Biocides formulation of essential oils having antimicrobial activity

Essential oils of fennel, peppermint, caraway, eucalyptus, geranium and lemon were tested for their antimicrobial activities against some plant pathogenic micro-organisms (Fusarium oxysporum, Alternaria alternate, Penicilium italicum Penicilium digitatum and Botyritus cinerea). Essential oils of fennel, peppermint, caraway were selected as an active ingredient for the formulation of biocides due to their efficiency in controlling the tested micro-organisms. Successful emulsifiable concentrates (biocides) were prepared from these oils using different emulsifiers (Emulgator B.L.M. Tween20 and Tween80) and different fixed oils (sesame, olive, cotton and soybean oils). Physico-chemical properties of the formulated biocide (spontaneous emulsification, emulsion stability test, cold stability and heat stability tests as well as viscosity, surface tension and pH) were measured. The prepared biocides were ready to be tested for application in a future work as a safe pesticide against different pathogens.     

Metagenomic insights into strategies of carbon conservation and unusual sulfur biogeochemistry in a hypersaline Antarctic lake

Organic Lake is a shallow, marine-derived hypersaline lake in the Vestfold Hills, Antarctica that has the highest reported concentration of dimethylsulfide (DMS) in a natural body of water. To determine the composition and functional potential of the microbial community and learn about the unusual sulfur chemistry in Organic Lake, shotgun metagenomics was performed on size-fractionated samples collected along a depth profile. Eucaryal phytoflagellates were the main photosynthetic organisms. Bacteria were dominated by the globally distributed heterotrophic taxa Marinobacter, Roseovarius and Psychroflexus. The dominance of heterotrophic degradation, coupled with low fixation potential, indicates possible net carbon loss. However, abundant marker genes for aerobic anoxygenic phototrophy, sulfur oxidation, rhodopsins and CO oxidation were also linked to the dominant heterotrophic bacteria, and indicate the use of photo- and lithoheterotrophy as mechanisms for conserving organic carbon. Similarly, a high genetic potential for the recycling of nitrogen compounds likely functions to retain fixed nitrogen in the lake. Dimethylsulfoniopropionate (DMSP) lyase genes were abundant, indicating that DMSP is a significant carbon and energy source. Unlike marine environments, DMSP demethylases were less abundant, indicating that DMSP cleavage is the likely source of high DMS concentration. DMSP cleavage, carbon mixotrophy (photoheterotrophy and lithoheterotrophy) and nitrogen remineralization by dominant Organic Lake bacteria are potentially important adaptations to nutrient constraints. In particular, carbon mixotrophy relieves the extent of carbon oxidation for energy production, allowing more carbon to be used for biosynthetic processes. The study sheds light on how the microbial community has adapted to this unique Antarctic lake environment.     

Nitrate reductase activity,biomass, yield,and quality in cotton in response to nitrogen fertilization

In the production of cotton (Gossypium hirsutum L.), nitrogen fertilization is one of the most costly crop practices, but important to reach high yields. However, high nitrogen (N) content in plants does not always translate into a high fibre production. One way of assessing the efficiency of the N fertilizer is through the enzymatic activity of the nitrate reductase (NR). This is a key enzyme in N assimilation, whose activity is regulated by a number of endogenous and exogenous factors that determine yield. The aim of this study was to assess the effect of N fertilization on yield, fibre quality, biomass, and NR enzymatic activity in vivo in the cotton variety Fiber Max 989. The evaluated application rates were 0, 50, 100, and 150 kg/ha of N, using urea as a source (46% N) in a randomizedblock design with three replicates. At harvest, the maximum yield of seed cotton and the greatest accumulation of total foliar biomass through time was reached after applying 150 kg N/ha. The different N-application rates did not affect the components of cotton-fibre quality. The activity of endogenous NR was greater on plants where 150 kg N/ha were applied. The highest cotton yield and N contents were obtained on these plants. Therefore, the NR activity in vivo could be used as a bioindicator of the N nutritional level in cotton.     

