23 results on '"Gopal Dharani"'
Search Results
2. Unraveling the potential of bacteria isolated from the equatorial region of Indian Ocean in mercury detoxification
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Gajendra Joshi, Pankaj Verma, Balakrishnan Meena, Prasun Goswami, D Magesh Peter, Dilip Kumar Jha, Nambali Valsalan Vinithkumar, and Gopal Dharani
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Global and Planetary Change ,Ocean Engineering ,Aquatic Science ,Oceanography ,Water Science and Technology - Abstract
The marine environment is most vital and flexible with continual variations in salinity, temperature, and pressure. As a result, bacteria living in such an environment maintain the adaption mechanisms that are inherent in unstable environmental conditions. The harboring of metal-resistant genes in marine bacteria contributes to their effectiveness in metal remediation relative to their terrestrial counterparts. A total of four mercury-resistant bacteria (MRB) i.e. NIOT-EQR_J7 (Alcanivorax xenomutans); NIOT-EQR_J248 and NIOT-EQR_J251 (Halomonas sp.); and NIOT-EQR_J258 (Marinobacter hydrocarbonoclasticus) were isolated from the equatorial region of the Indian Ocean (ERIO) and identified by analyzing the 16S rDNA sequence. The MRBs can reduce up to 70% of Hg(II). The mercuric reductase (merA) gene was amplified and the mercury (Hg) volatilization was confirmed by the X-ray film method. The outcomes obtained from ICP-MS validated that the Halomonas sp. NIOT-EQR_J251 was more proficient in removing the Hg from culture media than other isolates. Fourier transform infrared (FT-IR) spectroscopy results revealed alteration in several functional groups attributing to the Hg tolerance and reduction. The Gas Chromatography-Mass Spectrometry (GC-MS) analysis confirmed that strain Halomonas sp. (NIOT-EQR_J248 and NIOT-EQR_J251) released Isooctyl thioglycolate (IOTG) compound under mercury stress. The molecular docking results suggested that IOTG can efficiently bind with the glutathione S-transferase (GST) enzyme. A pathway has been hypothesized based on the GC-MS metabolic profile and molecular docking results, suggesting that the compound IOTG may mediate mercuric reduction via merA-GST related detoxification pathway.
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- 2022
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3. Comparative evaluation of heavy metal concentration in different organs of the asian seabass: A multivariate approach
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Manasi Venkat Koduvayur, Shrivarshini Vasudevan, Vikas Pandey, Jayapal Santhanakumar, Dilip Kumar Jha, and Gopal Dharani
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Global and Planetary Change ,Ocean Engineering ,Aquatic Science ,Oceanography ,Water Science and Technology - Published
- 2022
4. A Looming Chance of Bio Invasion by a Bryozoan Amathia verticillata Among the Sea Fan and Seagrass Population Along Tamil Nadu Coast: A Case Study
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J. Santhana Kumar, B. Rajan Babu, Dilip Kumar Jha, Vijaya Ravichandran, J. Prince Prakash Jeba Kumar, S. Ragumarn, Ganesan Nandhagopal, and Gopal Dharani
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education.field_of_study ,geography.geographical_feature_category ,biology ,Halophila ovalis ,Immunology ,Population ,Biodiversity ,Cell Biology ,Aquatic Science ,biology.organism_classification ,language.human_language ,Fishery ,Endocrinology ,Seagrass ,Geography ,Insect Science ,Tamil ,Cymodocea ,Genetics ,language ,Animal Science and Zoology ,Colonization ,education ,Reef ,Ecology, Evolution, Behavior and Systematics - Abstract
A rapid survey was carried out to evaluate the status of a diverging bryozoan Amathia verticillata (delle Chiaje 1822) around the natural milieu after their successions on artificial coastal defense structures Tamil Nadu coast. This research communicates its incidence with sea fan Subergorgia suberosa and seagrass Cymodocea serrulate, Halophila ovalis in the nearshore reef environment of Tuticorin coast, Tamil Nadu, India. Thus, the rare Colonization of bryozoan on the sea fan was unique and reported for the first time in India.
