Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.3.8 (phytase)
 1,997 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Differential agar media for the detection of microbial phytase activity use the disappearance of precipitated calcium or sodium phytate as an indication of enzyme activity. When this technique was applied to the study of ruminal bacteria, it became apparent that the method was unable to differentiate between phytase activity and acid production. Strong positive reactions (zones of clearing around microbial colonies) observed for acid producing, anaerobic bacteria, such as Streptococcus bovis, were not corroborated by subsequent quantitative assays. Experimentation revealed that acidic solutions generated false positive results on the selected differential medium. Empirical studies undertaken to find a solution to this limitation determined the false positive results could be eliminated through a two step counterstaining treatment (cobalt chloride and ammonium molybdate/ammonium vanadate) which reprecipitates acid solubilized phytate. This report discusses the application of the developed two step counterstaining treatment for the screening of phytase producing ruminal bacteria as well as its use in phytase zymogram assays.
 ...
PMID:A novel staining method for detecting phytase activity. 1057 3

Bacillus species producing a thermostable phytase was isolated from soil, boiled rice, and mezu (Korean traditinal koji). The activity of phytase increased markedly at the late stationary phase. An extracellular phytase from Bacillus sp. KHU-10 was purified to homogeneity by acetone precipitation and DEAE-Sepharose and phenyl-Sepharose column chromatographies. Its molecular weight was estimated to be 46 kDa on gel filtration and 44 kDa on SDS-polyacrylamide gel elctrophoresis. Its optimum pH and temperature for phytase activity were pH 6.5-8.5 and 40 degrees C without 10 mM CaCl2 and pH 6.0-9.5 and 60 degrees C with 10 mM CaCl2. About 50% of its original activity remained after incubation at 80 degrees C or 10 min in the presence of 10 mM CaCl2. The enzyme activity was fairly stable from pH 6.5 to 10.0. The enzyme had an isoelectric point of 6.8. As for substrate specificity, it was very specific for sodium phytate and showed no activity on other phosphate esters. The Km value for sodium phytate was 50 microM. Its activity was inhibited by EDTA and metal ions such as Ba2+, Cd2+, Co2+, Cr3+, Cu2+, Hg2+, and Mn2+ ions.
 ...
PMID:Purification and properties of extracellular phytase from Bacillus sp. KHU-10. 1159 62

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 degrees 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 beta-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.
 ...
PMID:Screening, selection and characterization of phytic acid degrading lactic acid bacteria from chicken intestine. 1948 Dec 82

Phytases catalyze the release of phosphate from phytic acid. In this study, a phytase producing bacterial strain Shigella sp. CD2 was isolated from the wheat rhizosphere. Phytase production started from the exponential phase of bacterial growth, showing the highest activity during the stationary phase. The enzyme activity was detected in both periplasmic and intracellular fractions. The enzyme was purified by about 133-fold with specific activity 780 U mg(-1) protein. The optimum pH and temperature of the enzyme was 5.5 and 60 degrees C, respectively. The enzyme was thermostable and retained 100% and 75% of its activity on pre-incubation at 70 degrees and 80 degrees C for 30 min, respectively. The Km value for the substrate sodium phytate was 0.25 mM. The enzyme was highly specific to substrate phytate, and no activity was detected in presence of other phosphorylated substrates, such as ATP, ADP, glucose 6-phosphate, fructose 6-phosphate and p-nirophenyl phosphate. The activity declined dramatically in presence of Cu2+, Zn2+ and Fe2+ and SDS, whereas Mg2+ and Co2+ slightly enhanced the enzyme activity. The addition of other metal ions or chemicals had little or no effect on phytase activity. The enzyme was resistant to both pepsin and trypsin. Due to high specific activity, substrate specificity, good pH profile, protease insensitivity and thermostability, phytase encoding gene from Shigella sp. CD2 could be an interesting candidate for industrial applications. Further studies on cloning and expression of Shigella phytase gene are currently in progress.
 ...
PMID:Purification, characterization and properties of phytase from Shigella sp. CD2. 2307 88