Harnessing chickpea bacterial endophytes for improved plant health and fitness.

Endophytic bacteria live asymptomatically inside the tissues of host plants without inflicting any damage. Endophytes can confer several beneficial traits to plants, which can contribute to their growth, development, and overall health. They have been found to stimulate plant growth by enhancing nutrient uptake and availability.

Promising non-model microbial cell factories obtained by genome reduction.

The development of sustainable processes is the most important basis to realize the shift from the fossil-fuel based industry to bio-based production. Non-model microbes represent a great resource due to their advantageous traits and unique of bioproducts. However, most of these microbes require modifications to improve their growth and production capacities as well as robustness in terms of genetic stability.

Corrigendum: Genome reduction in DSM 365 for chassis development.

[This corrects the article DOI: 10.3389/fbioe.2024.

Genome reduction in DSM 365 for chassis development.

The demand for highly robust and metabolically versatile microbes is of utmost importance for replacing fossil-based processes with biotechnological ones. Such an example is the implementation of DSM 365 as a novel platform organism for the production of value-added products such as 2,3-butanediol or exopolysaccharides. For this, a complete genome sequence is the first requirement towards further developing this host towards a microbial chassis.

Engineering the carbon and redox metabolism of Paenibacillus polymyxa for efficient isobutanol production.

Paenibacillus polymyxa is a non-pathogenic, Gram-positive bacterium endowed with a rich and versatile metabolism. However interesting, this bacterium has been seldom used for bioproduction thus far. In this study, we engineered P.

CRISPR-Cas9-Mediated Genome Editing in Paenibacillus polymyxa.

In recent years, the clustered regularly interspaced palindromic repeats-Cas (CRISPR-Cas) technology has become the method of choice for precision genome editing in many organisms due to its simplicity and efficacy. Multiplex genome editing, point mutations, and large genomic modifications are attractive features of the CRISPR-Cas9 system. These applications facilitate both the ease and velocity of genetic manipulations and the discovery of novel functions.

A PQS-Cleaving Quorum Quenching Enzyme Targets Extracellular Membrane Vesicles of .

The opportunistic pathogen uses quorum sensing to control its virulence. One of its major signal molecules, the quinolone signal PQS, has high affinity to membranes and is known to be trafficked mainly via outer membrane vesicles (OMVs). We previously reported that several 3-hydroxy-4(1)-quinolone 2,4-dioxygenases (HQDs) catalyze the cleavage of PQS and thus act as quorum quenching enzymes.

Insights in the Complex DegU, DegS, and Spo0A Regulation System of Paenibacillus polymyxa by CRISPR-Cas9-Based Targeted Point Mutations.

Despite being unicellular organisms, bacteria undergo complex regulation mechanisms which coordinate different physiological traits. Among others, DegU, DegS, and Spo0A are the pleiotropic proteins which govern various cellular responses and behaviors. However, the functions and regulatory networks between these three proteins are rarely described in the highly interesting bacterium Paenibacillus polymyxa.

A comparative study of N-hydroxylating flavoprotein monooxygenases reveals differences in kinetics and cofactor binding.

Many natural products comprise N-O containing functional groups with crucial roles for biological activity. Their enzymatic formation is predominantly achieved by oxidation of an amine to form a hydroxylamine, which enables further functionalization. N-hydroxylation by flavin-dependent enzymes has so far been attributed to a distinct group of flavoprotein monooxygenases (FPMOs) containing two dinucleotide binding domains.

CRISPR-Cas9-mediated Large Cluster Deletion and Multiplex Genome Editing in .

The use of molecular tools based on the clustered regularly interspaced short palindromic repeats-Cas (CRISPR-Cas) systems has rapidly advanced genetic engineering. These molecular biological tools have been applied for different genetic engineering purposes in multiple organisms, including the quite rarely explored . However, only limited studies on large cluster deletion and multiplex genome editing have been described for this highly interesting and versatile bacterium.

Systematic optimization of exopolysaccharide production by Gluconacetobacter sp. and use of (crude) glycerol as carbon source.

The usage of polysaccharides as biodegradable polymers is of growing interest in the context of a sustainable and ecofriendly economy. For this, the production of exopolysaccharides (EPS) by Gluconacetobacter sp. was investigated.

Structural basis of O-methylation of (2-heptyl-)1-hydroxyquinolin-4(1H)-one and related compounds by the heterocyclic toxin methyltransferase Rv0560c of Mycobacterium tuberculosis.

The S-adenosyl-L-methionine-dependent methyltransferase Rv0560c of Mycobacterium tuberculosis belongs to an orthologous group of heterocyclic toxin methyltransferases (Htm) which likely contribute to resistance of mycobacteria towards antimicrobial natural compounds as well as drugs. Htm catalyzes the methylation of the Pseudomonas aeruginosa toxin 2-heptyl-1-hydroxyquinolin-4(1H)-one (also known as 2-heptyl-4-hydroxyquinoline N-oxide), a potent inhibitor of respiratory electron transfer, its 1-hydroxyquinolin-4(1H)-one core (QNO), structurally related (iso)quinolones, and some mycobactericidal compounds. In this study, crystal structures of Htm in complex with S-adenosyl-L-homocysteine (SAH) and the methyl-accepting substrates QNO or 4-hydroxyisoquinoline-1(2H)-one, or the methylated product 1-methoxyquinolin-4(1H)-one, were determined at < 1.

Exploiting unconventional prokaryotic hosts for industrial biotechnology.

