Research Publications (Food Safety)

Prodiginines are a large family of microbial secondary metabolites with a core structure of tripyrrole rings. They exhibit not only diverse chemical structures but also rich biological activities, such as anti-cancer, anti-microbial, anti-algae, anti-parasitic, pesticides, and UV radiation resistance.

Cadmium (Cd2+) and copper (Cu2+) are considered immunotoxic metals and their presence in combination in the aquatic environment may cause effects on shrimp species as Litopenaeus vannamei. Thus, this research evaluates the combined effects of Cd2+ and Cu2+ on shrimp inoculated with Vibrio harveyi bacteria. The experiments were performed at 96-hours of exposure to sublethal concentrations of both metals.

Purpose It is unknown how the Cd-mediated changes in the rhizospheric nitrifier community affect plant growth under different water management practices.

Fish gut microbiota, encompassing a colossal reserve of microbes represents a dynamic ecosystem, influenced by a myriad of environmental and host factors. The current study presents a comprehensive insight into Sardinella longiceps gut microbiome using whole metagenome shotgun sequencing. Taxonomic profiling identified the predominance of phylum Proteobacteria, comprising of Photobacterium, Vibrio and Shewanella sp.

The importance of beef production for economy of Brazil and the growing demand for animal protein across the globe warrant an improvement in the beef production system. Although most attention has been on modulation of the rumen microbiome to improve ruminant production, the role of the lower gut microbiome in host health and nutrition remains relatively unexplored.

Acute hepatopancreatic necrosis disease (AHPND), caused by PirAvp- and PirBvp-releasing Vibrio parahaemolyticus strains, has resulted in massive mortality in shrimp aquaculture. Excessive use of antibiotics for AHPND management has led to antibiotic resistance, highlighting the urgency to search for alternatives. Using an in silico approach, we aimed to discover PirAvp/PirBvp-binding peptides from oilseed meals as alternatives to antibiotics.

The genome of Vibrio cholerae contains three structural genes for the NhaP-type cation-proton antiporter paralogues, Vc-NhaP1, Vc-NhaP2, and Vc-NhaP3, mediating exchange of K+ and or Na+ for protons across the membrane.

The discharge of untreated hospital and domestic wastewater into receiving water bodies is still a prevalent practice in developing countries.

The concurrence of structurally complex petroleum-associated contaminants at relatively high concentrations, with diverse climatic conditions and textural soil characteristics, hinders conventional bioremediation processes. Recalcitrant compounds such as high molecular weight polycyclic aromatic hydrocarbons (HMW-PAHs) and heavy alkanes commonly remain after standard soil bioremediation at concentrations above regulatory limits.

Coastal areas impacted by high anthropogenic pressures typically display sediment contamination by polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs). Microbial-based bioremediation represents a promising strategy for sediment reclamation, yet it frequently fails due to poor knowledge of the diversity and dynamics of the autochthonous microbial assemblages and to the inhibition of the target microbes in the contaminated matrix.

Amphiphilic siderophores including amphibactins are the most abundant siderophores in oceans. Genes putatively encoding the amphibactin system were proposed in some bacteria and homologues of these genes are particulary abundant in multiple bacterial lineages inhabitant of low‐iron seawater. However, since no defective mutant strains in any of these genes were studied to date, their role in amphibactin synthesis or uptake were not demonstrated.

Microorganisms are key players in the transformation of mercury into neurotoxic methylmercury (MeHg). Nevertheless, this mechanism and the opposite MeHg demethylation remain poorly understood.

Previous studies proved that heavy metals could increase the risk of disease by acting on the gut microbiota. Meanwhile, gut microbiota played important roles in detoxifying heavy metals. However, the response of gut microbiota to heavy metals and which microbes dominated this detoxification processes are still unclear.

Significance and Impact of the Study: Vibrio harveyi is a major pathogen of marine animals. The bacterium could enter into a viable but non‐culturable state (VBNC) state when exposed to harsh conditions, and retains its pathogenicity after resuscitation. In this work, we analysed the enzyme activities of a resuscitation‐promoting factor YeaZ and the relationship of protease activities with its promoting effect on the resuscitation of VBNC cells.

Microbial production of the neurotoxin methylmercury (MeHg) is a significant health and environmental concern, as it can bioaccumulate and biomagnify in the food web. A chalkophore or a copper-binding compound, termed methanobactin (MB), has been shown to form strong complexes with mercury [as Hg(II)] and also enables some methanotrophs to degrade MeHg. It is unknown, however, if Hg(II) binding with MB can also impede Hg(II) methylation by other microbes.

ICEpMERPH, the first integrative conjugative element (ICE) of the SXT/R391 familyisolated in the United Kingdom and Europe, was analyzed to determine the nature of its adaptivefunctions, its genetic structure, and its homology to related elements normally found in pathogenicVibrio or Proteus species. Whole genome sequencing of Escherichia coli (E. coli) isolate K802 (whichcontains the ICEpMERPH) was carried out using Illumina sequencing technology.

Author(s): Marisol Goni-Urriza, Christophe Klopp, Magali Ranchou-Peyruse, Anthony Ranchou-Peyruse, Mathilde Monperrus, Bahia Khalfaoui-Hassani, Rémy Guyoneaud

Author(s): Shenyuan He, Xueyi Li, Cuiqin Li, Hong Deng, Yuyu Shao, Li Yuan

Available online 10 July 2019

Author(s): Nguyen Thi Phuong Yen, Nguyen Thi Nhung, Nguyen Thi Bich Van, Nguyen Van Cuong, Le Tran Tien Chau, Huynh Ngoc Trinh, Chu Van Tuat, Nguyen Dong Tu, Nguyen Phu Huong Lan, James Campbell, Guy Thwaites, Stephen Baker, Juan Carrique-Mas

Methylmercury (MeHg) is a potent bioaccumulative neurotoxin that is produced by certain anaerobic bacteria and archaea. Mercury (Hg) methylation has been linked to the gene pair hgcAB, which encodes a membrane-associated corrinoid protein and a ferredoxin. Although microbial Hg methylation has been characterized in vivo, the cellular biochemistry and the specific roles of the gene products HgcA and HgcB in Hg methylation are not well understood.

Aquatic environments are reservoirs of the human pathogen Vibrio cholerae O1, which causes the acute diarrheal disease cholera. Upon low temperature or limited nutrient availability, the cells enter a viable but non-culturable (VBNC) state. Characteristic of this state are an altered morphology, low metabolic activity, and lack of growth under standard laboratory conditions. Here, for the first time, the cellular ultrastructure of V.

Plesiomonas shigelloides is a Gram-negative, flagellated, rod-shaped, ubiquitous, and facultative anaerobic bacterium. It has been isolated from various sources, such as freshwater, surface water, and many wild and domestic animals. P. shigelloides is associated with diarrheal diseases of acute secretory gastroenteritis, an invasive shigellosis-like disease, and a cholera-like illness in humans. At present, 102 somatic antigens and 51 flagellar antigens of P.

Abstract

Na+-translocating NADH:quinone oxidoreductase (Na+-NQR) catalyzes electron transfer from NADH to ubiquinone in the bacterial respiratory chain, coupled with Na+ translocation across the membrane. Na+-NQR maturation involves covalent attachment of FMN residues, catalyzed by flavin transferase encoded by the nqr-associated apbE gene.