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Teacher immediacy, which refers to the verbal and nonverbal behaviours that communicate approachability, availability, and involvement, has been found to have a positive impact on learner performance. Teachers need to promote and maintain classroom civility to improve their self-efficacy and effectiveness as educators. By creating a positive and respectful classroom environment where students feel valued and supported, teachers can feel more confident and effective in their teaching, leading to improved learning outcomes. This study investigates the relationship between teacher immediacy and classroom civility at undergraduate level. The study shows that there exist positive and significant relationship between teacher immediacy and classroom civility. Teacher immediacy has a positive impact on classroom civility by creating a more positive classroom climate and promoting respectful interactions between students and the teacher. Teacher behaviour is a regulating factor that decides the student behaviour. The paper highlights the importance of teacher training in enhancing teacher immediacy and promoting classroom civility. Keywords: Teacher immediacy, Classroom civility, Teacher training

Competencies have vital role in 21st century for successful personal and professional life. Certain good practices and educational experience of teachers serve as a basis for the design of procedures for the development of competencies in students. Teachers are the role models for the emerging student community. Transversal competencies are considered necessary for teachers to function within today’s complex and increasingly interconnected world. Present study is an attempt to evolve a teacher transversal competency grid which could be used in benchmarking teacher preparation courses. Through document analysis, data collection from teacher educators and expert validation relevant transversal competencies are identified. A survey was then conducted among teacher educators to explore the adequacy of the existing teacher education programmes in developing the transversal competencies among prospective teachers. The findings revealed that core competencies of knowledge management and thinking; personal competencies of emotional management and physical management and social competencies of career management in interpersonal skills and social system management are essential for prospective teachers. However, the survey showed that the existing programmes are not satisfactory in promoting linguistic competencies, stress management, impulse control, health management, financial literacy and entrepreneurial skills of prospective teachers. Hence the teacher education programmes need revamping with planned strategies for training in transversal competencies., Competencies have vital role in 21st century for successful personal and professional life. Certain good practices and educational experience of teachers serve as a basis for the design of procedures for the development of competencies in students. Teachers are the role models for the emerging student community. Transversal competencies are considered necessary for teachers to function within today's complex and increasingly interconnected world. Present study is an attempt to evolve a teacher transversal competency grid which could be used in benchmarking teacher preparation courses. Through document analysis, data collection from teacher educators and expert validation relevant transversal competencies are identified. A survey was then conducted among teacher educators to explore the adequacy of the existing teacher education programmes in developing the transversal competencies among prospective teachers. The findings revealed that core competencies of knowledge management and thinking; personal competencies of emotional management and physical management and social competencies of career management in interpersonal skills and social system management are essential for prospective teachers. However, the survey showed that the existing programmes are not satisfactory in promoting linguistic competencies, stress management, impulse control, health management, financial literacy and entrepreneurial skills of prospective teachers. Hence the teacher education programmes need revamping with planned strategies for training in transversal competencies.

Indiscriminate use of antibiotics has led to the emergence of antibiotic resistant microbes and the loss of natural flora in aquaculture systems ultimately necessitating the ban of many of the chemotherapeutants in aquaculture. Actinobacteria play a profound role in the biogeochemical cycling in the marine environment and they represent the principal source of secondary metabolites with antimicrobial property. In the present study, 98 marine derived actinomycete isolates were screened for antimicrobial activity against the common aquatic pathogens. A potent actinomycete isolate S26, identified as Streptomyces variabilis based on 16S rRNA gene sequencing was used for further study. Optimization of the fermentation medium for secondary metabolite production was carried out by response surface methodology (RSM) using DESIGN EXPERT. The ANOVA of the quadratic regression model demonstrated that the model was highly significant for the response concerned i.e., antimicrobial activity as evident from the Fisher’s F- test with a very low probability value [(P model>F) = 0.0001]. Of the 10 different solutions suggested by the software, the most suitable composition was found to be starch, 1.38 %; soy powder, 0.88 %; ammonium sulphate, 0.16 % and salinity, 27.76 ‰. S. variabilis S26 cultured in the optimized production medium was applied in the Penaeus monodon larval rearing system and the total Vibrio count and survival rate were estimated. S. variabilis S26 treatment showed a significant reduction in Vibrios and better survival in the Penaeus monodon culture system compared to the control.

