Enterocin DD14 can inhibit the infection of eukaryotic cells with enveloped viruses.

Bacteriocins are ribosomally synthesized bacterial peptides endowed with antibacterial, antiprotozoal, anticancer and antiviral activities. In the present study, we evaluated the antiviral activities of two bacteriocins, enterocin DD14 (EntDD14) and lacticaseicin 30, against herpes simplex virus type 1 (HSV-1), human coronavirus 229E (HCoV-229E) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Vero, Huh7 and Vero E6 cells, respectively. In addition, the interactions of these bacteriocins with the envelope glycoprotein D of HSV-1 and the receptor binding domains of HCoV-229E and SARS-CoV-2 have been computationally evaluated using protein-protein docking and molecular dynamics simulations.

Lipopeptide culture filtrates from Bacillus spp. provide effective protection to wheat against the foliar pathogen Zymoseptoria tritici.

Aims: Biocontrol products based on microorganisms and natural substances are promising alternatives to chemical pesticides that could contribute to develop a more sustainable agriculture. Here, we investigated the potential of cell-free culture filtrates (CFCFs) from two strains of the Bacillus subtilis group to inhibit Zymoseptoria tritici, a major fungal pathogen of wheat.

Methods And Results: Foliar application of CFCFs from Bacillus velezensis GA1 and Bacillus sp.

The Diversity of Lipopeptides in the Pseudomonas syringae Complex Parallels Phylogeny and Sheds Light on Structural Diversification during Evolutionary History.

Pseudomonas spp. colonize diverse aquatic and terrestrial habitats and produce a wide variety of secondary metabolites, including lipopeptides. However, previous studies have often examined a limited number of lipopeptide-producing strains.

Rhamnolipids and fengycins, very promising amphiphilic antifungal compounds from bacteria secretomes, act on fungi through different mechanisms.

Rhamnolipids (RLs) and fengycins (FGs) are amphiphilic lipid compounds from bacteria secretomes proposed to replace synthetic pesticides for crop protection. They both display plant defense triggering properties and direct antimicrobial activities. In particular, they have well reported antifungal effects against phytopathogenic fungi.

Bio-emulsifying and biodegradation activities of syringafactin producing Pseudomonas spp. strains isolated from oil contaminated soils.

Pseudomonas strains isolated from oil contaminated soils were screened for biosurfactant production. Three out of eleven Pseudomonas isolates were selected for their high emulsifying activity (E24 value on n-hexadecane ~ 78%). These isolates (E39, E311 and E313) were identified as members of the P.

Microbial lipopeptide production and purification bioprocesses, current progress and future challenges.

Lipopeoptides are amphiphilic compounds combining interesting physicochemical properties and biological activities. Due to their high foaming capacity in aerated bioreactor, the development of scalable bioprocesses for their production is a major bottleneck. In addition, the genes involved in the biosynthesis of these lipopeptides are mainly regulated by the quorum sensing, a global regulatory mechanism depending on cell density and known to be activated in biofilms.

High-throughput strategies for the discovery and engineering of enzymes for biocatalysis.

Innovations in novel enzyme discoveries impact upon a wide range of industries for which biocatalysis and biotransformations represent a great challenge, i.e., food industry, polymers and chemical industry.

The Tunisian oasis ecosystem is a source of antagonistic Bacillus spp. producing diverse antifungal lipopeptides.

The use of microbial products has become a promising alternative approach to controlling plant diseases caused by phytopathogenic fungi. Bacteria isolated from the date palm tree rhizosphere of the Tunisian oasis ecosystem could provide new biocontrol microorganisms adapted to extreme conditions, such as drought, salinity and high temperature. The aim of this study was to screen bacteria isolated from the rhizosphere of the date palm tree for their ability to inhibit phytopathogenic fungi, and to identify molecules responsible for their antifungal activity.

Controlled Enzymatic Hydrolysis: A New Strategy for the Discovery of Antimicrobial Peptides.

The use of antimicrobial peptides (AMPs) is an alternative to traditional antibiotics. AMPs are obtained using different methods such as bacterial synthesis, chemical synthesis and controlled enzymatic hydrolysis. The later is an interesting approach that deserves our attention because of the yields gathered and peptides engineered.

Adsorption of surfactin produced from Bacillus subtilis using nonwoven PET (polyethylene terephthalate) fibrous membranes functionalized with chitosan.

