Valsamma Joseph

• Cochin University of Science and Technology

KEYWORDS Pseudomonas aeruginosa, the Gram-negative aerobic rod belonging to the family Psuedomonadaceae is an aquatic and soil bacterium that can infect a range of organisms, including human. Meanwhile, Pseudomonas acts as a potential probiotic for marine finfish and shellfishes and has caused growth inhibition of several pathogens including Salmon...

Kavaratamide A (1), a new linear lipodepsipeptide possessing an unusual isopropyl-O-methylpyrrolinone moiety, was discovered from the tropical marine filamentous cyanobacterium Moorena bouillonii collected from Kavaratti, India. A comparative chemogeographic analysis of M. bouillonii collected from six different geographical regions led to the prio...

This study introduces a novel approach to making closed-loop sustainable intensive systems, such as backyard recirculating aquaculture systems, more accessible to farmers with low resources. Specifically, a cost-effective recirculating aquaculture system (RAS) for high-density fish culture was indigenously developed and implemented, focusing on emp...

Marine microalgae have emerged as a promising alternative to traditional feeds for preventive healthcare in aquaculture. This study validates the impact of chitosan-flocculated dried biomass of the marine picoalga Picochlorum maculatum MACC3 (Pmac-1) as a functional feed for ornamental fishes in large-scale settings. This follows a previous laborat...

Production and characterization of sulphated polysaccharides from tropical marine red microalga Dixonella grisea MACC1 Keshika, D., Ancy Varghese, Thasreefa, K., Bright Singh I.S. and Valsamma Joseph* ABSTRACT Polysaccharides derived from microalgae are biopolymers composed of long chains of sugar molecules and have gained significant attention du...

Conventional selective breeding in aquaculture has been effective in genetically enhancing economic traits like growth and disease resistance. However, its advances are restricted by heritability, the extended period required to produce a strain with desirable traits, and the necessity to target multiple characteristics simultaneously in the breedi...

The success of aquaculture production greatly depends on the health status of aquatic species and the proper management of the water quality. The significance of microbes in their contribution to the healthy aquatic environment, disease control and proper waste management is incredible. Among these, the role of bacteria in developing probiotics, va...

A Gram-negative, aerobic, non-motile, oxidase-positive, catalase-positive, rod-shaped bacterium, designated strain MCCB 386T was isolated from sediment samples collected from Kongsfjorden, an Arctic fjord. The strain MCCB 386T showed growth at 4–37 °C (optimum 27°C) in the presence of 1–8% NaCl (w/v, optimum 3.5%) and at pH 6.0–8.0 (optimum pH 7.0)...

In the zero-water exchange shrimp culture pond maintained with the application of indigenous bioaugmentor, low levels of total ammonia–nitrogen were reported, indicating the relevance of indigenous microbial communities. Sediments (0–5 cm layer) were sampled from the pond (85th day) and the bacterial and archaeal communities; specifically, the ammo...

Microalgae are a promising new source of biomass; however, large-scale economical harvesting of microalgal biomass is a major technological and economic challenge, limiting the commercial production of microalgal biomass for high-value compounds. In this study, the cationic polymer chitosan was used for the harvesting of the marine diatom Chaetocer...

Nannochloropsis oceanica is a marine eustigmatophyte with high nutritional value, especially with high content of eicosapentaenoic acid that makes it an interesting aquaculture feed. The medium composition and culture conditions were optimized using response surface methodology for large scale culturing of this alga with improved productivity and n...

The tropical marine cyanobacterium Moorena bouillonii occupies a large geographic range across the Indian and Western Tropical Pacific Oceans and is a prolific producer of structurally unique and biologically active natural products. An ensemble of computational approaches, including the creation of the ORCA (Objective Relational Comparative Analys...

A two-stage cultivation method involving the initial growth in optimized conditions for biomass production followed by those for lipid production in oleaginous brackish diatom Navicula phyllepta MACC8 resulted in a proportional increase of lipid concentration along with biomass production. The diatom was further subjected to stress conditions by al...

Protein kinases are validated drug targets for a number of therapeutic areas, as kinase deregulation is known to play an essential role in many disease states. Many investigated protein kinase inhibitors are natural product small molecules or their derivatives. Many marine-derived natural products from various marine sources, such as bacteria and c...

Protein kinases are validated drug targets for a number of therapeutic areas, as kinase deregulation is known to play an essential role in many disease states. Many investigated protein kinase inhibitors are natural product small molecules or their derivatives. Many marine-derived natural products from various marine sources, such as bacteria and c...

Diatoms hold great promise as potential sources of biofuel production. In the present study, the biomass and lipid production in the marine diatom Navicula phyllepta, isolated from Cochin estuary, India and identified as a potential biodiesel feedstock, were optimized using Plackett-Burman (PB) statistical experimental design followed by central co...

Marine microalgae have emerged as important feedstock for liquid biofuel production. The identification of lipid-rich native microalgal species with high growth rate and optimal fatty acid profile and biodiesel properties is the most challenging step in microalgae-based biodiesel production. In this study, attempts have been made to bio-prospect th...

