Novel approaches toward the development of an oral post-exposure DNA vaccine for latent tuberculosis using Salmonella typhimurium ΔaroA vector

Tuberculosis remains one of the major causes of global public health problems. There is no effective vaccine for the disease until now. Many reports show that DNA vaccines are promising to induce protection against Mycobacterium tuberculosis (M. tb); however, the efficiency of DNA vaccine is limited due to inadequate delivery systems. Among others, live attenuated bacterial vectors such as Salmonella enterica typhimurium (S. typhimurium) have significant promise as efficient mucosal delivery vehicles for DNA vaccines. In this study, we constructed recombinant attenuated S. typhimurium DNA vaccines carrying genes encoding resuscitation promoting factor (Rpf)-like proteins of M. tb on eukaryotic expression plasmid agianst latent tuberculosis and evaluated the plasmid stability and growth curve assays of the recombinant Salmonella vaccine constructs in vitro. Four Rpf gene fragments (RpfB, RpfC, RpfD, RpfE) associated with latency were amplified from genomic DNA of the H37Rv strain of M. tb, cloned into eukaryotic expression plasmid (pVR1020) and verified by sequencing. In later studies, we will demonstrate the potential use of the Salmonella-mediated DNA constructs as candidate post-exposure vaccines against tuberculosis through testing their immunogenicity and effectiveness for oral delivery in eukaryotic systems.Key words: Latent tuberculosis, resuscitation promoting factor (Rpf), DNA vaccine, recombinant Salmonella typhimurium

Draft genome sequence of <i>Bacillus</i> sp. strain X and <i>Salarachaeum</i> sp. strain III isolated from Lake Karum, Danakil Depression, Ethiopia

Here, we report the draft genome sequences of strains of Bacillus and Salarachaeum that were isolated from hypersaline water samples collected from Lake Karum, Danakil Depression, Ethiopia. The sequences pave the way for more targeted studies into the potential biological activities and secondary metabolite synthesis of these organisms

Dendritic Cells Activate and Mature after Infection with Mycobacterium tuberculosis

<p>Abstract</p> <p>Background</p> <p>Dendritic cells (DCs) can take up an array of different antigens, including microorganisms which they can process and present more effectively than any other antigen presenting cell. However, whether the interaction between the human DC and <it>Mycobacterium tuberculosis </it>represents a defense mechanism by the invaded host, or helping the invader to evade the defense mechanism of the host is still not clearly understood.</p> <p>Findings</p> <p>To analyze the interactions between <it>M. tuberculosis </it>and immune cells, human peripheral blood monocyte-derived immature DCs were infected with <it>M. tuberculosis </it>H37Rv wild type strain and flow cytometry was used to analyse cell surface expression markers. The ability of the <it>M. tuberculosis </it>infected DC to induce T cell proliferation using 5 and 6-carboxyfluorescein diacetate succinimidyl ester (CFSE) dilution technique was also investigated. DCs were found to internalize the mycobacteria and show dose dependent infection and necrosis with different multiplicity of infection. Flow cytometry analysis of cell surface expression markers CD40, CD54, CD80, CD83, CD86 and HLA DR in infected DC revealed significant (p < 0.05) up regulation following infection with <it>M. tuberculosis </it>in comparison to immature DC with no stimulation. Lipopolysaccharide (LPS) from <it>Salmonella abortus equi</it>, a known DC maturation agent, was used as a positive control and showed a comparable up regulation of cell surface markers as observed with <it>M. tuberculosis </it>infected DC. It was revealed that the <it>M. tuberculosis </it>infected DC induced T cell proliferation.</p> <p>Conclusion</p> <p>These data clearly demonstrate that <it>M. tuberculosis </it>induces activation and maturation of human monocyte-derived immature DC as well as induces T cell proliferation <it>in vitro</it>.</p

Reference soil groups map of Ethiopia based on legacy data and machine learning-technique: EthioSoilGrids 1.0

Up-to-date digital soil resource information and its comprehensive understanding are crucial to supporting crop production and sustainable agricultural development. Generating such information through conventional approaches consumes time and resources, and is difficult for developing countries. In Ethiopia, the soil resource map that was in use is qualitative, dated (since 1984), and small scaled (1 : 2 M), which limit its practical applicability. Yet, a large legacy soil profile dataset accumulated over time and the emerging machine-learning modeling approaches can help in generating a high-quality quantitative digital soil map that can provide better soil information. Thus, a group of researchers formed a Coalition of the Willing for soil and agronomy data-sharing and collated about 20 000 soil profile data and stored them in a central database. The data were cleaned and harmonized using the latest soil profile data template and 14 681 profile data were prepared for modeling. Random forest was used to develop a continuous quantitative digital map of 18 World Reference Base (WRB) soil groups at 250 m resolution by integrating environmental covariates representing major soil-forming factors. The map was validated by experts through a rigorous process involving senior soil specialists or pedologists checking the map based on purposely selected district-level geographic windows across Ethiopia. The map is expected to be of tremendous value for soil management and other land-based development planning, given its improved spatial resolution and quantitative digital representation.</p

