Determination of the Optimal Parameters for Self-Healing Efficiency of Encapsulated bacteria in Concrete Simulated Subtropical Climate

Concrete is a remarkable construction material. However, its low tensile strength makes it prone to cracking, which negatively affects its durability. To address this issue, bacterial concrete has been implemented as a self-healing alternative due to its capability to seal microcracks through microbial-induced calcium carbonate precipitation (MICCP). In this study, a bacterial strain (i.e, Bacillus Pseudiformus) was encapsulated through three different methods: encapsulation through hydrogel beads, vacuum impregnation on lightweight aggregates, and attachment to cellulose nanocrystals. Furthermore, three precursor types were used, magnesium acetate, calcium lactate, and sodium lactate were implemented. Compressive strength tests and flexural strength tests were performed on mortar specimens to characterize their mechanical properties. Once the crack was induced, samples were subjected to 28 days of wet/dry cycles in which the corresponding crack width was monitored. At the end of this period, the beams were retested to determine the strength recovery of the specimens. The results showed that the specimen groups in which calcium lactate was added to the cementitious matrix displayed the highest values in compressive strength. In terms of flexural strength, no major difference was found among the specimens. Moreover, the flexural strength recovery of the specimens did not show any significant difference as well. In terms of the healing efficiency, the sample that displayed the best results was the one containing calcium lactate as a precursor along with bacteria and yeast extract encapsulated in hydrogel beads. In addition, scanning electron microscopy (SEM) along with x-ray energy dispersive spectroscopy (EDS) was performed on the cracked specimens to characterize the healing products. Furthermore, a scale study was performed on concrete samples to determine the long-term implications of adding encapsulated bacteria along with calcium lactate and yeast extract in concrete

Maize growth promotion by inoculation with Azospirillum brasilense and metabolites of Rhizobium tropici enriched on lipo-chitooligosaccharides (LCOs)

There is an increasing interest in the development and use of inoculants carrying plant growth-promoting bacteria (PGPB) in crops of agronomic interest. The great majority of the inoculants commercialized worldwide contain rhizobia for legume crops, but the use of PGPB as Azospirillum spp. for non-legume is expanding, as well as of inoculants combining microorganisms and microbial metabolites. In this study we evaluated the effects of inoculants containing Azospirillum brasilense with or without metabolites of Rhizobium tropici strain CIAT 899 highly enriched in lipo-chitooligosaccharides (LCOs) in six field experiments performed for three summer crop seasons in Brazil with maize (Zea mays L.). Inoculants and metabolites were applied either at sowing by seed inoculation, or by leaf spray at the V3 stage of plant growth. Improvement in shoot dry weight (SDW) and total N accumulated in shoots (TNS) by single, but especially by dual inoculation was observed in some of the experiments. Statistically significant increases in grain yield in relation to the non-inoculated control were observed in five out of six experiments when maize was inoculated with Azospirillum supplied with enriched metabolites of R. tropici applied by seed or leaf spray inoculation. The results give strength to the development of a new generation of inoculants carrying microorganisms and microbial molecules

Confirmation of the utility of the International Staging System and identification of a unique pattern of disease in Brazilian patients with multiple myeloma

Santa Casa São Paulo, São Paulo, BrazilUniv Fed Rio de Janeiro, Rio de Janeiro, BrazilUniv São Paulo, São Paulo, BrazilHEMOPE, Recife, PE, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilUniv Fed Bahia, BR-41170290 Salvador, BA, BrazilHosp Brigadeiro São Paulo, São Paulo, BrazilUniv Fed Rio Grande do Sul, BR-90046900 Porto Alegre, RS, BrazilSch Med, Ribeirao Preto, BrazilUniv Fed Minas Gerais, Belo Horizonte, MG, BrazilUniv Fed Parana, BR-80060000 Curitiba, Parana, BrazilUniv Estadual Campinas, BR-13081970 Campinas, SP, BrazilInst Nacl Canc Rio Janeiro, Rio de Janeiro, BrazilCanc Res & Biostat, Seattle, WA USACedars Sinai Outpatient Canc Ctr, Aptium Oncol Inc, Los Angeles, CA USAUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc

Genome of Herbaspirillum seropedicae Strain SmR1, a Specialized Diazotrophic Endophyte of Tropical Grasses

