Journal of Microbiology and Biotechnology

1-4

Authors: Sunita D

Clean water that is free of toxic chemicals and pathogens is essential to human health. In countries such as India, 80% of the diseases are due to bacterial contamination of drinking water. The World Health Organization recommended that any water intended for drinking should contain fecal and total coliform counts of 0, in any 100 mL sample. When either of these groups of bacteria is encountered in a sample, immediate investigative action should be taken.The antibacterial potential of Magnesium oxide nanoparticle was detected by well diffusion method. Different concentrations of the nanoparticle were analysed by MIC and antibacterial effect. The MIC result reveals that MgO nanoparticle showed maximum inhibition at a concentration of 0.1 g/ml against E.coli. On comparing bactericidal activity it was observed that there was a continuous decrease in the number of colonies with the increase in concentration of MgO nanoparticle. Based on MIC results antibacterial activity of MgO nanoparticle was tested on water sample which was contaminated with E.coli culture. The growth of bacteria is completely inhibited when higher concentration (0.1 g /ml) of MgO nanoparticle was added in to 100 ml of water sample with 5ml of E.coli culture. Therefore from the above studies conducted, it can be inferred that the MgO nanoparticle has significant bactericidal activity, and overall may be more effective in the purification of water sample.

1-8

Authors: M Shailaja Raj

The anti-fungal activity of Zinc oxide and Titanium dioxide nano-particles was assessed by treating eight fungal cultures - Aspergillus niger, Trichophyton, Fonsecaea, Aspergillus flavus, Rhizopus oryzae, Fusarium, Ramichloridium schulzeri and Cladosporium, isolated from infected skin and dandruff flakes with the nanoparticles and analysing the extent of growth inhibition on agar and in broth media. The anti-fungal activity of these nano-particles was also compared to that of their respective bulk-particular forms, as well as to two commonly used anti-fungals, namely Amphotericin-B and Miconazole. The nano-particles were found to be more effective than the bulk-particles and almost equally efficient as Amphotericin-B, however Miconazole was found to be a better anti-fungal at an equal concentration. Zinc oxide nano-particles were better anti-fungals than Titanium dioxide, thus its anti-fungal activity at different concentrations was assessed to identify the concentration that shows similar anti-fungal activity as 3μg/ml of Miconazole. The reason for performing this study was to investigate the possibility of replacing presently used anti-fungal drugs with nano-particles in topical applications to treat mycosis.

1-6

Authors: Bhuvaneshwari J

Diabetes mellitus is a chronic disorder characterized by high blood glucose levels, whose critical management alleviates multiple complications. Ill-managed diabetes often precedes incidence of dyslipidaemia and cardiac diseases. Mangifera indica L (Anacardiaceae) is a popular Indian horticultural tree also used medicinally. Hypoglycaemic and/or antidiabetic activity of leaf has been investigated in various models; however a comparative account of hypoglycaemic potential of mature and tender leaf is not reported; effect of leaves on carbohydrate digesting enzymes also is not reported. The present study is a preliminary report on comparative hypoglycaemic properties of aqueous methanolic extracts of mature and tender leaves of M indica L var. Totapuri in glucose loaded Wistar Albino rats and In-vitro glucosidase and  amylase inhibition bioassays. Significant hypoglycaemic activity was observed with both extracts in oral glucose tolerance test at 500mg/Kg b.wt. given orally one hour prior glucose loading. The extracts also showed inhibition of rat intestinal alpha glucosidase ,as well as porcine pancreatic alpha amylase with IC50: 21.03 and 35.73 for mature leaf and 27.16 and 22.01 for tender leaf extracts respectively. Thus the hypoglycaemic potential of mango leaves may be due to inhibition of carbohydrate digesting enzymes. Polyphenols, flavonoids and saponins identified in the extracts may be responsible for their hypoglycaemic activity.