Dharmendra Kumar Meena

Beta-glucan: an ideal immunostimulant in aquaculture (a review)

The major hindrance in the development and sustainability of aquaculture industry is the occurrence of various diseases in the farming systems. Today, preventive and management measures are central concern to overcome such outbreak of diseases. Immunostimulants are considered as an effective tool for enhancing immune status of cultured organisms. Among different immunostimulants used in aquaculture practices, β-glucan is one of the promising immunostimulant, which is a homopolysaccharide of glucose molecule linked by the glycoside bond. It forms the major constituents of cell wall of some plants, fungi, bacteria, mushroom, yeast, and seaweeds. Major attention on β-glucan was captivated with the gain in knowledge on its receptors and the mechanism of action. The receptor present inside the animal body recognizes and binds to β-glucan, which in turn renders the animal with high resistance and enhanced immune response. This review highlights β-glucan as an immunostimulant, its effective dosages, and route of administration and furthermore provides an outline on role of β-glucan in enhancing growth, survival, and protection against infectious pathogens pertaining to fishes and shellfishes. Study also summarizes the effect of β-glucan on its receptors, recognition of proteins, immune-related enzymes, immune-related gene expression and their mechanisms of action.

Probiotics in fish and shellfish culture: immunomodulatory and ecophysiological responses

Abstract Aquaculture is emerging as one of the most viable and promising enterprises for keeping pace with the surging need for animal protein, providing nutritional and food security to humans, particularly those residing in regions where livestock is relatively scarce. With every step toward intensification of aquaculture practices, there is an increase in the stress level in the animal as well as the environment. Hence, disease outbreak is being increasingly recognized as one of the most important constraints to aquaculture production in many countries, including India. Conventionally, the disease control in aquaculture has relied on the use of chemical compounds and antibiotics. The development of non-antibiotic and environmentally friendly agents is one of the key factors for health management in aquaculture. Consequently, with the emerging need for environmentally friendly aquaculture, the use of alternatives to antibiotic growth promoters in fish nutrition is now widely accepted. In recent years, probiotics have taken center stage and are being used as an unconventional approach that has numerous beneficial effects in fish and shellfish culture: improved activity of gastrointestinal microbiota and enhanced immune status, disease resistance, survival, feed utilization and growth performance. As natural products, probiotics have much potential to increase the efficiency and sustainability of aquaculture production. Therefore, comprehensive research to fully characterize the intestinal microbiota of prominent fish species, mechanisms of action of probiotics and their effects on the intestinal ecosystem, immunity, fish health and performance is reasonable. This review highlights the classifications and applications of probiotics in aquaculture. The review also summarizes the advancement and research highlights of the probiotic status and mode of action, which are of great significance from an ecofriendly, sustainable, intensive aquaculture point of view.

Application of Probiotics in Shrimp Aquaculture: Importance, Mechanisms of Action, and Methods of Administration

ABSTRACT Shrimp aquaculture is the fastest growing animal food producing sectors in the world due to its high demand in developed countries; however, they are affected by diseases mainly caused by opportunistic pathogens results in huge economic losses. Today preventive and management measures are central concern to overcome such outbreak of diseases. The adverse effect of chemotherapeutics in shrimp farming has drawn attention for the development of non-antibiotic and environment friendly agents, which is one of the key factors for health management in shrimp aquaculture. In recent years, application of probiotics against virus and bacteria in shrimp farming had been a novel and safe approach since they promote the innate immune response. Probiotics for bacterial diseases like vibriosis is well reported, but for viral diseases, the authentic strains still need research. Apart from the discovery of new or better formulations, improvement in the probiotic benefits may be helpful. Thus, better and economic production methods, administration ways or combination with other preventive/therapeutic measures are welcomed. Further studies are still necessary to increase the knowledge about use of probiotics to control bacterial infections in shrimp but much more efforts are needed in the case of viral diseases. In this review, potential application of probiotics in shrimp aquaculture: importance, mechanisms of action and methods of administration are being focused. The article also explains the limitations and prospects of probiotics in sustainable and ecofriendly shrimp culture to augment the total shrimp aquaculture production.

Genetic differentiation in Indian Major Carp, Cirrhinus mrigala (Hamilton, 1822) from Indian Rivers, as revealed by direct sequencing analysis of mitochondrial Cytochrome b region

Abstract A 307 bp segment of Cytochrome b gene of mtDNA was sequenced and analyzed for 90 individuals of Cirrhinus mrigala collected across the three rivers, namely Ganges, Narmada and Brahmaputra. Analyses revealed the presence of 14 haplotypes with haplotype diversity (h) ranging from 0.304 to 0.692, and nucleotide diversity (π) 0.002–0.043. The majority of variation was found within the population (96.21%), and the FST value (0.035) as well as the value of exact test of population differentiation (0.893) were found to be insignificant (p < 0.05). Analysis of molecular variance (AMOVA) also indicated insignificant differentiation among sub-populations. Generally, low genetic differences were observed even though those populations were from different geographic locations. The present study suggests a single panmictic population of C. mrigala across the three rivers of India.