Application of Microbial Bioenzymes in Soil Stabilization

Soil stabilization is a mechanical or chemical alteration of one or more soil properties to create an improved soil material possessing the desired engineering properties. The aim of this article was to review bioenzyme-based soil stabilization techniques with an emphasis on bioenzymes production, mechanism of soil stabilization and future challenges, and opportunities of the sector. Soils are stabilized to increase strength and durability or to prevent erosion and dust generation. Cost-effective soil stabilization technology has been a fundamental part of any construction and is very important for economic growth in any country. In some cases, construction has been challenged due to the high cost of soil stabilization processes. Besides, methods of stabilizations using common stabilizing agents are getting costly. Currently, there is a growing interest to identify new and green technology to improve construction techniques and to expand the road network. Therefore, the search for new materials and improved techniques to process the local materials has received an increased focus. For developing countries, bioenzymes are now creating an opportunity to improve soil stability with tremendous effectiveness in the overall process of soil stabilization. In the world, bioenzymes have been used in different projects for several years and are generally proprietary products, often of patented formulation that needs intensive field tests. Currently, the use and production of bioenzymes is becoming the most promising key for the advancement of a country by saving time, energy, and finance. It also reduces environmental pollution due to carbon emission by the conventional stabilizers. Thus, a better understanding of this emerging technology is of utmost importance to exploit any improvement it can offer to soil stability. With little research and practice, it is possible to produce soil stabilizing bioenzymes using local raw materials. Due to this, production of low cost, easily and widely applicable, and environmentally friendly enzymatic formulations from locally available raw materials should be the interest of research and academic institutes of any country

Mycelium-Based Composite: The Future Sustainable Biomaterial

Because of the alarming rate of human population growth, technological improvement should be needed to save the environment from pollution. The practice of business as usual on material production is not creating a circular economy. The circular economy refers to an economic model whose objective is to produce goods and services sustainably, by limiting the consumption and waste of resources (raw materials, water, and energy). Fungal-based composites are the recently implemented technology that fulfills the concept of the circular economy. It is made with the complex of fungi mycelium and organic substrates by using fungal mycelium as natural adhesive materials. The quality of the composite depends on both types of fungi and substrate. To ensure the physicochemical property of the fabricated composite, mycelium morphology, bimolecular content, density, compressive strength, thermal stability, and hydrophobicity were determined. This composite is proven to be used for different applications such as packaging, architectural designs, walls, and insulation. It also has unique features in terms of low cost, low emission, and recyclable

Production of Mycoblock from the Mycelium of the Fungus Pleurotus ostreatus for Use as Sustainable Construction Materials

As the global population rises, resource depletion and environmental pollution also aggravate. To meet the needs of the population, different products have been manufactured. However, most industrially manufactured products are not eco-friendly, costly, and locally unavailable. To solve these problems, using and enhancing locally available biomaterials are the key option. Three substrates sawdust, bagasse, and coffee husk and the fungus Pleurotus ostreatus were used. Mycelium was fully colonized by 9, 14, and 27 days on potato dextrose agar (PDA), sorghum grain, and substrate, respectively. The mycelium growth on coffee husk showed the fastest growth rate whereas that of the sawdust was slowest. The fully colonized substrates were molded for 7, 14, and 21 days by plastic mold to maintain their regular 3D structure. The result shows that the block made with sawdust at 21 molding period has higher compressive strength and density of 750 kPa and 343.44 Kg/m3, respectively, followed by bagasse and coffee husk. These variations were due to the mycelium density difference between the substrates. Physicochemical and mechanical characteristics such as mycelium morphology, bimolecular and elemental analysis of substrates, density, water absorption, and compressive strength of the block were analyzed. This technology has the potential to replace conventional construction and packaging materials used for indoor applications such as insulation, partition walls, and other design and architectural applications. It also benefits in terms of its low cost, green synthesis approach, nontoxicity, low environmental emission, recyclability, and local availability

The Optimum Design Parameters in Terms of Total Specific Energy Requirements for the Rotary Blade Power Tiller under Unsaturated Sandy Clay Loam Soil Condition

ABSTRACT A mathematical modeling approach was applied to predict optimum design parameters in terms of the total specific energy requirements of a &quot;Pick&quot;, a &quot;C&quot;, an &quot;I&quot;, an &quot;L&quot; and a &quot;J&quot;-shaped rotary blades. The modified total specific energy requirement model mainly has been includeds, the forward speed of the machine, the rotational speed, the depth of soil cut, the width of soil cut, the rotor radius, the angle of periphery, the angle of rotation, the specific soil resistance, the dry soil bulk density and volume of soil tilled. At the same working conditions the total specific energy requirement was predicted to be 231. 61, 160.72, 196.87, 168.56 and 167.56 kJ / m 3 for the &quot;Pick&quot;, the &quot;C&quot;, the &quot;I&quot;, the &quot;L&quot; and the &quot;J&quot;-shaped rotary blades, respectively. The highest specific energy requirement was exhibited by the &quot;Pick&quot;-shaped and the lowest by the &quot;C&quot;-shaped blade. The higher total specific energy requirement the lower volume of soil tilled and the most effective and optimum soil tillage operational cost is achieved. Compared to another study at the same soil condition the specific energy requirement per volume of soil tilled by the &quot;Pick&quot;-shaped blade was exhibited 1900 kJ / m 3 which was higher by 87.81 % than the &quot;Pick&quot;-shaped blade in the present study. Therefore, the model suggests rotary tiller development under local conditions

