Probiotics and Antimicrobial Proteins, May 23, 2013
Hepcidin is a family of short cysteine-rich antimicrobial peptides (AMPs) participating in variou... more Hepcidin is a family of short cysteine-rich antimicrobial peptides (AMPs) participating in various physiological functions with inevitable role in host immune responses. Present study deals with identification and characterisation of a novel hepcidin isoform from coral fish Zanclus cornutus. The 81 amino acid (aa) preprohepcidin obtained from Z. cornutus consists of a hydrophobic aa rich 22 mer signal peptide, a highly variable proregion of 35 aa and a bioactive mature peptide with 8 conserved cysteine residues which contribute to the disulphide back bone. The mature hepcidin, Zc-hepc1 has a theoretical isoelectric point of 7.46, a predicted molecular weight of 2.43 kDa and a net positive charge of ?1. Phylogenetic analysis grouped Z. cornutus hepcidin with HAMP2 group hepcidins confirming the divergent evolution of hepcidin-like peptide in fishes. Zc-hepc1 can attain a b-hairpin-like structure with two antiparallel b-sheets. This is the first report of an AMP from the coral fish Z. cornutus.
International Journal of Current Microbiology and Applied Sciences, Jan 10, 2018
Pseudomonas aeruginosa MCCB 123 is a potent producer of enzymes such as β-1,3 glucanase, LasA and... more Pseudomonas aeruginosa MCCB 123 is a potent producer of enzymes such as β-1,3 glucanase, LasA and LasB proteases, which have been identified to have greater significance in the biotechnology sector. However, pathogenicity assessment of bacteria is essential for its industrial survival. Pathogenicity was assessed by a panel of virulence assays such as the presence of type III secretion toxin genes, motility assays, biofilm formation, adhesion and invasion assays on Hep-2 and HeLa monolayers and antibiogram profiling. Analysis of the major cytotoxic exoU gene revealed the absence of the gene, thus confirms the non-cytotoxic phenotype of the bacterium. P. aeruginosa exhibited three types of motilities viz., swimming, swarming and twitching motilities and proved to be a moderate biofilm producer with a 3.10±0.52-fold increase in the optical density at Abs 570 when compared to control. Antibiogram suggested the possibility of antibiotic treatment as an effective method for eradication of its biofilm. The non-pathogenic nature of the bacterium suggests industrially viability of this organism for the production of biotechnological relevant enzymes.
Biochar production from biomass is a globally adopted strategy for carbon sequestration and also ... more Biochar production from biomass is a globally adopted strategy for carbon sequestration and also for integrated agricultural applications. In the present study biochar was produced at 600 o C by slow pyrolysis of lignocellulosic agro industrial residue coir pith. Chemical and structural transformation of coir pith happened due to pyrolysis process. Changes in cellulose crystallinity was analysed by XRD and FTIR method. XRD analysis indicates cellulose crystallinity index change. FTIR analysis shows several characteristic peak changes indicating structural transformations of cellulosic components.
Journal of Genetic Engineering and Biotechnology, Mar 28, 2022
Background: Increase of antibiotic resistance in pathogenic microbes necessitated novel molecules... more Background: Increase of antibiotic resistance in pathogenic microbes necessitated novel molecules for curing infection. Antimicrobial peptides (AMPs) are the gene-encoded evolutionarily conserved small molecules with therapeutic value. AMPs are considered as an alternative drug for conventional antibiotics. Hepcidin, the cysteinerich antimicrobial peptide, is an important component in innate immune response. In this study, we identified and characterized hepcidin gene from the fish, Catla catla (Indian major carp) and termed it as Cc-Hep. Open reading frame of Cc-Hep consists of 261 base pair that encodes 87 amino acids. Cc-Hep is synthesized as a prepropeptide consisting of 24 amino acid signal peptide, 36 amino acid propeptide, and 26 amino acid mature peptide. Sequence analysis revealed that Cc-Hep shared sequence similarity with hepcidin from Sorsogona tuberculata. Phylogenetic analysis indicated that Cc-Hep was grouped with HAMP2 family. Structure analysis of mature Cc-Hep identified two antiparallel beta sheets stabilized by four disulphide bonds and a random coil. The mature peptide region of Cc-Hep has a charge of + 2, isoelectric value 8.23 and molecular weight 2.73 kDa. Functional characterization predicted antibacterial, antioxidant, and anticancer potential of Cc-Hep, which can be explored in aquaculture or human health care.
