Arbuscular mycorrhiza support plant sulfur supply through organosulfur mobilizing bacteria in the hypho-and rhizosphere

This study aimed to elucidate the role of bacteria colonising mycorrhizal hyphae in organi?cally bound sulfur mobilisation, the dominant soil sulfur source that is not directly plant available.The effect of an intact mycorrhizal symbiosis with access to stable isotope organo-34S enriched soils encased in 35 µm mesh cores was tested in microcosms with Agrostis stolonifera and Plantago lanceolata.Hyphae and associated soil were sampled from static mesh cores with mycorrhizal ingrowth and ro?tating mesh cores that exclude mycorrhizal ingrowth as well as corresponding rhizosphere soil, while plant shoots were analysed for 34S uptake. Static cores increased uptake of 34S at early stages of plant growth when sulfur demand appeared to be high and harboured significantly larger populations of sulfonate mobilising bacteria. Bacterial and fungal communities were significantly different in the hyphospheres of static cores when compared to rotating cores, not associated with plant hosts. Shifts in bacterial and fungal communities occurred not only in rotated cores but also in the rhizosphere. Arylsulfatase activity was significantly higher in the rhizosphere when cores stayed static, while atsA and asfA gene diversity was distinct in the microcosms with static and rotating cores. This study demonstrated that AM symbioses can promote organo-S mobilization and plant uptake through interactions with hyphospheric bacteria, enabling AM fungal ingrowth into static cores creating a positive feedback-loop, detectable in the microbial rhizosphere communities.</p

Bacterial Communities Established in Bauxite Residues with Different Restoration Histories

Bauxite residue is the alkaline byproduct generated when alumina is extracted from bauxite ores and is commonly deposited in impoundments. These sites represent hostile environments with increased salinity and alkalinity and little prospect of revegetation when left untreated. This study reports the establishment of bacterial communities in bauxite residues with and without restoration amendments (compost and gypsum addition, revegetation) in samples taken in 2009 and 2011 from 0 to 10 cm depth. DNA fingerprint analysis of bacterial communities based on 16S rRNA gene fragments revealed a significant separation of the untreated site and the amended sites in both sampling years. 16S amplicon analysis (454 FLX pyrosequencing) revealed significantly lower alpha diversities in the unamended in comparison to the amended sites and hierarchical clustering separated the unamended site from the amended sites. The taxonomic analysis revealed that the restoration resulted in the accumulation of bacterial populations typical for soils including <i>Acidobacteriaceae, Nitrosomonadaceae</i>, and <i>Caulobacteraceae</i>. In contrast, the unamended site was dominated by taxonomic groups including <i>Beijerinckiaceae</i>, <i>Xanthomonadaceae</i>, <i>Acetobacteraceae</i>, and <i>Chitinophagaceae</i>, repeatedly associated with alkaline salt lakes and sediments. While bacterial communities developed in the initially sterile bauxite residue, only the restoration treatments created diverse soil-like bacterial communities alongside diverse vegetation on the surface

Additional file 5: of Species classifier choice is a key consideration when analysing low-complexity food microbiome data

Figure S3. Species detected ≥ 2.5% relative abundance in kefir samples using each species classifier with the total number of reads from each sequencer. (PNG 96 kb

ITS phylogenetic composition of the fungal component of the kefir grain (A) and kefir fermented milk (B) at genus level.

<p>ITS phylogenetic composition of the fungal component of the kefir grain (A) and kefir fermented milk (B) at genus level.</p

16S phylogenetic composition of the bacterial component of the kefir grain (A) and kefir fermented milk (B) at genus level.

<p>16S phylogenetic composition of the bacterial component of the kefir grain (A) and kefir fermented milk (B) at genus level.</p

List of fungal species identified in the study, listed in teleomorph form with anamorph or synonym names and previous kefir association.

<p>List of fungal species identified in the study, listed in teleomorph form with anamorph or synonym names and previous kefir association.</p

Procrustes imaging of unweighted UniFrac distance matrices highlight the diversity amongst the 16S bacterial component (A) and fungal component (B) of the different kefir samples.

<p>The two different sample types are linked with a bar (white represents grain flora; red represents milk flora). The direction of each axis is arbitrary.</p

Principle Coordinate Analysis (PCoA) plots, based on unweighted UniFrac distance matrices, show the diversity within bacterial populations from kefir grains (A) and kefir fermented milk (B) and fungal grain (C) and milk (D) populations.

<p>Green = Irish kefir, Orange = Belgian kefir, Light Brown = Spanish kefir, Red = German kefir, Grey = US kefir, Pink = Italian kefir and Purple = UK kefir.</p

Unweighted principal component analysis.

<p>For: a) control and treatment animals in day 0 (blue), control animals in day 21 (green) and treatment animals in day 21 (red) b) control animals in day 0 (blue) and control animals in day 21 (red) c) treatment animals in day 0 (blue) and treatment animals in day 21(red) d) control animals in day 21 (blue) and treatment animals in day 21 (red). UPGMA clustering and Jackkniffing for the unweighted UniFrac data e) For the UPGMA cladogram on the left: Orange colour represents animals in day 0; red for the control animals in day 21 and blue for the treatment animals in day21. d) For the Jackknife supported tree layout the labels are coloured according to the group as: Black for animals in day 0; red for the control animals in day 21 and blue for treatment animals in day 21. The lines are coloured by the Jackknife supported percentages: Red for 75–100% support; Green for 50–75% support; Yellow for 25–50% support and Blue for <25% support.</p

Percentage relative abundance of OTUs observed at the phylum, class, order and family levels in the pig distal gut microbiota at day 0, day 21 C (control) and day 21 T (treatment-cider yeast supplemented) groups.

<p>Percentage relative abundance of OTUs observed at the phylum, class, order and family levels in the pig distal gut microbiota at day 0, day 21 C (control) and day 21 T (treatment-cider yeast supplemented) groups.</p