Investigation of the cell disruption methods for maximizing the extraction of arginase from mutant <Emphasis Type="Italic">Bacillus licheniformis</Emphasis> (M09) using statistical approach

Arginase, an intracellular enzyme produced by Bacillus licheniformis (NRS-1264) is effectively used as a drug in the treatment of arginine-dependent cancers, and it is essential for controlling acute neurological disorders. We investigated the effect of various cell disruption methods for maximizing the extraction of intracellular arginase from mutant Bacillus licheniformis (M09), followed by comparing optimization methods, one factor at a time (OFAT), evolutionary operation (EVOP) and response surface method (RSM). Ultrasonication for 2-5 min having a suspension volume in the range of 12-20 mL at a radio frequency power between 30–70 W appeared to be the most effective extraction technique for arginase. The arginase yield decreased in the range of 50–70 W of RF power/16-20 mL suspension volume and 4-5 min sonication time. EVOP predicted a maximum arginase extraction of 3,910 IU·L^-1 at 2 min sonication having 16 mL suspension volume at 30W RF power. However, response surface optimization suggested an optimized condition of 3 min sonication having 14.5 mL suspension volume at 35W RF power in which the maximum arginase activity in the medium was 3,600 IU·L^-1.     

A clinically relevant HIV-1 subunit vaccine protects rhesus macaques from in vivo passaged simian-human immunodeficiency virus infection

OBJECTIVES: To investigate whether immunization with recombinant HIV-1 envelope protein derived from a clinical isolate could protect macaques from infection with an in vivo passaged chimeric simian-human immunodeficiency virus (SHIV). DESIGN AND METHODS: A total of 16 animals were studied from which three groups of four animals were immunized with vaccine formulations of the CC-chemokine receptor-5-binding recombinant gp120 of HIV-1W6.1D. Four weeks after the last immunization, all 16 animals were intravenously challenged with in vivo passaged SHIV derived from the same HIV-1 group B clinical isolate (W6.1D) as the vaccines. RESULTS: Vaccine protection from infection was demonstrated in 10 out of 12 macaques immunized with recombinant gp120. Complete protection from infection was achieved with all of the animals that received the SBAS2-W6.1D formulation, a potent inducer of both T-cell and humoral immune responses. Partial protection was achieved with SBAS1-W6.1D, a formulation based on immunomodulators known to induce T-cell responses in humans. In vaccinated animals that were infected, virus load was reduced and infection was delayed. CONCLUSIONS: In a relatively large number of primates, vaccine efficacy was demonstrated with a clinically relevant HIV-1 vaccine. These results reveal that it is possible to induce sterilizing immunity sufficient to protect from infection with SHIV which was passaged multiple times in vivo. Our findings have implications for current HIV-1 clinical vaccine trials and ongoing efforts to develop safe prophylactic AIDS vaccines.     

Lactobacillus acidophilus: Characterization of the Species and Application in Food Production

L. acidophilus is a homofermentative, microaerophilic, short chain gram positive microorganism with rod morphology having its bacteriocins belonging to class II a. Several bacteriocins of L. acidophilus have been isolated and characterized. These are structurally similar, but their molecular weight varies as well as their spectrum of antimicrobial activity. They exhibit important technical properties, i.e., thermostability and retaining of activity at a wide pH range along with strong inhibitory actions against food spoilage and pathogenic bacteria make them an important class of biopreservatives. L. acidophilus can be added as an adjunct in many food fermentation processes contributing to unique taste, flavor, and texture. It also preserves the products by producing lactic acid and bacteriocins. A lot of new information regarding the bacteriocins of L. acidophilus has emerged during the last few years. In this review, an attempt has been made to summarize and discuss all the available information regarding the sources of bacteriocins production, their characteristics, and their antimicrobial action along with their application.     

Thermal,electrical, and physical properties of novel phase stabilized material: hybrid plastilina nanocomposites for effective thermal management in electronics

Journal of Materials Science: Materials in Electronics - To operate efficiently, high-performance devices require excellent heat dissipation to counteract overheating. Therefore, high thermal...     

Variability of sea surface salinity in the tropical Indian Ocean as inferred from Aquarius and in situ data sets

Sea surface salinity (SSS) is one of the key components of the Earth’s global water cycle. Reliable information on SSS is very important for ocean modelling, data assimilation, and ocean and climate research applications. In this study, SSS variability in the tropical Indian Ocean (TIO) was analysed using the Aquarius instrument on board the SAC-D satellite and in situ observations from the Research Moored Array for African–Asian–Australian Monsoon Analysis and Prediction (RAMA) buoys and Array for Real-Time Geostrophic Oceanography (ARGO) data sets for the period 2012–2013. Comparison of two recent versions (V2 and V3) of Aquarius-based SSS estimates to nine RAMA buoys on a daily timescale showed excellent mutual agreement. The systematic underestimation of SSS by satellite-based V2 products over the TIO shows a clear advantage for the new version product (V3). A larger root-mean-square error of the order of 0.50 psu in the satellite-based SSS was observed over the highly variable (larger standard deviation) Bay of Bengal region as compared with ARGO data sets. In the eastern equatorial Indian Ocean region, satellite-based SSS overestimated SSS below 34 psu and underestimated SSS of 34–35 psu as compared with ARGO data. However, the V3 SSS from Aquarius showed marginal improvement over V2 SSS. Monthly variation and fast Fourier analysis of the satellite-based SSS estimates are in reasonably good agreement with in situ observations which suggest that Aquarius is able to capture SSS variability in the TIO. The Aquarius-based V3 SSS showed a temporal autocorrelation of 0.6 over most parts of the TIO up to day 10, and decreased gradually with time. Overall analysis suggests that Aquarius-derived V3 SSS can detect variability in SSS satisfactorily in the TIO and is in reasonably good agreement with in situ observations.     

Heat transfer and friction in solar air heater duct with V-shaped rib roughness on absorber plate

In this work, results of an experimental investigation of the effect of geometrical parameters of V-shaped ribs on heat transfer and fluid flow characteristics of rectangular duct of solar air heater with absorber plate having V-shaped ribs on its underside have been reported. The range of parameters for this study has been decided on the basis of practical considerations of the system and operating conditions. The investigation has covered a Reynolds number (Re) range of 2500-18000, relative roughness height (e/D_h) of 0.02-0.034 and angle of attack of flow (α) of 30-90° for a fixed relative pitch of 10. Results have also been compared with those of smooth duct under similar flow conditions to determine the enhancement in heat transfer coefficient and friction factor. The correlations have been developed for heat transfer coefficient and friction factor for the roughened duct.     

Stabilization of emulsion and butter like products containing essential fatty acids using kalonji seeds extract and curcuminoids

Owing to the tendency of essential fatty acids (EFAs) to undergo autoxidation, their storage becomes a key problem. Generally, they are stabilized by synthetic antioxidants like TBHQ that are toxic in nature. Recently many studies were reported where these EFAs are stabilized by natural antioxidants. In the present study, curcuminoids and kalonji seeds ethanol extract (KEE) were used to stabilize these EFAs in refined sunflower oil (RSFO), water-in-oil (w/o) emulsion and butter like products (BLPs). In RSFO, though curcuminoids alone exerted pro-oxidant effect, KEE and curcuminoids showed synergistic antioxidant activity that was comparable to TBHQ. KEE exhibited good antioxidant activity in emulsions and BLPs, providing fine physical properties like slipping point, dropping point and spreadability. EFAs increased the nutritional value of BLPs and antioxidants added for their stabilization provided their medicinal benefits.