Raju Mohanraju

Pondicherry University · Department of Ocean Studies and Marine Biology

Marine bacteria are of extensive significance as new ‘budding springs’ of a vast number of organic active artefacts. Till now, only a fraction of microorganisms have been scrutinized for bioactive metabolites, yet a colossal sum of these metabolites with unique structural drafts remains untouched and unexploited. In this respect, the species of Bac...

Green chemistry has paved an ‘avant-garde avenue’ in the production and fabrication of eco-friendly stable nanoparticles employing the utilization of biological agents. In the present study we present the first report on the potential of the marine bacterium Lysinibacillus odysseyi PBCW2 for the extracellular production of gold nanoparticles (AuNPs...

Seagrasses are unique marine flowering plants that play an important ecological role by yielding primary production and carbon sequestration to the marine environment. Seagrass ecosystems are rich in organic matter, supporting the growth of bio-medically important epi and endophytic microorganisms and harbor rich marine biodiversity. They are an es...

Climate change has triggered an increased incidence of cyanobacterial blooms in the marine ecosystem. While most bloom-forming species cause widespread algal blooms, Lyngbya bouillonii, a benthic marine cyanobacteria forms localized blooms. This cyanobacteria, reported only from the tropical Pacific Ocean, has gained immense biomedical interest owi...

Marine environments are natural endowments, known to be "treasured hideouts" of novel molecules of biologically dynamic chemical species of potent activity, lingered largely uncharted, prospecting vibrant applications in pharmaco-dynamics and drug kinetics. Bioprospecting of marine microbes has discerned many astonishing milestones in pharmacology,...

Luminous bacteria are light emitting prokaryotes found in terrestrial, freshwater and mostly in marine environments. The taxonomy, ecology and pathogenicity of several luminous bacterial species (except Aliivibrio fischeri, Vibrio harveyi, Photobacterium leiognathi, P. phosphoreum, Photorhabdus luminescens and Shewanella hanedai) have not been deli...

A specimen of the false stone fish Scorpaenopsis diabolus(Cuvier, 1829)was captured at the Burmanallah coast in the Andaman Islands, India. Identification was done combining traditional taxonomy, based on the observation and measurement of morphology traits, with DNA barcoding in an integrative taxonomy approach. On this basis, S. diabolus constitu...

Silver nanoparticles (AgNPs) were fabricated by using Rhizophora apiculata aqueous leaf extract (RALE) and their antimicrobial potential was assessed. Their studies of characterization was done by UV-Visible spectrophotometry, X-ray diffraction, HR-TEM, SAED pattern and FTIR analysis. The characteristic peak of RALE-AgNPs was found at a intensity o...

The present study reports a new insight on the isolation of plastic degrading and commercially important L-asparaginase enzyme producing bacteria from the pristine mangrove ecosystem of Guptapara, South Andaman. Seven out of 38 isolated bacterial strains exhibited significant plastic degradation in a period of 3 months. Bacterial strains MJ42, MJ10...

Bioluminescence is a natural phenomenon of light emission produced by metabolic enzymatic reactions of the living organisms. Luminous bacteria, found either as free-living or symbiont in host, are the major light emitters widely distributed in the oceanic realms. These bacterial species emit blue-green light at 490 nm by the activity of the enzyme...

Ascidians are crucial group for the evolutionary studies of deuterstomes and origin of chordates. Most of the literature has laid emphasis on its diversity, species composition and evolutionary history and not much has been highlighted on its antimicrobial potential. In the present study, antibacterial activity of the ascidian, Didemnum psammatode...

Marine biosphere possesses a rich and luxuriant source of various faunal species, especially the invertebrates which are emerging as the novel targets for bioextraction of variety of diverse natural compounds of different unique chemical structures, promising great pharmacological value. In lieu of sparse reports on the antimicrobials produced by b...

An increase in the commercial demand for nanoparticles, due to their all-embracing applicability in various areas, has led to the formulation of different production processes. The traditional "Wet chemical technique" employs the usage of toxic and flammable reactants for the synthesis of metallic nanoparticles. In the present study, a simple, envi...