Significance and Impact of the Study: In sustainable aquaculture, application of antibiotics is p... more Significance and Impact of the Study: In sustainable aquaculture, application of antibiotics is prohibited to manage vibriosis, including the one caused by Vibrio harveyi. In lieu of antibiotics, an eco-friendly alternative method, phage therapy, is recommended here. To facilitate the same, a set of six broad spectrum V. harveyi phages, as cocktail, has been constituted and characterized based on morphological traits and by employing molecular tools. These phages were also found to infect other aquaculture pathogens belonging to Vibrio and Aeromonas. Subsequent to in vivo trials, they can find application in shrimp hatcheries as prophylactics and therapeutics.
Background Invertebrates like crabs employ their own immune systems to fight against a number of ... more Background Invertebrates like crabs employ their own immune systems to fight against a number of invasive infections. Anti-lipopolysaccharide factors (ALFs) are an important class of antimicrobial peptides (AMPs) exhibiting binding and neutralizing activities against lipopolysaccharides. Results This study identified and characterized a novel homolog of ALF (Pp-ALF) from the blue swimmer crab Portunus pelagicus. Pp-ALF has a 369bp open-reading frame encoding a protein with 123 amino acids. The deduced protein featured an LPS-binding domain and a signal peptide. The predicted tertiary structure of Pp-ALF contains three α helices packed against four β sheets. The deduced amino acid sequence of Pp-ALF had a net positive charge of +10.75 and an isoelectric point of 9.8. Phylogenetic analysis revealed that Pp-ALF has a strong ancestral relationship with crab ALFs. Conclusion Antibacterial, antiviral, antifungal, anticancer, and antibiofilm activities of Pp-ALF could be revealed by in sil...
Isolation and in vitro propagation of Infectious Hypodermal Hematopoietic Necrosis Virus (IHHNV/ ... more Isolation and in vitro propagation of Infectious Hypodermal Hematopoietic Necrosis Virus (IHHNV/ PstDVI) in PmLyO-Sf9 could be successfully performed. After few hours of post inoculation with the virus, cytopathic changes such as (a) clustering (b) enlargement (c) syncytium formation (d) granulation (e) vacuole formation (f) tapering (g) irregular plasma membrane with extended tails (h) detachment (i) cell death and cellular debris formation were observed. Expression of viral genes, presence of virions and cytological changes demonstrated through TEM suggested replication of the virus in the shrimp - insect hybrid cell line. The virus could be purified by ultracentrifugation, negatively stained, and demonstrated under electron microscope. The same was found to be infective both in vitro and in vivo. This development opens avenues for the study of basic molecular mechanism of IHHNV infection, pathogenesis and replication kinetics much required for developing antiviral strategy in aqu...
In the zero-water exchange shrimp culture pond maintained with the application of indigenous bioa... more In the zero-water exchange shrimp culture pond maintained with the application of indigenous bioaugmentor, low levels of total ammonia–nitrogen were reported, indicating the relevance of indigenous microbial communities. Sediments (0–5 cm layer) were sampled from the pond (85th day) and the bacterial and archaeal communities; specifically, the ammonia oxidizers (ammonia-oxidizing bacteria, ammonia-oxidizing archaea, and anaerobic ammonia-oxidizing bacteria) in the sediment metagenome of the pond were analysed using the 16S rRNA and functional genes. Bacterial and archaeal 16S rRNA genes showed the relative abundance of Delta-Proteobacteria and Bacteroidetes groups performing sulphur respiration and organic matter degradation, archaeal groups of anaerobic sulphur respiring Crenarchaeotae, and chemolithoautotrophic ammonia oxidizers belonging to Thaumarchaeota. The presence of these diverse bacterial and archaeal communities denotes their significant roles in the cycling the carbon, n...
Crustacean hyperglycemic hormone (CHH) family neuropeptides have been in research limelight for t... more Crustacean hyperglycemic hormone (CHH) family neuropeptides have been in research limelight for the past two decades due to their importance in the regulation of glycemia, moulting and gonad development in crustaceans. Under natural conditions, low levels of CHH neuropeptide and the structural similarity of the three CHH family neuropeptides limit their purification directly from the animal. In this study, we isolated the mature region of the CHH1 gene, constructed the recombinant translation expression vector (pET32a+ PmCHH1) and produced thioredoxin fused protein in Escherichia coli (BL21 (DE3) pLysS). The translation expression vector construct (pET32a+ PmCHH1) was successfully built for production of thioredoxin fused mature CHH1 protein (mf-PmCHH1-29.47 kDa). Mf-PmCHH1 produced a hyperglycemic effect similar to that of the eyestalk extract when experimentally injected into adult eyestalk ablated Penaeus monodon. The polyclonal antiserum (anti-mf-PmCHH1) was developed in mice ag...