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- 2021
5. Evaluating the effect of various environmental factors on the growth of the marine microalgae, Chlorella vulgaris
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Anthony Josephine, Thalavai Shivasankarasubbiah Kumar, Baskaran Surendran, Sundaram Rajakumar, Ramalingam Kirubagaran, and Gopal Dharani
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Global and Planetary Change ,Ocean Engineering ,Aquatic Science ,Oceanography ,Water Science and Technology - Published
- 2022
6. Assessment of biogrowth assemblages with depth in a seawater intake system of a coastal power station
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G. A. Ramadass, B. N. Jyothi, D. Muthukumaran, Toleti Subba Rao, M. Murugesan, R. Ramesh, J. Santhanakumar, D. S. Narayanan, P. S. Murthy, Gopal Dharani, A. Vadivelan, and P. Veeramani
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0301 basic medicine ,Biomass (ecology) ,Biofouling ,030106 microbiology ,Aquatic Science ,Silt ,Applied Microbiology and Biotechnology ,Bivalvia ,03 medical and health sciences ,030104 developmental biology ,Oceanography ,Abundance (ecology) ,Animals ,Environmental science ,Seawater ,Biomass ,Water Science and Technology - Abstract
Marine biogrowth infestation of a seawater intake system was investigated. A digital camera fixed onto a skid was used to record the biogrowth at intervals of 5 m up to a depth of 55 m. Divers inspected the intake shaft and collected the biogrowth samples for biomass estimation. A biomass density of 7.5 kg m-2 and 28.2 kg m-2 was recorded at 5 and 30 m depths respectively. Inspection by the divers revealed that hard-shelled organisms such as oysters and brown and green mussels were observed in plenty up to a thickness of 15 cm and bryozoans grew as epibionts. At lower depths (
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- 2021
7. Evaluation of Physicochemical Characteristics of Coastal Waters of Nellore, Southeast Coast of India, by a Multivariate Statistical Approach
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Krupa Ratnam, Dilip Kumar Jha, M. Prashanthi Devi, and Gopal Dharani
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Global and Planetary Change ,Ocean Engineering ,Aquatic Science ,Oceanography ,Water Science and Technology - Abstract
The Swarnamukhi river estuary (SRE), and the surrounding sea in Nellore, southeast coast of India, is one of the least studied marine environments, notably for physicochemical characteristics. Seawater samples were collected from five stations every month from 2014 to 2017 to assess physicochemical characteristics. The open sea (OS) station was significantly different from the inner stations, according to non-metric multidimensional scaling and cluster analysis. The variability was shown by strong factor loadings of atmospheric temperature (0.87), water temperature (0.84), biochemical oxygen demand (0.77), ammonia (0.85), and total nitrogen (0.78). Furthermore, one-way ANOVA and box-whisker plots facilitated simplifying and corroborating multivariate results that showed high concentration in the inner stations. Based on the N/P and Si/N ratios, nitrate and silicate were the key limiting factors in this study. The findings are critical for establishing reference conditions for comparison studies with other comparable ecosystems in the tropical region for better environmental conservation and management.
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- 2022
8. Evaluation of trace metals in seawater, sediments, and bivalves of Nellore, southeast coast of India, by using multivariate and ecological tool
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Dilip Kumar Jha, S. Rajaguru, M. Prashanthi Devi, Gopal Dharani, Krupa Ratnam, and Ramalingam Kirubagaran
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0106 biological sciences ,Geologic Sediments ,Multivariate statistics ,Metal contamination ,Oceans and Seas ,India ,010501 environmental sciences ,Aquatic Science ,Oceanography ,01 natural sciences ,Open sea ,Risk index ,Animals ,Seawater ,Trace metal ,0105 earth and related environmental sciences ,Ecology ,010604 marine biology & hydrobiology ,Urbanization ,Sediment ,Contamination ,Pollution ,Bivalvia ,Trace Elements ,Metals ,Environmental chemistry ,Environmental science ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
Urbanization in recent years has driven us to investigate metal contamination on Nellore coast by collecting seawater, sediment, and bivalve samples monthly at five stations from 2015 to 2017. Non-metric multidimensional scaling and cluster analysis indicated that open sea (OS) samples were markedly different from the samples collected at other stations. Strong factor loadings of Al (0.76), Mn (0.79), and Cd (0.78) showed variability in seawater, while those for Fe (0.76), Ni (0.77), Zn (0.85), and Pb (0.81) showed variability in sediment. The mean values of Fe (346 ppm) and Mn (21 ppm) were high in bivalves compared to the mean values of other metals. A higher contamination factor was observed for Cd at Buckingham Canal, while the lowest was observed for sediment in OS. The order of trace metals in sediments according to risk index was Cd > Pb > Cu > Cr > Zn. The results obtained are essential to establish a reference for better comparison of tropical environments.
