Loading...
6 results
Search Results
Now showing 1 - 6 of 6
- Microalgal omicas and their applicationsPublication . Hemaiswarya, Shanmugam; Raja, R.; Ravikumar, R.; Yogesh Kumar, A.; Carvalho, Isabel Saraiva deMicroalgae constitute a large and diverse group of unicellular phototrophic and heterotrophic organisms, which comprise the base of the food chain and are evolutionarily distinct from other species. They have emerged as a promising group in the production of bioproducts and biofuel, as well as for the remediation of effluents. Indigenous populations have used microalgae for centuries and the commercial application of microalgae has been extensively reviewed [1–4]. The efficiency of the microalgal production process depends on higher biomass, yield, productivity, and process robustness. These parameters highly depend on the host microorganism. Natural screening, mutagenesis, selection, bioprocess development, genetic engineering, and metabolic engineering strategies have been adopted to increase the metabolic capabilities of the host microorganisms [5]. Nevertheless, problems such as the accumulation of toxic intermediates or metabolic stress resulting in a decreased cellular fitness need to be solved. The lack of knowledge about the regulatory mechanisms of key enzymes and the complex relationships between genotype and phenotype are still barriers to the development of efficient cell factories. The overexpression, deletion, or introduction of heterologous genes in specific metabolic pathways does not always result in the desired phenotype. Recent remarkable innovations in platforms for omics-based research and application development have provided crucial solutions to these problems. A combinatorial approach using multiple omics platforms and the integration of their outcomes is now an effective strategy for clarifying the molecular systems that are integral to improving algal productivity.
- Mechanism of action of probioticsPublication . Hemaiswarya, Shanmugam; Raja, R.; Ravikumar, R.; Carvalho, Isabel Saraiva deThe modern diet doesn't provide the required amount of beneficial bacteria. Maintenance of a proper microbial ecology in the host is the main criteria to be met for a healthy growth. Probiotics are one such alternative that are supplemented to the host where by and large species of Lactobacillus, Bifidobacterium and Saccharomyces are considered as main probiotics. The field of probiotics has made stupendous strides though there is no major break through in the identification of their mechanism of action. They exert their activity primarily by strengthening the intestinal barrier and immunomodulation. The main objective of the study was to provide a deep insight into the effect of probiotics against the diseases, their applications and proposed mechanism of action.
- Isolation and characterization of two novel plasmids pCYM01 and pCYM02 of Cylindrospermum stagnalePublication . Ganesan, Venkatesan; Raja, Rathinam; Hemaiswarya, Shanmugam; Carvalho, Isabel S.; Anand, NarayanaswamyCyanobacteria play a vital role in supplying nitrogen into the soil and aquatic ecosystem. It has an extra chromosomal DNA, whose role is not yet defined well. Isolation and characterization of extra chromosomal DNA in cyanobacteria might help to understand its survival mechanism. Cylindrospermum stagnale isolated (and deposited in NRMCF 3001) from soil showed presence of four plasmids namely pCYLM01, pCYLM02, pCYLM03, and pCYLM04. The following plasmids pCYLM01 and pCYLM02 were subjected to restriction digestion using HindIII restriction enzyme and cloned into pBlueScriptSK(-) vector. The sequence of pCYLM01 contained 4 potential open reading frames (ORFs) that have amino acids in the range of 59-299. Among them, ORF1 shows high sequence homology to the bacterial replication initiator family protein as evident from BLASTP analysis. The analysis of 4359 bp plasmid pCYLM02 sequence revealed 7 ORFs which are longer than 50 amino acids in length. The ORF2 of pCYLM02 has 243 amino acids and is represented in the plasmid sequence from 3045 to 3776 bp. The ORF3 of pCYLM02 corresponds to the plasmid sequence from 2323 to 2976 and codes for a putative protein of 217 amino acids long. A number of small ORFs below 50 bp were also found in the sequence analysis.
- Microalgae taxonomy and breedingPublication . Hemaiswarya, Shanmugam; Raja, R.; Ravikumar, R.; Carvalho, Isabel Saraiva deMicroalgae are a diverse group of organisms that form the basic component of many eco- systems. The systemic classification of algae is primarily based on their pigment composition and is divided into nine classes. The largest groups are Chlorophyceae (green algae), Phaeophyceae (brown algae), Pyrrophyceae (dinoflagellates), Chrysophyceae (golden brown algae), Bacillariophyceae (diatoms) and Rhodo phyceae (red algae). It has been estimated that between 22,000 and 26,000 species exist (Norton et al., 1996), of which only a few species have been identified to be useful for commercial application, such as Spirulina, Chlorella, Haematococcus, Dunaliella, Botryococcus, Phaeodactylum and Porphyridium. Several other species that are also cultivated commercially for the hatcheries in the aquaculture field include Chaetoceros, Crypthecodinium, Isochrysis, Nannochloris, Nitzschia, Schizochytrium, Tetraselmis and Skeletonema (Raja et al., 2008).
- An Indian scenario on renewable and sustainable energy sources with emphasis on algaePublication . Hemaiswarya, Shanmugam; Raja, R.; Carvalho, Isabel Saraiva de; Ravikumar, R.; Zambare, Vasudeo; Barh, DebmalyaIndia is the fifth largest primary energy consumer and fourth largest petroleum consumer after USA, China, and Japan. Despite the global economic crisis, India’s economy is expected to grow at 6 to 8 %/year. There is an extreme dependence on petroleum products with considerable risks and environmental issues. Petroleum-derived transport fuels are of limited availability and contribute to global warming, making renewable biofuel as the best alternative. The focus on biogas and biomass-based energy, such as bioethanol and biohydrogen, will enhance costeffectiveness and provide an opportunity for the rural community. Among all energy sources, microalgae have received, so far, more attention due to their facile adaptability to grow in the photobioreactors or open ponds, high yields, and multiple applications. Microalgae can produce a substantial amount of triacylglycerols as a storage lipid under photooxidative stress or other adverse environmental conditions. In addition to renewable biofuels, they can provide different types of highvalue bioproducts added to their advantages, such as higher photosynthetic efficiency, higher biomass production, and faster growth compared to any other energy crops. The viability of first-generation biofuels production is, however, questionable because of the conflict with food supply. In the future, biofuels should ideally create the environmental, economic, and social benefits to the communities and reflect energy efficiency so as to plan a road map for the industry to produce third-generation biofuels.
- Recent developments in therapeutic applications of CyanobacteriaPublication . Raja, Rathinam; Hemaiswarya, Shanmugam; Ganesan, Venkatesan; Carvalho, Isabel Saraiva deThe cyanobacteria (blue-green algae) are photosynthetic prokaryotes having applications in human health with numerous biological activities and as a dietary supplement. It is used as a food supplement because of its richness in nutrients and digestibility. Many cyanobacteria (Microcystis sp, Anabaena sp, Nostoc sp, Oscillatoria sp., etc.) produce a great variety of secondary metabolites with potent biological activities. Cyanobacteria produce biologically active and chemically diverse compounds belonging to cyclic peptides, lipopeptides, fatty acid amides, alkaloids and saccharides. More than 50% of the marine cyanobacteria are potentially exploitable for extracting bioactive substances which are effective in killing cancer cells by inducing apoptotic death. Their role as anti-viral, anti-tumor, antimicrobial, anti-HIV and a food additive have also been well established. However, such products are at different stages of clinical trials and only a few compounds have reached to the market.