Soil Bacteria and Fungi

Layman's summary: Fungi are extrememly important ecological architects. We studied the interaction between a highly sought after prize mushroom Morchella rufobrunnea (Ascomycota; Pezizales) and its adjacent bacterial population. We found distinct bacterial populations, indicating a shift in soil prokaryotic functions. Institutions: Migal Galilee Research Institute, University of Wisconsin, Lansing. Funding: BSF-NSF. Published in Environmental Microbiology on November 01, 2021. doi: 10.1111/1462-2920.15692 

Abstract: Morchella rufobrunnea is a saprobic edible mushroom, found in a range of ecological niches, indicating nutritional adjustment to different habitats and possible interaction with soil prokaryotic microbiome (SPM). Using the 16S rRNA gene, we examined the SPM of M. rufobrunnea that appeared in a natural habitat in Northern Israel. Three sample types were included: bare soil without mushroom, soil beneath young mushroom initials and soil beneath the mature fruiting body. Morchella rufobrunnea developmental stage was significantly associated with changes in bacterial populations (PERMANOVA, p < 0.0005). Indicator analysis with point-biserial correlation coefficient found 180 operational taxonomic units (OTU) uniquely associated with distinct stages of development. The Functional Annotation of Prokaryotic Taxonomy (FAPROTAX) database helped to infer ecological roles for indicator OTU. The functional ecological progression begins with establishment of a photoautotrophic N-fixing bacterial mat on bare soil. Pioneer heterotrophs including oligotrophs, acidifying nutrient mobilizers and nitrifiers are congruent with appearance of young M. rufobrunnea initials. Under the mature fruiting body, the population changed to saprobes, organic-N degraders, denitrifiers, insect endosymbionts and fungal antagonists.