Optimization of bacteriocin production by Lactobacillus sp. MSU3IR against shrimp bacterial pathogens

BACKGROUND: Aquaculture is one amongst the growing and major food producing sectors. Shrimp culture is one of the subsectors of aquaculture that attracts more attention because of the economic interest. However, the shrimp culture systems have been facing severe consequences and economical losses due to disease outbreaks. Risk of disease outbreak can be combated with the application of probiotics. For economically viable production of such probiotic products, the present study provides information on the optimization and partial purification of bacteriocin produced by a goat milk isolate Lactobacillus sp. MSU3IR against the shrimp bacterial pathogens. RESULTS: Bacteriocin production was estimated as a measure of bactericidal activity (arbitrary Unit/ml) over the test strains. The optimum culture conditions and media components for maximum bacteriocin production by Lactobacillus sp. MSU3IR were: pH: 5.0, temperature: 30°C, carbon source: lactose; nitrogen source: ammonium acetate; NaCl: 3.0% and surfactant: Tween 80. MRS medium was found to extend better bacteriocin production than other tested media. Upon partial purification of bacteriocin, the SDS-PAGE analysis had manifested the presence of two peptide bands with the molecular weight of 39.26 and 6.38 kDa, respectively. CONCLUSION: The present results provide baseline trend for the statistical optimization, scale up process and efficient production of bacteriocin by the candidate bacterial strain Lactobacillus sp. MSU3IR which could be used to replace the usage of conventional chemotherapeutics in shrimp culture systems

Comparative shoot regeneration in diploid and amphidiploid Brassica species and their interspecific hybrids

Shoot regeneration response in interspecific hybrids of Brassica species were assessed in relation to the diploid pollen parents and amphidiploid female parents. Superior regeneration responses were observed in interspecific combinations of B. carinata and B. nigra (BBC), B. juncea and B. campestris (AAB), and B. napus and B. campestris (AAC). Though synthetic B. napus regenerated with a frequency less than that of the better regenerating parent (B. oleracea), higher regeneration response was observed in the hybrid between B. napus and B. campestris. Two triploid combinations of the genetic constitution ABC, one obtained by crossing synthetic B. napus with B. nigra and the other by crossing natural B. juncea with B. oleracea, showed low regeneration responses. The response improved substantially in a tetraploid of the constitution ABBC obtained by crossing B. juncea with B. carinata. Key words: Brassica, alloploids, shoot regeneration

Parallel symbolic state-space exploration is difficult, but what is the alternative?

State-space exploration is an essential step in many modeling and analysis problems. Its goal is to find the states reachable from the initial state of a discrete-state model described. The state space can used to answer important questions, e.g., "Is there a dead state?" and "Can N become negative?", or as a starting point for sophisticated investigations expressed in temporal logic. Unfortunately, the state space is often so large that ordinary explicit data structures and sequential algorithms cannot cope, prompting the exploration of (1) parallel approaches using multiple processors, from simple workstation networks to shared-memory supercomputers, to satisfy large memory and runtime requirements and (2) symbolic approaches using decision diagrams to encode the large structured sets and relations manipulated during state-space generation. Both approaches have merits and limitations. Parallel explicit state-space generation is challenging, but almost linear speedup can be achieved; however, the analysis is ultimately limited by the memory and processors available. Symbolic methods are a heuristic that can efficiently encode many, but not all, functions over a structured and exponentially large domain; here the pitfalls are subtler: their performance varies widely depending on the class of decision diagram chosen, the state variable order, and obscure algorithmic parameters. As symbolic approaches are often much more efficient than explicit ones for many practical models, we argue for the need to parallelize symbolic state-space generation algorithms, so that we can realize the advantage of both approaches. This is a challenging endeavor, as the most efficient symbolic algorithm, Saturation, is inherently sequential. We conclude by discussing challenges, efforts, and promising directions toward this goal

