Characterization of hydrocortisone bioconversion and 16S RNA gene in Synechococcus nidulans cultures.

A unicellular cyanobacterium, Synechococcus nidulans (Pringsheim) Komárek, was isolated from paddy-fields and applied in the biotransformation experiment of hydrocortisone (1). This strain has not been previously tested for steroid bioconversion. Fermentation was carried out in BG-11 medium supplemented with 0.05% substrate at 25 degrees C for 14 days of incubation. The obtained products were chromatographically purified followed by their characterization using spectroscopic methods. 11beta,17beta-dihydroxyandrost-4-en-3-one (2), 11beta-hydroxyandrost-4-en-3,17-dione (3), and androst-4-ene-3,17-dione (4) were the main bioproducts in the hydrocortisone bioconversion. The observed bioreaction characteristics were the side chain degradation of the substrate to prepare compounds (2) and (3) following the 11beta-dehydroxylation for accumulation of the compound (4). Time course study showed the accumulation of the product (2) from the second day of the fermentation and compounds (3) and (4) from the third day. All the metabolites reached their maximum concentration in seven days. Cyanobacterial 16S rRNA gene was also amplified by PCR. Sequences were amplified using the universal prokaryotic primers which amplify a approximately 400-bp region of the 16S rRNA gene. PCR products were sequenced to confirm their authenticity as 16S rRNA gene of cyanobacteria. The result of PCR blasted with other sequenced cyanobacteria in NCBI showed 99% identity to the 16S small subunit rRNA of seven Synechococcus species.

Paromomycin-loaded mannosylated chitosan nanoparticles: Synthesis, characterization and targeted drug delivery against leishmaniasis.

Cutaneous leishmaniasis is the most common form of leishmaniasis caused by different species of Leishmania parasites. The emergence of resistance, toxicity, long term treatment, high cost of the current drugs, and intracellular nature of the parasite are the major difficulties for the treatment of leishmaniasis. Although the therapeutic effect of paromomycin (PM) on leishmaniasis has been investigated in different studies, it has a low oral absorption and short half-life, leading to a decreased drug efficacy. Therefore, new and targeted carriers with no such problems are needed. In the present study, PM was loaded into chitosan (CS) nanoparticles accompanied by targeting to macrophages (as the host of Leishmania parasite). PM-loaded into mannosylated CS (MCS) nanoparticles using dextran (PM-MCS-dex-NPs) was prepared by ionic gelation and then characterized. The particle size and zeta potential of PM-MCS-dex-NPs were obtained as 246 nm and +31 mV, respectively. Mannosylation of CS was qualitatively evaluated by Fourier-transform infrared spectroscopy and quantitatively measured by CHNO elemental analysis; also, a mannosylation level of 17% (w) was attained. Encapsulation efficiency (EE), drug release profile, and THP-1 cell uptake potential were determined. A value of 83.5% for EE and a higher release rate in acidic media were achieved. THP-1 cell uptake level of PM-MCS-dex-NPs after 6 h was ˜2.8 and ˜3.9 times of non-mannosylated CS nanoparticles (PM-CS-dex-NPs) and PM aqueous solution, respectively. In vitro cell cytotoxicity and promastigote and amastigote viabilities were evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Half-maximal inhibitory concentration values toward the THP-1 cells for PM aqueous solution, Glucantim, PM-CS-dex-NPs, and PM-MCS-dex-NPs after 48 h were obtained as 1846 ±â€¯158, 1234 ±â€¯93, 784 ±â€¯52 and 2714 ±â€¯126 µg mL-1, respectively. Half-maximal inhibitory concentration values toward the promastigotes for PM aqueous solution, Glucantim, PM-CS-dex-NPs, and PM-MCS-dex-NPs after 48 h were obtained as 105.0 ±â€¯14.0, 169.5 ±â€¯9.8, 65.8 ±â€¯7.3 and 17.8 ±â€¯1.0 µg mL-1, respectively. Selectivity (therapeutic) indices for PM aqueous solution, Glucantim, PM-CS-dex-NPs and PM-MCS-dex-NPs after 48 h were obtained as 24.6, 17.5, 3.7 and 214, respectively. The parasite burden in THP-1 cells after 48 h treatment with PM aqueous solution, Glucantim, PM-CS-dex-NPs, and PM-MCS-dex-NPs at a typical concentration of 20 µg mL-1 were 71.78, 69.94, 83.14 and 33.41%, respectively. While the effect of PM-CS-dex-NPs was more salient on amastigotes, PM-MCS-dex-NPs effectively affected both stages of the parasite, especially the amastigote one. This indicated that the mannosylated formulation acts as a targeted delivery system. The findings of this study revealed that this novel targeted formulation represented a strong anti-leishmanial activity.

