Phytate and Microbial Suspension Amendments Increased Soybean Growth and Shifted Microbial Community Structure

Abstract

Phytate represents an organic pool of phosphorus in soil that requires hydrolysis by phytase enzymes produced by microorganisms prior to its bioavailability by plants. We tested the ability of a microbial suspension made from an old growth maple forest’s undisturbed soil to mineralize phytate in a greenhouse trial on soybean plants inoculated or non-inoculated with the suspension. MiSeq Amplicon sequencing targeting bacterial 16S rRNA gene and fungal ITS was performed to assess microbial community changes following treatments. Our results showed that soybean nodulation and shoot dry weight biomass increased when phytate was applied to the nutrient-poor substrate mixture. Bacterial and fungal diversities of the root and rhizosphere biotopes were relatively resilient following inoculation by microbial suspension; however, bacterial community structure was significantly influenced. Interestingly, four arbuscular mycorrhizal fungi (AMF) were identified as indicator species, including Glomus sp., Claroideoglomus etunicatum, Funneliformis mosseae and an unidentified AMF taxon. We also observed that an ericoid mycorrhizal taxon Sebacina sp. and three Trichoderma spp. were among indicator species. Non-pathogenic Planctobacteria members highly dominated the bacterial community as core and hub taxa for over 80% of all bacterial datasets in root and rhizosphere biotopes. Overall, our study documented that inoculation with a microbial suspension and phytate amendment improved soybean plant growth.

Mycorrhizal-based inoculants in the root microbiome enhanced phytocannabinoid production in medical Cannabis cultivars

“…Five replicates were prepared for each inoculant × cultivar combination, for a total of 100 pots. The four treatments in this study were: Ferticann (F, mixture of bene cial microbes containing 5000 spores/g (0-120 micrometers, carrier silicate) of Rhizophagus irregularis, 10 9 CFU/g (0-120 micrometer and carrier dextrose) of Trichoderma harzianum and Bacillus subtilis, and microalga Dictyosphaerium chlorelloides); microbial suspension from forest soil (K1) dominated by planctobacteria described by Ahmed et al [13]; forest microbial suspension plus R. irregularis isolate DAOM 197198 (K2); and control (KO) without any inoculants. With a photoperiod of 16/8 hours, the temperature during the experiment was from 22 to 27°C.…”

“…DNA yield was measured using a NanoDropTM 2000/2000c Spectrophotometer (ThermoFisher Scienti c, Ottawa, ON, Canada) and then electrophoresed on 1% agarose gel and visualized by a GelDoc System (BioRad, Saint-Laurent, QC, Canada). Bacterial 16S rDNA and fungal ITS regions were ampli ed by PCR according to previously published methods [13,14]. The PCR reaction was performed in a 25 µL reaction volume according to our previous study [7,14].…”

“…Patescibacteria, together with Actinobacteria and Proteobacteria, were recently discovered in abundance in the microbiome of chrysanthemum roots [41]. Ahmed et al (2021) also found that Tepidisphaerales were abundant in soybean soil microbiome in an experiment where phytate was used as the sole source of phosphorus and a forest-microbial suspension-based amendment was applied [13].…”

“…Genotypes can have a unique core microbiome (a group of microbial taxa that are always associated with a speci c host). For example, soybean inoculated with a microbial suspension from forest soil increased by 23% the total phosphate accumulation provided phytate as the sole phosphate source, due to a core microbiome that was correlated with phytate mineralization [13] Identifying the core microbiome of a particular genotype, which is associated with its optimal growth and nutrition, could be a diagnostic test to explain suboptimal plant performance. It might also reveal a lack of essential microorganisms, that should be added to improve plant growth and enhance other desired functions, including biosynthesis of secondary compounds [7].…”

Cultural techniques capture diverse phosphate-solubilizing bacteria in rock phosphate-enriched habitats

“…) with the aid of organic acids and enzymes such as phosphatases and phytases (Goldstein, 1995;Ahmed et al, 2021). This, in turn, allows them to benefit from P while also enabling other organisms, such as plants, to access it as a nutrient source (Raymond et al, 2021).…”