In Vitro Community Synergy between Bacterial Soil Isolates Can Be Facilitated by pH Stabilization of the Environment

TY - JOUR

T1 - In Vitro Community Synergy between Bacterial Soil Isolates Can Be Facilitated by pH Stabilization of the Environment

AU - Herschend, Jakob

AU - Koren, Klaus

AU - Røder, Henriette L.

AU - Brejnrod, Asker

AU - Kühl, Michael

AU - Burmølle, Mette

PY - 2018

Y1 - 2018

N2 - The composition and development of naturally occurring microbial communities are defined by a complex interplay between the community and the surrounding environment and by interactions between community members. Intriguingly, these interactions can in some cases cause synergies, where the community is able to outperform its single-species constituents. However, the underlying mechanisms driving community interactions are often unknown and difficult to identify due to high community complexity. Here, we show how opposite pH drift induced by specific community members leads to pH stabilization of the microenvironment, acting as a positive interspecies interaction, driving in vitro community synergy in a model consortium of four coisolated soil bacteria, Microbacterium oxydans, Xanthomonas retroflexus, Stenotrophomonas rhizophila, and Paenibacillus amylolyticus. We use microsensor pH measurements to show how individual species change the local pH microenvironment and how cocultivation leads to a stabilized pH regime over time. Specifically, in vitro acid production from P. amylolyticus and alkali production primarily from X. retroflexus led to an overall pH stabilization of the local environment over time, which in turn resulted in enhanced community growth. This specific type of interspecies interaction was found to be highly dependent on medium type and concentration; however, similar pH drift from the individual species could be observed across medium variants.

AB - The composition and development of naturally occurring microbial communities are defined by a complex interplay between the community and the surrounding environment and by interactions between community members. Intriguingly, these interactions can in some cases cause synergies, where the community is able to outperform its single-species constituents. However, the underlying mechanisms driving community interactions are often unknown and difficult to identify due to high community complexity. Here, we show how opposite pH drift induced by specific community members leads to pH stabilization of the microenvironment, acting as a positive interspecies interaction, driving in vitro community synergy in a model consortium of four coisolated soil bacteria, Microbacterium oxydans, Xanthomonas retroflexus, Stenotrophomonas rhizophila, and Paenibacillus amylolyticus. We use microsensor pH measurements to show how individual species change the local pH microenvironment and how cocultivation leads to a stabilized pH regime over time. Specifically, in vitro acid production from P. amylolyticus and alkali production primarily from X. retroflexus led to an overall pH stabilization of the local environment over time, which in turn resulted in enhanced community growth. This specific type of interspecies interaction was found to be highly dependent on medium type and concentration; however, similar pH drift from the individual species could be observed across medium variants.

KW - bacteria

KW - coculture

KW - microbiology

KW - microsensor

KW - multispecies

KW - pH stabilization

U2 - 10.1128/aem.01450-18

DO - 10.1128/aem.01450-18

M3 - Journal article

C2 - 30143509

AN - SCOPUS:85055073233

SN - 0099-2240

VL - 84

JO - Applied and Environmental Microbiology

JF - Applied and Environmental Microbiology

IS - 21

M1 - e01450

ER -