Journal of Genetic Engineering and Biotechnology, 2021
Background The concern regarding a post-antibiotic era with increasing drug resistance by pathoge... more Background The concern regarding a post-antibiotic era with increasing drug resistance by pathogens imposes the need to discover alternatives for existing antibiotics. Antimicrobial peptides (AMPs) with their versatile therapeutic properties are a group of promising molecules with curative potentials. These evolutionarily conserved molecules play important roles in the innate immune system of several organisms. The β-defensins are a group of cysteine rich cationic antimicrobial peptides that play an important role in the innate immune system by their antimicrobial activity against the invading pathogens. The present study deals with a novel β-defensin isoform from the red-toothed trigger fish, Odonus niger. Total RNA was isolated from the gills, cDNA was synthesized and the β-defensin isoform obtained by polymerase chain reaction was cloned and subjected to structural and functional characterization in silico. Results A β-defensin isoform could be detected from the gill mRNA of red-...
A two-stage cultivation method involving the initial growth in optimized conditions for biomass p... more A two-stage cultivation method involving the initial growth in optimized conditions for biomass production followed by those for lipid production in oleaginous brackish diatom Navicula phyllepta MACC8 resulted in a proportional increase of lipid concentration along with biomass production. The diatom was further subjected to stress conditions by altering the nutrient components such as nitrate, phosphate, silicate, and temperature. Silicon deprivation resulted in the highest lipid percentage of 28.78% of weight at the end of the 18th day of the second stage. A significant increase in lipid content was observed on the complete removal of the nutrients silicon and urea one at a time, while the biomass showed a considerable reduction. The application of multiple nutrient stress conditions had a profound influence on the increased rate of lipid production. A combination of phosphate deprivation, silicate limitation and temperature reduction resulted in a significant increase in lipid percentage of 32.13% at the cost of reduced biomass (1.1 g L -1 ), whereas phosphate deprivation, urea limitation, and temperature reduction resulted in lipid percentage of 27.58% with a biomass of 1.44 g L -1 at the end of the second stage. Further, the results were supported by Nile red staining, FTIR, fatty acid profile and oxidative stress marker analyses. The changes in biochemical composition and oxidative stress parameters within the various stress conditions demonstrated the profound influence of the selected stress factors on the biodiesel productivity of the diatom, besides its stress tolerance. A two-phase culturing system, with multifactor stress application, especially nitrogen limitation along with phosphate starvation and temperature stress, would be the suitable method for gaining maximum biomass productivity and lipid content in diatom Navicula phyllepta MACC8 towards biofuel production.
After screening marine actinomycetes isolated from sediment samples collected from the Arctic fjo... more After screening marine actinomycetes isolated from sediment samples collected from the Arctic fjord Kongsfjorden for potential anticancer activity, an isolate identified as Streptomyces artemisiae MCCB 248 exhibited promising results against the NCI-H460 human lung cancer cell line. H460 cells treated with the ethyl acetate extract of strain MCCB 248 and stained with Hoechst 33342 showed clear signs of apoptosis, including shrinkage of the cell nucleus, DNA fragmentation and chromatin condensation. Further to this treated cells showed indications of early apoptotic cell death, including a significant proportion of Annexin V positive staining and evidence of DNA damage as observed in the TUNEL assay. Amplified PKS 1 and NRPS genes involved in secondary metabolite production showed only 82% similarity to known biosynthetic genes of Streptomyces, indicating the likely production of a novel secondary metabolite in this extract. Additionally, chemical dereplication efforts using LC-MS/MS...
Recent advances in culture-independent studies of microbes had proved to be more reliable and eff... more Recent advances in culture-independent studies of microbes had proved to be more reliable and efficient than the conventional ones. The isolation of good quality and quantity of total community DNA are one of the major hurdles in this endeavour. Shearing of DNA during the extraction process and the co-extraction of inhibitory compounds reduce the quality of the isolated nucleic acids making it unsuitable for the construction of large insert metagenomic libraries. In the present study, a multi-level filtration step was brought in which efficiently isolated total bacterial DNA from three different environment samples. The preprocessing method could efficiently improve the 260/230 ratio of the isolated DNA by 2.3-45 % and decreased the protein contamination by 22.5-34.5 % on saltpan and arctic sediment samples, respectively. The more significant part of the experiment was that the DNA obtained was of high quality with minimal shearing making it most suitable for the construction of large insert genomic libraries. PCR amplification of 16S rRNA gene confirmed that the filtration method was effective in the isolation of high-quality DNA.
