Insight into phytase-producing microorganisms for phytate solubilization and soil sustainability

Abstract

The increasing demand for food has increased dependence on chemical fertilizers that promote rapid growth and yield as well as produce toxicity and negatively affect nutritional value. Therefore, researchers are focusing on alternatives that are safe for consumption, non-toxic, cost-effective production process, and high yielding, and that require readily available substrates for mass production. The potential industrial applications of microbial enzymes have grown significantly and are still rising in the 21st century to fulfill the needs of a population that is expanding quickly and to deal with the depletion of natural resources. Due to the high demand for such enzymes, phytases have undergone extensive research to lower the amount of phytate in human food and animal feed. They constitute efficient enzymatic groups that can solubilize phytate and thus provide plants with an enriched environment. Phytases can be extracted from a variety of sources such as plants, animals, and microorganisms. Compared to plant and animal-based phytases, microbial phytases have been identified as competent, stable, and promising bioinoculants. Many reports suggest that microbial phytase can undergo mass production procedures with the use of readily available substrates. Phytases neither involve the use of any toxic chemicals during the extraction nor release any such chemicals; thus, they qualify as bioinoculants and support soil sustainability. In addition, phytase genes are now inserted into new plants/crops to enhance transgenic plants reducing the need for supplemental inorganic phosphates and phosphate accumulation in the environment. The current review covers the significance of phytase in the agriculture system, emphasizing its source, action mechanism, and vast applications.

Insoluble-Phytate Improves Plant Growth and Arsenic Accumulation in As-Hyperaccumulator Pteris vittata: Phytase Activity, Nutrient Uptake, and As-Metabolism

“…The plants were watered by sterile 0.2× P-free HNS, 0.2 mM NaH 2 PO 4 , or 0.2 mM Na-phytate. For insoluble Ca/Fe-phytate treatments, excess Ca/Fe-phytate-P (30 mM) corresponding to the P content in typical soil was added into the substrates before use . After 1 month of growth, the plants were harvested for FW and P content analysis.…”

“…3 Phytate, which contains six phosphate moieties, is an important organic P (P o ) in soils, which can account up to 25% of total soil P. 4 However, soil phytate is stable as it resists to biochemical degradation, rendering it relatively unavailable to most plants and resulting in its accumulation in soils. 5 Given its strong ligands, phytate has high anionic charge, facilitating its interactions with soil minerals by complexing with metal cations. 6 Typically, phytate binds with Fe/Al under acidic conditions, and Ca/Mg under alkaline conditions, forming insoluble Fe/Al/Ca/Mg-phytate in soils.…”

Phosphate Solubilization and Plant Growth Promotion by Pantoea brenneri Soil Isolates

“…P. brenneri strains 3.1, 3.2, 3.5.2, and 3.6.1 were originally isolated from soil samples of the Republic of Tatarstan according to their phytate-hydrolyzing activity [ 11 ]. The strains were cultured on LB medium containing 10 g tryptone, 5 g yeast extract, and 5 g NaCl per 1 L distilled water, at pH 7.0.…”

“…However, soil phytates cannot be directly utilized by plants. Phosphate ester (C-O-P), phosphoanhydride (P-O-P), or phosphonate (C-P) must first be dephosphorylated through phytase-mediated hydrolysis [ 11 ]. Plants and microbes have developed strategies to improve phytate bioavailability by secreting organic acids and hydrolyzing enzymes—namely, phytases [ 10 ].…”

Phytin recovered from grain distillation can serve as a phosphorus fertilizer for maize and soybean

“…Lack of phytate-rich inputs at our field site (e.g., manure) could have led to a lower abundance of phytaseproducing microorganisms. This points to the potential of soil microbial inoculants to expedite phytin mineralization (Kaur, 2020;Rizwanuddin et al, 2023) or pretreatment of phytin with purified phytases, as has been successfully performed with manures (Angel et al, 2005;Menezes-Blackburn et al, 2014) to increase the inorganic P fraction prior to field application. To understand the extent to which phytin P can mineralize during a growing season, controlled mesocosm studies using 33 P or 32 P labeling for radioisotopic dilution afford high precision of mineralization rates and cumulative P mineralization under varying temperature and moisture conditions and across soils of varying properties (e.g., texture) (Bünemann, 2015).…”