Bacteriocin as Weapons in the Marine Animal-Associated Bacteria Warfare: Inventory and Potential Applications as an Aquaculture Probiotic

As the association of marine animals with bacteria has become more commonly recognized, researchers have increasingly questioned whether these animals actually produce many of the bioactive compounds originally isolated from them. Bacteriocins, ribosomally synthesized antibiotic peptides, constitute one of the most potent weapons to fight against pathogen infections. Indeed, bacteriocinogenic bacteria may prevent pathogen dissemination by occupying the same ecological niche. Bacteriocinogenic strains associated with marine animals are a relevant source for isolation of probiotics. This review draws up an inventory of the marine bacteriocinogenic strains isolated from animal-associated microbial communities, known to date. Bacteriocin-like inhibitory substances (BLIS) and fully-characterized bacteriocins are described. Finally, their applications as probiotics in aquaculture are discussed

Characterisation of the Fish Producing and Fish Processing Sectors in Mauritius

Since a few years, there is a focus on the expansion of the fish industry in Mauritius in view of its contribution in boosting the economic situation of the country. This study was undertaken to characterise the two main sub-sectors of this industry namely the fish producing and fish processing sectors. A survey was carried out in two phases: a desk review to identify the relevant companies and a mail survey to obtain the requisite details about them to enable their characterisation. The survey findings reveal that there are 14 fishing, 10 fish processing, 1 fish farming companies in Mauritius and 1 which is involved in both fishing and processing activities. Various other features like their number of employees, annual turnover, nature of activities (fishing or fish processing), market (local or overseas), state (chilled or frozen) in which the fish is sold and the range of fish products manufactured were determined. The companies were also classified in terms of ‘small’, ‘medium’ and ‘large’ based on their annual turnover. This preliminary survey provides essential background information for wider national surveys to be carried out.Keywords: fish industry, characterisation, survey, seafood hu

Ruminococcin A, a New Lantibiotic Produced by a Ruminococcus gnavus Strain Isolated from Human Feces

When cultivated in the presence of trypsin, the Ruminococcus gnavus E1 strain, isolated from a human fecal sample, was able to produce an antibacterial substance that accumulated in the supernatant. This substance, called ruminococcin A, was purified to homogeneity by reverse-phase chromatography. It was shown to be a 2,675-Da bacteriocin harboring a lanthionine structure. The utilization of Edman degradation and tandem mass spectrometry techniques, followed by DNA sequencing of part of the structural gene, allowed the identification of 21 amino acid residues. Similarity to other bacteriocins present in sequence libraries strongly suggested that ruminococcin A belonged to class IIA of the lantibiotics. The purified ruminococcin A was active against various pathogenic clostridia and bacteria phylogenetically related to R. gnavus. This is the first report on the characterization of a bacteriocin produced by a strictly anaerobic bacterium from human fecal microbiota