Research programs are advancing for tackling the pollution risks of coir pith by converting the s... more Research programs are advancing for tackling the pollution risks of coir pith by converting the substrate into valuable products. The product development process shall generate byproducts or effluents that may be toxic in nature. An efficient oxidative delignification process was developed followed by lignin recovery from the process effluent. The toxicity assessment of effluent generated during lignin recovery process is of utmost importance for the safe disposal plans and the present study aims at assessing the phytotoxicity of the effluent. The test involved 96 hour exposure of Oryza sativa to 0.0% to 100% effluent concentrations. The parameters of analysis included root length (RL), shoot length (SL), seedling length (SDL), seed germination (SG), germination index (GI) and seed vigour index (SVI). The effluent produced significant inhibitory effect on growth of the plant. Root length (EC 25 =3.05, EC 50 =5.14) and germination index (EC 25 =2.78, EC 50 =4.78) were the most sensit...
Lysozyme gene from Fenneropenaeus indicus was cloned, expressed in Escherichia coli and character... more Lysozyme gene from Fenneropenaeus indicus was cloned, expressed in Escherichia coli and characterized. The cDNA consists of 477 base pairs and encodes amino acid sequence of 159 residues. F. indicus lysozyme had high identity (98 %) with Fenneropenaeus merguiensis and Fenneropenaeus chinensis and exhibits low to moderate identities with lysozymes of other invertebrates and vertebrates. This lysozyme is presumed to be chicken types as it possesses two catalytic and eight cysteine residues that are conserved across c-type lysozymes and a c-terminal extension, which is a characteristic of lysozymes from marine invertebrates. Further, the antimicrobial properties of the recombinant lysozyme from F. indicus were determined in comparison with recombinant hen egg white lysozyme. This exhibited high activity against a Gram-negative pathogenic bacterium Salmonella typhimurium and two fungal strains Pichia pastoris and Saccharomyces cerevisiae in turbidimetric assay. Distribution of lysozyme ...
Hepcidin is cysteine-rich short peptide of innate immune system of fishes, equipped to perform pr... more Hepcidin is cysteine-rich short peptide of innate immune system of fishes, equipped to perform prevention and proliferation of invading pathogens like bacteria and viruses by limiting iron availability and activating intracellular cascades. Hepcidins are diverse in teleost fishes, due to the varied aquatic environments including exposure to pathogens, oxygenation and iron concentration. In the present study, we report a 87-amino acid (aa) preprohepcidin (Hepc-CB1) with a signal peptide of 24 aa, a prodomain of 39 aa and a bioactive mature peptide of 24 aa from the gill mRNA transcripts of the deep-sea fish spinyjaw greeneye, Chlorophthalmus bicornis. Molecular characterisation and phylogenetic analysis categorised the peptide to HAMP2-like group with a mature peptide of 2.53 kDa; a net positive charge (?3) and capacity to form b-hairpin-like structure configured by 8 conserved cysteines. The present work provides new insight into the mass gene duplication events and adaptive evolution of hepcidin isoforms with respect to environmental influences and positive Darwinian selection. This work reports a novel hepcidin isoform under the group HAMP2 from a nonacanthopterygian deep-sea fish, C. bicornis.
Shrimp cell lines are yet to be reported and this restricts the prospects of investigating the as... more Shrimp cell lines are yet to be reported and this restricts the prospects of investigating the associated viral pathogens, especially white spot syndrome virus (WSSV). In this context, development of primary cell cultures from lymphoid organs was standardized. Poly-l-lysine-coated culture vessels enhanced growth of lymphoid cells, while the application of vertebrate growth factors did not, except insulin-like growth factor-1 (IGF-1). Susceptibility of the lymphoid cells to WSSV was confirmed by immunofluoresence assay using monoclonal antibody against the 28 kDa envelope protein of WSSV. Expression of viral and immunerelated genes in WSSV-infected lymphoid cultures could be demonstrated by RT-PCR. This emphasizes the utility of lymphoid primary cell culture as a platform for research in virus-cell interaction, virus morphogenesis, up and downregulation of shrimp immune-related genes, and also for the discovery of novel drugs to combat WSSV in shrimp culture.