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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 aquaculture.

Hepcidin, a cysteine-rich antimicrobial peptide, with multiple disulfide bonds plays an important role in the defense mechanism and iron metabolism of organisms. In this study, we characterized a hepcidin from a fish under IUCN Red List i.e., tuberculated flathead, Sorsogona tuberculata. The hepcidin consists of an open reading frame of 261 base pairs encoding 86 amino acids with a signal peptide of 24 amino acids, a prodomain of 36 amino acids and a biologically active mature peptide of 26 amino acids. A conserved RX (K/R) R motif and eight conserved cysteine residues were observed. Mature peptide of St-hep is found to have a molecular weight of 2.73 kDa and the predicted three dimensional structure was similar to hepcidins from other animals, which can attain a β-hairpin-like structure with two antiparallel β-sheets. The Ramachandran plot showed 100 % of the residues in favourable and allowed regions, which confirmed the accuracy of the model. Functional characterization of St-hep was carried out using various bioinformatic resource portals. The results suggested that St-hep possesses antibacterial, antiviral, antifungal, anticancer, and immunomodulatory properties indicating its importance as a defense molecule that can be explored for therapeutic applications in aquaculture.

The present study deals with the mangrove associated endophytic fungi and their bioactivity profile. The fungal endophytes were isolated from the leaves of three mangrove species (Aegiceras corniculatum, Lumnitzera racemosa and Ceriops tagal) and identified by morphological and molecular methods (Internal Transcribed Spacer and β-tubulin (Ben A) sequencing). The isolates mainly belonged to Ascomycota (95%) and the Basidiomycota comprised only 5%. They come under 5 classes, 11 orders, 16 genera and 25 species. Under Ascomycota, four classes, viz., Sordariomycetes (44.5%), Eurotiomycetes (32.46%), Dothideomycetes (17.28%) and Saccharomycetes (1.83%) comprising 10 orders were recorded. Under Basidiomycota a single class viz., Agaricomycetes (3.93%) comprising 1 order (Agaricales) was observed. Colletotrichum (30.2%) was the dominant genus followed by Aspergillus (17.8%), Penicillium (14.1%), Phyllosticta (9.1%) etc. Penicillium citrinum was the dominant fungus (22%) in A. corniculatum; Colletotrichum siamense (31%) in L. racemosa and Aspergillus sydowii (35%) in C. tagal (Fig. 3). Among the isolates, the Colonization frequency (CF%) was maximum for Colletotrichum siamense (18%) followed by Phyllosticta capitalensis (11.6%). Penicillium citrinum was found in all the three plant species. Isolates from Ceriops tagal were found to exhibit higher antibacterial as well as hydrolytic enzyme production potential. Aspergillus montevidensis EF 30, Cladosporium oxysporum EF 316, Colletotrichum siamense EF 272, Penicillium chrysogenum EF 362, Colletotrichum fruticola EF 22, Ascotricha chartarum EF 374, Aspergillus sydowii EF 239, Talaromyces purpurogenus EF 313, Meyerozyma caribbica EF 347 and Schizophyllum commune EF 309 were segregated as potential strains for hydrolytic enzyme production. A. aculeatus EF 10, T. purpurogenus EF 313, C. oxysporum EF 316, C. fruticola EF 74, P. capitalensis EF 187, A. sydowi EF 226 and P. chrysogenum EF 363 showed notable antimicrobial property. T purprogenus EF 313 endowed with pigment (red) production has potential for application in dyeing industry. During the current study, 25 different species of endophytic fungal species could be recovered from three host mangrove plants and some of them were having high bioactive potential for possible commercial applications with respect to bioremediation and as antimicrobials in medicine and aquaculture.