In the present study 6 pigmented marine bacterial (PMB) strains BNO10, BNO20, BSO14, BNY11, CSP15 and BNB21 from marine sediment and 2 strains BWR18 and BWCY16 from seawater sample were isolated on Zobell Marine agar. These PMB appeared to be in blue, orange, pink, red, dark brownish yellow and yellowish green in colour. Phylogenetic analysis on th...

Present study consists the evaluated antiluminous bacterial activity of Areca catechu palm tree nut methanol extraction and found high degree of inhibition activity against luminous Vibrio campbellii. Gas Chromatography and Mass Spectrometry (GC-MS) analysis of the nut extraction revealed five major compounds, 2-tert-Butyl-4-isopropyl-5-methylpheno...

The present study was undertaken to investigate the antibacterial activities of marine luminous bacteria against 17 human pathogenic bacteria. Fourteen strains isolated from coastal marine samples of South Andaman, India, have exhibited antibacterial activity against at least one human pathogenic bacteria. 16s rRNA gene sequence analysis identified...

The biodiversity of marine luminous bacteria has been well defined from their typical habitats viz. light organ containing squids and fishes. However, distribution and diversity of luminous bacteria among various non-luminous marine niches (non-typical habitats) are not fully investigated yet. This report describes the genetic diversity of luminous...

Notions are always essential to inspect the past, present and future events. The present study constructed the hypothetical lux operon of luminous bacterial ancestor i.e. " luxZYLOPUMNQRSTICDABFEGH-ribEBHA " by assembling the regulatory lux genes, structural lux genes and other flanking genes that exists at upstream and downstream of the lux operon...

Abdopus aculeatus are residents of shallow and intertidal reef flats familiar to Indonesian, Australian, Philippine waters. They are commonly referred as Algae octopuses due to their typical resting camouflage that resembles a gastropod shell residing on algae. The present study confirms new record of the present species in Indian waters and depict...

Larval distribution of a luminous Odontosyllis sp. on different marine niches such as the articulated coralline red algae Amphirova anceps, algal mats on boats, seawater and sediment is being reported here for the first time from Burmanallah Coast. The freshly collected luminous larvae of Odontosyllis sp. from these niches emitted an intense glow o...

Areca nuts are prevalent in endorsed forms of chewing products like supari, pan and gutka in most of the South Asian countries. The teeth and oral tissues of areca nut masticators spanning school children's to older people were found to be stained extrinsically and also found to be weak and damaged in later stages. Therefore, present study examined...

We investigated 42 different mantle tissue patterns in Tridacna species along the coast of Burmanallah, Andamans. Out of 42 mantle tissue patterns, T. maxima showed 18 different mantle patterns, T. crocea showed 22 different mantle patterns and T. squamosa showed only two patterns. T. maxima showed dominance of distribution than T. crocea and T. sq...

Two luminescent bacterial strains KOOS1and KOOS2 isolated from surface mucus of Octopus sp. collected from Andaman were identified by their cellular fatty acid composition analyzation with the help of Microbial Identification system (MIDI). SIM indexes obtained for these isolated strains were 0.772 (KOOS1) and 0.754 (KOOS2) respectively and were id...

Objective: To evaluate the antimicrobial potential of partially purified leaf, bark and root extracts obtained from two mangrove species Rhizophora apiculata and Bruguiera gymnorrhiza from South Andaman against clinical bacterial and fungal pathogens. Methods: Roots, bark and leaves were dried in the shade and subjected to organic solvent extractio...

The present study is focussed on the isolation, molecular characterization and screening of extracellular enzymes produced by Vibrio alginolyticus obtained from the seaweeds of Andaman Islands. Totally twenty isolates from 9 species of seaweeds were isolated and identified as Vibrio alginolyticus by PCR based methods and confirmed by 16S rRNA seque...

Biotic and abiotic components in the marine environment supports the growth of several surface associated microbial communities. Present study focuses on one such microbial community, the Vibrios associated to marine macro algae of Andaman Islands. A total of 48 strains comprising 10 species of Vibrios were isolated from 10 macro algal species. All...