Germination of <i>Eryngium regnellii</i>: a major species for ecological restoration of plant-pollinator interactions in the Southern Pampas (Buenos Aires,Argentina)

Eryngium regnellii Malme belongs to the largest genera in the Apiaceae family, with 250 species worldwide and 65 represented in South America. It is a herbaceous species typical of hill plant communities, which, along with remnant grassland patches, are the most relevant natural habitats for the maintenance of diversity in the Southern Pampas. Eryngium regnellii is key to the maintenance of pollination mutualisms, being a generalist (displaying a diverse assemblage of pollinators) and ubiquitous species (present in all studied sierras). However, fragmentation of the Pampean landscape due to agricultural intensification has led to the loss of natural environments. Therefore, the reintroduction of E. regnellii in strategic places would facilitate the occurrence of wild pollinators, while favoring pollination services in the agroecosystem. The germination requirements of E. regnellii were studied because a better knowledge of the reproductive biology of this species would provide information relevant to its reproduction and reintroduction into degraded areas. Germination percentages and mean time to germination were evaluated, using one control and two pre-germination treatments: chemical scarification with sulfuric acid, and mechanical scarification with sand paper. Chemical scarified seeds did not germinate. Mechanically scarified and control seed groups showed no significant differences either in germination percentages (49% and 59% respectively) or in mean germination time (13 and 14 days, respectively). Results indicate that E. regnellii shows no physical dormancy, and does not require specific pre-germination treatments for germination under the studied laboratory conditions. The high germination capacity of E. regnellii, along with its ecological attributes, make it a potential species for restoring plant-pollinator interactions in the fragmented landscapes of the Southern Pampas.     

Anti-inflammatory roles of mesenchymal stromal cells during acute Streptococcus pneumoniae pulmonary infection in mice

Background

Pneumonia is the fourth leading cause of death worldwide, and Streptococcus pneumoniae is the most commonly associated pathogen. Increasing evidence suggests that mesenchymal stromal cells (MSCs) have anti-inflammatory roles during innate immune responses such as sepsis. However, little is known about the effect of MSCs on pneumococcal pneumonia.

Isolation of Basal Cells and Submucosal Gland Duct Cells from Mouse Trachea

The large airways are directly in contact with the environment and therefore susceptible to injury from toxins and infectious agents that we breath in ¹. The large airways therefore require an efficient repair mechanism to protect our bodies. This repair process occurs from stem cells in the airways and isolating these stem cells from the airways is important for understanding the mechanisms of repair and regeneration. It is also important for understanding abnormal repair that can lead to airway diseases ². The goal of this method is to isolate a novel stem cell population from the mouse tracheal submucosal gland ducts and to place these cells in in vitro and in vivo model systems to identify the mechanisms of repair and regeneration of the submucosal glands ³. This production shows methods that can be used to isolate and assay the duct and basal stem cells from the large airways ³.This will allow us to study diseases of the airway, such as cystic fibrosis, asthma and chronic obstructive pulmonary disease. Currently, there are no methods for isolation of submucosal gland duct cells and there are no in vivo models to study the regeneration of submucosal glands.     

Polymorphisms of TNFalpha, IL1beta, and IL1RN genes in chronic obstructive pulmonary disease

It is recognized that genetic factors play a role in the susceptibility to COPD. COPD is characterized by airflow limitation. Chronic inflammation causes small airway disease and parenchymal destruction, leading to the airflow limitation. Polymorphisms in pro-inflammatory cytokine genes may confer a risk for the development of COPD. A case-control association study was performed in Japanese population (88 COPD patients and 61 controls) and Egyptian population (106 patients and 72 controls). Genotype and allele frequencies of the TNFalpha -308 G/A and +489 G/A polymorphisms, the IL1beta -511 C/T, -31 T/C, and +3954 C/T polymorphisms, and a VNTR polymorphism in intron 2 of the IL1RN gene were investigated. In addition, pairwise haplotype frequencies were analyzed. When studied independently, none of the polymorphisms were associated with the development of COPD in both populations. However, in the Egyptian population, the distributions of the haplotype (IL1beta -31 T/C : IL1beta +3954 C/T) were significantly different between the COPD patients and the controls (p(corr)=0.0037). Our findings suggest that this haplotype within the IL1beta gene may be involved in the pathogenesis of COPD and that the genetic factors of COPD susceptibility might be different between different populations.