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- 2019
9. Characteristics and dynamics of Salmonella diversity and prevalence of biomarker genes in Port Blair Bays, South Andaman, India
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Gopal Dharani, Balakrishnan Meena, Karuppaiya Selvaganapathi, Nambali Valsalan Vinithkumar, and Lawrance Anburajan
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0106 biological sciences ,Serotype ,Salmonella ,Veterinary medicine ,medicine.drug_class ,Microorganism ,Antibiotics ,Virulence ,India ,Microbial Sensitivity Tests ,010501 environmental sciences ,Aquatic Science ,Biology ,Oceanography ,medicine.disease_cause ,01 natural sciences ,Antibiotic resistance ,medicine ,Prevalence ,Humans ,Ecosystem ,0105 earth and related environmental sciences ,010604 marine biology & hydrobiology ,biology.organism_classification ,Pollution ,Anti-Bacterial Agents ,Multiple drug resistance ,Bays ,Salmonella enterica ,Biomarkers - Abstract
Salmonella is a major cause of morbidity and mortality in humans worldwide, and the infection with multidrug-resistant strains can cause severe diseases. Many coastal cities around the world discharge their wastewaters into the marine environment. These wastewaters contain a variety of pathogenic microorganisms that may have a role in the contamination of this ecosystem and have potential risks for public health. Using an environmental approach, the present study investigated the presence of Salmonella in sediment and water samples collected from Port Blair Bays. In this environmental approach, the provided information about the diversity of the Salmonella serovars, antibiotic resistance and the prevalence of virulence factors in Salmonella, especially from the coastal waters of Port Blair Bays. The occurrence of Salmonellae was significantly higher in water column samples (2.9%) than in those taken from the marine sediments (0.7%). Of the 133 positive Salmonella strains, 22 different serovars were identified. Salmonella enterica serovar Senftenberg was the predominant serovar, being represented by 54 isolates (42.5%), followed by serovar Typhimurium (19 isolates [15%]) and serovar Agona (12 isolates [9.4%]). The presence of virulence genes (filC, sitC, hilA, invA, sipC, hilD, hilC, invF, invE, invH, sipF, aadA, pare, gyrA, spaP and parC) and susceptibility studies with 10 selected antibiotics were also performed. The results of this study revealed that all Salmonella isolates were positive for targeted virulence genes and were resistant to at least one antibiotic. Antibiotic susceptibility studies revealed the presence of multidrug resistant Salmonella strains in coastal water, which usually from land base sources end up in the marine environment and may pose a significant risk on public health.
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- 2020
10. First evidence of microplastics bioaccumulation by marine organisms in the Port Blair Bay, Andaman Islands
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Nambali Valsalan Vinithkumar, Prasun Goswami, and Gopal Dharani
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0106 biological sciences ,Pollution ,Microplastics ,Aquatic Organisms ,media_common.quotation_subject ,010501 environmental sciences ,Aquatic Science ,Oceanography ,01 natural sciences ,Zooplankton ,Animals ,Shellfish ,Ecosystem ,0105 earth and related environmental sciences ,media_common ,Islands ,010604 marine biology & hydrobiology ,Sediment ,Bioaccumulation ,Fishery ,Bays ,Environmental science ,Plastic pollution ,Bay ,Plastics ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
Microplastic (MP) pollution has become a global concern. We aim to quantify the extent of MP pollution in the coastal ecosystem of the Port Blair Bay, A&N Islands. Water, sediment, zooplankton, finfish, and shellfish samples were collected from the Port Blair Bay and analyzed for the presence of MP. Average concentrations of MP in water, sediment, zooplankton, finfish, and shellfishes were found to be 0.93 ± 0.59 particles per m3, 45.17 ± 25.23 particles per kilogram, 0.12 ± 0.07 pieces per zooplankter and 10.65 ± 7.83 particles per specimen, respectively. High amount of MP retention was observed in the zooplankton community. Maximum MP ingestion was observed in adult Carangoides malabaricus. Fiber was most abundant in water, sediment, and fish samples, followed by fragment and pellet. However, fragments were predominant in zooplankton. Nylon, acrylic, and ionomer surlyn were most abundant polymer types in the bay environment. These results demand further attention to combat plastic pollution in the coastal ecosystem.
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- 2020
11. Evaluation of the environmental quality of Parangipettai, Southeast Coast of India, by using multivariate and geospatial tool
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Dilip Kumar Jha, Thangaraj Satheeswaran, Velmurugan Karthikeyan, Gopal Dharani, Thangavel Balasubramanian, Palani Damotharan, Purushothaman Yuvaraj, and Ramalingam Kirubagaran
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0106 biological sciences ,Multivariate statistics ,India ,010501 environmental sciences ,Aquatic Science ,Oceanography ,01 natural sciences ,Water Quality ,Phytoplankton ,Seawater ,Ecosystem ,0105 earth and related environmental sciences ,Hydrology ,geography ,geography.geographical_feature_category ,010604 marine biology & hydrobiology ,Temperature ,Sampling (statistics) ,Phosphorus ,Estuary ,Atmospheric temperature ,Pollution ,Multivariate Analysis ,Geographic Information Systems ,Environmental science ,Common spatial pattern ,Water quality ,Estuaries ,Environmental Monitoring - Abstract
The anthropogenic pressure in recent years has driven us to investigate the environmental quality at 22 stations in Parangipettai by collecting seawater samples monthly from 2014 to 2015. The sampling stations were grouped into three different environments, namely, Vellar Estuary (VE), Coleroon Estuary (CE), and Open Sea (OS). Factor analysis showed a total variance of 65.63% and exhibited a strong factor loading for atmospheric temperature (0.914), water temperature (0.917), ammonia (0.767), inorganic phosphate (0.897), total phosphorus (0.783), and phytoplankton (0.829). The index value showed water quality was good in OS (74.18), whereas it was moderate in VE (69.73) and CE (68.47). The visual model developed using Geographical Information System (GIS) displayed a spatial pattern of water temperature and phytoplankton dispersion in a distinct manner. The results obtained through multivariate analysis and GIS-based model are imperative to establish reference for a comparative study with other similar ecosystem for better planning and management of tropical seawaters.