Nutrition, diet and immunosenescence

Ageing is characterized by immunosenescence and the progressive decline in immunity in association with an increased frequency of infections and chronic disease. This complex process affects both the innate and adaptive immune systems with a progressive decline in most immune cell populations and defects in activation resulting in loss of function. Although host genetics and environmental factors, such as stress, exercise and diet can impact on the onset or course of immunosenescence, the mechanisms involved are largely unknown. This review focusses on identifying the most significant aspects of immunosenescence and on the evidence that nutritional intervention might delay this process, and consequently improve the quality of life of the elderly

Experimental and numerical investigations of laced built-up lightweight concrete encased columns subjected to cyclic axial load

The steel-concrete composite column comprises a steel core and surrounding concrete. The purpose of the system is to provide analysis and design techniques for a newly invented class of laced steel-concrete composite short columns for cyclic axial loads. To minimize the increasing density issues associated with nominal strength concrete and in consideration of the depletion of natural resources required to produce concrete, factory-obtained lightweight sintered fly ash aggregates with and without basalt fiber are employed. The normal-weight concrete containing basalt fiber is shown to be more ductile than any other column. The axial deformation of columns LNA and LSA at failure was found to be 3.5 mm, whereas columns LNAF and LSAF reached an axial shortening of 4.5 mm at failure. The column LSAF was found to have 5.3% more energy absorption than the LSA and 11.5% less than the column LNAF. It was observed that the rigidity of these fabricated components had been enhanced. It was found that the section configuration with a lacing system had improved confinement effects and ductility. Comparing the finite element analysis to the experimental data revealed a strong connection with numerical modeling, with a variance of around 8.77%

Innovative use of copper mine tailing as an additive in cement mortar

This research assesses the feasibility of recycling copper mine tailings (CMT) by analyzing the durability and mechanical characteristics of cement mortar using these tailings as filler additives. CMT are mineral wastes generated during the process of mining. In this work, specimens of cement mortar were incorporated with up to 30 wt.% of a CMT. Bulk density, dynamic modulus of elasticity, apparent density, ultrasonic pulse velocity, flexural and compressive strengths tests were evaluated. Total amount of voids, sorptivity, water absorption and chemical resistance tests were also obtained to evaluate the mortar durability. When10wt.%CMTwasincorporated, overall amount of voids in the mortar was reduced by 20% and mechanical performance was improved by 16% after 28 days. The flexural strength of the mortar was also found to increase, with the 20% wt.% CMT mortar incorporation reaching a flexural strength of 5.89 MPa. Thus represents 16% increase compared to the control 0% CMT strength. The results indicated that there was not a perfect correlation between these results and the mechanical strength results for the 15and 20wt.% CMT mortars. In addition, the CMT acts as a protective barrier against harmful chemicals. The results of this research indicate that reusing CMT by incorporating into cement mortar is a feasible method for their recycling. Mortar made with as much as 15 wt.% CMT presented the same strength and durability as mortar with traditional sand and cement

Photoluminescence Properties of Two Closely Related Isostructural Series Based on Anderson-Evans Cluster Coordinated With Lanthanides [Ln(H2O)7{X(OH)6Mo6O18}]•yH2O, X = Al, Cr

The paper describes synthesis and structural characterization of the whole series of two closely related lanthanide coordinated chromium or aluminum hexamolybdates (Anderson-Evans cluster) including twelve new members hitherto unreported: [Ln(H2O)7{X(OH)6Mo6O18}]·4H2O and [Ln(H2O)7{X(OH)6Mo6O18}Ln(H2O)7]{X(OH)6Mo6O18}·16H2O where X = Al or Cr and Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y. Crystal structures of all the solids were established by powder and single crystal X-ray diffraction techniques. The two series are dictated by a different aggregation of the same set of molecular species: Lighter lanthanides favor coordination interaction between lanthanide ions and molybdate cluster forming 1D chains (Series I) while the heavier lanthanides result in the stacking of a cation, a pair of lanthanide hydrates coordinating to the cluster, and an anion, the discrete cluster is further stabilized through a large number of water molecules (Series II). Crystallization with Er3+ and Tm3+ ions results in a concomitant mixture of Series I and II. Photoluminescence of single crystals of all the chromium molybdates was dominated by a ruby-like emission including those which contain optically active ions Pr, Sm, Eu, Tb, Dy, and Tm. In contrast, aluminum analogs showed photoluminescence corresponding to characteristic lanthanide emissions. Our results strongly suggest a possible energy transfer from f levels of lanthanide ions to d levels of chromium (III) causing the quenching of lanthanide emission when coordinated with chromium molybdates. Intensity measurements showed that the emission from chromium molybdates are almost two orders of magnitude lower than naturally occurring ruby with broader line widths at room temperature

