ABSTRACT
This study aim to isolate, identify a bacterial isolate and optimize production medium using frying oil waste for lipase production. Nine strains were isolated from an Egyptian soil samples. Among the isolates, a potent bacterial candidate ASSCRC-P1 was found to be the most potent lipase producer strain at 60 °C. Genotypic identification of ASSCRC-P1 showed 94% similarity with Bacillus sp. strains. Phylogenetic tree confirmed that ASSCRC-P1 was nearly similar to Bacillus cereus. Therefore, it was given the name Bacillus cereus ASSCRC-P1 and its 16S rRNA nucleotide has been deposited in the GenBank Data Library under the accession number: KJ531440. A sequential optimization strategy, based on statistical experimental designs, was employed to enhance the lipase production by this strain. A 2-level Plackett–Burman design was applied to differentiate between the bioprocess parameters that significantly influence lipase production followed by Box-Behnken design to optimize the amounts of variables which have the highest positive significant effect on lipase production. Overall more than 2.15-fold improvement in lipase production was achieved due to optimization compared to that obtained using the basal medium.
ABSTRACT
Aims: The objective of the current study was to formulate nystatin (Nyst) into nanostructured lipid carriers (NLCs) to enhance its antifungal activity. Place and Duration of Study: Department of pharmaceutical technology, national research centre, Egypt, between mars 2011 to april 2013 Methodology: Nyst loaded NLCs (NYST-NLCs) were prepared by the hot homogenization and ultrasonication method followed by evaluation of its topical effect on the cutaneous candidiasis. The prepared Nyst-NLCs were characterized for entrapment efficiency, particle size, zeta potential, morphology (transmission electron microscopy), thermal characterisation (differential scanning calorimetry) and in vitro drug release. The study design involves the investigation of the effect of three independent variables namely liquid lipid type (Miglyol 812 and Squalene), liquid lipid concentration (30 and 50%) and Nyst concentration (0.125 and 0.25%). A stability study for 6 months was performed. A microbiological study was conducted in male rats infected with Candida albicans. Results: NLC dispersions were spherical in shape with particle size ranging from 68.06±6.56 to 141.8±3.33 nm. The entrapment efficiencies ranged from 45.50±2.34 to 92.73±0.33% with zeta potential ranging from -26.2 to -39.2 mV. The stability studies done for 6 months indicated that Nyst-NLCs were stable for more than 6 monthes.the microbiological studies showed A least number of colonies forming units (cfu/ml) were recorded for the selected Nyst-NLCs compared to the drug solution and the Nystatin® cream present in the market. Conclusion: It can be fulfilled from this work that NLCs represent promising carrier for topical delivery of Nyst offering good physical stability, high entrapment efficiency and controlled drug release. Nyst-NLCs are a good candidate for cutaneous treatment of fungal infection.