This article deals with an alternative method for bio-separation of surfactin produced by Bacillus subtilis using sorption method on nonwoven PET (polyethylene terephthalate) fibrous membranes functionalized with chitosan. In the first part of the study, surface functionalization of the PET nonwoven fibrous membranes is carried out with aqueous 65% deacetylated chitosan solution with or without a prior surface activation using air-atmospheric plasma treatment. Very small modification of the PET fibrous nonwoven air-permeability confirms the functionalization of PET fibre surface with little reduction of membrane porosity.

Production of surfactin and fengycin by Bacillus subtilis in a bubbleless membrane bioreactor.

Surfactin and fengycin are lipopeptide biosurfactants produced by Bacillus subtilis. This work describes for the first time the use of bubbleless bioreactors for the production of these lipopeptides by B. subtilis ATCC 21332 with aeration by a hollow fiber membrane air-liquid contactor to prevent foam formation.

Effect of pps disruption and constitutive expression of srfA on surfactin productivity, spreading and antagonistic properties of Bacillus subtilis 168 derivatives.

Aims: To analyse the effects of plipastatin operon disruption and constitutive expression of surfactin operon in Bacillus subtilis 168 on surfactin productivity, in vitro invasive growth and antagonism against fungi.

Methods And Results: The srfA native promoter was replaced by the constitutive promoter P(repU) in B. subtilis 168 after integration of a functional sfp gene.

Ion-pairing separation of bioactive peptides using an aqueous/octan-1-ol micro-extraction system from bovine haemoglobin complex hydrolysates.

The ion-pair concept was applied on complex haemoglobin hydrolysates to extract two opioid peptides, LVV-haemorphin-7 and VV-haemorphin-7, in an aqueous/octan-1-ol micro-extraction system in the presence of alkyl-sulfonic acid as a surfactant agent and in relation to the haemorphin physico-chemical properties (charge, hydrophobicity). The effect of combined alkyl chain length/aqueous phase pH and the haem behaviour during the extraction, on the haemorphin recovery yield and enrichment has been determined. It has proved that transport over the organic phase is mediated by the alkyl-sulfonic acids, whatever be the aqueous phase pH.

The mineralization of 5-amino-2,4,6-triiodoisophthalic acid by a two-stage fixed-bed reactor.

Iodinated X-ray contrast media have been detected in hospital effluent, sewage treatment plant effluent, rivers and groundwater aquifers. No process has been developed to remove triiodinated aromatic molecules. In this paper, we present a biological sequential process using an anaerobic fixed-bed reactor coupled in series with an aerobic fixed-bed reactor for degrading 5-amino-2,4,6-triiodoisophthalic acid (ATIA), the core structure of a X-ray contrast media family.

An on-line technique for monitoring propionic acid fermentation.

An on-line technique, based on measuring the increase in pressure due to CO(2) release in a closed air-tight reactor, was used to evaluate the fermentation of lactate by propionibacteria. The method was applied to batch cultures of Propionibacterium shermanii grown in yeast extract/sodium lactate medium containing lactate as a carbon source under micro-aerophilic conditions. Gas pressure evolution was compared both with substrate consumption and metabolites production and with acidification and growth.

Adhesion of a Pseudomonas putida strain isolated from a paper machine to cellulose fibres.

The adhesion to cellulose fibres of a strain of Pseudomonas putida isolated from a paper machine was studied under different environmental conditions. The physicochemical properties of both P. putida cells and cellulose fibres were also determined to better understand the adhesion phenomenon.

Enrichment and properties of an anaerobic mixed culture that reductively deiodinates 5-amino-2,4,6-triiodoisophthalic acid, an X-ray contrast agent precursor.

5-Amino-2,4,6-triiodoisophthalic acid (ATIA), both a precursor and a degradative intermediate of triiodinated contrast media, was anaerobically converted by sludge from a wastewater treatment plant. ATIA conversion took place only when an electron donor such as ethanol was added. A stable mixed culture was established by transfer to a defined synthetic mineral medium with ATIA and ethanol.

Phylogenetic analysis of an anaerobic microbial consortium deiodinating 5-amino-2,4,6-triiodoisophthalic acid.

The dehalogenating performance of an anaerobic 5-amino-2,4,6-triiodoisophthalic acid (ATIA) fixed-bed reactor was evaluated. The reactor operating conditions were set for ATIA deiodination. A phylogenetic survey for a stable anaerobic ATIA-deiodinating microbial consortium was carried out using 16S rDNA restriction fragment length polymorphism, and unique clones were sequenced.