Macromolecular Fingerprinting of <i>Sulfolobus</i> Species in Biofilm: A Transcriptomic and Proteomic Approach Combined with Spectroscopic Analysis

Microorganisms in nature often live in surface-associated sessile communities, encased in a self-produced matrix, referred to as biofilms. Biofilms have been well studied in bacteria but in a limited way for archaea. We have recently characterized biofilm formation in three closely related hyperthermophilic crenarchaeotes: <i>Sulfolobus acidocaldarius</i>, <i>S. solfataricus</i>, and <i>S. tokodaii</i>. These strains form different communities ranging from simple carpet structures in <i>S. solfataricus</i> to high density tower-like structures in <i>S. acidocaldarius</i> under static condition. Here, we combine spectroscopic, proteomic, and transcriptomic analyses to describe physiological and regulatory features associated with biofilms. Spectroscopic analysis reveals that in comparison to planktonic life-style, biofilm life-style has distinctive influence on the physiology of each <i>Sulfolobus</i> spp. Proteomic and transcriptomic data show that biofilm-forming life-style is strain specific (eg ca. 15% of the <i>S. acidocaldarius</i> genes were differently expressed, S. <i>solfataricus</i> and <i>S. tokodaii</i> had ∼3.4 and ∼1%, respectively). The -omic data showed that regulated ORFs were widely distributed in basic cellular functions, including surface modifications. Several regulated genes are common to biofilm-forming cells in all three species. One of the most striking common response genes include putative Lrs14-like transcriptional regulators, indicating their possible roles as a key regulatory factor in biofilm development