myo-inositol hexaphosphate, IP6). This molecule is highly charged with six phosphate groups extending from the central myo-inositol ring and is often reported to be an anti-nutritional factor for humans and animals as it acts as an excellent chelator of cations such as Ca 2+ , Mg 2+ , Fe 2+ and Zn 2+ . It also complexes the basic amino group of proteins, hindering their absorption and reducing their dietary availability (De Angelis et al., 2003; Reale et al., 2004; Kerovuo et al., 1998; Lopez et al., 2000; Palacios et al., 2005). Phytate is very important to infants, children, adults and people in clinical situations, but high phytate diet decreases the retention of calcium and iron significantly. The phosphorylation degree of myo-inositol phosphates determines in which proportion the mineral absorption is inhibited, enhanced or unaffected. The lower inositol phosphates (IP 1–4 ) and myo-inositol on the other hand are recognized as beneficial through different biological roles. Phytate should be avoided among vulnerable groups and eliminated by extraneous processing efforts (Reale et al., 2007). Phytic acid levels may be reduced by phytase [myo-inositol hexakis (dihydrogen phosphate) phosphohydrolase, EC 3.1.3.8], an enzyme that catalyzes the sequential hydrolysis of phytate to phosphate and inositol via penta to monophosphates. This decreases or eliminates the anti-nutritional effect and results in the bioavailability of divalent cationic essential dietary minerals (Palacios et al., 2008). Phytase enzyme is widely distributed in nature, like plants, animal tissues and microorganisms (Lopez et al., 2000). However, phytase activity has been found to be low in human small intestine showing the highest activity in the duodenum and the lowest activity in the ileum (Haros et al., 2007). Microbial sources of phytase are the most promising ones for the production of cereal based fermented foods on a commercial level. The overall activity of these bacteria enhances the shelf life and nutritional value of the final products and contributes to their unique organoleptic properties (Palacios et al., 2005). Sourdough fermenta- tion was reported to have significantly reduced the phytate content in plant-based foods (Reale et al., 2007). Lactic acid bacteria (LAB) are known as an ingredient of several traditional fermented foods and dairy products (Reddy et al., 2007). Most of the LAB isolated from different food fermentations and ecosystems are shown to possess phosphatase activity with low levels of activity against phytate (Palacios et al., 2008). Of late LAB isolated from the gastrointestinal tract (GIT) of animals and humans constitute an important source of new functional bacteria, which can develop biological roles during the gastrointestinal transit (probiotics) or during food processing (Palacios et al., 2008). These organisms should possess the ability to cross the barriers from mouth to intestine, such as low pH in the stomach and bile in the duodenum. They should also adhere to the intestinal micelle and exhibit antagonistic activity International Journal of Food Microbiology 133 (2009) 129–134 ⁎ Corresponding author. Food Microbiology Department, Central Food Technological Research Institute, Mysore-20, India. Tel.: +91 821 2517539; fax: +91 821 2517233. E-mail address: foodmicro@cftri.res.in (P.M. Halami). 0168-1605/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.ijfoodmicro.2009.05.006 Contents lists available at ScienceDirect International Journal of Food Microbiology journal homepage: www.elsevier.com/locate/ijfoodmicro