Developing cost-efficient biotechnological processes is a major challenge in replacing fossil-based industrial production processes. The remarkable progress in genetic engineering ensures efficient and fast tailoring of microbial metabolism for a wide range of bioconversions. However, improving intrinsic properties such as tolerance, handling, growth, and substrate consumption rates is still challenging.

Lipid nanovesicles for biomedical applications: 'What is in a name'?

Vesicles, generally defined as self-assembled structures formed by single or multiple concentric bilayers that surround an aqueous core, have been widely used for biomedical applications. They can either occur naturally (e.g.

Crystal structure of the sugar acid-binding protein CxaP from a TRAP transporter in Advenella mimigardefordensis strain DPN7.

Recently, CxaP, a sugar acid substrate binding protein (SBP) from Advenella mimigardefordensis strain DPN7 , was identified as part of a novel sugar uptake strategy. In the present study, the protein was successfully crystallized. Although several SBP structures of tripartite ATP-independent periplasmic transporters have already been solved, this is the first structure of an SBP accepting multiple sugar acid ligands.

Interaction of cyanobacteria with calcium facilitates the sedimentation of microplastics in a eutrophic reservoir.

Low-density microplastics are frequently found in sediments of many lakes and reservoirs. The processes leading to sedimentation of initially buoyant polymers are poorly understood for inland waters. This study investigated the impact of biofilm formation and aggregation on the density of buoyant polyethylene microplastics.

Screening of Bacterial Quorum Sensing Inhibitors in a LuxR-Based Synthetic Fluorescent Biosensor.

A library of 23 pure compounds of varying structural and chemical characteristics was screened for their quorum sensing (QS) inhibition activity using a synthetic fluorescent biosensor that incorporates a modified version of lux regulon of . Four such compounds exhibited QS inhibition activity without compromising bacterial growth, namely, phenazine carboxylic acid (PCA), 2-heptyl-3-hydroxy-4-quinolone (PQS), 1-2-methyl-4-quinolone (MOQ) and genipin. When applied at 50 µM, these compounds reduced the QS response of the biosensor to 33.

Artificial vs natural Stachybotrys infestation-Comparison of mycotoxin production on various building materials.

The genus Stachybotrys belongs to filamentous fungi found in indoor environment, mostly on cellulose-rich substrates after water-damage. The major purpose of this study was to investigate the influence of different building materials in case of mold infestation on the mycotoxin production of Stachybotrys species. Fifteen Stachybotrys mycotoxins including satratoxins, phenylspirodrimanes, and recently discovered stachybotrychromenes were in the focus of the investigations.

Biotransformation of poly(cis-1,4-isoprene) in a multiphase enzymatic reactor for continuous extraction of oligo-isoprenoid molecules.

Biotechnological processes for the partial degradation or transformation of poly(cis-1,4-isoprene) rubber have been investigated during recent decades with promising results. The use of the enzyme 'latex clearing protein' (Lcp) to transform the polymer into more hydrophilic oligo-isoprenoids results in modifications of the rubber structure and the synthesis of new material. In order to find an alternative process to recover the degradation products, a continuous extraction method using a biphasic system is described.

Steroids originating from bacterial bile acid degradation affect Caenorhabditis elegans and indicate potential risks for the fauna of manured soils.

Bile acids are steroid compounds from the digestive tracts of vertebrates that enter agricultural environments in unusual high amounts with manure. Bacteria degrading bile acids can readily be isolated from soils and waters including agricultural areas. Under laboratory conditions, these bacteria transiently release steroid compounds as degradation intermediates into the environment.

Aerobic Growth of BCP1 Using Selected Naphthenic Acids as the Sole Carbon and Energy Sources.

Naphthenic acids (NAs) are an important group of toxic organic compounds naturally occurring in hydrocarbon deposits. This work shows that BCP1 cells not only utilize a mixture of eight different NAs (8XNAs) for growth but they are also capable of marked degradation of two model NAs, cyclohexanecarboxylic acid (CHCA) and cyclopentanecarboxylic acid (CPCA) when supplied at concentrations from 50 to 500 mgL. The growth curves of BCP1 on 8XNAs, CHCA, and CPCA showed an initial lag phase not present in growth on glucose, which presumably was related to the toxic effects of NAs on the cell membrane permeability.

Functional Characterization of Three Specific Acyl-Coenzyme A Synthetases Involved in Anaerobic Cholesterol Degradation in Sterolibacterium denitrificans Chol1S.

The denitrifying betaproteobacterium Chol1S catabolizes steroids such as cholesterol via an oxygen-independent pathway. It involves enzyme reaction sequences described for aerobic cholesterol and bile acid degradation as well as enzymes uniquely found in anaerobic steroid-degrading bacteria. Recent studies provided evidence that in , the cholest-4-en-3-one intermediate is oxygen-independently oxidized to Δ-dafachronic acid (C-oic acid), which is subsequently activated by a substrate-specific acyl-coenzyme A (acyl-CoA) synthetase (ACS).

Genome Sequence of the Bile Salt-Degrading Bacterium sp. Strain Chol11, a Model Organism for Bacterial Steroid Catabolism.

Many bacteria from different phylogenetic groups are able to degrade eukaryotic steroid compounds, but the underlying metabolic pathways are still not well understood. sp. strain Chol11 is a steroid-degrading alphaproteobacterium.

The role of the two-component systems Cpx and Arc in protein alterations upon gentamicin treatment in Escherichia coli.

Background: The aminoglycoside antibiotic gentamicin was supposed to induce a crosstalk between the Cpx- and the Arc-two-component systems (TCS). Here, we investigated the physical interaction of the respective TCS components and compared the results with their respective gene expression and protein abundance. The findings were interpreted in relation to the global proteome profile upon gentamicin treatment.