Unravelling the secondary metabolome and biocontrol potential of the recently described species Bacillus nakamurai.

In the prospect of novel potential biocontrol agents, a new strain BDI-IS1 belonging to the recently described Bacillus nakamurai was selected for its strong in vitro antimicrobial activities against a range of bacterial and fungal phytopathogens. Genome mining coupled with metabolomics revealed that BDI-IS1 produces multiple non-ribosomal secondary metabolites including surfactin, iturin A, bacillaene, bacillibactin and bacilysin, together with some some ribosomally-synthesized and post-translationally modified peptides (RiPPs) such as plantazolicin, and potentially amylocyclicin, bacinapeptin and LCI. Reverse genetics further showed the specific involvement of some of these compounds in the antagonistic activity of the strain.

Characterization of Bacillus velezensis 32a metabolites and their synergistic bioactivity against crown gall disease.

Crown gall disease caused by Agrobacterium tumefaciens is considered to be the main bacterial threat of stone fruit plants in Mediterranean countries. In a previous study, Bacillus velezensis strain 32a was isolated from Tunisian rhizosphere soil and revealed high antagonistic potential against A. tumefaciens strains.

Pectic homogalacturonan sensed by acts as host associated cue to promote establishment and persistence in the rhizosphere.

isolates are among the most promising plant-associated beneficial bacteria used as biocontrol agents. However, various aspects of the chemical communication between the plant and these beneficials, determining root colonization ability, remain poorly described. Here we investigated the molecular basis of such interkingdom interaction occurring upon contact between and its host via the sensing of pectin backbone homogalacturonan (HG).

Plant-associated Bacillus mobilizes its secondary metabolites upon perception of the siderophore pyochelin produced by a Pseudomonas competitor.

Bacillus velezensis is considered as model species for plant-associated bacilli providing benefits to its host such as protection against phytopathogens. This is mainly due to the potential to secrete a wide range of secondary metabolites with specific and complementary bioactivities. This metabolite arsenal has been quite well defined genetically and chemically but much remains to be explored regarding how it is expressed under natural conditions and notably how it can be modulated upon interspecies interactions in the competitive rhizosphere niche.

Role of Dissimilative Pathway of (): Formaldehyde Toxicity and Energy Metabolism.

(aka ) is a yeast able to grow in methanol as the sole carbon and energy source. This substrate is converted into formaldehyde, a toxic intermediary that can either be assimilated to biomass or dissimilated to CO through the enzymes formaldehyde dehydrogenase (FLD) and formate dehydrogenase, also producing energy in the form of NADH. The dissimilative pathway has been described as an energy producing and a detoxifying route, but conclusive evidence has not been provided for this.

Coculture of and Based on Metabolic Cross-Feeding Modulates Lipopeptide Production.

Cocultures have been widely explored for their use in deciphering microbial interaction and its impact on the metabolisms of the interacting microorganisms. In this work, we investigate, in different liquid coculture conditions, the compatibility of two microorganisms with the potential for the biocontrol of plant diseases: the fungus IHEM5437 and the bacterium GA1 (a strong antifungal lipopeptide producing strain). While the overgrew the in a rich medium due to its antifungal lipopeptide production, a drastically different trend was observed in a medium in which a nitrogen nutritional dependency was imposed.

Lipopeptide Interplay Mediates Molecular Interactions between Soil Bacilli and Pseudomonads.

Some species, such as B. velezensis, are important members of the plant-associated microbiome, conferring protection against phytopathogens. However, our knowledge about multitrophic interactions determining the ecological fitness of these biocontrol bacteria in the competitive rhizosphere niche is still limited.

Surfactin Stimulated by Pectin Molecular Patterns and Root Exudates Acts as a Key Driver of the -Plant Mutualistic Interaction.

Bacillus velezensis is considered as a model species belonging to the so-called Bacillus subtilis complex that evolved typically to dwell in the soil rhizosphere niche and establish an intimate association with plant roots. This bacterium provides protection to its natural host against diseases and represents one of the most promising biocontrol agents. However, the molecular basis of the cross talk that this bacterium establishes with its natural host has been poorly investigated.

Impact of oxygen availability on heterologous geneexpression and polypeptide secretion dynamics in Yarrowia lipolytica-based protein production platforms.

Industrially relevant traits of Yarrowia lipolytica, like high growth rate, capacity to grow at high cell density or to synthesize biomolecules with high productivities, strongly rely on sufficient oxygen provision. Although the impact of oxygen availability (OA) on the physiology of Y. lipolytica has been already studied, its influence on recombinant protein (rProt) synthesis and secretion has been largely neglected to date.

Comprehensive comparison of Yarrowia lipolytica and Pichia pastoris for production of Candida antarctica lipase B.

