Polyextremophile engineering: a review of organisms that push the limits of life.

Nature exhibits an enormous diversity of organisms that thrive in extreme environments. From snow algae that reproduce at sub-zero temperatures to radiotrophic fungi that thrive in nuclear radiation at Chernobyl, extreme organisms raise many questions about the limits of life. Is there environment where life could not "find a way"? Although many individual extremophilic organisms have been identified and studied, there remain outstanding questions about the limits of life and the extent to which extreme properties can be enhanced, combined or transferred to new organisms.

Tool Kit (KTK): A Modular Cloning System for Multigene Constructs and Programmed Protein Secretion from Cellulose Producing Bacteria.

Bacteria proficient at producing cellulose are an attractive synthetic biology host for the emerging field of Engineered Living Materials (ELMs). Species from the genus produce high yields of pure cellulose materials in a short time with minimal resources, and pioneering work has shown that genetic engineering in these strains is possible and can be used to modify the material and its production. To accelerate synthetic biology progress in these bacteria, we introduce here the tool kit (KTK), a standardized modular cloning system based on Golden Gate DNA assembly that allows DNA parts to be combined to build complex multigene constructs expressed in bacteria from plasmids.

Bacterial cellulose spheroids as building blocks for 3D and patterned living materials and for regeneration.

Engineered living materials (ELMs) based on bacterial cellulose (BC) offer a promising avenue for cheap-to-produce materials that can be programmed with genetically encoded functionalities. Here we explore how ELMs can be fabricated in a modular fashion from millimetre-scale biofilm spheroids grown from shaking cultures of Komagataeibacter rhaeticus. Here we define a reproducible protocol to produce BC spheroids with the high yield bacterial cellulose producer K.

Biofilm formation displays intrinsic offensive and defensive features of .

Biofilm formation is a strategy of many bacterial species to adapt to a variety of stresses and has become a part of infections, contaminations, or beneficial interactions. In this study, we demonstrate that profound physiological changes permit to switch from a floating to a sessile lifestyle, to undergo further maturation of the biofilm and to differentiate into the offensive or defensive features. We report that floating and biofilm cells are populations that differentiate metabolically, with members of each subpopulation developing different branches of certain metabolic pathways.

Two genomic regions encoding exopolysaccharide production systems have complementary functions in B. cereus multicellularity and host interaction.

Bacterial physiology and adaptation are influenced by the exopolysaccharides (EPS) they produce. These polymers are indispensable for the assembly of the biofilm extracellular matrix in multiple bacterial species. In a previous study, we described the profound gene expression changes leading to biofilm assembly in B.

Molecular architecture of bacterial amyloids in biofilms.

The formation of biofilms provides structural and adaptive bacterial response to the environment. In species, the biofilm extracellular matrix is composed of exopolysaccharides, hydrophobins, and several functional amyloid proteins. We report, using multiscale approaches such as solid-state NMR (SSNMR), electron microscopy, X-ray diffraction, dynamic light scattering, attenuated total reflection Fourier transform infrared (FTIR), and immune-gold labeling, the molecular architecture of and pathogenic functional amyloids.

Beyond the expected: the structural and functional diversity of bacterial amyloids.

Intense research has confirmed the formerly theoretical distribution of amyloids in nature, and studies on different systems have illustrated the role of these proteins in microbial adaptation and in interactions with the environment. Two lines of research are expanding our knowledge on functional amyloids: (i) structural studies providing insights into the molecular machineries responsible for the transition from monomer to fibers and (ii) studies showing the way in which these proteins might participate in the microbial fitness in natural settings. Much is known about how amyloids play a role in the social behavior of bacteria, or biofilm formation, and in the adhesion of bacteria to surfaces; however, we are still in the initial stages of understanding a complementary involvement of amyloids in bacteria-host interactions.

A genomic region involved in the formation of adhesin fibers in Bacillus cereus biofilms.

Bacillus cereus is a bacterial pathogen that is responsible for many recurrent disease outbreaks due to food contamination. Spores and biofilms are considered the most important reservoirs of B. cereus in contaminated fresh vegetables and fruits.

Nascent histamine induces α-synuclein and caspase-3 on human cells.

Histamine (Hia) is the most multifunctional biogenic amine. It is synthetized by histidine decarboxylase (HDC) in a reduced set of mammalian cell types. Mast cells and histaminergic neurons store Hia in specialized organelles until the amine is extruded by exocytosis; however, other immune and cancer cells are able to produce but not store Hia.