New Bacterial Phytase through Metagenomic Prospection

Abstract

Alkaline phytases from uncultured microorganisms, which hydrolyze phytate to less phosphorylated myo-inositols and inorganic phosphate, have great potential as additives in agricultural industry. The development of metagenomics has stemmed from the ineluctable evidence that as-yet-uncultured microorganisms represent the vast majority of organisms in most environments on earth. In this study, a gene encoding a phytase was cloned from red rice crop residues and castor bean cake using a metagenomics strategy. The amino acid identity between this gene and its closest published counterparts is lower than 60%. The phytase was named PhyRC001 and was biochemically characterized. This recombinant protein showed activity on sodium phytate, indicating that PhyRC001 is a hydrolase enzyme. The enzymatic activity was optimal at a pH of 7.0 and at a temperature of 35 °C. β-propeller phytases possess great potential as feed additives because they are the only type of phytase with high activity at neutral pH. Therefore, to explore and exploit the underlying mechanism for β-propeller phytase functions could be of great benefit to biotechnology.

Functional Metagenomics Reveals an Overlooked Diversity and Novel Features of Soil-Derived Bacterial Phosphatases and Phytases

“…So far, few studies have attempted to discover phosphatases/phytases encoded by metagenomes using a function-based approach. Within these studies, only three genes and one of the corresponding proteins which exhibited phytase activity were recovered and described (34–36). We found 31 candidate genes, and 24 of them encoded phosphatase activity after individual heterologous expression (Table 2).…”

Interaction between Humic Substances and Plant Hormones for Phosphorous Acquisition

“…The first group includes mineralizing microorganisms which produce nuclease enzymes, phospholipases, and phytases which hydrolyse P-organic compounds. In particular, phytase has great importance in the mineralization process, as 50% of the soil organic P is in the form of phytate (Na-IHP) [127]. After hydrolysis, the resulting phosphomonoesters are further hydrolysed by phosphatase enzymes, releasing soluble phosphorus and other chelated minerals [128].…”

Functional Metagenomics Reveals a New Catalytic Domain, the Metallo-β-Lactamase Superfamily Domain, Associated with Phytase Activity

“…With the identification of metagenome-derived phytases, the temperature range of the optimal phytase activity changed. PhyRC001, a metagenome-derived phytase from red rice, showed optimal activity at 30°C (15). The Mblp02 activity optimum was 35°C.…”

“…Other phytases contribute to the virulence potency in human fungal pathogens such as Candida albicans (10–13). The vast majority of reported phytases are derived from a small culturable fraction of microorganisms, but recent reports implementing functional metagenomic approaches demonstrated the potential of environmental samples as source of novel phosphatases/phytases (14, 15).…”