Photovoltaic biofilms are ubiquitous in freshwater and marine environments where they are essential for the geochemical cycle, food webs, and industrial applications. In streams, photosynthetic biofilms dominate benthic microbial life and house an enormous prokaryotic and eukaryotic microbial diversity with biotic interactions across domains and trophic levels under light constraints, the dominant photosynthetic images, including diatoms and cyanobacteria, showed remarkable flexibility in the photosynthesis mechanism They are manifested in a higher abundance of messenger RNAs (mRNAs) involved in photosynthesis and chloroplast RNA. Under high light availability, bacterial mRNAs involved in phosphorous metabolism, mainly from Betaproteobacteria and cyanobacteria, have increased, potentially compensating for nutrient depletion in thick biofilms with high biomass. Consumers, including the various giants, have shown societal shifts indicating preferential grazing over algae rather than bacteria under high light. For the first time, we showed that the functional integration of current biofilms under changing light availability is maintained through structural and functional adaptations at several trophic levels. Our findings shed new light on complex biofilms, or "microbial jungles," where diverse and multi-feeding societies, such as forests, stabilize the functioning of an ecosystem. This multi-trophic perspective, which transcriptomics science is coupled with measurements of the process, could advance the understanding of microbial-driven ecosystems outside biofilms, including plankton and soil environments.