Methods for nanoemulsion and nanoencapsulation of food bioactives

Environmental Chemistry Letters - Nanoencapsulation is a promising technology allowing miniaturized dosage and administration of valuable volatiles, degradable bioactives and biologicals. The...     

Enumeration of hydro-biological parameters and assessment of eco-aquafarming potential in the Velachery Lake (Chennai)

In recent years, aquaculture has acquired vast potential in providing livelihood, security as well as fulfilling the nutritional requirements of the growing population. The hydro-biological parameters studied in Velachery Lake revealed that a large number of essential parameters are conforming to the levels suggested for a shrimp farm. The abundance and availability of zooplankton population reveal their importance in prawn culture.     

Copper sulphate (CuSO4) toxicity on tissue phosphatases activity and carbohydrates turnover in Achatina fulica

A time course study on the sublethal toxicity of CuSO4 on tissue carbohydrate metabolites level and their phosphatases activity in Achatina fulica revealed differential response. The levels of total carbohydrates and glycogen in the body mass muscle, foot muscle and hemolymph revealed their involvement in the endogenous derivation of energy during stress. The same metabolites in digestive gland revealed its importance to reproduction and development. The lactate accumulated in all the tissues implied the mechanism of CuSO4 toxicosis in the metabolic acidosis. The decrease of pyruvate in foot muscle, body mass muscle and hemolymph inferred the preponderance of glycolysis in energy derivation. In contrast, the pyruvate concentration in digestive gland revealed its differential response in the stress metabolic sequence of changes, as a unique tissue. The lactate/pyruvate ratio and the calcium content in tissues constitute direct evidences for the snails adaptation to toxic stress.     

Freshwater lakes--a potential source for aquaculture activities--a model study on Perumal Lake, Cuddalore, Tamil Nadu

The freshwater Perumal lake located at Cuddalore was assessed for its suitability and potential for aquaculture practices. Various hydrobiological parameters determined reveals that the various physicochemical characteristics are with in normal range of values. The DO level, BOD and COD values determined in the lake revealed the consequences of community activities and pollution possibilities. The primary productivity data revealed maximum productivity during March which infer that the lake is unaffected by anthropogenic disturbance and community contamination. The bacterial count remained higher during the monsoon periods, which characterize profuse rainfall and storm water discharge into the lake. The microfauna includes zooplankter such as cladocerans, copepods, rotifers and ostracods. Benthos include carps, catfishes, mullets and prawns. The above study revealed that the various parameters in the lake conform to the levels suited for freshwater fish culture and represents a resource for scientific management.     

Silver nanoparticle antimicrobial activity explained by membrane rupture and reactive oxygen generation

Silver nanoparticles are widely used as antimicrobial compounds based on empirical observations. However, there is few knowledge on the mechanism ruling the antimicrobial activity and toxicity of Ag nanoparticles. Here, we investigated this mechanism. Nano-Ag was synthesised by thermal co-reduction. Mutagenicity analysis was performed using Salmonella typhimurium histidine auxotrophic strains TA 98 and TA 100 at nano-silver concentrations of 100 to 500 µg per plate. Dose-dependent analysis for reactive oxygen species generation has been performed using 2,7-dichlorofluorescein diacetate dye. Membrane integrity has been analyzed at 260 nm, before and after treatment. We also used scanning electron microscopy, membrane permeabilization test, and superoxide formation determinations. Results show that the average particle size of Ag nanoparticle is 60.4 ± 3.8 nm. The minimum inhibitory concentration of Ag nanoparticles for E.coli is 30 µg/mL; the minimum bactericidal concentration is 40 µg/mL. Ames mutagenicity tests showed negative results, which may be explained by the antimicrobial activity of nano-silver. Bacterial inner wall were indeed ruptured, and cytoplasmic content was released after 5 min of treatment in a dose-dependent manner. We thus propose that reactive oxygen generation and alteration of membrane integrity and permeability are the major mechanism of antimicrobial activity of nano-silver.     

Degradation of indulin, a kraft pine lignin, by Serratia marcescens

Serratia marcescens isolated from decaying coconut pith exhibited high lignolytic activity. Growth on indicator medium, analysis of residual indulin, and infra-red spectroscopic analysis indicated the lignolytic potential of the isolate. Ortho-Coumaric acid, ferulic acid, 2,3-dihydroxy cinnamic acid and protocatechuic acid were identified as intermediates involved in indulin degradation by S. marcescens. Qualitative confirmation and quantitative estimation of the intermediates were carried out by high performance thin layer chromatography (HPTLC).     

Food-grade nanoencapsulation of vitamins

Environmental Chemistry Letters - Vitamin deficiency arises when the dietary intake of essential vitamins is too low. Insufficient levels of vitamin weaken the body and induce diseases. Although...     

Influence of Vibrio parahaemolyticus MTCC 451 on the levels of ascorbic acid and histamine in Penaeus monodon (Fabricius)

Juvenile shrimps (Penaeus monodon) weighing about 15-20 gms were procured from the grow-out ponds and reared under laboratory conditions. They were challenged with Vibrio parahaemolyticus MTCC 451 and their LD50 value was evaluated. The ascorbic acid and the histamine activity of both the control and experimental groups were assessed. The results showed a marked decline in both the parameters at all intervals. This reveals the pathogenesis of the inoculated bacterial strain, which affects the defense mechanism by reducing the glutathione content by the decreased level of ascorbic acid and letharginess by the decreased histamine content of the experimental prawns.     

Effect of mercuric chloride on circulating hormones in adult albino rats

The effect of mercuric chloride at two different doses, 0.5 mg/kg body weight (low dose), 1 mg/kg body weight (high dose), for 30 days, was seen on the circulating hormones in the mature male albino rats. Testosterone level was markedly decreased in the low dose (P < 0.01) and high dose (P < 0.001) treated animals. The level of luteinizing hormone (LH) was also reduced in the low dose (P < 0.01) as well as in the high dose (P < 0.001) treated animals. However, follicle stimulating hormone (FSH) and prolactin (PRL) levels were found to be decreased only in the high dose (P < 0. 05) treated animals and no change was observed in the low dose treated animals. The changes in the hormone levels caused by the mercuric chloride treatment suggest the dysfunction of pituitary-testicular axis.