Shrimp progressively gets more attention among marine invertebrates from researchers all over the world due to it being a healthy food as well as having economic importance. There were a lot of attempts to develop a continuous cell line from shrimp but none successful. In this context a novel hybrid cell line named 'PmLyO-Sf9' could be developed by fusing shrimp lymphoid organ cells with Sf9 cells after to metabolic blocking of Sf9 cells using puromycin and actinomycin D and effecting the fusion by way of PEG application. The cells are maintained and multiplied in a mixture of SCCM and TNM-FH having osmolality 550 mOsm kg-1 and pH 6.8. Transmission electron microscopy of the hybrid cells revealed the presence of two nuclei during the initial stages and a single nucleus subsequently. The cell line is with shrimp and Sf9 genomic components and shrimp specific protein and is susceptible to WSSV. Shrimp elongation factor, Sf9 beta-actin, shrimp STAT and peroxinectin could be expresses through RT-PCR in the cell line. This is the first successful report of a hybrid cell line with shrimp genomic components and envisaged to be recognized a model system for multitudes of biomedical research in vitro. The cell line is in the National Cell Line Repository of ICAR - National Bureaue of Fish Genetic Resources, Lucknow, India.

Antimicrobial peptides (AMPs) are biologically active molecules involved in host defense present in a variety of organisms. They are an integral component of innate immunity, forming a front line of defense against potential pathogens, including antibiotic-resistant ones. Fishes are proven to be a prospective source of AMPs as they are constantly being challenged by a variety of pathogens and the AMPs are reported to play an inevitable role in fish immunity. Among them, β-defensins form one of the most studied multifunctional peptides with early evolutionary history and recently being considered as host defense peptides. The present study highlights the first-ever report on β-defensin AMP sequences from common goby (Pomatoschistus microps) and silver trevally (Pseudocaranx georgianus). A 192 bp cDNA fragment with an open reading frame encoding 63 amino acids (aa) comprising a 20 aa signal peptide region at the N-terminal was obtained from the mRNA of gill tissue of both P. microps and P. georgianus by RT-PCR. These peptide sequences when characterized in silico at the molecular level revealed a 43 aa cationic mature peptide with the signature intra-molecular disulphide bonded cysteine residue pattern ascertaining its β-defensin identity, further confirmed by phylogenetic analysis. The data collected will pave the way for further research on varied facets of the peptide-like, tissue level expressions, antimicrobial activities on commonly encountered pathogens, and its feasibility as a therapeutant in the aquaculture scenario.

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-toothed trigger fish, Odonus niger. The cDNA encoded a 63 amino acid peptide, β-defensin, with a 20 amino acid signal sequence followed by 43 amino acid cationic mature peptide (On-Def) having a molecular weight of 5.214 kDa and theoretical pI of 8.89. On-Def possessed six highly conserved cysteine residues forming disulfide bonds between C1–C5, C2–C4, and C3–C6, typical of β-defensins. An anionic pro-region was observed prior to the β-defensin domain within the mature peptide. Clustal alignment and phylogenetic analyses revealed On-Def as a group 2 β-defensin. Furthermore, it shared some structural similarities and functional motifs with β-defensins from other organisms. On-Def was predicted to be non-hemolytic with anti-bacterial, anti-viral, anti-fungal, anti-cancer, and immunomodulatory potential. Conclusion On-Def is the first report of a β-defensin from the red-toothed trigger fish, Odonus niger. The antimicrobial profile showed the potential for further studies as a suitable candidate for antimicrobial peptide therapeutics.

Polyhydroxyalkanoates (PHAs) are natural polyesters produced by microorganisms as a source of intracellular energy reserves. These polymers have been extensively studied for tissue engineering and drug delivery applications due to their desirable material properties. Solvent-cast film of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), produced by Bacillus cereus MCCB 281 was characterized to study the surface morphology, roughness, thermal and mechanical properties. PHBV films were slightly hydrophilic with an average surface roughness of 43.66 nm. In vitro cell viability and proliferation studies on PHBV film surface investigated using L929 fibroblasts showed good cell attachment and proliferation. Hemocompatibility of PHBV evaluated by hemolysis assay, in vitro platelet adhesion and coagulation assays demonstrated good blood compatibility for use as blood contact graft materials. Therefore, PHBV produced from the marine bacterium favoured cellular growth of L929 fibroblasts indicating its potential to be used as a biomaterial substrate for cell adhesion in tissue engineering and medical applications.