Bacterial isolates (6 nos) were obtained from the coralline red algae Amphiroa anceps. Crude extract of these isolated were tested for antimicrobial activity against 20 different human pathogenic bacterial and fungal strains. Among this crude extract of a single red pigmented strain AA1 was found to show activity against (12) bacterial pathogens an...

Coralline red algae Mastophora rosea (Corallinaceae, Corallinales, Rhodophyta) were collected from tide pools from Little Andaman during August 2013. Collected sample was found to be bluish purple in color, dichotomously branched, round shaped carpogonial conceptacles were found on the surface of thallus, tetrasporangial open pore size 120 µm was s...

Mackerels are widely distributed in Indo-Pacific region and form an important commercial fishery resource of India contributing about 90% of the world mackerel production. The annual marine fish landings for India were found to be 3.78 million tonnes in 2013. In the present study fifteen morphometric characters were compared between the two mackere...

Objective: To evaluate the antimicrobial properties of tissues extracts of different nudibranchs such as Phyllidia varicosa, Plakobranchus ocellatus, Phyllidiella rosans and Halgerda stricklandi against bacterial and fungal pathogens. Methods: Nudibranchs tissue samples were subjected to organic solvent extraction for antimicrobial activity by well...

The impact of light on movement response of some zooplanktons was observed with a light experiment spanning different wavelengths of lights pertaining to VIBGYOR, UV, Laser, White and Dark. Certain zooplanktons exhibited positive phototaxis to Red light (gastropod and medusa larvaes), Laser light (nauplii and brachiolaria larvaes), Yellow light (bi...

A study was attempted to DNA barcodeCaulerpaspecies (Caulerpales, Chlorophyta) from the intertidal region of South and Little Andaman Islands, India. Preliminary identification of fiveCaulerpaspecies was carried out based on the morphological characters. For molecular characterization two gene markers ITS2 and chloroplasttufAregions were used to ba...

Secondary metabolites derived from marine organisms such as plants, invertebrates and microorganisms have a vital role in drug design in the pharmaceutical industry. Due to this reason, microorganisms associated with marine algae and marine invertebrates are vastly targeted by various researchers around the globe. These associated microorganisms ar...

Antibacterial activities of five seaweeds comprising of two green algae Dictyosphaeria cavernosa, Acetabularia calyculus, two red algae Portieria hornemanni, Corallina sp and one brown algae Galaxura marginata were tested against human pathogenic bacterial strains of E.coli, Staphylococcus aureus, Salmonella typhi, Pseudomonas aeruginosa and Klebsi...

Present study consists the survey conducted on the several patterns of diseases in corals from Burmanallah coast of the Andaman Islands. It was observed that Porites sp. were found to be highly sensitive to coral diseases, as they were found with yellow spot disease, pink line syndrome, white line syndrome, white plague and black band diseases. Rin...

In the present study the occurrence of a rare lamellibranch Coriocella hibyae from Andaman Islands is being reported. Three samples of C. hibyae were found in an undisturbed shallow water coral reef region in Burmanallah and the biology of this species is described and identified based on their internal shell and radula structures as C. hibyae whic...

Precopulatory mate guarding is a characteristic feature in the mating behaviour of many Malacostraca, and a necessary prerequisite for those species in which female receptivity for males is restricted to a short period of time after the pubertal/reproductive moult. This study deals with the pre-mate guarding behaviour of the semi-terrestrial isopod...

In vitro results obtained from this study show that light, temperature, salin- ity and glycerol are major factors that induce and inhibit the growth and lumi- nescence of V. campbellii (strain STF1). These results will also help us to induce luminescence in dark mutant strains.

Stomach contents of banded archerfish, Toxotes jaculatrix (Pallas 1767) (Toxotidae) ranging from 13-24 cm total length (TL) collected from brackish waters of South Andaman, India were examined. Brachyuran crabs were the dominant prey item with an occurrence frequency (%F) of 89 followed by insects (71). Though insects were present in all length cat...