Probiotics and Antimicrobial Proteins, May 23, 2013
Hepcidin is a family of short cysteine-rich antimicrobial peptides (AMPs) participating in variou... more Hepcidin is a family of short cysteine-rich antimicrobial peptides (AMPs) participating in various physiological functions with inevitable role in host immune responses. Present study deals with identification and characterisation of a novel hepcidin isoform from coral fish Zanclus cornutus. The 81 amino acid (aa) preprohepcidin obtained from Z. cornutus consists of a hydrophobic aa rich 22 mer signal peptide, a highly variable proregion of 35 aa and a bioactive mature peptide with 8 conserved cysteine residues which contribute to the disulphide back bone. The mature hepcidin, Zc-hepc1 has a theoretical isoelectric point of 7.46, a predicted molecular weight of 2.43 kDa and a net positive charge of ?1. Phylogenetic analysis grouped Z. cornutus hepcidin with HAMP2 group hepcidins confirming the divergent evolution of hepcidin-like peptide in fishes. Zc-hepc1 can attain a b-hairpin-like structure with two antiparallel b-sheets. This is the first report of an AMP from the coral fish Z. cornutus.
International Journal of Current Microbiology and Applied Sciences, Jan 10, 2018
Pseudomonas aeruginosa MCCB 123 is a potent producer of enzymes such as β-1,3 glucanase, LasA and... more Pseudomonas aeruginosa MCCB 123 is a potent producer of enzymes such as β-1,3 glucanase, LasA and LasB proteases, which have been identified to have greater significance in the biotechnology sector. However, pathogenicity assessment of bacteria is essential for its industrial survival. Pathogenicity was assessed by a panel of virulence assays such as the presence of type III secretion toxin genes, motility assays, biofilm formation, adhesion and invasion assays on Hep-2 and HeLa monolayers and antibiogram profiling. Analysis of the major cytotoxic exoU gene revealed the absence of the gene, thus confirms the non-cytotoxic phenotype of the bacterium. P. aeruginosa exhibited three types of motilities viz., swimming, swarming and twitching motilities and proved to be a moderate biofilm producer with a 3.10±0.52-fold increase in the optical density at Abs 570 when compared to control. Antibiogram suggested the possibility of antibiotic treatment as an effective method for eradication of its biofilm. The non-pathogenic nature of the bacterium suggests industrially viability of this organism for the production of biotechnological relevant enzymes.
Biochar production from biomass is a globally adopted strategy for carbon sequestration and also ... more Biochar production from biomass is a globally adopted strategy for carbon sequestration and also for integrated agricultural applications. In the present study biochar was produced at 600 o C by slow pyrolysis of lignocellulosic agro industrial residue coir pith. Chemical and structural transformation of coir pith happened due to pyrolysis process. Changes in cellulose crystallinity was analysed by XRD and FTIR method. XRD analysis indicates cellulose crystallinity index change. FTIR analysis shows several characteristic peak changes indicating structural transformations of cellulosic components.
Journal of Genetic Engineering and Biotechnology, Mar 28, 2022
Background: Increase of antibiotic resistance in pathogenic microbes necessitated novel molecules... more Background: Increase of antibiotic resistance in pathogenic microbes necessitated novel molecules for curing infection. Antimicrobial peptides (AMPs) are the gene-encoded evolutionarily conserved small molecules with therapeutic value. AMPs are considered as an alternative drug for conventional antibiotics. Hepcidin, the cysteinerich antimicrobial peptide, is an important component in innate immune response. In this study, we identified and characterized hepcidin gene from the fish, Catla catla (Indian major carp) and termed it as Cc-Hep. Open reading frame of Cc-Hep consists of 261 base pair that encodes 87 amino acids. Cc-Hep is synthesized as a prepropeptide consisting of 24 amino acid signal peptide, 36 amino acid propeptide, and 26 amino acid mature peptide. Sequence analysis revealed that Cc-Hep shared sequence similarity with hepcidin from Sorsogona tuberculata. Phylogenetic analysis indicated that Cc-Hep was grouped with HAMP2 family. Structure analysis of mature Cc-Hep identified two antiparallel beta sheets stabilized by four disulphide bonds and a random coil. The mature peptide region of Cc-Hep has a charge of + 2, isoelectric value 8.23 and molecular weight 2.73 kDa. Functional characterization predicted antibacterial, antioxidant, and anticancer potential of Cc-Hep, which can be explored in aquaculture or human health care.