Isolation and screening of low-density polyethylene (LDPE) bags degrading bacteria from Addis Ababa municipal solid waste disposal site “Koshe”

Abstract Purpose This study aims to screen bacterial isolates from the Addis Ababa municipal solid waste dumping site (Koshe) for the biodegradation of low-density polyethylene bags and analyzes their efficiency in degrading plastic bags. Methods In this study, low-density polyethylene bag-degrading bacteria were isolated from the Koshe municipal solid waste disposal area in Addis Ababa, Ethiopia. Screening of isolates for low-density polyethylene bag biodegradation was carried out using a clear zone method. Additionally, the efficiency of the isolates for low-density polyethylene biodegradation was evaluated using the weight loss method, scanning electron microscopy analysis, and Fourier transform infrared analysis. Finally, molecular identification of potential low-density polyethylene degrader bacterial isolates was done by 16S rDNA sequencing. Results Isolates KS35, KS14, and KS119 resulted in significant weight loss of low-density polyethylene film (42.87 ± 1.91%, 37.2 ± 3.06%, and 23.87 ± 0.11% weight loss, respectively). These isolates were selected for further biodegradation study using scanning electron microscopy and Fourier transform infrared analysis. Scanning electron microscopy analysis shows the formation of pores, pits, and distortion of the plastic surface. Fourier transform infrared analysis indicates the appearance of new peaks at the surface of low-density polyethylene films. Phylogenetic analysis of the three potential bacterial isolates was also carried out, and the result indicates that the sequence of isolate KS35 had 99% similarity with sequences of Methylobacterium radiotolerans MN525302. Isolate KS119 had 100% similarity with Methylobacterium fujisawaense KT720189, and the sequence of isolate KS14 had 99% similarity with species of Lysinibacillus fusiformis. Conclusions Weight loss, scanning electron microscopy analysis, and Fourier transform infrared analysis results show that isolates KS35, KS14, and KS119 have high potential in degrading low-density polyethylene bags

Microbial carbohydrate active enzyme (CAZyme) genes and diversity from Menagesha Suba natural forest soils of Ethiopia as revealed by shotgun metagenomic sequencing

Abstract Background The global over-reliance on non-renewable fossil fuels has led to the emission of greenhouse gases, creating a critical global environmental challenge. There is an urgent need for alternative solutions like biofuels. Advanced biofuel is a renewable sustainable energy generated from lignocellulosic plant materials, which can significantly contribute to mitigating CO2 emissions. Microbial Carbohydrate Active Enzymes (CAZymes) are the most crucial enzymes for the generation of sustainable biofuel energy. The present study designed shotgun metagenomics approaches to assemble, predict, and annotate, aiming to gain an insight into the taxonomic diversity, annotate CAZymes, and identify carbohydrate hydrolyzing CAZymes from microbiomes in Menagesha suba forest soil for the first time. Results The microbial diversity based on small subunit (SSU) rRNA analysis revealed the dominance of the bacterial domain representing 81.82% and 92.31% in the studied samples. Furthermore, the phylum composition result indicated the dominance of the phyla Proteobacteria (23.08%, 27.27%), Actinobacteria (11.36%, 20.51%), and Acidobacteria (10.26%, 15.91%). The study also identified unassigned bacteria which might have a unique potential for biopolymer hydrolysis. The metagenomic study revealed that 100,244 and 65,356 genes were predicted from the two distinct samples. A total number of 1806 CAZyme genes were identified, among annotated CAZymes, 758 had a known enzyme assigned to CAZymes. Glycoside hydrolases (GHs) CAZyme family contained most of the CAZyme genes with known enzymes such as β-glucosidase, endo-β-1,4-mannanase, exo-β-1,4-glucanase, α-L-arabinofuranosidase and oligoxyloglucan reducing end-specific cellobiohydrolase. On the other hand, 1048 of the identified CAZyme genes were putative CAZyme genes with unknown enzymatical activity and the majority of which belong to the GHs family. Conclusions In general, the identified putative CAZymes genes open up an opportunity for the discovery of new enzymes responsible for hydrolyzing biopolymers utilized for biofuel energy generation. This finding is used as a first-hand piece of evidence to serve as a benchmark for further and comprehensive studies to unveil novel classes of bio-economically valuable genes and their encoded products