The large-scale production of recombinant proteins (rProt) is becoming increasingly economically important. Among the different hosts used for rProt production, yeasts are gaining popularity. The so-called non-conventional yeasts, such as the methylotrophic Pichia pastoris and the dimorphic Yarrowia lipolytica, are popular choices due to their favorable characteristics and well-established expression systems.

In Yarrowia lipolytica erythritol catabolism ends with erythrose phosphate.

In response to osmotic stress, the yeast Yarrowia lipolytica produces erythritol, a four-carbon sugar alcohol, from erythrose-P, an intermediate of the pentose phosphate pathway. Under non-stressing conditions (isotonic environment), the produced erythritol is subsequently recycled into erythrose-P that can feed the pentose phosphate pathway. Herein, gene YALI0F01584g was characterized as involved in the erythritol catabolic pathway.

Expression of recombinant enhanced green fluorescent protein provides insight into foreign gene-expression differences between Mut+ and MutS strains of Pichia pastoris.

Pichia pastoris is a very popular yeast for recombinant protein production, mainly due to the strong, methanol-inducible P promoter. Methanol induction however poses several drawbacks. One approach to improve processes is to use MutS strains with reduced methanol catabolic ability.

Identification and characterization of EYD1, encoding an erythritol dehydrogenase in Yarrowia lipolytica and its application to bioconvert erythritol into erythrulose.

In this study, gene YALI0F01650g has been isolated and characterized. Several experimental evidences suggest that the identified gene, renamed EYD1, encodes an erythritol dehydrogenase. An efficient bioreactor process for the bioconversion of erythritol into erythrulose was also developed.

Stimulation of Fengycin-Type Antifungal Lipopeptides in in the Presence of the Maize Fungal Pathogen .

Most isolates belonging to the subsp. clade retain the potential to produce a vast array of structurally diverse antimicrobial compounds that largely contribute to their efficacy as biocontrol agents against numerous plant fungal pathogens. In that context, the role of cyclic lipopeptides (CLPs) has been well-documented but still little is known about the impact of interactions with other soil-inhabiting microbes on the expression of these molecules.

Enhancing erythritol productivity in Yarrowia lipolytica using metabolic engineering.

Erythritol (1,2,3,4-butanetetrol) is a four-carbon sugar alcohol with sweetening properties that is used by the agrofood industry as a food additive. In this study, we demonstrated that metabolic engineering can be used to improve the production of erythritol from glycerol in the yeast Yarrowia lipolytica. The best results were obtained using a mutant that overexpressed GUT1 and TKL1, which encode a glycerol kinase and a transketolase, respectively, and in which EYK1, which encodes erythrulose kinase, was disrupted; the latter enzyme is involved in an early step of erythritol catabolism.

Key Impact of an Uncommon Plasmid on subsp. S499 Developmental Traits and Lipopeptide Production.

The rhizobacterium subsp. S499 (S499) is particularly efficient in terms of the production of cyclic lipopeptides, which are responsible for the high level of plant disease protection provided by this strain. Sequencing of the S499 genome has highlighted genetic differences and similarities with the closely related rhizobacterium subsp.

Deciphering how LIP2 and POX2 promoters can optimally regulate recombinant protein production in the yeast Yarrowia lipolytica.

Background: In recent years, the non-conventional model yeast species Yarrowia lipolytica has received much attention because it is a useful cell factory for producing recombinant proteins. In this species, expression vectors involving LIP2 and POX2 promoters have been developed and used successfully for protein production at yields similar to or even higher than those of other cell factories, such as Pichia pastoris. However, production processes involving these promoters can be difficult to manage, especially if carried out at large scales in fed-batch bioreactors, because they require hydrophobic inducers, such as oleic acid or methyl oleate.

Identification and characterization of a halotolerant, cold-active marine endo-β-1,4-glucanase by using functional metagenomics of seaweed-associated microbiota.

A metagenomic library was constructed from microorganisms associated with the brown alga Ascophyllum nodosum. Functional screening of this library revealed 13 novel putative esterase loci and two glycoside hydrolase loci. Sequence and gene cluster analysis showed the wide diversity of the identified enzymes and gave an idea of the microbial populations present during the sample collection period.

Bacillus subtilis as a tool for screening soil metagenomic libraries for antimicrobial activities.

Finding new antimicrobial activities by functional metagenomics has been shown to depend on the heterologous host used to express the foreign DNA. Therefore, efforts are devoted to developing new tools for constructing metagenomic libraries in shuttle vectors replicatable in phylogenetically distinct hosts. Here we evaluated the use of the Escherichia coli-Bacillus subtilis shuttle vector pHT01 to construct a forest-soil metagenomic library.