Significance and Impact of the Study: In sustainable aquaculture, application of antibiotics is p... more Significance and Impact of the Study: In sustainable aquaculture, application of antibiotics is prohibited to manage vibriosis, including the one caused by Vibrio harveyi. In lieu of antibiotics, an eco-friendly alternative method, phage therapy, is recommended here. To facilitate the same, a set of six broad spectrum V. harveyi phages, as cocktail, has been constituted and characterized based on morphological traits and by employing molecular tools. These phages were also found to infect other aquaculture pathogens belonging to Vibrio and Aeromonas. Subsequent to in vivo trials, they can find application in shrimp hatcheries as prophylactics and therapeutics.
Background Invertebrates like crabs employ their own immune systems to fight against a number of ... more Background Invertebrates like crabs employ their own immune systems to fight against a number of invasive infections. Anti-lipopolysaccharide factors (ALFs) are an important class of antimicrobial peptides (AMPs) exhibiting binding and neutralizing activities against lipopolysaccharides. Results This study identified and characterized a novel homolog of ALF (Pp-ALF) from the blue swimmer crab Portunus pelagicus. Pp-ALF has a 369bp open-reading frame encoding a protein with 123 amino acids. The deduced protein featured an LPS-binding domain and a signal peptide. The predicted tertiary structure of Pp-ALF contains three α helices packed against four β sheets. The deduced amino acid sequence of Pp-ALF had a net positive charge of +10.75 and an isoelectric point of 9.8. Phylogenetic analysis revealed that Pp-ALF has a strong ancestral relationship with crab ALFs. Conclusion Antibacterial, antiviral, antifungal, anticancer, and antibiofilm activities of Pp-ALF could be revealed by in sil...
Isolation and in vitro propagation of Infectious Hypodermal Hematopoietic Necrosis Virus (IHHNV/ ... more Isolation and in vitro propagation of Infectious Hypodermal Hematopoietic Necrosis Virus (IHHNV/ PstDVI) in PmLyO-Sf9 could be successfully performed. After few hours of post inoculation with the virus, cytopathic changes such as (a) clustering (b) enlargement (c) syncytium formation (d) granulation (e) vacuole formation (f) tapering (g) irregular plasma membrane with extended tails (h) detachment (i) cell death and cellular debris formation were observed. Expression of viral genes, presence of virions and cytological changes demonstrated through TEM suggested replication of the virus in the shrimp - insect hybrid cell line. The virus could be purified by ultracentrifugation, negatively stained, and demonstrated under electron microscope. The same was found to be infective both in vitro and in vivo. This development opens avenues for the study of basic molecular mechanism of IHHNV infection, pathogenesis and replication kinetics much required for developing antiviral strategy in aqu...
In the zero-water exchange shrimp culture pond maintained with the application of indigenous bioa... more In the zero-water exchange shrimp culture pond maintained with the application of indigenous bioaugmentor, low levels of total ammonia–nitrogen were reported, indicating the relevance of indigenous microbial communities. Sediments (0–5 cm layer) were sampled from the pond (85th day) and the bacterial and archaeal communities; specifically, the ammonia oxidizers (ammonia-oxidizing bacteria, ammonia-oxidizing archaea, and anaerobic ammonia-oxidizing bacteria) in the sediment metagenome of the pond were analysed using the 16S rRNA and functional genes. Bacterial and archaeal 16S rRNA genes showed the relative abundance of Delta-Proteobacteria and Bacteroidetes groups performing sulphur respiration and organic matter degradation, archaeal groups of anaerobic sulphur respiring Crenarchaeotae, and chemolithoautotrophic ammonia oxidizers belonging to Thaumarchaeota. The presence of these diverse bacterial and archaeal communities denotes their significant roles in the cycling the carbon, n...
Crustacean hyperglycemic hormone (CHH) family neuropeptides have been in research limelight for t... more Crustacean hyperglycemic hormone (CHH) family neuropeptides have been in research limelight for the past two decades due to their importance in the regulation of glycemia, moulting and gonad development in crustaceans. Under natural conditions, low levels of CHH neuropeptide and the structural similarity of the three CHH family neuropeptides limit their purification directly from the animal. In this study, we isolated the mature region of the CHH1 gene, constructed the recombinant translation expression vector (pET32a+ PmCHH1) and produced thioredoxin fused protein in Escherichia coli (BL21 (DE3) pLysS). The translation expression vector construct (pET32a+ PmCHH1) was successfully built for production of thioredoxin fused mature CHH1 protein (mf-PmCHH1-29.47 kDa). Mf-PmCHH1 produced a hyperglycemic effect similar to that of the eyestalk extract when experimentally injected into adult eyestalk ablated Penaeus monodon. The polyclonal antiserum (anti-mf-PmCHH1) was developed in mice ag...
