Estimation of growth and exopolysaccharide production by two soil cyanobacteria,Scytonema tolypothrichoides and Tolypothrix bouteillei as determined by cultivation in irradiance and temperature crossed gradients

Two filamentous cyanobacteria of the genera Scytonema and Tolypothrix were reported to be effective for stabilizing soil in arid areas due to the production of significant amounts of extracellular polysaccharides (EPS). These EPS may also have applications in the biotechnology industry. Therefore, two cyanobacterial species, Scytonema tolypothrichoides and Tolypothrix bouteillei were examined using crossed gradients of temperature (8–40°C) and irradiance (3–21 W m^?2) to identify their temperature and irradiance optima for maximum biomass and EPS production. According to their reported temperature requirements, both strains were considered mesophilic. The optimum growth range of temperature in S. tolypothrichoides (27 to 34°C) was higher than T. bouteillei (22–32°C). The optimum irradiance range for growth of S. tolypothrichoides (9–13 W m^?2) was slightly lower than T. bouteillei (7–18 W m^?2). Maximum EPS production by S. tolypothrichoides occurred at similar temperatures (28–34°C) as T. bouteillei (27–34°C), both slightly higher than for maximum growth. The optimum irradiance range for EPS production was comparable to that for growth in S. tolypotrichoides (8–13 W m^?2), and slightly lower in T. bouteillei (7–17 W m^?2). The Redundancy Analysis confirmed that temperature was the most important controlling factor and protocols for field applications or for mass cultivation can now be developed.     

A systems biology approach to model neural stem cell regulation by notch, shh, wnt, and EGF signaling pathways

The Notch, Sonic Hedgehog (Shh), Wnt, and EGF pathways have long been known to influence cell fate specification in the developing nervous system. Here we attempted to evaluate the contemporary knowledge about neural stem cell differentiation promoted by various drug-based regulations through a systems biology approach. Our model showed the phenomenon of DAPT-mediated antagonism of Enhancer of split [E(spl)] genes and enhancement of Shh target genes by a SAG agonist that were effectively demonstrated computationally and were consistent with experimental studies. However, in the case of model simulation of Wnt and EGF pathways, the model network did not supply any concurrent results with experimental data despite the fact that drugs were added at the appropriate positions. This paves insight into the potential of crosstalks between pathways considered in our study. Therefore, we manually developed a map of signaling crosstalk, which included the species connected by representatives from Notch, Shh, Wnt, and EGF pathways and highlighted the regulation of a single target gene, Hes-1, based on drug-induced simulations. These simulations provided results that matched with experimental studies. Therefore, these signaling crosstalk models complement as a tool toward the discovery of novel regulatory processes involved in neural stem cell maintenance, proliferation, and differentiation during mammalian central nervous system development. To our knowledge, this is the first report of a simple crosstalk map that highlights the differential regulation of neural stem cell differentiation and underscores the flow of positive and negative regulatory signals modulated by drugs.     

In vitro anti- biofilm and anti-bacterial activity of Sesbania grandiflora extract against Staphylococcus aureus

The main objective of this research is to investigate the anti-biofilm and anti-bacterial activity of Sesbania grandiflora (S. grandiflora) against Staphylococcus aureus. S. grandiflora extract were prepared and analyzed with UV –Vis spectroscopy, Fourier transform infrared spectroscopy, Dynamic light scattering. Biofilm forming pathogens were identified by congo-red assay. Quantification of Extracellular polymeric substance (EPS) particularly protein and carbohydrate were calculated. The efficacy of the herbal extract S. grandiflora and its inhibition against the pathogenic strain of S. aureus was also evaluated. The gradual decrease or disappearance of peaks reveals the reduction of protein and carbohydrate content in the EPS of S. aureus when treated with S. grandiflora. The antibacterial activity of S. grandiflora extract against the bacterial strain S. aureus showed that the extract were more active against the strain. To conclude, anti-biofilm and antibacterial efficacy of S. grandiflora plays a vital role over biofilm producing pathogens and act as a good source for controlling the microbial population.     

