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

Microorganisms in nature often live in surfaceassociated 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: Sulfolobus acidocaldarius, S. solfataricus, and S. tokodaii. These strains form different communities ranging from simple carpet structures in S. solfataricus to high density tower-like structures in S. acidocaldarius 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 Sulfolobus spp. Proteomic and transcriptomic data show that biofilm-forming life-style is strain specific (eg ca. 15% of the S. acidocaldarius genes were differently expressed, S. solfataricus and S. tokodaii 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

Synthesis of Functionalized Perfluorinated Porphyrins for Improved Spin Switching

We have established a method to synthesize perfluorinated <i>meso</i>-phenylporphyrins with one phenyl group bearing a substituent in the <i>ortho</i> position. These novel electron-deficient porphyrins are interesting for model enzymes, catalysis, photodynamic therapy, and electron transfer. The key step is the synthesis of an iodine-substituted porphyrin and its Suzuki cross coupling with boronic acid derivatives. We applied the novel strategy to synthesize a highly electron-deficient, azopyridine-substituted Ni–porphyrin that undergoes an improved ligand-driven coordination-induced spin-state switch

Molybdenum 17- and 18-Electron Bis- and Tris(Butadiene) Complexes: Electronic Structures, Spectroscopic Properties, and Oxidative Ligand Substitution Reactions

New results on the electronic structures, spectroscopic properties, and reactivities of the molybdenum tris­(butadiene) and tris­(2,3-dimethylbutadiene) complexes [Mo­(bd)₃] (<b>1</b>^<b>bd</b>) and [Mo­(dmbd)₃] (<b>1</b>^<b>dmbd</b>), respectively, are reported. Importantly, the metal ligand bonding interaction can be weakened by oxidizing the metal center with ferrocenium salts. The addition of the bidentate phosphine ligand 1,2-bis­(diphenylphosphino)­ethane then leads to a new type of stable 17-electron complex, [Mo­(dmbd)₂(dppe)]­(X) (<b>2</b>; X = BF₄^–, PF₆^–, BPh₄^–), where one of the butadiene ligands is exchanged by a chelating phosphine. Reduction of the cationic complexes <b>2</b> generates the corresponding 18-electron complex [Mo­(dmbd)₂(dppe)] (<b>3</b>), thus establishing a new strategy for ligand substitution reactions in [Mo­(bd)₃] complexes via one-electron oxidized intermediates. The new heteroleptic molybdenum complexes are characterized by X-ray structure analysis; vibrational, NMR, and EPR spectroscopy; and electrochemistry. DFT calculations are performed to explain the structural and specroscopic trends observed experimentally. For compound <b>1</b>^<b>bd</b>, a normal coordinate analysis is presented, providing additional information on the bonding situation in this type of complex

Ionothermal Synthesis of Four New Nickel Thiophosphate Anions: [Ni(P₂S₈)₂]^2–, [Ni(P₃S₉)(P₂S₈)]^3–, [Ni(P₃S₉)₂]^4–, and [(NiP₃S₈)₄(PS₄)]^7–

Four new nickel thiophosphate anions have been isolated as 1-ethyl-3-methylimidazolium (EMIM) salts: [EMIM]₂[Ni­(P₂S₈)₂] (<b>1</b>), [EMIM]₃[Ni­(P₃S₉)­(P₂S₈)] (<b>2</b>), [EMIM]₄[Ni­(P₃S₉)₂] (<b>3</b>), and [EMIM]₇[(NiP₃S₈)₄(PS₄)] (<b>4</b>). Single crystals of each were prepared by ionothermal reaction of the elements in [EMIM]­[BF₄]. <b>1</b> can also be obtained from [EMIM]­[CF₃SO₃]. In all four anions, Ni atoms are octahedrally coordinated and P atoms are tetrahedrally coordinated. In the anion found in <b>1</b>, two tridentate 1,3-P₂S₈^2– ligands are cis to each other. The anion in <b>2</b> contains two different tridentate thiophosphate ligands, 1,3-P₂S₈^2– and P₃S₉^3–, whereas the anion in <b>3</b> consists of two P₃S₉^3– ligands coordinated to the central Ni atom. The anion in <b>4</b> is complex, consisting of four NiP₃S₈^– clusters surrounding a central PS₄ tetrahedron; within the NiP₃S₈^– groups, one P atom is directly bound to Ni. The discovery of these four new compounds demonstrates the versatility of ionothermal methods for the synthesis of novel thiophosphates