Journal of Genetic Engineering and Biotechnology, 2021
Background The concern regarding a post-antibiotic era with increasing drug resistance by pathoge... more Background The concern regarding a post-antibiotic era with increasing drug resistance by pathogens imposes the need to discover alternatives for existing antibiotics. Antimicrobial peptides (AMPs) with their versatile therapeutic properties are a group of promising molecules with curative potentials. These evolutionarily conserved molecules play important roles in the innate immune system of several organisms. The β-defensins are a group of cysteine rich cationic antimicrobial peptides that play an important role in the innate immune system by their antimicrobial activity against the invading pathogens. The present study deals with a novel β-defensin isoform from the red-toothed trigger fish, Odonus niger. Total RNA was isolated from the gills, cDNA was synthesized and the β-defensin isoform obtained by polymerase chain reaction was cloned and subjected to structural and functional characterization in silico. Results A β-defensin isoform could be detected from the gill mRNA of red-...
A two-stage cultivation method involving the initial growth in optimized conditions for biomass p... more A two-stage cultivation method involving the initial growth in optimized conditions for biomass production followed by those for lipid production in oleaginous brackish diatom Navicula phyllepta MACC8 resulted in a proportional increase of lipid concentration along with biomass production. The diatom was further subjected to stress conditions by altering the nutrient components such as nitrate, phosphate, silicate, and temperature. Silicon deprivation resulted in the highest lipid percentage of 28.78% of weight at the end of the 18th day of the second stage. A significant increase in lipid content was observed on the complete removal of the nutrients silicon and urea one at a time, while the biomass showed a considerable reduction. The application of multiple nutrient stress conditions had a profound influence on the increased rate of lipid production. A combination of phosphate deprivation, silicate limitation and temperature reduction resulted in a significant increase in lipid percentage of 32.13% at the cost of reduced biomass (1.1 g L -1 ), whereas phosphate deprivation, urea limitation, and temperature reduction resulted in lipid percentage of 27.58% with a biomass of 1.44 g L -1 at the end of the second stage. Further, the results were supported by Nile red staining, FTIR, fatty acid profile and oxidative stress marker analyses. The changes in biochemical composition and oxidative stress parameters within the various stress conditions demonstrated the profound influence of the selected stress factors on the biodiesel productivity of the diatom, besides its stress tolerance. A two-phase culturing system, with multifactor stress application, especially nitrogen limitation along with phosphate starvation and temperature stress, would be the suitable method for gaining maximum biomass productivity and lipid content in diatom Navicula phyllepta MACC8 towards biofuel production.
After screening marine actinomycetes isolated from sediment samples collected from the Arctic fjo... more After screening marine actinomycetes isolated from sediment samples collected from the Arctic fjord Kongsfjorden for potential anticancer activity, an isolate identified as Streptomyces artemisiae MCCB 248 exhibited promising results against the NCI-H460 human lung cancer cell line. H460 cells treated with the ethyl acetate extract of strain MCCB 248 and stained with Hoechst 33342 showed clear signs of apoptosis, including shrinkage of the cell nucleus, DNA fragmentation and chromatin condensation. Further to this treated cells showed indications of early apoptotic cell death, including a significant proportion of Annexin V positive staining and evidence of DNA damage as observed in the TUNEL assay. Amplified PKS 1 and NRPS genes involved in secondary metabolite production showed only 82% similarity to known biosynthetic genes of Streptomyces, indicating the likely production of a novel secondary metabolite in this extract. Additionally, chemical dereplication efforts using LC-MS/MS...
Recent advances in culture-independent studies of microbes had proved to be more reliable and eff... more Recent advances in culture-independent studies of microbes had proved to be more reliable and efficient than the conventional ones. The isolation of good quality and quantity of total community DNA are one of the major hurdles in this endeavour. Shearing of DNA during the extraction process and the co-extraction of inhibitory compounds reduce the quality of the isolated nucleic acids making it unsuitable for the construction of large insert metagenomic libraries. In the present study, a multi-level filtration step was brought in which efficiently isolated total bacterial DNA from three different environment samples. The preprocessing method could efficiently improve the 260/230 ratio of the isolated DNA by 2.3-45 % and decreased the protein contamination by 22.5-34.5 % on saltpan and arctic sediment samples, respectively. The more significant part of the experiment was that the DNA obtained was of high quality with minimal shearing making it most suitable for the construction of large insert genomic libraries. PCR amplification of 16S rRNA gene confirmed that the filtration method was effective in the isolation of high-quality DNA.