The seaweed flora of India is highly diversified and comprises mostly of tropical species, but boreal, temperate, and subtropical elements have also been reported. A total 1,153 species and 271 genera of marine algae, including forms and varieties, have been recorded from Indian waters, and about 105 species have been reported in Andaman and Nicoba...

Diversity and distribution of seaweeds were studied from intertidal region in North Andaman during March 2012 and in South Andaman from October 2011 to August 2012. Sampling was made at 9 stations covering Ramnagar, Ariel Bay and Khalipur beach of Diglipur in North Andaman and Chatham, Carbyn's cove, Burmanallah, Kodiyaghat, Chidiyatapu and Wandoor...

A survey was conducted in Little Andaman during July and August 2012. Altogether 52 species belonging to 28 genera of seaweeds were recorded at five stations. Among these, 32 species comprising Graci/aria. Gelidie/la. Caulerpa. Sargassum. Turbinaria. Acanthophora. Viva. Halymenia and Laurencia are commercially important. These algae were found grow...

Study was made to isolate Vibrios from green, brown and red algae and a total of 22 isolates were obtained from the selected seaweeds plated on TCBS medium. Among these, 17 were sucrose positive (Yellow- Vibrio cholerae like organisms) and 5 were sucrose negative (Green- V. parahaemolyticus like organisms). All the isolates showed positive results...

Cephalopods are well known for their bioactive secondary metabolites like Ink and very few studies have been carried with respect to bioactivity of their tissues. This study focuses on the antibacterial activity of the methanolic extracts from the body tissues of selected cephalopod species Sepioteuthis lessoniana, Sepia brevimana and Octopus cyane...

Caulerpa (Chlorophyta) species inhabit the intertidal and shallow sub tidal region along the coast of Wandoor Marine National Park, South Andaman, India. In a survey conducted during the month of January 2012 to January 2013, we found seven species of Caulerpa, Caulerpa serrulata (Forskal) J. Agardh, C. peltata (Lamouroux), C. racemosa (Forskkal) J...

Concentration levels of Mn, Pb, Zn, Cd, Cu and Cr in six seaweed samples (Acetabularia calyculus, Corallina sp., Galaxura marginata, Sargassum duplicatum, Sargassum swartzi and Dict-yota bartayresiana) were determined from Wandoor, south Andaman Island. Metals were extracted from sample homogenates and quantified by atomic absorption spectrometry....

Abstract. A methanogenic bacterium was enriched with trimethylamine and isolated from mangrove sediments. The isolate was a non-spore-forming regular to slightly irregular coccus (0.4–1 mm in diameter). The isolate required sodium chloride for growth with maximal methanogenesis at 420 mM NaCl at 30C. The optimal growth temperature was 30–35C with m...

Numerical abundance and composition of microzooplankton in the upper 200 m were studied from the central and eastern Arabian Sea during three seasons. Protozoans, comprising of ciliates (loricates and aloricates), flagellates and sarcodines were dominant, ranging from 55% to 91%. Among metazoans, nauplii and copepodite stages were common. Microzoop...

Measurements of primary production, chlorophyll a, participate organic carbon (POC) and nitrogen (PON) were carried out during the inter-monsoon, winter monsoon and summer monsoon seasons of 1994-95 in the central and eastern Arabian Sea. The integrated production rate varied between 193-199, 337-643 and 770 mgCm-2 d-1 respectively in the open ocea...

The occurrence of methanogenic bacteria in the Kodiakkarai (10 18 N; 79 52 E) mangrove sediments, whereAvicennia spp are predominant, was studied. Trimethylamine under N2:CO2 (80:20% v/v) was used as the substrate. Most Probable Number (MPN) of methanogenic bacteria was determined for a period of one year from July 1987 to June 1988 with monthly sa...

Methanogenic bacteria numbers were highest (1.1 × 105 cells per gram of wet sediment) during the month of July 1987 and from February to June 1988. During October-December 1987 the numbers of methanogens were lower (2 × 102 cells per gram) when the salinity was also lower due to the higher influence of fresh water. Salinity was found to play a majo...