White spot syndrome virus (WSSV) is the most devastating pathogen found in shrimp aquaculture. The lack of certified continuous/established cell lines from penaeid shrimp restricts in vitro studies on the viruses to bring out effective prophylactic and therapeutic measures. In this context, a novel hybrid cell line named, PmLyO-Sf9, consisting of shrimp and Sf9 genomes has been established and employed to study WSSV susceptibility and multiplication. The hybrid cells were exposed to the shrimp virus WSSV and cytopathic effects (CPE) such as (a) enlargement of cells, (b) cessation cell division, (c) granulation of cytoplasm, (d) rounding off of cells, shortening and disappearance of tail-like structures and (e) detachment from the flask. Expression of immediate early genes such as ie 1, dnapol, rr1, tk-tmk, and pk 1could be confirmed indicating that viral DNA replication in the PmLyO-Sf9 took place followed by the expression of late genes such as VP-28, VP-26, VP-15 and VP-19. Electron micrograph of WSSV infected cells demonstrated marginated dense zones in the nucleus with clumped chromatin, and the mid zone with virus-like particles. However, neither discrete virus particles nor the culture supernatant having infectivity could be observed suggesting that virions were not getting formed in the cells. This is the first report of the susceptibility of PmLyO-Sf9 to WSSV, and the 'PmLyO-Sf9 - WSSV Complex' formed, defined as the infected status of PmLyO-Sf9 with WSSV, could be of use for unraveling at molecular level the mechanism of viral entry, replication impediments and cellular apoptosis.

Antilipopolysaccharide factors (ALFs) are important effectors of innate immunity in crustaceans with broad spectrum antimicrobial activity. Present study deals with the molecular and functional characterization of a 98-amino acid ALF isoform from, crucifix crab, Charybdis feriatus termed as Cf-ALF2. The ALF isoform Cf-ALF2 exhibits characteristic features of an AMP including a cationic net charge of + 9 and a total hydrophobic ratio of 34%. Recombinant peptide rCf-ALF2 showed remarkable antimicrobial activity against Gram-negative and Gram-positive bacteria especially against Staphylococcus aureus (minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 5 µM) and Escherichia coli (MIC 10 µM and MBC 20 µM). Using scanning electron microscopy, bacterial membrane blebbing, disruption, and cell content leakage were observed in peptide treated E. coli. The recombinant peptide was found to be non-hemolytic and non-cytotoxic in NCI-H460 cell line at the highest tested concentration (20 µM). Thus, this study identified a novel isoform of ALF from C. feriatus and revealed the potent antimicrobial property of the recombinant peptide Cf-ALF2 and the future prospects of using the peptide for therapeutic applications in the future.

The ammonia oxidizing bacterial consortium (AMOPCU-1) has been under use for efficient biological removal of ammonia from the recirculating aquaculture system. In this context a metaproteomic approach to the study of the consortium was undertaken to analyse the proteins involved in nitrification. Ammonia removal efficiency was monitored while amplifying the consortium in 2 L fermenter under standard conditions, and the consortium kept under substrate starvation served as the control. When the bacterial consortium attained peak ammonia removal efficiency, their total proteins were extracted. Protein profiling was done using one dimensional and two-dimensional SDS-PAGE. Eleven visible protein spots, which appeared during peak ammonia oxidation were identified by MALDI-TOF analysis. The proteins could be linked to metabolic processes that were active during nitrification. These included enzymes that influenced ammonia oxidation by regulating intracellular cytoplasmic pH of bacterial cells and transcription of ammonia monooxygenase, proteins having key roles in electron transport chain, ATP generation and fatty acid synthesis, and bacterial signal proteins that respond to environmental nitrite and nitrate and nitrous oxide reductase, a key enzyme in complete nitrate reduction. The present study is the first of its kind undertaken to investigate the metaproteome of ammonia oxidising consortium through which relevant proteins involved in efficient nitrification-denitrification could be revealed.

Antimicrobial peptides (AMPs) are gene encoded short peptides which play an important role in the innate immunity of almost all living organisms ranging from bacteria to mammals. Histones play a very important role in defense as precursors to bioactive peptides. The present study is an attempt to decipher the antimicrobial activity of a histone H2A derived peptide, Harriottin-1 from sicklefin chimaera, Neoharriotta pinnata. Analysis in silico predicted the molecule with potent antibacterial and anticancer property. The Harriottin-1 was recombinantly produced and the recombinant peptide rHar-1 demonstrated potent antibacterial activity at 25 μM besides anticancer activity. The study strongly suggests the importance of histone H2A derived peptides as a model for the design and synthesis of potent peptide drugs.