Paromomycin-loaded mannosylated chitosan nanoparticles: Synthesis, characterization and targeted drug delivery against leishmaniasis.

Cutaneous leishmaniasis is the most common form of leishmaniasis caused by different species of Leishmania parasites. The emergence of resistance, toxicity, long term treatment, high cost of the current drugs, and intracellular nature of the parasite are the major difficulties for the treatment of leishmaniasis. Although the therapeutic effect of paromomycin (PM) on leishmaniasisLeishmania parasite). PM-loaded into mannosylated CS (MCS) nanoparticles using dextran (PM-MCS-dex-NPs) was prepared by ionic gelation and then characterized. The particle size and Zeta potential of PM-MCS-dex-NPs were obtained as 246 nm and + 31 mV, respectively. Mannosylation of CS was qualitatively evaluated by Fourier-transform infrared spectroscopy and quantitatively measured by CHNO elemental analysis; also, a mannosylation level of 17% (w) was attained. Encapsulation efficiency (EE), drug release profile, and THP-1 cell uptake potential were determined. A value of 83.5% for EE and a higher release rate in acidic media were achieved. THP-1 cell uptake level of PM-MCS-dex-NPs after 6 h was ˜2.8 and ˜3.9 times of non-mannosylated CS nanoparticles (PM-CS-dexIn vitroGlucantim, PM-CS-dex-NPs, and PM-MCS-dex-NPs after 48 h were obtained as 1846 ±â€¯158, 1234 ±â€¯93, 784 ±â€¯52 and 2714 ±â€¯126 µg mL-1Glucantim, PM-CS-dex-NPs, and PM-MCS-dex-NPs after 48 h were obtained as 105.0 ±â€¯14.0, 169.5 ±â€¯9.8, 65.8 ±â€¯7.3 and 17.8 ±â€¯1.0 µg mL-1Glucantim, PM-CS-dex-NPs and PM-MCS-dexGlucantim, PM-CS-dex-NPs, and PM-MCS-dex-NPs at a typical concentration of 20 µg mL-1 were 71.78, 69.94, 83.14 and 33.41%, respectively. While the effect of PM-CS-dex-NPs was more salient on amastigotes, PM-MCS-dex-NPs effectively affected both stages of the parasite, especially the amastigote one. This indicated that the mannosylated formulation acts as a targeted delivery system. The findings of this study revealed that this novel targeted formulation represented a strong anti-leishmanial activity.

Isolation and characterization of some moderately halophilic bacteria with lipase activity.

Lipases are an important class of enzymes which catalyze the hydrolysis of long chain triglycerides and constitute the most prominent group ofbiocatalysts for biotechnological applications. There are a number of lipases, produced by some halophilic microorganisms. In this study, some lipase producing bacteria from Maharlu salt lake located in south of Iran were isolated. All isolates were screened for true lipase activity on plates containing olive oil. The lipase activity was measured using titrimetric methods. Among thirty three isolates, thirteen strains demonstrating orange zone around colonies under UV light, were selected for identification using the molecular methods and some morphological characteristics. The bacterium Bacillus vallismortis BCCS 007 with 3.41 +/- 0.14 U/mL lipase activity was selected as the highest lipase producing isolate. This is the first report of isolation and molecular identification of lipase producing bacteria from Maharlu lake.