Resource Mismatch in Phototrophic Subaerial Biofilms and Resulting Phototroph/Heterotroph Ratios
- 1Department of Mathematics, Temple University
Abstract
Photosynthesis-driven microbial communities are frequently observed on air-exposed stone such as, for example, marble surfaces. These environments are stark, subject to varying water, temperature, UV and other stresses. As a consequence, resident microbes likely have significant maintenance requirements. Those microbes however, have access to plentiful energy when conditions are favorable for photosynthesis. High rates of photosynthesis for purposes of energy generation may also generate excess organic carbon which can be released as extracellular overflow, becoming available for heterotrophic organisms. Here we propose a simple model to explore possible consequences of this hypothesized resource mismatch. The model predicts that heterotrophs can invade purely phototrophic communities, with the resulting mixed community eventually approaching a phototroph/heterotroph ratio at steady state as a consequence of stoichiometric balance. Results from field observations at three geographically separated sites (Lincoln Memorial, Washington D.C., Merchants' Exchange, Philadelphia PA, and the Federal Hall National Memorial, New York NY), analyzed using two independent methods, are seen to match model predictions, demonstrating both cyanobacterial dominated communities as well as, mostly, mixed communities with a heterotrophs-to-cyanobacteria biovolume ratio of approximately 0.4.
Related
- Anoxygenic phototrophic Chlorobi use broad metabolic and resource acquisition strategies to support stable near-clonal blooms
- Phototroph-specific nitrogen isotopes detail N2-fixation increases at the end-Triassic extinction
- Pulling water from a stone: subaerial biofilm water dynamics on porous solid materials
- Zn isotope fractionation during interaction with phototrophic biofilm
- Functional Analysis of Carotenoid Biosynthetic Genes and Pathway of the Filamentous Anoxygenic Phototrophic Bacterium Chloroflexus aurantiacus.
BibTeX
@misc{tenore2026resource,
title = {{Resource Mismatch in Phototrophic Subaerial Biofilms and Resulting Phototroph/Heterotroph Ratios}},
author = {A. Tenore and F. Russo and J. Jacob and J.-D. Grattepanche and B. Buttaro and I. Klapper},
howpublished = {bioRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.16.759371},
url = {https://www.biorxiv.org/content/10.64898/2026.10.16.759371v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Resource Mismatch in Phototrophic Subaerial Biofilms and Resulting Phototroph/Heterotroph Ratios
AU - A. Tenore
AU - F. Russo
AU - J. Jacob
AU - J.-D. Grattepanche
AU - B. Buttaro
AU - I. Klapper
PY - 2026
DA - 2026/10/16
PB - bioRxiv
DO - 10.64898/2026.10.16.759371
UR - https://www.biorxiv.org/content/10.64898/2026.10.16.759371v1
AB - Photosynthesis-driven microbial communities are frequently observed on air-exposed stone such as, for example, marble surfaces. These environments are stark, subject to varying water, temperature, UV and other stresses. As a consequence, resident microbes likely have significant maintenance requirements. Those microbes however, have access to plentiful energy when conditions are favorable for photosynthesis. High rates of photosynthesis for purposes of energy generation may also generate excess organic carbon which can be released as extracellular overflow, becoming available for heterotrophic organisms. Here we propose a simple model to explore possible consequences of this hypothesized resource mismatch. The model predicts that heterotrophs can invade purely phototrophic communities, with the resulting mixed community eventually approaching a phototroph/heterotroph ratio at steady state as a consequence of stoichiometric balance. Results from field observations at three geographically separated sites (Lincoln Memorial, Washington D.C., Merchants' Exchange, Philadelphia PA, and the Federal Hall National Memorial, New York NY), analyzed using two independent methods, are seen to match model predictions, demonstrating both cyanobacterial dominated communities as well as, mostly, mixed communities with a heterotrophs-to-cyanobacteria biovolume ratio of approximately 0.4.
ER -