Interkingdom interactions between soil bacteria and fungi may play a critical role in occurrence of disease suppressive soils, yet our understanding of these interactions remains limited. Streptomyces are well-known producers of antimicrobial compounds important to medicine and agriculture. Production of these secondary metabolites is often mediated by quorum sensing. Most Streptomyces research occurs in single species experiments, yet new metabolites have been discovered in interspecies co-culture experiments. Interspecies, intergenic, and interkingdom co-culture research will likely reveal many valuable compounds, and strengthen our understanding of complex ecological interactions in soil microbiomes. Interactions between sympatric Streptomyces and Fusarium isolates from disease suppressive soils were investigated in this study. Dual layer agar inhibition assay revealed inhibition of Streptomyces by Fusarium in all pairwise combinations, while only 46% of pairwise combinations showed Fusarium inhibition by Streptomyces. Streptomyces isolate S2-2 was shown to produce antifungal compounds in a population density dependent manner, likely governed by quorum sensing. Exposure of S2-2 broth culture to conditioned media which likely contained autoinducers from mature S2-2 culture was shown to cause a significant increase in antifungal production earlier than control groups. Simultaneous inoculation of S2-2 and Fusarium isolate F10-8 was shown to cause a significant decrease in antifungal production. Exploring these interactions is of great importance for antimicrobial drug discovery, identifying useful microbial biological control agents, and improving our ability to promote disease suppression in soils.
","abstract_html":"<p>Interkingdom interactions between soil bacteria and fungi may play a critical role in occurrence of disease suppressive soils, yet our understanding of these interactions remains limited. <em>Streptomyces</em> are well-known producers of antimicrobial compounds important to medicine and agriculture. Production of these secondary metabolites is often mediated by quorum sensing. Most <em>Streptomyces</em> research occurs in single species experiments, yet new metabolites have been discovered in interspecies co-culture experiments. Interspecies, intergenic, and interkingdom co-culture research will likely reveal many valuable compounds, and strengthen our understanding of complex ecological interactions in soil microbiomes. Interactions between sympatric <em>Streptomyces</em> and <em>Fusarium</em> isolates from disease suppressive soils were investigated in this study. Dual layer agar inhibition assay revealed inhibition of <em>Streptomyces</em> by <em>Fusarium</em> in all pairwise combinations, while only 46% of pairwise combinations showed <em>Fusarium</em> inhibition by <em>Streptomyces</em>. <em>Streptomyces</em> isolate S2-2 was shown to produce antifungal compounds in a population density dependent manner, likely governed by quorum sensing. Exposure of S2-2 broth culture to conditioned media which likely contained autoinducers from mature S2-2 culture was shown to cause a significant increase in antifungal production earlier than control groups. Simultaneous inoculation of S2-2 and <em>Fusarium</em> isolate F10-8 was shown to cause a significant decrease in antifungal production. Exploring these interactions is of great importance for antimicrobial drug discovery, identifying useful microbial biological control agents, and improving our ability to promote disease suppression in soils.</p>","abstract_has_math":false,"creators":["Olk-Szost, Lehren A"],"institution":null,"degree_name":"Master of Science","degree_level":"Thesis","degree_discipline":"Biology","degree_department":null,"school":null,"contributors":["Donna Maki"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2023,"date_issued":"2023-07-01T07:00:00Z","date_published":"2023-07-01T07:00:00Z","updated_at":"2026-07-24T03:24:24Z","subjects":["Streptomyces","Fusarium","Antifungal","Sympatric","Microbial Biological Control Agent","Co-culture","Disease Suppressive Soils","Agriculture","Bacteriology","Biochemistry","Biodiversity","Biology","Ecology and Evolutionary Biology","Environmental Microbiology and Microbial Ecology"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://commons.nmu.edu/theses/757","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Donna Maki"]},{"key":"dc:creator","label":"Author","values":["Olk-Szost, Lehren A"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2023-07-12T07:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Streptomyces","Fusarium","Antifungal","Sympatric","Microbial Biological Control