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- 2018
12. Deep-sea mercury resistant bacteria from the Central Indian Ocean: A potential candidate for mercury bioremediation
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Gajendra Joshi, Jibananand Nayak, Pankaj Verma, Balakrishnan Meena, Gopal Dharani, and Nambali Valsalan Vinithkumar
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0106 biological sciences ,Bacillus ,chemistry.chemical_element ,010501 environmental sciences ,Aquatic Science ,Oceanography ,01 natural sciences ,Deep sea ,Bioremediation ,Pseudoalteromonas ,RNA, Ribosomal, 16S ,Indian Ocean ,0105 earth and related environmental sciences ,Bacteria ,biology ,010604 marine biology & hydrobiology ,Pseudomonas ,Mercury ,biology.organism_classification ,Pollution ,Mercury (element) ,Biodegradation, Environmental ,chemistry ,Environmental chemistry ,Seawater - Abstract
Deep-sea bacteria when grown in normal environmental conditions get morphologically and genetically adapted to resist the provided culture conditions for their survival, making them a possible aspirant in mercury bioremediation. In this study, seawater samples were collected from different depths of the Central Indian Ocean and seven mercury resistant bacteria (resistant to 100 mg L-1 concentration of inorganic Hg as HgCl2) were isolated. Based on 16S rRNA gene sequencing, the identified isolates belong to the genera Pseudomonas, Bacillus and Pseudoalteromonas. The presence of the merA gene in the isolates contributes to the effective volatilization of mercury. The Inductively Coupled Plasma Mass-Spectroscopy analysis revealed that the isolates can reduce up to >80% of inorganic mercury. Moreover, Fourier Transform Infrared spectrum analysis indicates that functional groups play a key role in the mechanism of adaptation towards Hg2+ reduction. Thus, the deep-sea bacteria expressed significant tolerance and reduction potential towards ionic mercury.
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- 2021
13. Evaluation of factors influencing the trace metals in Puducherry and Diu coasts of India through multivariate techniques
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S. Rajaguru, Pankaj Verma, Gopal Dharani, Dilip Kumar Jha, R. Sendhil Kumar, and Krupa Ratnam
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0106 biological sciences ,Geologic Sediments ,Multivariate statistics ,010604 marine biology & hydrobiology ,India ,Sediment ,010501 environmental sciences ,Aquatic Science ,Contamination ,Oceanography ,Risk Assessment ,01 natural sciences ,Pollution ,Metals, Heavy ,Environmental chemistry ,Risk index ,Sediment contamination ,Environmental science ,Trace metal ,Water Pollutants, Chemical ,Environmental Monitoring ,0105 earth and related environmental sciences - Abstract
In recent years, urban and industrial development initiatives at Puducherry and Diu such as tourism, shipping, and fisheries have led to sediment contamination by trace metals, and contributed to this investigation that extended from 2016 to 2017. Strong factor loadings of Cd (0.94), Ni (0.84), Al (0.84), Cr (0.83), Co (0.82), and Fe (0.78) illustrated the variability at Puducherry, whereas Cr (0.88), Cd (0.86), Ni (0.83), Co (0.77), Cu (0.77), and Fe (0.77) showed variability at Diu. The mean rank order distribution of the top three metals in sediment was Fe > Al > Mn, which exhibited higher variability. The highest contamination factor was observed for Cd at Diu, whereas the lowest was observed at Puducherry for Al. Similarly, the risk index also exhibited considerable risk which could be attributed to Cd contamination in the sediment at Diu compared with that at Puducherry. The results obtained are essential to establish a reference for better comparison and management of the tropical environments.
