Effect of Cd+2 on phosphate solubilizing abilities and hydrogen peroxide production of soil-borne micromycetes isolated from Phragmites australis-rhizosphere

Abstract

The aims of this work were to evaluate the phosphate-solubilization and hydrogen peroxide (H2O2) production by the soil-borne micromycetes, Aspergillus japonicus, Penicillium italicum and Penicillium dipodomyicola, isolated from Phragmites australis rhizosphere and to study the effect of several concentrations of Cadmium (Cd(2+)) on both variables. Our results showed that P. italicum achieved a higher P-solubilization and H2O2 production than A. japonicus and P. dipodomyicola, as only P. italicum showed a positive correlation (R(2) = 0.71) between P-solubilization and H2O2 production. In dose-response assays, P. italicum was also more tolerant to Cd(2+) (0.31 mM) in comparison to A. japonicus (0.26 mM). Analysis of the 2(4) factorial experimental design showed that P-solubilization by P. italicum was negatively affected by increases in Cd(2+) (p = 0.04) and yeast extract (p = 0.02) in the culture medium. The production of H2O2 was positively affected only by glucose (p = 0.002). Fungal biomass production was reduced significantly (p = 0.0009) by Cd(2+) and increased (p = 0.0003) by high glucose concentration in the culture medium. The tolerance and correlation between P-solubilization and H2O2 production in the presence of Cd(2+) was strain and species dependent. The effects of Cd(2+), glucose, ammonium sulfate and yeast extract on those variables were evaluated through a two-level factorial design. P. italicum is promising for P-solubilization in soils contaminated with Cd(2+) and may be an alternative for manufacture of biofertilizers to replace chemical fertilizers.

Phosphate solubilization by fungi with nematicidal potential

“…Some nematophagous fungi, such as Arthrobotrys oligospora and Purpureocillium lilacinum (=Paecilomyces lilacinus), have also shown mineralsolubilizing abilities (Duponnois et al, 2006;Hernandez-Leal et al, 2011). In recent years, several studies have focused on the characterization and evaluation of mineral-solubilizing microorganisms with the aim of incorporating them into sustainable agricultural management strategies (Sharma et al, 2013;Yin et al, 2015;Fu et al, 2016;Zúñiga-Silva et al, 2016).…”

The rhizosphere microbiome improves the adaptive capabilities of plants under high soil cadmium conditions

“…Importantly, microbial P solubilization was also reported to mobilize Cd from soils by increasing the soil acidity ( Chen Y. et al, 2020 ). The microbial P solubilization gene is widely distributed in microbes in Cd-contaminated environments ( Zuniga-Silva et al, 2016 ). In addition, this gene was affiliated with Gemmatimonas and Sphingomonas at the genus level, both of which were enriched in the rhizosphere microbiomes of the AE of S. alfredii .…”

Screening of nutritional factors through a Plackett-Burman experimental design during the solubilization of tricalcium phosphate by Penicillium hispanicum

“…In another study on native SBM from a Mexican coffee plantation, Hernando-Posada et al (2013) reported that Paecilomyces marquandii and Penicillium janthinelum released 1.9 and 7.0 mg/L of P from Ca 3 (PO 4 ) 2 in the culture medium at 24 days; these values were lower than those achieved by Penicillium SP1 and P. hispanicum. The ability of a fungal strain to release P from an inorganic source is known to be strain and species dependent and can also be influenced by multiple environmental factors (Zúñiga-Silva et al, 2016).…”

“…Only Penicillium isolate SP16 was identified at molecular level using the methodology described by Zúñiga-Silva et al (2016). After genomic DNA extraction, PCR amplification of the internal transcribed spacers (ITS regions: 26S and 16S regions) were carried out using the following primers ITS1 (5´-TCCGTAGGTGAACCTGCGG-3´) and ITS4 (5´-TCCTCCGCTTATTGATATGC-3´).…”

“…In agricultural soils with low abundance and diversity of P-solubilizing microorganisms, biofertilizing microorganisms can be directly applied using a bioaugmentation strategy (Khan et al, 2014). In this sense, soil borne micromycetes have been described as suitable microorganisms for releasing P from inorganic sources such as Ca 3 (PO 4 ) 2 , FePO 4 and AlPO 4 (Oliveira-Mendes et al, 2016;Zúñiga-Silva et al, 2016).…”