Hypobaric-hypoxia Induces Alteration in Microbes and Microbes-associated Enzyme Profile in Rat Colonic Samples

Present study deals with the straight impact of hypobaric hypoxia on the quantity and composition of some predominant fecal microflora and its functional aspects. For that, isolated fecal contents of rat were exposed to two different simulated air pressures （70 kPa and 40 kPa） for different time durations （1, 3, and 5 h） and the bacterial community composition was compared with normobaric groups （101.3 kPa）. It was found that the total anaerobes, Escherichio coli, Enterbocters spp., Bi^idobocterium spp., CIostridium spp. were increased whereas total aerobes were decreased at both hypobaric treatments. The increased number of amplicon was detected in the pressure-treated groups than the control that clearly mentioned the disruption of microbiota structure at different simulated hypobaric-hypoxia. The amylase, protease, tannase, 13-glucuronidase, and alkaline phosphatase activities were increased at these atmospheric pressures. Thus, the present investigation demonstrates that the hypobaric hypoxia is an important environmental factor which can strongly modulate the composition of intestinal flora as well as microfiora-derived functional aspects.

The curative effect of fucoidan on visceral leishmaniasis is mediated by activation of MAP kinases through specific protein kinase C isoforms

Fucoidan can cure both antimony-sensitive and antimony-resistant visceral leishmaniasis through immune activation. However, the signaling events underlying this cellular response remain uncharacterized. The present study reveals that fucoidan induces activation of p38 and ERKI/2 and NF-κB DNA binding in both normal and Leishmania donovani.infected macrophages, as revealed by western blotting and electrophoretic mobility shift assay （EMSA）, respectively. Pharmacological inhibition of p38, ERKI/2 or the NF-κB pathway markedly attenuated fucoidan-induced pro-inflammatory cytokine synthesis and inducible nitric oxide synthase （iNOS） gene transcription, resulting in a reduction of parasite clearance. To decipher the underlying mechanism of fucoidan-mediated parasite suppression, the expression and functionality of various protein kinase C （PKC） isoforms were evaluated by immunoblotting and enzyme activity assay. Fucoidan elicited an increase in expression and activity of PKC-α, -β1 and -βⅡ isoforms in infected macrophages. Functional knockdown of PKC-α and -β resulted in downregulation of p38 and ERKI/2, along with a marked reduction of IL-12 and TNF-α production in fucoidan-treated infected macrophages. Collectively, these results suggest that the curative effect of fucoidan is mediated by PKC-dependent activation of the mitogen-activated protein kinase （MAPK）/NF-κB pathway, which ultimately results in the production of nitric oxide （NO） and disease-resolving pro-inflammatory cytokines.

Pathogenicity of Vibrio harveyi and its biocontrol using bacteriophages

Vibrio harveyi is a Gram-negative,rod-shaped,polar flagellate,facultatively anaerobic,halophilic,bioluminescent marine bacteria that belongs to the family of Vibrionaceae,class,Gammaproteobacteria.This pathogenic organism is responsible for various diseases of vertebrates and invertebrates in marine habitats,including shrimp aquaculture.Various symptoms like lesions,gastroenteritis,skin ulcers,eye lesions,and tail rot have been observed due to V.harveyi infection.The pathogenic-ity mechanism of V.harveyi involves endotoxin lipopolysaccharide,extracellular proteases,and bacteriophage interaction.Hemolysin genes encoded extracellular hemolysin-like phospholipase B toxin could inactivate fish species via the caspase inactivation pathway,ultimately leading to apoptosis.In addition,VBNC(viable but nonculturable)cells are another basis of vibriosis outbreaks in the shrimp aquaculture sector.The extensive amount of antibiotic use promotes the generation of multidrug-resistant strains.Therefore,as an alternative strategy to combat V.harveyi infection,bacteriophages are utilized as a biocontrol agent.However,there is a lack of research on the immobilization and development of encapsulation strategies of V.harveyi-infecting bacteriophages which need to be studied further.In conclusion,the pathogenicity of V.harveyi and its biocontrol by bacteriophages has been documented in this review.

Preparation of rice fermented food using root of Asparagus racemosus as herbal starter and assessment of its nutrient profle

The popularity of traditional fermented food products is based on their healthiness.The addition of a starter brings consistent,desirable,and predictable food changes with improved nutritive,functional,and sensory qualities.The addition of a mixture of plant residues as a starter or source of microbes is an age-old practice to prepare traditional fermented food and beverages,and most of the reported data on traditional foods were based on the analysis of the fnal product.The contribution of an individual starter component(plant residue)is not experimentally substantiated for any traditional fermented food,but this data are very essential for the formulation of an efective starter.In this study,Asparagus racemosus,which used as a common ingredient of starter for preparation of rice fermented food in the Indian sub-continent,was used as a starter for the preparation of rice fermented food under laboratory scale,and its microbial and nutrient profle was evaluated.The fermented product was a good source of lactic acid bacteria,Bifdobacterium sp.,yeast,etc.The food product was acidic and enriched with lactic acid and acetic acid with titratable acidity of 0.65%.The content of protein,fat,minerals,and vitamins(water-soluble)was considerably improved.Most notably,oligosaccharide(G3-matotriose),unsaturated fatty acids(ω3,ω6,ω7,andω9),and a pool of essential and non-essential amino acids were enriched in the newly formulated food.Thus,the herbal starter-based rice fermented food would provide important macro-and micronutrients.They could also deliver large numbers of active microorganisms for the sustainability of health.Therefore,the selected plant part conferred its suitability as an efective starter for the preparation of healthier rice-based food products.