The population structure and genetic divergence of Labeo gonius (Hamilton, 1822) analyzed through mitochondrial DNA cytochrome b gene for conservation in Indian waters

Abstract The present study explains the population structure and genetic diversity of medium carp Labeo gonius by analyzing partial sequence of mitochondrial DNA cytochrome b gene. Labeo gonius is a lower risk Near Threatened species, distributed throughout the North Indian major rivers, reservoirs and lakes. This species has a larger scope as an alternative candidate species in carp aquaculture system. In the present investigation, 223 individuals of Labeo gonius were collected from five locations of phylo-geographically isolated riverine ecosystems of India resulted in 12 haplotypes. These haplotypes showed 14 variables, out of which 9 were singletons and 5 were parsimony informative sites of nucleotide positions. The haplotypes H1 was considered as ancestral haplotype. All the haplotypes were connected to each other by 1–4 nucleotide mutations. The Narmada haplotypes (H10; H11 and H12) were isolated from H1 by four nucleotide mutations. The analyses resulted maximum expansion events (τ = 4.13672) in Narmada, with Fst scores more than other population pairs. The analysis of molecular variance (AMOVA) showed significant genetic differentiation among populations (ØST = 0.69470, p < .000). The genetic differentiation patterns were significantly consistence with geographical distributions. This study rejected the null hypothesis of single panmictic population of medium carp, Labeo gonius in Indian water.

Population structure and genetic diversity of Indian Major Carp, Labeo rohita (Hamilton, 1822) from three phylo-geographically isolated riverine ecosystems of India as revealed by mtDNA cytochrome b region sequences

Abstract The population structure and genetic diversity of Rohu (Labeo rohita Hamilton, 1822) was studied by analysis of the partial sequences of mitochondrial DNA cytochrome b region. We examined 133 samples collected from six locations in three geographically isolated rivers of India. Analysis of 11 haplotypes showed low haplotype diversity (0.00150), nucleotide diversity (π) (0.02884) and low heterogeneity value (0.00374). Analysis of molecular variance (AMOVA) revealed the genetic diversity of L. rohita within population is very high than between the populations. The Fst scores (−0.07479 to 0.07022) were the indication of low genetic structure of L. rohita populations of three rivers of India. Conspicuously, Farakka-Bharuch population pair Fst score of 0.0000, although the sampling sites are from different rivers. The phylogenetic reconstruction of unique haplotypes revealed sharing of a single central haplotype (Hap_1) by all the six populations with a point mutations ranging from 1–25 nucleotides.

Genetic variation in wild and hatchery population of Catla catla (Hamilton, 1822) analyzed through mtDNA cytochrome b region

Abstract Catla (Catla catla) is a one of the most harvested Indian major carps and is widely cultured fish species in Indian subcontinent. In the present study, genetic variability between hatchery and wild stocks of Catla was surveyed using sequence data of mitochondrial DNA of partial 307 bp of cytochrome b region. A total of 174 Catla individuals were examined from three different river basins and hatcheries. Significant genetic heterogeneity was observed for the sequence data (FST = 0.308, p ≤ 0.001). However, analysis of molecular variance (AMOVA) resulted in insignificant genetic differentiation among the samples of three rivers and culture zones (FCT = −0.10, p = 0.44). The result suggested a significant genetic variation within different riverine system, low genetic differentiation among samples from river basins and a lack of genetic variation in hatchery populations.

Draft Genome Sequence of the Extremely Halophilic Bacterium Halomonas salina Strain CIFRI1, Isolated from the East Coast of India

ABSTRACT Halomonas salina strain CIFRI1 is an extremely salt-stress-tolerant bacterium isolated from the salt crystals of the east coast of India. Here we report the annotated 3.45-Mb draft genome sequence of strain CIFRI1 having 86 contigs with 3,139 protein coding loci, including 62 RNA genes.

Erratum for Behera et al., Draft Genome Sequence of the Extremely Halophilic Bacterium Halomonas salina Strain CIFRI1, Isolated from the East Coast of India

Volume 3, no. 1, [e01321-14][1], 2015. Page 1: The affiliation line should read as given above. [1]: /lookup/doi/10.1128/genomeA.01321-14