Agent","Co-culture","Disease Suppressive Soils","Agriculture","Bacteriology","Biochemistry","Biodiversity","Biology","Ecology and Evolutionary Biology","Environmental Microbiology and Microbial Ecology"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://commons.nmu.edu/theses/757"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Interkingdom interactions between soil bacteria and fungi may play a critical role in occurrence of disease suppressive soils, yet our understanding of these interactions remains limited. Streptomyces are well-known producers of antimicrobial compounds important to medicine and agriculture. Production of these secondary metabolites is often mediated by quorum sensing. Most Streptomyces research occurs in single species experiments, yet new metabolites have been discovered in interspecies co-culture experiments. Interspecies, intergenic, and interkingdom co-culture research will likely reveal many valuable compounds, and strengthen our understanding of complex ecological interactions in soil microbiomes. Interactions between sympatric Streptomyces and Fusarium isolates from disease suppressive soils were investigated in this study. Dual layer agar inhibition assay revealed inhibition of Streptomyces by Fusarium in all pairwise combinations, while only 46% of pairwise combinations showed Fusarium inhibition by Streptomyces. Streptomyces isolate S2-2 was shown to produce antifungal compounds in a population density dependent manner, likely governed by quorum sensing. Exposure of S2-2 broth culture to conditioned media which likely contained autoinducers from mature S2-2 culture was shown to cause a significant increase in antifungal production earlier than control groups. Simultaneous inoculation of S2-2 and Fusarium isolate F10-8 was shown to cause a significant decrease in antifungal production. Exploring these interactions is of great importance for antimicrobial drug discovery, identifying useful microbial biological control agents, and improving our ability to promote disease suppression in soils.
"]},{"key":"dc:title","label":"Title","values":["Sympatric Soil Microbe Interactions between Streptomyces and Fusarium Isolates"]}]}],"canonical_facts":{"dc:contributor":["Donna Maki"],"dc:creator":["Olk-Szost, Lehren A"],"dc:date.available":["2023-07-12T07:00:00Z"],"dc:description.abstract":["Interkingdom interactions between soil bacteria and fungi may play a critical role in occurrence of disease suppressive soils, yet our understanding of these interactions remains limited. Streptomyces are well-known producers of antimicrobial compounds important to medicine and agriculture. Production of these secondary metabolites is often mediated by quorum sensing. Most Streptomyces research occurs in single species experiments, yet new metabolites have been discovered in interspecies co-culture experiments. Interspecies, intergenic, and interkingdom co-culture research will likely reveal many valuable compounds, and strengthen our understanding of complex ecological interactions in soil microbiomes. Interactions between sympatric Streptomyces and Fusarium isolates from disease suppressive soils were investigated in this study. Dual layer agar inhibition assay revealed inhibition of Streptomyces by Fusarium in all pairwise combinations, while only 46% of pairwise combinations showed Fusarium inhibition by Streptomyces. Streptomyces isolate S2-2 was shown to produce antifungal compounds in a population density dependent manner, likely governed by quorum sensing. Exposure of S2-2 broth culture to conditioned media which likely contained autoinducers from mature S2-2 culture was shown to cause a significant increase in antifungal production earlier than control groups. Simultaneous inoculation of S2-2 and Fusarium isolate F10-8 was shown to cause a significant decrease in antifungal production. Exploring these interactions is of great importance for antimicrobial drug discovery, identifying useful microbial biological control agents, and improving our ability to promote disease suppression in soils.
"],"dc:identifier":["https://commons.nmu.edu/theses/757"],"dc:subject":["Streptomyces","Fusarium","Antifungal","Sympatric","Microbial Biological Control Agent","Co-culture","Disease Suppressive Soils","Agriculture","Bacteriology","Biochemistry","Biodiversity","Biology","Ecology and Evolutionary Biology","Environmental Microbiology and Microbial Ecology"],"dc:title":["Sympatric Soil Microbe Interactions between Streptomyces and Fusarium Isolates"],"thesis:degree_discipline":["Biology"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Master of Science"]},"updated_at":"2026-07-24T03:24:24Z"}