Identification of compendial nonionic detergents for the replacement of Triton X-100 in bioprocessing

We have systematically investigated six compendial nonionic detergents as potential replacements for Triton ×-100 in bioprocessing applications. Use of compendial raw materials in cGMP bioprocessing is advantageous for a variety of reasons including material specifications developed to meet stringent pharmaceutical product quality requirements, regulatory familiarity and comfort, and availability from vendors experienced supplying the biopharmaceutical industry. We first examine material properties of the detergents themselves including melting point and viscosity. Process performance and product contact in real-world bioprocess applications are then investigated. Lastly, we test the detergents in virus inactivation (VI) experiments with recombinant proteins and adeno-associated virus. Two of the detergents tested, PEG 9 Lauryl Ether and PEG 6 Caprylic/Capric Glycerides, showed favorable properties that make them attractive for use as potential Triton X-100 replacements. Process performance testing indicated negligible impact of the detergents on product yield, purity, and activity compared to a control with no detergent. Importantly, both PEG 9 Lauryl Ether and PEG 6 Caprylic/Capric Glycerides demonstrated very fast VI kinetics with complete inactivation of XMuLV observed in less than 1 min at a target 1% detergent concentration. Potential advantages and disadvantages of both candidate detergents for use in cGMP bioprocessing are summarized and discussed.     

Aquisphaera insulae sp. nov., a new member in the family Isosphaeraceae,isolated from the floating island of Loktak lake and emended description of the genus Aquisphaera

Antonie van Leeuwenhoek - Strain JC669T was isolated from a floating island of Loktak lake, Manipur, India and shares the highest 16S rRNA gene sequence identity with Aquisphaera giovannonii OJF2T....     

Nanocrystallization by Evaporative Antisolvent Technique for Solubility and Bioavailability Enhancement of Telmisartan

Telmisartan is an orally active nonpeptide angiotensin II receptor antagonist used in the management of hypertension. It is a Biopharmaceutics Classification System class II drug having aqueous solubility of 9.9 μg/ml. Telmisartan (TEL) nanocrystals were prepared by evaporative antisolvent precipitation technique using different stabilizers as PVPK30, TPGS, Poloxamer 188, and PEG 6000 in combination or singly. The nanosuspensions were characterized in terms of particle size distribution, zeta potential, and polydispersity index. The suspension containing PVPK30 and TPGS (1:1) showed least average particle size of 82.63 nm and polydispersity index of 0.472. The zeta potential of nanosuspensions ranged between 6.54 and 10.8 mV. An increase of 116.45% was evident in the specific surface area of the freeze-dried product. Contact angle of nanoparticles was also lowered to 27° as compared to 50.8° for TEL. Saturation solubility studies in various media revealed a significant increase in comparison to plain drug. An increase of 3.74× in saturation solubility in FaSSIF and 5.02× in FeSSIF was seen. In vitro dissolution profile of nanosuspension coated on pellets revealed release of 85% in water, 95% in 0.1 N HCl, and 75% in phosphate buffer in 30 min. Nanosuspensions were found to be stable in the presence of univalent and bivalent electrolytes. A tenfold increase in bioavailability was evident. Nanoparticles of telmisartan prepared by bottom-up technique proved to be effective in improving the oral bioavailability as a result of enhanced solubility and dissolution rate.Key words: biorelevant media, contact angle, specific surface area, telmisartan, TPGS     

Synthesis,characterization and evaluation of antimicrobial efficacy and brine shrimp lethality assay of Alstonia scholaris stem bark extract mediated ZnONPs

Alstonia scholaris is one of the most important medicinal plants and herein, we present the synthesis of zinc oxide nanoparticles using the bark extract of Alstonia scholaris, and evaluation of their antimicrobial efficacy. Stable ZnO nanoparticles were formed by treating 90 mL of 1 mM zinc nitrate aqueous solution with 10 mL of 10% bark extract. The formation of Alstonia scholaris bark extract mediated zinc oxide nanoparticles was confirmed by UV–visible spectroscopic analysis and recorded the localized surface plasmon resonance (LSPR) at 430 nm. Fourier transform infrared spectroscopic (FT-IR) analysis revealed that primary and secondary amine groups in combination with the proteins present in the bark extract is responsible for the reduction and stabilization of the ZnONPs. The crystalline phase of the nanocrystals was determined by XRD analysis and morphology was studied using transmission electron microscopy (TEM). The hydrodynamic diameter (26.2 nm) and a positive zeta potential (43.0 mV) were measured using the dynamic light scattering technique. The antimicrobial activity of Alstonia scholaris ZnONPs was evaluated (in-vitro) using disc diffusion method against fungi, Gram-negative and Gram-positive bacteria which were isolated from the biofilm formed in drinking water PVC pipelines. The results obtained suggested that ZnO nanoparticles exhibit a good anti-fungal activity than bactericidal effect towards all pathogens tested in in-vitro disc diffusion method (170 ppm, 100 ppm and 50 ppm). Further, the toxicity of biosynthesized ZnONPs was tested against Alstonia scholaris to evaluate the cytotoxic effect that displayed LC₅₀ value of 95% confidence intervals.