David Ravindran
Madras University India, Microbiology, Undergraduate
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Phycocyanin is a major light harvesting pigment of cyanobacteria, it has gained importance in many biotechnological applications in food sciences, the rapy, immunodiagnostics, cosmetics and pharmacological processes. Screening of... more
Phycocyanin is a major light harvesting pigment of cyanobacteria, it has gained importance in many biotechnological applications in food sciences, the rapy, immunodiagnostics, cosmetics and pharmacological processes. Screening of cyanobacterial strain showe d maximum phycobiliprotein in Spirulina platensis . A number of drying methods studied for the processing of Spirulina (oven dried and sun dried) resulted in loss of phycocyanin. Therefore phycocyanin extraction from fresh biomass was studied. Of the extraction method s tested, homogenisation using a mortar and pestle yi elded 18.11% phycocyanin while freezing and thawing extraction yielded 17.68%. Acid treatment also resu lted in phycocyanin leaching. Effective phycocyanin extraction was achieved only with 8‐10 N hydrochloric acid and yielded phycocyanin ranging from 5% to 46%. Phycocyanin sample was analysed by Fourier transform infrared spectroscopy.
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Rare earth elements (REE) are found to be beneficial to plants in order to improve crop yield. The present study reveals the response of leguminous plant (Arachis hypogaea L.) to monazite soil containing Rare earth elements (Lanthanum and... more
Rare earth elements (REE) are found to be beneficial to plants in order to improve crop yield. The present study reveals the response of leguminous plant (Arachis hypogaea L.) to monazite soil containing Rare earth elements (Lanthanum and Samarium). This particular study explains the effects of rare earths on factors such as growth, total leaf chlorophyll content, number of root nodules and nitrogenase activity of groundnut plant. A significant increase in plant biomass and total chlorophyll content are observed. The increase in number of root nodules and the nitrogenase activity (Acetylene reduction, 20.72 n moles C2H4 formed / h/ g fresh nodules) were observed in the plants exposed to REEs. A profound effect of Lanthanum and Samarium present in the rare earth soil on the chlorophyll content, amylase activity, SOD and POD level were noticed.
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Nitrogen fixation can be considered as one of the most interesting microbial activity as it involves in the recycling of nitrogen on earth and maintains nitrogen homeostasis in the biosphere. Nitrogen input to ecosystem is usually... more
Nitrogen fixation can be considered as one of the most interesting microbial activity as it involves in the recycling of nitrogen on earth and maintains nitrogen homeostasis in the biosphere. Nitrogen input to ecosystem is usually mediated mainly by biological nitrogen fixation by termite gut microbial flora. Most of the subterranean termite species feed on the plant residues with high carbon and nitrogen content. In addition to the carbon mineralization, they have an ecological impact in terms of nitrogen. T. trinervoides and O.obesus species cum mound materials recorded higher N2 fixation rate on the intial day and decline in N2 fixation activity was observed in successive days. More over live termite posses higher N2 fixation rate than mound materials on the first day of sampling and a decline in N fixation activity was observed in successive days. The ability of termites to contribute the environmental nitrogen have identified termites as ecological keystone species.
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Microorganisms are one of the primary causes of spo ilage and off-flavors in food products. Consequentl y, the production of consistent, high-quality food product s requires the implementation of a through, well-pl anned cleaning and... more
Microorganisms are one of the primary causes of spo ilage and off-flavors in food products. Consequentl y, the production of consistent, high-quality food product s requires the implementation of a through, well-pl anned cleaning and sanitizing program aimed at controlling and/or reducing the amount of bacteria entering products d uring and after processing / preparation. The microbial sampl ing and enumeration of food contact surfaces and fo od products. To evaluate and record the microbial condition of f ood products and food contact surfaces. In order to know that food is being processed safely, the best indicator is the Aerobic Plate Count (APC) of the food. In th is study, Microbial air and surface swab microbial contaminat ion from Herbal medicine production unit was examined. The main objective was given to the surfaces in the are a of herbal medicine production, the air present in the each and every cabinet of processing unit.
Soil microorganisms play an important role in soil processes that determine plant productivity. Phosphate solubilizing Bacteria (PSB) is the important microbial group associated with plant nutrition. They are capable of hydrolysing... more
Soil microorganisms play an important role in soil processes that determine plant productivity. Phosphate solubilizing Bacteria (PSB) is the important microbial group associated with plant nutrition. They are capable of hydrolysing organic and inorganic phosphorus from insoluble compounds. P-solubilization ability of the microorganisms is considered to be one of the important characteristic features for soil fertility, plant growth and potential yield. PSMs include different groups of microorganisms, which not only assimilate phosphorus from insoluble forms of phosphates, but they also cause a large portion of soluble phosphates to be released in quantities in excess of their requirements. Termite soil contains microbial population which are capable of mobilizing important nutritional elements in the soil. This group covers bacteria, fungi and some actinomycetes. These organisms solubilize the unavailable forms of inorganic-P like tricalcium, iron, and aluminum into soluble forms by...
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This study focuses on isolation, screening, and characterization of novel probiotics from gastrointestinal tract of free-range chicken (Gallus gallus domesticus). Fifty seven colonies were isolated and three isolates (FR4, FR9, and FR12)... more
This study focuses on isolation, screening, and characterization of novel probiotics from gastrointestinal tract of free-range chicken (Gallus gallus domesticus). Fifty seven colonies were isolated and three isolates (FR4, FR9, and FR12) were selected and identified as Lactobacillus gasseri FR4, Bacillus tequilensis FR9, and L. animalis FR12 by 16S rRNA sequencing. Three strains were able to survive in stimulated acidic and bile conditions and inhibit the growth of pathogens. Especially, FR9 exhibited maximum inhibition against Listeria monocytogenes and none of them exhibited hemolytic activity. Native-PAGE revealed the presence of low molecular weight (3.4-5.0 KDa) antimicrobial peptide. The peptide was further purified by Sephadex G-50 column and RP-HPLC using C18 column. N-terminal amino acid sequencing of antimicrobial peptide showed 100% consensus to antilisterial peptide Subtilosin A and SboA gene was amplified from FR9 genome. FR9 showed maximum aggregation activity, exopoly...
