Statistical method for testing the neutral mutation hypothesis by DNA polymorphism.

Value-added food: Single cell protein

Digestion of food depends on three main factors: (i) the ingested food and the extent to which the food is susceptible to the effects of digestive enzymes, (ii) the activity of the digestive enzymes and (iii) the length of time the food is exposed to the action of the digestive enzymes. Each of these factors is affected by a multitude of secondary factors. The present review highlights the experimental results on the secondary factor, enzymatic activity and possible contribution of the fish gut microbiota in nutrition. It has been suggested that fish gut microbiota might have positive effects to the digestive processes of fish, and these studies have isolated and identified the enzyme-producing microbiota. In addition to Bacillus genera, Enterobacteriaceae and Acinetobacter, Aeromonas, Flavobacterium, Photobacterium, Pseudomonas, Vibrio, Microbacterium, Micrococcus, Staphylococcus, unidentified anaerobes and yeast are also suggested to be possible contributors. However, in contrast to endothermic animals, it is difficult to conclude the exact contribution of the gastrointestinal microbiota because of the complexity and variable ecology of the digestive tract of different fish species, the presence of stomach and pyloric caeca and the relative intestinal length. The present review will critically evaluate the results to establish whether or not intestinal microbiota do contribute to fish nutrition.

Enzyme‐producing bacteria isolated from fish gut: a review

Bioactive peptides from marine processing waste and shellfish: A review

https://digital.csic.es/bitstream/10261/44879/1/Perspectives%20on%20fish%20gonadotropins%20and%20their%20receptors%20Levavi%20Sivan%20et%20al%202010%20Gen%20Comp%20Endocrinol.pdf

Perspectives on fish gonadotropins and their receptors.

Persistence of the antivibrio property of the potential antagonistic probiotics, Pseudomonas MCCB 102 and 103, at diierent temperatures, pH and in organic solvents was studied. The antivibrio compound was extracted, puri¢ed and characterized using thin-layer chromatography, high-pressure liquid chromatography, liquid chromatography-mass spectroscopy, UV^Vis and nuclear magnetic resonance spectroscopy and identi¢ed as N-methyl-1-hydroxyphenazine, a phenazine antibiotic. The toxicity of the compound was tested in Penaeus monodon haemocyte culture and the IC50 value was found to be 1.4 0.31mg L 1 . The compound was found to be bacteriostatic at 0.5 mg L 1 . Its stability to varying temperature, pH, organic solvents, prolonged shelflife and vibriostatic nature point to its suitability for prophylatic aquaculture application.

http://eprints.cmfri.org.in/5809/1/AR2.pdf

An inhibitory compound produced by Pseudomonas with effectiveness on Vibrio harveyi

Pyocyanin is a redox active phenazine pigment produced by Pseudomonas aeruginosa, with broad antibiotic activity having pharmacological, aquaculture, agriculture and industrial applications. In the present work cytotoxicity induced by pyocyanin is demonstrated in a human embryonic lung epithelial cell line (L-132), a rainbow trout gonad cell line (RTG-2) and a Spodoptera frugiperda pupal ovarian cell line (Sf9). For toxicity evaluation, cellular morphology, mitochondrial function (XTT), membrane leakage of lactate dehydrogenase, neutral red uptake, affinity of electrostatic binding of protein with sulforhodamine B dyes, glucose metabolism, and reactive oxygen species, were assessed. Results showed that higher pyocyanin concentration is required for eliciting cytotoxicity in L-132, RTG-2 and Sf9. The microscopic studies demonstrated that the cell lines exposed to pyocyanin at higher concentrations alone showed morphological changes such as clumping and necrosis. Among the three cell lines L-132 showed the highest response to pyocyanin than the others. In short, pyocyanin application at concentrations ranging from 5 to 10 mg l−1 were not having any pathological effect in eukaryotic systems and can be used as drug of choice in aquaculture against vibrios in lieu of conventional antibiotics and as biocontrol agent against fungal and bacterial pathogens in agriculture. This is besides its industrial and pharmacological applications.

Pyocyanin induced in vitro oxidative damage and its toxicity level in human, fish and insect cell lines for its selective biological applications.

Antimicrobial peptides are humoral innate immune components of molluscs that provide protection against pathogenic microorganisms. Among these, histone-H2A-derived antimicrobial peptides are known to actively participate in host defense responses of molluscs. Present study deals with identification of putative antimicrobial sequences from the histone-H2A of back-water oyster Crassostrea madrasensis, rock oyster Saccostrea cucullata, grey clam Meretrix casta, fig shell Ficus gracilis, and ribbon bullia Bullia vittata. A 75 bp fragment encoding 25 amino acid residues was amplified from cDNA of these five bivalves and was named “Molluskin.” The 25 amino acid peptide exhibited high similarity to previously reported histone-H2A-derived AMPs from invertebrates indicating the presence of an antimicrobial sequence motif. Physicochemical properties of the peptides are in agreement with the characteristic features of antimicrobial peptides, indicating their potential role in innate immunity of molluscs.

/pdf/identification-and-molecular-characterization-of-molluskin-a-rd55sykg07.pdf

Identification and Molecular Characterization of Molluskin, a Histone-H2A-Derived Antimicrobial Peptide from Molluscs.

https://dyuthi.cusat.ac.in/xmlui/bitstream/handle/purl/4049/Anti-lipopolysaccharide%20factor%20and%20crustin-III,%20the%20anti-white%20spot%20virus%20peptides%20inPenaeus%20monodon%20Control%20of%20viral%20infection%20by%20up-regulation.pdf;sequence=1

Anti-lipopolysaccharide factor and crustin-III, the anti-white spot virus peptides in Penaeus monodon: Control of viral infection by up-regulation

The immunostimulatory property of glucan isolates from three marine yeasts (Debaryomyces hansenii S8, Debaryomyces hansenii S169 and Candida tropicalis S186) and one Baker's yeast (Saccharomyces cerevisiae S36) as examined for potential application as immunostimulants in Penaeus monodon postlarvae against White Spot Syndrome Virus (WSSV) infection. Structural characterization of the glucan component in the isolates by proton nuclear magnetic resonance (NMR) indicated similar structures containing (1-3)-linked anhydroglucose repeat units (AGRUs) in the backbone with (1-6)-linked AGRUs in side chains that are (1-6)-linked to the backbone AGRUs. Glucan from C. tropicalis (S186) with the highest molecular weight and the lowest level of branching supported maximum survival (69%) followed by the other two marine yeast (S169 and S8) glucans of 27% and 23% respectively while glucan from Baker's yeast, S. cerevisiae S36 with the lowest molecular weight and the highest level of branching exhibited poor survival (4%) in P. monodon post challenge WSSV. The present study showed that the glucan isolate from marine yeast with a higher molecular weight and a lower degree of branching acts as better immunostimulants in P. monodon postlarvae than did the glucan isolate from S. cerevisiae.

Rosamma Philip

Papers

An inhibitory compound produced by Pseudomonas with effectiveness on Vibrio harveyi

Pyocyanin induced in vitro oxidative damage and its toxicity level in human, fish and insect cell lines for its selective biological applications.

Identification and Molecular Characterization of Molluskin, a Histone-H2A-Derived Antimicrobial Peptide from Molluscs.

Anti-lipopolysaccharide factor and crustin-III, the anti-white spot virus peptides in Penaeus monodon: Control of viral infection by up-regulation

Marine yeast glucans confer better protection than that of Baker's yeast in Penaeus monodon against white spot syndrome virus infection.