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- 2021
14. Microplastics particles in seafloor sediments along the Arabian Sea and the Andaman Sea continental shelves: First insight on the occurrence, identification, and characterization
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Prasun Goswami, Gopal Dharani, and Nambali Valsalan Vinithkumar
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0106 biological sciences ,Geologic Sediments ,Microplastics ,Oceans and Seas ,010501 environmental sciences ,Aquatic Science ,Oceanography ,01 natural sciences ,Sink (geography) ,Spectroscopy, Fourier Transform Infrared ,Marine debris ,0105 earth and related environmental sciences ,geography ,geography.geographical_feature_category ,Continental shelf ,010604 marine biology & hydrobiology ,Sediment ,Pollution ,Seafloor spreading ,Benthic zone ,Plastics ,Water Pollutants, Chemical ,Geology ,Environmental Monitoring - Abstract
Microplastics (MPs) are widely-recognized contaminants and marine sediments act as a sink of MPs and therefore may cause a potential threat to benthic communities. We aim to analyze the MPs abundances and characteristics in the seafloor sediments from the continental shelves of the Arabian and Andaman seas. Twenty-two seafloor sediments were collected from 8 and 14 locations of the Arabian and Andaman seas, respectively. MPs concentrations varied from not detected (ND) to 267 particles kg−1 with mean values of 128.02 ± 33.92 and 15.36 ± 2.61 particles kg−1, respectively for the Arabian and Andaman seas. Among different shapes, fiber had the highest distribution over fragments and pellet. FT-IR analysis revealed acrylic was most dominant polymer, followed by polyethylene, and nylon. Mean MP concentration at the Arabian Sea was significantly higher (p
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- 2021
15. Studies on diversity of Vibrio sp. and the prevalence of hapA, tcpI, st, rtxAC, acfB, hlyA, ctxA, ompU and toxR genes in environmental strains of Vibrio cholerae from Port Blair bays of South Andaman, India
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Nambali Valsalan Vinithkumar, Apurba Kumar Das, Gopal Dharani, T. Sathish, Balakrishnan Meena, Lawrance Anburajan, and Ramalingam Kirubagaran
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0106 biological sciences ,Veterinary medicine ,Tetracycline ,Virulence Factors ,Virulence ,India ,010501 environmental sciences ,Aquatic Science ,Oceanography ,medicine.disease_cause ,01 natural sciences ,Species Specificity ,Drug Resistance, Bacterial ,medicine ,Prevalence ,Humans ,Vibrio cholerae ,0105 earth and related environmental sciences ,geography ,geography.geographical_feature_category ,biology ,010604 marine biology & hydrobiology ,Vibrio parahaemolyticus ,Species diversity ,Estuary ,Biodiversity ,biology.organism_classification ,Pollution ,Vibrio ,Bays ,Genes, Bacterial ,Bay ,medicine.drug - Abstract
Vibrio species are widely distributed in the estuarine and coastal waters that possess the greatest threat to human health worldwide. In this study it is aimed to isolate and observe the abundance of Vibrio sp. and prevalence of biomarker genes and antibiotic resistance profile of V. cholerae isolated from the Port Blair bays of South Andaman. A total of 56 water samples were collected from the seven sampling stations of Port Blair bays in which maximum number of Vibrio sp. population density (1.78 × 104) was recorded in Phoenix Bay. Among the 786 isolates 57.38% of the isolates were confirmed as Vibrio sp., Vibrio cholerae and Vibrio parahaemolyticus. PCR results revealed that the prevalence of biomarker genes was recorded maximum in the isolates from Phoenix Bay and Junglighat Bay samples. Upon further analysis, it was observed that the prevalence of hlyA gene (215 bp), was found to be the most widespread biomarker determinant in 84.17% of isolates. Major virulence determinants; ctxA, ompU and toxR genes were not detected in V. cholerae isolates from Port Blair bays. Maximum antibiotic resistance pattern was observed in Phoenix Bay isolates and maximum number of V. cholerae isolates was resistance to tetracycline (60.76%). Cluster and Principal Component Analysis were employed to understand the diversity and distribution of Vibrio isolates and its biomarker genes. Upon PCA analysis seasonal influence was not much perceived in Vibrio species diversity in Port Blair bays and the lack of significant difference in the detection of species diversity in this study is due to resemblance in geographical conditions and sources of pollution.
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- 2019
16. Biodegradation of crude oil using self-immobilized hydrocarbonoclastic deep sea bacterial consortium
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Gopal Dharani, A. Ganesh Kumar, Ramalingam Kirubagaran, and N. Nivedha Rajan
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0106 biological sciences ,Dietary Fiber ,Geologic Sediments ,Magnetic Resonance Spectroscopy ,Nitrogen ,Ruegeria ,Microbial Consortia ,010501 environmental sciences ,Aquatic Science ,Oceanography ,01 natural sciences ,Gas Chromatography-Mass Spectrometry ,Bioremediation ,RNA, Ribosomal, 16S ,Spectroscopy, Fourier Transform Infrared ,Seawater ,Food science ,Microbial biodegradation ,Rhodobacteraceae ,Indian Ocean ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,biology ,Acinetobacter ,Chemistry ,010604 marine biology & hydrobiology ,Phosphorus ,Biodegradation ,Cells, Immobilized ,Photobacterium ,biology.organism_classification ,Exiguobacterium ,Pollution ,Hydrocarbons ,Pseudoalteromonas ,Hydrocarbon ,Biodegradation, Environmental ,Petroleum ,Energy source - Abstract
Hydrocarbonoclastic bacterial consortium that utilizes crude oil as carbon and energy source was isolated from marine sediment collected at a depth of 2100 m. Molecular characterization by 16S rRNA gene sequences confirmed that these isolates as Oceanobacillus sp., Nesiotobacter sp., Ruegeria sp., Photobacterium sp., Enterobacter sp., Haererehalobacter sp., Exiguobacterium sp., Acinetobacter sp. and Pseudoalteromonas sp. Self-immobilized consortium degraded more than 85% of total hydrocarbons after 10 days of incubation with 1% (v/v) of crude oil and 0.05% (v/v) of Tween 80 (non-ionic surfactant) at 28 ± 2 °C. The addition of nitrogen and phosphorus sources separately i.e. 0.1% (v/v) of CO (NH2)2 or K2HPO4 enhanced the hydrocarbon utilization percentage. The pathways of microbial degradation of hydrocarbons were confirmed by FTIR, GC–MS, 1H and 13C NMR spectroscopy analyses. These results demonstrated a novel approach using hydrocarbonoclastic self-immobilized deep sea bacterial consortium for eco-friendly bioremediation.