Antimicrobial peptides (AMPs) derived from histone proteins form an important category of peptide antibiotics. Present study deals with the molecular and functional characterization of a 27-amino acid histone H2A derived AMP from the Indian White shrimp, Fenneropenaeus indicus designated as Fi-Histin. This peptide displayed distinctive features of AMPs such as amphiphilic alpha helical structure and a net charge of +6. The synthetic peptide exhibited significant antimicrobial activity against Gram-negative and Gram-positive bacteria especially against V. vulnificus, P. aeruginosa, V. parahaemolyticus, V. cholera and S. aureus. Disruption of cell membrane and cell content leakage were observed in peptide treated V. vulnificus using scanning electron microscopy. The synthetic peptide Fi-His1-21 exhibited DNA binding activity and found to be non-haemolytic at the tested concentrations. Peptide was also found to possess anticancer activity against NCI–H460 and HEp-2 cell lines with an IC50 of 22.670 ± 13.939 μM and 31.274 ± 24.531 μM respectively. This is the first report of a histone H2A derived peptide from F. indicus with a specific antimicrobial activity and anticancer activity, which could be a new candidate for future applications in aquaculture and medicine.

Antimicrobial peptides (AMPs) are an important element of the innate immune system of all living organisms and serve as a barrier that safeguards the organisms against a wide range of pathogens. Fishes are proven to be a prospective source of AMPs, and β-defensins form an important family of AMPs with potent antimicrobial, chemotactic and immunomodulatory activities. The present study reports a β-defensin AMP sequence (Lc-BD) from the Asian sea bass, Lates calcarifer, a commercially important fish species in tropical and subtropical regions of Asia and the Pacific. A 202-bp cDNA fragment with an open reading frame encoding 63 amino acids (aa) was obtained from the mRNA of gill tissue by RT-PCR. The deduced aa sequence of Lc-BD possessed a signal and a mature peptide region with 20 and 43 aa residues, respectively. Lc-BD was characterized at the molecular level, and a molecular weight of 5.24 kDa and a net charge of +4.5 was predicted for the mature peptide. The molecular characterization of Lc-BD revealed the presence of three intramolecular disulphide bonds involving the six conserved cysteine residues in the sequence, and the phylogenetic analysis of Lc-BD showed a close relationship with β-defensins from fishes like Siniperca chuatsi, Argyrosomus regius, Trachinotus ovatus and Oplegnathus fasciatus.

Cell line development from shrimp is not a novel venture as researchers across the globe have been trying to have crustacean cell lines over 30 years. The reason for not attaining a crustacean or precisely a shrimp cell line is believed to be the replicative senescence and the inability to maintain telomere length in vitro. Moreover, spontaneous in vitro transformations do not happen in shrimp cells. Oncogenic induction in primary cell culture is one of the ways to attain in vitro transformation by way of disrupting the mechanisms which involve cellular senescence. In this context, a recombinant baculovirus with shrimp viral promoter IHHNV-P2 was used for the transduction aimed at immortalization. An oncogene, H-ras, was successfully amplified and cloned in to the baculoviral vector, downstream to shrimp viral promoter IHHNV-P2 and upstream to GFP. Recombinant baculovirus with H-ras was generated and used for transduction into shrimp lymphoid cells during early dividing stage. Accordingly, fibroblast-like primary cell culture got developed, and H-ras and GFP expression could be confirmed. The study suggests that the simple method of incubating recombinant baculovirus with minced tissue enables in vitro transduction during early dividing stage of the cells, and the transduction efficiency gets enhanced by adding 5 mM sodium butyrate to the culture medium.