A floristic study on herbs and climbing plants at Puducherry, South India: an approach to biodiversity conservation and regeneration through eco-restoration

A qualitative floristic exploration with life form classifications and monitoring of flowering and fruiting phenology has been carried out at a restored site near Puducherry, South India in 2009 and 2010. The species were classified into three categories based on their occurrence status, namely, Naturally Occurring, Naturally Regenerated and Introduced. The present study focuses only on two life forms, the Herbaceous and the Climbing plants. The site selected for eco-restoration originally comprised of an eroded and severely degraded landscape with scattered remnant species. However, active human intervention over a thirty year period included the introduction of appropriate plant species and other physical measures to enhance soil fertility and ground water level, and regenerate and conserve the deteriorating typical Tropical dry evergreen forest (TDEF) vegetation. A large number of naturally ccurring herbaceous, climbing species (172) and a consistent number of naturally regenerated species (44) are now observed as a result of eco-restoration. Lowland herbaceous species have also established themselves as a green cover at ground level. At present, parts of the area have fertile soils and rich floristic composition with the herbaceous life form represented by 165 species encompassed in 105 genera and 37 families, and the climbing plants represented by 68 species belonging to 54 genera and 25 families. ‘Genus to family’ and ‘species to genus’ ratios indicate the establishment of diverse vegetation in the study site. Nearly one third of the species have been observed flowering throughout the year and about half of the species were observed fruiting throughout the year. We emphasize that the two fold approach of land and vegetation reclamation has been very effective in helping restore the unique TDEF vegetation at the local level and the same may be extended to help regenerate and conserve the Coromandel Coastal vegetation at the regional scale

Antifouling and toxic properties of the bioactive metabolites from the seagrasses Syringodium isoetifolium and Cymodocea serrulata

International audienceThe present study documents the antifouling and toxic properties of seagrasses Syringodium isoetifolium and Cymodocea serrulata. For that, the seagrasses S. isoetifolium and C. serrulata were extracted individually using organic solvents viz. dichloromethane, acetone and methanol. Amongst the extracts, the maximum antimicrofouling and antimacrofouling activities were exhibited by methanol extracts of both the seagrasses. The Minimal Inhibitory Concentration (MIC) of methanolic extracts of seagrasses was ranged from 1.0 to 10 mu g/ml against test biofilm bacteria and microalgal strains. Similarly, 100% fouling inhibition of limpet Patella vulgata was found at 6.0 mg/ml of methanolic extracts of seagrasses. The mussel Perna indica showed 50% of byssal production and attachment inhibition at 21.51 +/- 2.03, 17.82 +/- 1.07 mu g/ml and the anticrustaecean activity for 50% mortality of Anemia sauna was recorded at 732.14 +/- 921 and 394.16 +/- 5.16 mu g/ml respectively for methanolic extracts of S. isoetifolium and C serrulata. The minimal inhibitory and higher lethal concentrations of active methanol extracts shows it's less toxic nature. Based on the prolific results, methanol extracts of S. isoetifolium and C serrulata were subjected to purification using silica gel column and thin layer chromatography. Then the active compounds of the bioassay guided fractions were partially characterized using gas chromatography coupled with mass spectroscopy (GC-MS) and keyed out that fatty acids (C-16 to C-24) were the major components which responsible for the antifouling properties of the candidate seagrasse