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- 2018
17. Assessment of ecological health of Swarnamukhi river estuary, southeast coast of India, through AMBI indices and multivariate tools
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Vikas Pandey, P. Sathish Kumar, S. Rajaguru, Dilip Kumar Jha, Srinivas Venkatnarayanan, Gopal Dharani, and Krupa Ratnam
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0106 biological sciences ,Pollution ,Geologic Sediments ,Multivariate statistics ,media_common.quotation_subject ,India ,010501 environmental sciences ,Aquatic Science ,Silt ,Oceanography ,01 natural sciences ,Rivers ,Metals, Heavy ,Organic matter ,Ecosystem ,0105 earth and related environmental sciences ,media_common ,chemistry.chemical_classification ,Hydrology ,geography ,geography.geographical_feature_category ,010604 marine biology & hydrobiology ,Sediment ,Ecological assessment ,Estuary ,chemistry ,Benthic zone ,Environmental science ,Estuaries ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
A combination of biotic indices, geo-accumulation (Igeo) index, and a multivariate approach were applied to assess the anthropogenic influence on the benthic community at five stations from 2018 to 2019 in the Swarnamukhi river estuary, Nellore, India. Non-metric multidimensional scaling and cluster analysis indicated that the Buckingham canal (BC) station showed azoic conditions and formed a separate cluster. Strong positive factor loadings of Cd (0.96), Al (0.93), Zn (0.91), Fe (0.90), Co (0.89), Cu (0.89), Ni (0.87), Pb (0.85), Cr (0.77), organic matter (0.94), Silt (0.92), and clay (0.93) and negative loading of sand (−0.90) showed the variability in sediment. AMBI results illustrated the disturbance status of each station and classified BC station as ‘extremely disturbed’ class, and M-AMBI assessed the ecological status as ‘bad’. The Igeo index also revealed metal (Cd) contamination. The present study illustrated that the combined approach is effective for ecological assessment of coastal ecosystem.
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- 2021
18. Impact of a dinoflagellate bloom on the marine plankton community structure of Port Blair Bay, Andaman Island
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Gopal Dharani, Nambali Valsalan Vinithkumar, Ramalingam Kirubagaran, Sanjoy Gupta, Prasun Goswami, and Apurba Kumar Das
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0106 biological sciences ,education.field_of_study ,010504 meteorology & atmospheric sciences ,Ecology ,biology ,010604 marine biology & hydrobiology ,Population ,Dinoflagellate ,Aquatic Science ,Plankton ,biology.organism_classification ,01 natural sciences ,Algal bloom ,Oceanography ,Phytoplankton ,Environmental science ,Animal Science and Zoology ,education ,Bloom ,Bay ,Ecology, Evolution, Behavior and Systematics ,Copepod ,0105 earth and related environmental sciences - Abstract
An intense heterotrophic dinoflagellate bloom caused by Protoperidinium quinquecorne was observed at Port Blair Bay during May 2017. The bloom appeared during a period of significantly higher (p ± 1 . 66 ° C) and seawater salinity (33.21 ± 0.27 PSU) than the pre-bloom and post-bloom phase. Subsequently, we investigated the bloom impact on water quality and plankton community structure. Dissolved oxygen (DO) was reduced significantly (p ± 1 . 27 μ mol l−1) and chlorophyll-a (0.86 ± 0.7 mg m−3) concentrations, respectively were observed during the bloom phase, that coincided with an increase in P. quinquecorne grazing pressure on the diatom population. Ammonia enrichment was recorded post-bloom, which was associated with anaerobic decomposition of dead bloom biomass. P. quinquecorne population density increased from 20 cells l−1 (pre-bloom) to 3.36x106 cells l−1 (bloom) and contributed up to 99.93% of the total phytoplankton community. P. quinquecorne grazed on micro-diatom and smaller tintinnids, resulting in a significant decrease in their abundance. The cyclopoid copepod Oithona spp. responded positively to the P. quinquecorne population and caused a considerable reduction in their abundance during post-bloom. This heterotrophic bloom was the result of high temperature and salinity conditions, coupled with the availability of preferred prey species (micro-diatom). Future monitoring studies are needed to predict harmful algal blooms (HABs) occurrence and their impact on the coastal fishery.