Research programs are advancing for tackling the pollution risks of coir pith by converting the s... more Research programs are advancing for tackling the pollution risks of coir pith by converting the substrate into valuable products. The product development process shall generate byproducts or effluents that may be toxic in nature. An efficient oxidative delignification process was developed followed by lignin recovery from the process effluent. The toxicity assessment of effluent generated during lignin recovery process is of utmost importance for the safe disposal plans and the present study aims at assessing the phytotoxicity of the effluent. The test involved 96 hour exposure of Oryza sativa to 0.0% to 100% effluent concentrations. The parameters of analysis included root length (RL), shoot length (SL), seedling length (SDL), seed germination (SG), germination index (GI) and seed vigour index (SVI). The effluent produced significant inhibitory effect on growth of the plant. Root length (EC 25 =3.05, EC 50 =5.14) and germination index (EC 25 =2.78, EC 50 =4.78) were the most sensit...
Lysozyme gene from Fenneropenaeus indicus was cloned, expressed in Escherichia coli and character... more Lysozyme gene from Fenneropenaeus indicus was cloned, expressed in Escherichia coli and characterized. The cDNA consists of 477 base pairs and encodes amino acid sequence of 159 residues. F. indicus lysozyme had high identity (98 %) with Fenneropenaeus merguiensis and Fenneropenaeus chinensis and exhibits low to moderate identities with lysozymes of other invertebrates and vertebrates. This lysozyme is presumed to be chicken types as it possesses two catalytic and eight cysteine residues that are conserved across c-type lysozymes and a c-terminal extension, which is a characteristic of lysozymes from marine invertebrates. Further, the antimicrobial properties of the recombinant lysozyme from F. indicus were determined in comparison with recombinant hen egg white lysozyme. This exhibited high activity against a Gram-negative pathogenic bacterium Salmonella typhimurium and two fungal strains Pichia pastoris and Saccharomyces cerevisiae in turbidimetric assay. Distribution of lysozyme ...
Hepcidin is cysteine-rich short peptide of innate immune system of fishes, equipped to perform pr... more Hepcidin is cysteine-rich short peptide of innate immune system of fishes, equipped to perform prevention and proliferation of invading pathogens like bacteria and viruses by limiting iron availability and activating intracellular cascades. Hepcidins are diverse in teleost fishes, due to the varied aquatic environments including exposure to pathogens, oxygenation and iron concentration. In the present study, we report a 87-amino acid (aa) preprohepcidin (Hepc-CB1) with a signal peptide of 24 aa, a prodomain of 39 aa and a bioactive mature peptide of 24 aa from the gill mRNA transcripts of the deep-sea fish spinyjaw greeneye, Chlorophthalmus bicornis. Molecular characterisation and phylogenetic analysis categorised the peptide to HAMP2-like group with a mature peptide of 2.53 kDa; a net positive charge (?3) and capacity to form b-hairpin-like structure configured by 8 conserved cysteines. The present work provides new insight into the mass gene duplication events and adaptive evolution of hepcidin isoforms with respect to environmental influences and positive Darwinian selection. This work reports a novel hepcidin isoform under the group HAMP2 from a nonacanthopterygian deep-sea fish, C. bicornis.
Shrimp cell lines are yet to be reported and this restricts the prospects of investigating the as... more Shrimp cell lines are yet to be reported and this restricts the prospects of investigating the associated viral pathogens, especially white spot syndrome virus (WSSV). In this context, development of primary cell cultures from lymphoid organs was standardized. Poly-l-lysine-coated culture vessels enhanced growth of lymphoid cells, while the application of vertebrate growth factors did not, except insulin-like growth factor-1 (IGF-1). Susceptibility of the lymphoid cells to WSSV was confirmed by immunofluoresence assay using monoclonal antibody against the 28 kDa envelope protein of WSSV. Expression of viral and immunerelated genes in WSSV-infected lymphoid cultures could be demonstrated by RT-PCR. This emphasizes the utility of lymphoid primary cell culture as a platform for research in virus-cell interaction, virus morphogenesis, up and downregulation of shrimp immune-related genes, and also for the discovery of novel drugs to combat WSSV in shrimp culture.
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