Anti-lipopolysaccharide factors (ALFs) are antimicrobial peptides of approximately 100 amino acid residues with a broad spectrum of antimicrobial activity. It is an amphipathic peptide with an N-terminal hydrophobic region and a lipopolysaccharide binding domain (LBD). In the present study, we report an isoform of the anti-lipopolysaccharide factor (Mm-ALF) from the speckled shrimp, Metapenaeus monoceros. A 359 bp cDNA encoded 119 amino acids, and the sequence showed 99.16% similarity to ALF from the shrimp Fenneropenaeus indicus. The mature peptide of 94 amino acids has a net charge of +8, molecular weight 10.62 kDa, and pI 10.11. The mature peptide Mm-ALF was recombinantly expressed in E. coli Rosetta-gami cells, and the peptide was isolated and purified. The rMm-ALF exhibited notable antibacterial activity against Gram-positive (Staphylococcus aureus and Bacillus cereus) and Gram-negative (Escherichia coli, Edwardsiella tarda, Aeromonas hydrophila, Pseudomonas aeruginosa, Vibrio parahaemolyticus, Vibrio harveyi, Vibrio alginolyticus, Vibrio proteolyticus, Vibrio cholerae and Vibrio fluvialis) bacteria.

A new species of marine free living nematode Spinonema gracilispiculum sp. n. is described from the oxygen minimum zone of the eastern Arabian Sea (216m) margin. This new nematode species was found exclusively in the station with sandy texture and dissolved oxygen level 0.35 ml/l and are represented by only few individuals from a single location, despite analysing 288 core samples from an extensive survey along the eastern Arabian Sea OMZ region covering from 06°57′19″N to 21°30′639″N. Spinonema gracilispiculum sp. n. differs from other known species of the genus in the body length, position of the dorsal spine, contour and span of lateral alae, size and shape of spicules, number of pre cloacal setae and sexual dimorphism in presence of dorsal spine and amphideal fovea shape. This is the first record of the genus Spinonema from the Indian Ocean. A pictorial and dichotomous keys to the species of Spinonema are also provided, supplemented with comparative morphometric details of all valid species based on published information.

Antimicrobial peptides (AMPs) are biologically active molecules involved in host defense present in a variety of organisms. They are an integral component of innate immunity, forming a front line of defense against potential pathogens, including antibiotic-resistant ones. Fishes are proven to be a prospective source of AMPs as they are constantly being challenged by a variety of pathogens and the AMPs are reported to play an inevitable role in fish immunity. Among them, β-defensins form one of the most studied multifunctional peptides with early evolutionary history and recently being considered as host defense peptides. The present study highlights the first-ever report on β-defensin AMP sequences from common goby (Pomatoschistus microps) and silver trevally (Pseudocaranx georgianus). A 192 bp cDNA fragment with an open reading frame encoding 63 amino acids (aa) comprising a 20 aa signal peptide region at the N-terminal was obtained from the mRNA of gill tissue of both P. microps and P. georgianus by RT-PCR. These peptide sequences when characterized in silico at the molecular level revealed a 43 aa cationic mature peptide with the signature intra-molecular disulphide bonded cysteine residue pattern ascertaining its β-defensin identity, further confirmed by phylogenetic analysis. The data collected will pave the way for further research on varied facets of the peptide-like, tissue level expressions, antimicrobial activities on commonly encountered pathogens, and its feasibility as a therapeutant in the aquaculture scenario.

Diversity studies of endophytic assemblages are emerging challenges, which unveil novel phenotypes producing interesting chemical entities and a better understanding of their ecological significance. In the present investigation, we selected an extremely complex and unique environment supporting unexplored endophytes, ‘Macroalgae of Kerala coast, India’. Unlike terrestrial flora and mangroves, reports displaying endophytic assemblages of marine flora remain limited, especially from India. The main goal of this study was to expose hidden endophytic fungi from macroalgae and examination of their bioactive potential. An ecological investigation of four red, four green and three brown algae resulted in 133 fungal taxa with 29 distinct morphospecies. Aspergillus and Penicillium were found to be the dominant genera. Penicillium chrysogenum was the sole fungi that contributed 11% of the entire endophytic community. Antimicrobial activity against various aquaculture/human pathogens revealed that around 59% of endophytes inhibited at least one of the pathogens screened. The maximum number of isolates (37%) inhibited Escherichia coli tailed by Aspergillus fumigatus (27%). Antimicrobial profile of fungal endophytes endorses them as a potential source of bioactive molecules that can be explored to find a solution for drug resistance in microbial pathogens.