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- 2020
19. Review on plastic wastes in marine environment – Biodegradation and biotechnological solutions
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K Anjana, K. Sujitha, A. Ganesh Kumar, M. Hinduja, and Gopal Dharani
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0106 biological sciences ,Pollution ,Aquatic Organisms ,Polymers ,media_common.quotation_subject ,Marine life ,010501 environmental sciences ,Aquatic Science ,Oceanography ,01 natural sciences ,Marine species ,0105 earth and related environmental sciences ,media_common ,Waste Products ,Waste management ,010604 marine biology & hydrobiology ,fungi ,Research needs ,Contamination ,Biodegradation ,Biodegradation, Environmental ,Microbial enzymes ,Environmental science ,Plastic pollution ,Plastics ,Water Pollutants, Chemical - Abstract
The marine plastic pollution has drastic effect on marine species. The importance in environmental issues increases the demand to develop a significant technology which does not burden the marine environment or marine life forms. To mitigate the foreseen problems of micro and nanoplastic contamination, different biotechnological solutions has to be considered. Microbial communities exposed to plastic contaminated sites can adapt and form dense biofilms on the plastic surface and produce active catalytic enzymes. These enzymes can be able to degrade the synthetic polymers. In view of their high catalytic activity, microbial enzymes can be applicable for the degradation of synthetic polymers. This review highlights the toxicity of micro and nanoplastics on marine organisms, biodegradation of plastics and futuristic research needs to solve the issues of plastic pollution in marine environment.
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- 2020
20. Assessment of trace metal contamination in the marine sediment, seawater, and bivalves of Parangipettai, southeast coast of India
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Dilip Kumar Jha, Thangaraj Satheeswaran, Gopal Dharani, Palani Damotharan, Thangavel Balasubramanian, Ramalingam Kirubagaran, Velmurugan Karthikeyan, and Purushothaman Yuvaraj
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0106 biological sciences ,Pollution ,Geologic Sediments ,Oceans and Seas ,media_common.quotation_subject ,India ,010501 environmental sciences ,Aquatic Science ,Oceanography ,01 natural sciences ,Marine pollution ,Metals, Heavy ,Animals ,Seawater ,Trace metal ,0105 earth and related environmental sciences ,media_common ,Hydrology ,Ecology ,010604 marine biology & hydrobiology ,Sampling (statistics) ,Sediment ,Tropics ,Contamination ,Bivalvia ,Trace Elements ,Environmental science ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
Industrial and domestic discharge into the coastal environment has driven us to propose an integrated approach to delineate stations contaminated with metals on the Parangipettai coast by collecting sediment and seawater samples monthly at 18 stations from 2015 to 2017. Descriptive statistics revealed that the concentrations of some metals in the sediment and seawater samples were beyond the permissible level. Further, factor analysis showed a sampling adequacy of 0.90 with high positive loading for Ni (0.94), Cd (0.91), Co (0.90), Pb (0.89), and Zn (0.87) in sediment samples. The degree of contamination by metals was evaluated using pollution indices. The results of the contamination index revealed that some stations in the study area were moderately polluted, and those of the ecological index showed that open sea was under low risk while other stations were in the moderate-to-high-risk category. The results obtained are essential to establish the reference condition for a comparative study in similar environments in the tropical regions.
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- 2019
21. Complex bacterial communities in the deep-sea sediments of the Bay of Bengal and volcanic Barren Island in the Andaman Sea
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Che Ok Jeon, Hyo Jung Lee, Padmanaban Vishnu Priya, Rangamaran Vijaya Raghavan, Ramalingam Kirubagaran, Pankaj Verma, and Gopal Dharani
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0301 basic medicine ,DNA, Bacterial ,Geologic Sediments ,Firmicutes ,030106 microbiology ,India ,Aquatic Science ,Deep sea ,Actinobacteria ,03 medical and health sciences ,RNA, Ribosomal, 16S ,Genetics ,Seawater ,Islands ,biology ,Bacteria ,Ecology ,Sediment ,Biodiversity ,Sequence Analysis, DNA ,biology.organism_classification ,030104 developmental biology ,Metagenomics ,Species richness ,Proteobacteria ,Bay - Abstract
Deep-sea environments are gaining global attention as potential sources of useful microorganisms, thereby warranting a better understanding of the diversity and genomic potential of the microbes present. To this end, here we provide the first insights into the composition of the bacterial communities in deep-sea sediment samples from the southwestern Bay of Bengal and the geographically distinct volcanic Barren Island in the Andaman Sea. High-throughput 16S rRNA gene sequencing of the sediments revealed the presence of >44,000 operational taxonomic units (OTUs) in each of the samples, suggesting high bacterial diversity. Actinobacteria was the most dominant phylum, representing >20% of the taxonomically assignable OTUs, followed by Firmicutes, Proteobacteria, and Chloroflexi. Numerous bacteria that are potentially involved in the sulfur cycle were observed in the Barren Island sediment sample, while bacteria with clinical and industrial potential were observed in the samples from the southwestern Bay of Bengal. Correlation analysis of the biotic and abiotic parameters showed that the differences in bacterial richness and community composition between the sampling sites were mainly dependent on sediment texture. Using a predictive functional metagenomic approach, this study also discusses the genetic variations that may provide an adaptive advantage to sediment bacterial communities for survival in these extreme deep-sea environments. The results from this study should aid future studies focused on bioprospecting and geochemical cycling in the deep sea.
