Phytase activity in lichens

Abstract

Summary Phytase activity was investigated in 13 lichen species using a novel assay method. The work tested the hypothesis that phytase is a component of the suite of surface‐bound lichen enzymes that hydrolyse simple organic forms of phosphorus (P) and nitrogen (N) deposited onto the thallus surface.Hydrolysis of inositol hexaphosphate (InsP6, the substrate for phytase) and appearance of lower‐order inositol phosphates (InsP5–InsP1), the hydrolysis products, were measured by ion chromatography. Phytase activity in Evernia prunastri was compared among locations with contrasting rates of N deposition.Phytase activity was readily measurable in epiphytic lichens (e.g. 11.3 μmol InsP6 hydrolysed g−1 h−1 in Bryoria fuscescens) but low in two terricolous species tested (Cladonia portentosa and Peltigera membranacea). Phytase and phosphomonoesterase activities were positively correlated amongst species. In E. prunastri both enzyme activities were promoted by N enrichment and phytase activity was readily released into thallus washings. InsP6 was not detected in tree canopy throughfall but was present in pollen leachate.Capacity to hydrolyse InsP6 appears widespread amongst lichens potentially promoting P capture from atmospheric deposits and plant leachates, and P cycling in forest canopies. The enzyme assay used here might find wider application in studies on plant root–fungal–soil systems.

Peltigera frigida Lichens and Their Substrates Reduce the Influence of Forest Cover Change on Phosphate Solubilizing Bacteria

“…Phytate is accumulated by plants ( Balaban et al, 2016 ), and to a lesser extent by microorganisms ( Turner et al, 2021 ), as a P storage compound. The capacity to hydrolyse phytate has been reported as widespread among lichens, which potentially contributes to P capture from atmospheric deposits and plant leachates ( Higgins and Crittenden, 2015 ). Phosphonates, on the other hand, can be found in membranes or excretions of microorganisms ( Horsman and Zechel, 2017 ; Calcott et al, 2018 ) and groups of phosphonate biosynthetic genes have been reported in lichenized Nostoc ( Gagunashvili and Andrésson, 2018 ).…”

“…Thus, despite the lower abundance of organic phosphate solubilizers in comparison to mineral phosphate solubilizers, the former could play an essential role in recycling the old parts of the thallus ( Grube et al, 2015 ), releasing phosphate that members of the lichen symbiosis could use. It is important to highlight that phosphatase and phytase activity have been reported in several species of lichens ( Whiteford et al, 2010 ; Higgins and Crittenden, 2015 ), attributed to lichen enzymes being produced by the mycobiont. However, the primers chosen for this study were designed to amplify bacterial genes ( Bergkemper et al, 2016a ), which would indicate that the lichen microbiome is at least contributing to P turnover.…”

The Importance of Considering Levels of P and N Fertilization to Promote Beneficial Interaction between Rapeseed and Phosphate-Solubilizing Bacteria

“…Moreover, N limitation could impede the process of P solubilization. Thus, for example, a N effect has been demonstrated on phytase activities in lichens [70]. Authors have shown a decrease in phytase activity along with the N availability in these complex microorganisms, for which phytate degradation is generally attributed to the fungal part of lichens.…”

Isolation of phytase-producing yeasts from rice seedlings for prospective probiotic applications

“…The increasing mined phosphate prices demand alternative phosphate sources and the efficient phosphate utilization technology around the world (Brinch-Pedersen et al 2014). Phytin is a mixed salt (K + , Ca 2+ , Mg 2+ or Zn 2+ ) with phytate, account for up to 85% of total organic phosphorus in seeds and straws (Higgins and Crittenden 2015). High levels of unutilized phytate lead to phosphorus runoff from oversupplied agricultural soils to aquatic ecosystems.…”

“…Phytase was viewed as a tool for determining the phytin degradation and phosphorus bioavailability (Brinch-Pedersen et al 2014). It can be produced most notably in germinating seeds and microbes (Nasri et al 2011;Higgins and Crittenden 2015). However, the mature plant and monogastric animals have only limited phytase activity in their nutrition absorption organs.…”