After screening marine actinomycetes isolated from sediment samples collected from the Arctic fjord Kongsfjorden for potential anticancer activity, an isolate identified as Streptomyces artemisiae MCCB 248 exhibited promising results against the NCI-H460 human lung cancer cell line. H460 cells treated with the ethyl acetate extract of strain MCCB 2...

Cost effective harvesting of biomass is a major challenge in microalgal industries as it involves the recovery of small sized algal cells from large volumes of culture medium. The present work evaluated the potential of chitosan and aluminium sulfate (AS) in the flocculation of the marine picoalga, Picochlorum maculatum MACC3 using response surface...

The hexane fractions of the marine cyanobacteria: Leptolyngbya sp. and Limnothrix sp., collected from Arabian Sea were found to display promising antioxidant properties than their ethyl acetate fraction during radical scavenging ABTS/DPPH assays (IC50=30/330 and 60/260 µg ml-1 respectively). Phytochemical analyses of the fractions indicated presenc...

The marine centric diatom Chaetoceros muelleri has been widely used as live feed in fish and shellfish aquaculture due to its excellent nutritional properties. The growth of microalgae is affected by various nutritional and environmental parameters, and species specific optimization of these parameters is essential for the development of cost-effec...

Stringed Bed Suspended Bioreactor (SBSBR) is a fixed film bioreactor activated with indigenous nitrifying bacterial consortia under salinity regimes of 15 and 30 ppt for rapid nitrification in brackish water and marine aquaculture systems respectively. Compared to domestic wastewater; total ammonia nitrogen (TAN) is a limiting factor for nitrific...

White Spot Syndrome Virus (WSSV) is the most devastating disease affecting shrimp culture around the world. Though, considerable progress has been made in the detection and molecular characterization of WSSV in recent years, information pertaining to immune gene expression in shrimps with respect to WSSV infection remains limited. In this context,...

BACKGROUND: A packed bed bioreactor (PBBR) activated with an indigenous nitrifying bacterial consortia was developed and commercialized for rapid establishment of nitrification in brackish water and marine hatchery systems in the tropics. The present study evaluated nitrification in PBBR integrated into a Penaeus monodon recirculating maturation sy...

Recirculation aquaculture systems (RAS) depend on nitrifying biofilters for the maintenance of water quality, increased biosecurity and environmental sustainability. To satisfy these requirements a packed bed bioreactor (PBBR) activated with indigenous nitrifying bacterial consortia has been developed and commercialized for operation under differen...

In view of their sensitivity and importance, an ecological-economic analysis of wetlands has been carried out for various Indian states. Subsequently, the ecological wealths of different zones (north, south, east and west) have been computed and compared. Amongst states, Karnataka (7896.5 million US dollars yr(-1)), Gujarat (7689.4 million US dolla...

Contamination of groundwater due to pesticides has become a major issue of concern in India. However, there are now attempts to contain and control this problem through phytoremediation, which is a very cost-effective and innovative technology. On the other hand, none of the hitherto developed models for groundwater contamination has incorporated a...

The microalgal community as primary producers has to play a significant role in the biotic and abitoic interactions of any aquatic ecosystem. Whenever a community is exposed to a pollutant, responses can occur because individuals acclimate to pollutant caused changes and selection can occur favouring resistant genotypes within a population and sele...

Sulfate aerosols have been found to be the major contributors to precipitation acidity. Thus, in view of the long-term ecological repercussions they have on aquatic ecosystems and their acidity-potential, the present analysis focuses on a case study application of the layer-averaged aerosol-scavenging model (Okita et al., 1996) for predicting value...

The ecology and photosynthetic behaviour of the microalgalcommunity in an oil refinery wastewater holding pond was studiedwith a view to assess the role of algae in industrial effluenttreatment ponds. The biological and physico-chemical parameterswere measured for one year from February 1994 to February 1995.The assessment of algal population based...

Many of even the most recently applied ecological risk assessment models have dealt with ecological risks only on the basis of single-species toxicity tests. Moreover, they have seldom treated the integrated and the complete ecological unit for the risk assessment. In other words, they have ignored parameters which regulate many of those very impor...

Although a very useful tool, Ecological Footprint (EF) analysis has recently been subject to quite a bit of criticism. One of the most important weaknesses that EF suffers from is the fact that it is not a dynamic EF-model. An attempt has, therefore, been made in this article to develop a suitable dynamic EF-model. The dynamic EF-model, thus develo...

Water weeds Azolla pinnata and Lemna minor and the chlorophycean alga Scendesmus bijugatus were grown in a paper mill wastewater. The objective of the study was to assess the viability of these species upon exposure to such effluents and to assess their potential in the improvement of effluent quality. The wastewater was analysed before and after t...

Agricultural run-offs and sediment loads have significant impact on adjacent lakes by way of affecting the growth and mortality of various aquatic species, thereby significantly perturbing the ecological stability of the watershed through associated food-web interactions. It was during our monitoring and surveys of various Indian lakes, viz. Ambaza...