Salinity is an important environmental factor which usually goes unnoticed in shrimp growout systems. In the present study an attempt was done to analyse the physiological and immunological responses of Penaeus monodon to Vibrio harveyi infection under acute salinity stress. Shrimps were challenged with V. harveyi under 5‰ salinity stress, 35‰ salinity stress and optimal salinity (15‰) conditions by intramuscular injection. A control was maintained without bacterial challenge. Haemolymph was collected from shrimps soon after salinity change before V. harveyi challenge (post salinity change day (PSD) 0), on post challenge day (PCD) 2, 7 and 10. Immune variables viz., total haemocyte count (THC), phenol oxidase activity (PO), Nitroblue tetrazolium salt (NBT) reduction, alkaline phosphatase activity (ALP), acid phosphatase activity (ACP) and metabolic variables viz., total protein (TP), total carbohydrates (TC), total free amino acids (TFAA), total lipids (TL), glucose (Gl) and cholesterol (Ch) were then determined. One way ANOVA followed by Duncan's multiple comparison of the means revealed significant differences between shrimps subjected to different salinity conditions and then challenged with V. harveyi (P < 0.05). Post challenge survival was significantly higher in shrimps maintained at 15‰ and acute salinity stress reduced the survival rate. However, pathogenicity of V. harveyi was slightly higher at 35‰ than at 5‰. At the onset of salinity stress, parameters viz., THC, NBT and ACP significantly reduced and TC increased at 5‰ and 35‰. Following V. harveyi challenge, an overall increase could be observed in metabolic variables on PCD2 and immune variables on PCD2 and 7 in P. monodon maintained at 15‰ compared to the control. Even though an increase in immune response and metabolic variables could be obtained on post challenge days in shrimps under salinity stress compared to the control, it was considerably low in comparison with shrimps maintained at 15‰. Regression analysis proved that NBT, ALP, TP and TL could be proposed as potential stress indicators to evaluate shrimp health status. In brief, it may be concluded from the study that acute salinity changes evoke physiological responses that affect the immunocompetence and metabolic performance of P. monodon against V. harveyi challenge, thereby increasing the susceptibility to infection. Moreover higher salinity enhanced the pathogenicity of V. harveyi.

Antimicrobial peptides (AMPs) comprise molecules that involve in the defense mechanism of various organisms towards pathogens such as bacteria, fungi, parasites and viruses. Crustins are generally defined as multi-domain cationic antimicrobial peptides containing one whey acidic protein (WAP) domain at the C-terminus as the functional unit. In this study, we identified and characterized a novel crustin homolog (Fi-Crustin2) with 354 bp fragment cDNA encoding 117 amino acids and an ORF of 100 amino acids with a net charge of +1 from the mRNA of F. indicus haemocytes. This study forms the second report of a crustin isoform from F. indicus. Blast analysis revealed that Fi-crustin2 exhibits similarity to shrimp crustins already reported. The active mature peptide has a molecular weight of 10.61 kDa and pI of 7.59 with a beta sheeted structure. The mature peptide was cloned into pET-32a(+) with a N-terminal hexa-histidine tag fused in-frame, and expressed in Escherichia coli, and the recombinant crustin, Fi-crustin2 inhibited the growth of Gram-negative bacteria with low MIC. All these features suggest that Fi-crustin2 is a potent antibacterial protein against Gram-negative bacteria and could play an important role in the innate immune mechanism of F. indicus.

Endophytic fungi have currently been acknowledged as the most promising source of bioactive compounds for drug discovery, and considerable progress has been made in exploring their diversity, species richness, and bioprospecting. Fungal endophytes from unique environmental settings offer a pool of potentially useful medicinal entities. Owing to the constant stresses imposed on macroalgae by marine environments, it is believed that algae and their associated endophytic symbionts represent a good source of structurally diverse bioactive secondary metabolites. Despite the proven significance of active metabolites of algal endophytes, little have been exploited. This review highlights the latest discoveries in algicolous endophytic research, with particular focus on the bioactive metabolites from algal endophytes. Compounds are classified according to their reported biological activities, like anticancer, antibacterial, antifungal, and antioxidant properties. Present experimental evidence suggests that a majority of the bioactive metabolites were reported from Phaeophyceae followed by Rhodophyceae and Chlorophyceae. An intensive search for newer and more effective bioactive metabolites has generated a treasure trove of publications, and this review partially covers the literature published up to 2016.