- Published
- 2016
22. Farming of spiny lobsters in sea cages in India
- Author
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T. Senthil Murugan, M. C. Remany, M. Vijayakumaran, S. Syed Jahan, Dilip Kumar Jha, S. Kathiroli, J. Mary Leema Thilakam, T.S. Kumar, K. Selvan, Ramasamy Venkatesan, and Gopal Dharani
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Specific growth ,Homarus ,Ecology ,biology ,Panulirus ornatus ,Panulirus homarus ,Aquatic Science ,biology.organism_classification ,Body weight ,Fishery ,Animal science ,Stocking ,Cage ,Spiny lobster ,Ecology, Evolution, Behavior and Systematics ,Water Science and Technology - Abstract
Pueruli and post‐pueruli, early juveniles and sub‐adults of the spiny lobster, Panulirus homarus and juveniles of P. ornatus were grown in different floating sea cages along the southeast coast of India from May 2003 to May 2007. The first type of cage had a galvanised iron pipe frame (2.0 m × 2.0 m × 1.2 m) with steel woven mesh and four inner detachable compartments (0.75 m × 0.75 m × 1.10 m). Fibre‐reinforced plastic was used subsequently to fabricate cages (1 m × 1 m × 1 m). Pueruli and post‐pueruli of P. homarus (1.58 ± 0.62 g SD), stocked at 60 individuals/m2, grew to an average weight of 123.10 ± 26.22 g in 266 days with a survival rate of 70%. Sub‐adults of P. homarus with an average weight (± SD) of 123.61 ± 29.26 g reached 341.25 ± 46.22 g in 225 days at a stocking density of 21 individuals/m2 with a survival of 73 ± 6%. The post‐pueruli grew by 0.46 ± 0.10 g per day with a specific growth rate (SGR) of 1.64, whereas sub‐adults had a growth rate of 0.97 ± 0.20 g per day with a SGR of 0....
- Published
- 2009
23. Changes in verte brate‐type steroids and 5‐hydroxytryptamine during ovarian recrudescence in the Indian spiny lobster,Panulirus homarus
- Author
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Gopal Dharani, Ramalingam Kirubagaran, Nambali Valsalan Vinithkumar, Dassiah M. Peter, Gopinathapillai Sreeraj, and Muthukamatchi Ravindran
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medicine.medical_specialty ,animal structures ,Ecology ,biology ,Panulirus homarus ,Ovary ,Aquatic Science ,Stage ii ,biology.organism_classification ,medicine.anatomical_structure ,Endocrinology ,Internal medicine ,Hemolymph ,medicine ,Peak level ,Thoracic ganglia ,Stage iv ,Spiny lobster ,hormones, hormone substitutes, and hormone antagonists ,Ecology, Evolution, Behavior and Systematics ,Water Science and Technology - Abstract
Vertebrate‐type steroids (estradiol‐17β and progesterone) and 5‐hydroxytryptamine (5‐HT) were examined during the different stages of ovarian maturation in the Indian spiny lobster Panulirus homarus. Estradiol‐17β and progesterone in the haemolymph and ovary were quantified by radioim‐munoassay. Estradiol‐17β was not detectable in the haemolymph when the oocytes were in stage I. It appeared in the haemolymph only as the oocytes attained stage II. Subsequently, a sharp increase in the level of estradiol‐17β was observed in the haemolymph of lobsters with stage III oocytes; it then showed a significant fall when the ovary was full of stage IV oocytes. Although progesterone was also not detectable in the haemolymph when the oocytes were in stage I, it gradually increased during stages II and III and reached a peak level during stage IV. Surprisingly, both estradiol‐17β and progesterone were detectable in the ovary from stage I onwards. In the ovary, estradiol‐17β and progesterone showed peak levels ...
- Published
- 2005
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