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Hetero-exopolysaccharide secreted by Bacillus tequilensis FR9 (BtqEPS), was produced and fractioned on DEAE-Sepharose and phenyl sepharose CL-6B column. HPLC analysis revealed the existence of five monosaccharides including glucose,... more
Hetero-exopolysaccharide secreted by Bacillus tequilensis FR9 (BtqEPS), was produced and fractioned on DEAE-Sepharose and phenyl sepharose CL-6B column. HPLC analysis revealed the existence of five monosaccharides including glucose, galactose, mannose, arabinose and xylose. FT-IR spectroscopy confirmed the presence of carboxyl and hydroxyl groups. (1)H NMR and (13)C NMR spectra analysis showed the presence of α and β-d-(+)-glucose residues and glycosidic linkages. The fibrous, porous nature and elemental composition (C, O, N, Cl, Na, P, S) of BtqEPS was inferred from SEM and EDX analysis. AFM proved that the micro-structure of BtqEPS is compact and rough. XRD analysis confirmed the amorphous nature of BtqEPS with 15.6% crystallinity index. TGA curve indicated the degradation temperature (Td) of 239.72°C. Furthermore, BtqEPS exhibited antioxidant effects by scavenging reactive oxygen species (ROS) and demonstrated strong reducing power. All the above findings on BtqEPS paves way to f...
Research Interests: Chemistry, Free Radicals, Medicine, Antioxidants, Reactive Oxygen Species, and 14 moreAnimals, Bacillus, Monosaccharide chemistry, Crystallinity, Chickens, Xylose, Molecular weight, Elsevier, Biological Macromolecules, Galactose Binding, Biochemistry and cell biology, N-glycosidic bond, Monosaccharides, and Chemical Phenomena
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The present study was aimed to enumerate the total bacterial count in Spirulina platensis powder and to reduce their bacterial level by different treatments such as storaging in different temperature, N2 and CO2 gas packaging,... more
The present study was aimed to enumerate the total bacterial count in Spirulina platensis powder and to reduce their bacterial level by different treatments such as storaging in different temperature, N2 and CO2 gas packaging, Lactobacillus and glucose, tyndalization. While comparing the sample with the treated samples, the bacterial load was found to be reduced in treated samples. Treatments such as CO2 gas packaging and storage in 5 and 120C shows increased level.
... Pandian Prabakaran and A. David Ravindran* Department of Biology, Gandhigram Rural Institute-Deemed University, Gandhigram 624 302, India ... Palar dam 10°24′30.61″N 77°29′38.39″E Haematococcus sp. Palani pond 10°26′12.59″N... more
... Pandian Prabakaran and A. David Ravindran* Department of Biology, Gandhigram Rural Institute-Deemed University, Gandhigram 624 302, India ... Palar dam 10°24′30.61″N 77°29′38.39″E Haematococcus sp. Palani pond 10°26′12.59″N 77°30′52.27″E Ulothrix ...
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A lysogenic Streptomyces sp., strain NS.A4, which was isolated from the nodule surface of black gram ( Vigna mungo (L.) Hepper), was found to inhibit rhizobia of fast-and slow-growing strains of cowpeas and soybeans. It exhibited plaques... more
A lysogenic Streptomyces sp., strain NS.A4, which was isolated from the nodule surface of black gram ( Vigna mungo (L.) Hepper), was found to inhibit rhizobia of fast-and slow-growing strains of cowpeas and soybeans. It exhibited plaques when there was a change in cultural conditions. Repeated culturing of the organism in nutrient agar and broth confirmed the infection of Streptomyces sp. strain NS.A4 by an actinophage. Addition of the culture filtrate of Streptomyces sp. strain NS.A4 to shaken broth cultures of three other Streptomyces spp. resulted in phage infection.
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Three methods were used to prepare the cell-bound exopolysaccharides (c-EPS) of Lactobacillus plantarum 70810, and the maximum yield (64.17 mg/mL) was obtained by ultrasonic extraction. After anion exchange and gel filtration... more
Three methods were used to prepare the cell-bound exopolysaccharides (c-EPS) of Lactobacillus plantarum 70810, and the maximum yield (64.17 mg/mL) was obtained by ultrasonic extraction. After anion exchange and gel filtration chromatography, the c-EPS was fractionated as a single peak with a molecular weight of 169.6 kD. Its structural characteristics were investigated by gas chromatography (GC), methylation, Fourier-transform infrared spectroscopy (FTIR), and nuclear magnetic resonance (NMR) analysis. Based on obtained data, the novel c-EPS was found to be a galactan containing a backbone of α-D-(1→6)-linked galactcosyl, β-D-(1→4)-linked galactcosyl, β-D-(1→2,3)-linked galactcosyl residues and a tail end of β-D-(1→)-linked galactcosyl residues. Preliminary in vitro tests revealed that c-EPS significantly inhibited the proliferation of HepG-2, BGC-823, especially HT-29 tumor cells. Our results suggested that the c-EPS produced by L. plantarum 70810 might be suitable for use as functional foods and natural antitumor drugs.