Aim Production and characterization of polyhydroxybutyrate (PHB) from moderately halophilic bacterium Vibrio harveyi MCCB 284 isolated from tunicate Phallusia nigra. Methods and Results Twenty five bacterial isolates were obtained from tunicate samples and three among them exhibited an orange fluorescence in Nile red staining indicating the presence of PHB. One of the isolates, MCCB 284, which showed rapid growth and good polymer yield, was identified as V. harveyi. The optimum conditions of the isolate for the PHB production were pH 8.0, sodium chloride concentration 20 g l−1, inoculum size 0.5% (v/v), glycerol 20 g l−1 and 72 h of incubation at 30°C. Cell dry weight of 3.2 g l−1, PHB content of 2.3g l−1 and final PHB yield of 1.2 g l−1 were achieved. The extracted PHB was characterized by FTIR, NMR and DSC-TGA techniques. Conclusion An isolate of Vibrio harveyi that could effectively utilize glycerol for growth and PHB accumulation was obtained from tunicate Phallusia nigra. PHB produced was up to 72% based on cell dry weight. Significance and impact of the study This is the first report of an isolate of Vibrio harveyi which utilizes glycerol as the sole carbon source for PHB production with high biomass yield. This isolate could be of use as candidate species for commercial PHB production using glycerol as the feed stock or as source of genes for recombinant PHB production or for synthetic biology. This article is protected by copyright. All rights reserved.

Antimicrobial peptides play a crucial role in the innate immune defence mechanism of various organisms. Anti-lipopolysaccharide factors (ALFs) and their derivatives are a type of cationic AMPs which exhibit broad spectrum antimicrobial activities. This study identified and characterized an anti-lipopolysaccharide factor (Md-ALF) from the haemocytes of Indian flower tail shrimp, Metapenaeus dobsoni. The cDNA of Md-ALF consisted of 294 bp with 98 deduced amino acids. The deduced protein sequence possessed a LPS binding domain and shared highest sequence identity with shrimp ALFs. It showed an isoelectric point of 9.76 and a net positive charge of +7. The secondary structure analysis revealed the presence of three helices, four β turns and three β hairpin like structures. In silico analysis revealed that Md-ALF has anti-bacterial, anti-viral, anti-fungal and anti-cancer properties. Phylogenetic analysis revealed the ancestral relationship of Md-ALF with other shrimp ALFs. Molecular and physico- chemical characterization of Md-ALF showed similarity with reported ALFs from other crustaceans, suggesting its possible role in the innate defence mechanism of M. dobsoni.

A novel esterase, designated as EstSP was identified by function based screening from a soil metagenomic fosmid library of solar saltern of Goa. EstSP gene of 1065 bp encoding a putative esterase of 354 amino acids showing 55% identity to esterase from gamma proteobacterium HIMB55 was identified. The enzyme EstSP belongs to family IV hormone sensitive lipase with novel sequence characteristics and a unique motif GDSGG. EstSP expressed as a His-tag fusion protein of mass 58 kDa was visualized on SDS PAGE and confirmed by Western blot analysis. The enzyme is an alkaline esterase that exhibited highest catalytic activity towards p-nitrophenyl acetate with optimum temperature 40 °C and pH 8.0. The catalytic efficiency and specific activity of EstSP for p-nitrophenyl acetate was 7407.4 min−1 mM−1 and 915.23 U mg−1 respectively. EstSP showed remarkable stability in the presence of polar and non-polar solvents, retaining >80% of its activity after 72 h. Furthermore, the enzyme is halotolerant with optimum activity at 1 M NaCl and maintained 60% residual activity after 24 h exposure to 5 M NaCl. This novel enzyme with remarkable properties could be a promising candidate for industrial bioprocesses in non-aqueous media as well as pharmaceutical, food and biotechnological applications.