The molecular mechanisms of plant recognition, colonization, and nutrient exchange between diazotrophic endophytes and plants are scarcely known. Herbaspirillum seropedicae is an endophytic bacterium capable of colonizing intercellular spaces of grasses such as rice and sugar cane. The genome of H. seropedicae strain SmR1 was sequenced and annotated by The Paraná State Genome Programme—GENOPAR. The genome is composed of a circular chromosome of 5,513,887 bp and contains a total of 4,804 genes. The genome sequence revealed that H. seropedicae is a highly versatile microorganism with capacity to metabolize a wide range of carbon and nitrogen sources and with possession of four distinct terminal oxidases. The genome contains a multitude of protein secretion systems, including type I, type II, type III, type V, and type VI secretion systems, and type IV pili, suggesting a high potential to interact with host plants. H. seropedicae is able to synthesize indole acetic acid as reflected by the four IAA biosynthetic pathways present. A gene coding for ACC deaminase, which may be involved in modulating the associated plant ethylene-signaling pathway, is also present. Genes for hemagglutinins/hemolysins/adhesins were found and may play a role in plant cell surface adhesion. These features may endow H. seropedicae with the ability to establish an endophytic life-style in a large number of plant species

Soil macrofauna communities in Brazilian land-use systems

Soil animal communities include more than 40 higher-order taxa, representing over 23% of all described species. These animals have a wide range of feeding sources and contribute to several important soil functions and ecosystem services. Although many studies have assessed macroinvertebrate communities in Brazil, few of them have been published in journals and even fewer have made the data openly available for consultation and further use. As part of ongoing efforts to synthesise the global soil macrofauna communities and to increase the amount of openly-accessible data in GBIF and other repositories related to soil biodiversity, the present paper provides links to 29 soil macroinvertebrate datasets covering 42 soil fauna taxa, collected in various land-use systems in Brazil. A total of 83,085 georeferenced occurrences of these taxa are presented, based on quantitative estimates performed using a standardised sampling method commonly adopted worldwide to collect soil macrofauna populations, i.e. the TSBF (Tropical Soil Biology and Fertility Programme) protocol. This consists of digging soil monoliths of 25 x 25 cm area, with handsorting of the macroinvertebrates visible to the naked eye from the surface litter and from within the soil, typically in the upper 0-20 cm layer (but sometimes shallower, i.e. top 0-10 cm or deeper to 0-40 cm, depending on the site). The land-use systems included anthropogenic sites managed with agricultural systems (e.g. pastures, annual and perennial crops, agroforestry), as well as planted forests and native vegetation located mostly in the southern Brazilian State of Paraná (96 sites), with a few additional sites in the neighbouring states of São Paulo (21 sites) and Santa Catarina (five sites). Important metadata on soil properties, particularly soil chemical parameters (mainly pH, C, P, Ca, K, Mg, Al contents, exchangeable acidity, Cation Exchange Capacity, Base Saturation and, infrequently, total N), particle size distribution (mainly % sand, silt and clay) and, infrequently, soil moisture and bulk density, as well as on human management practices (land use and vegetation cover) are provided. These data will be particularly useful for those interested in estimating land-use change impacts on soil biodiversity and its implications for below-ground foodwebs, ecosystem functioning and ecosystem service delivery.Quantitative estimates are provided for 42 soil animal taxa, for two biodiversity hotspots: the Brazilian Atlantic Forest and Cerrado biomes. Data are provided at the individual monolith level, representing sampling events ranging from February 2001 up to September 2016 in 122 sampling sites and over 1800 samples, for a total of 83,085 ocurrences

The Genome of Anopheles darlingi, the main neotropical malaria vector

Anopheles darlingi is the principal neotropical malaria vector, responsible for more than a million cases of malaria per year on the American continent. Anopheles darlingi diverged from the African and Asian malaria vectors ∼100 million years ago (mya) and successfully adapted to the New World environment. Here we present an annotated reference A. darlingi genome, sequenced from a wild population of males and females collected in the Brazilian Amazon. A total of 10 481 predicted protein-coding genes were annotated, 72% of which have their closest counterpart in Anopheles gambiae and 21% have highest similarity with other mosquito species. In spite of a long period of divergent evolution, conserved gene synteny was observed between A. darlingi and A. gambiae. More than 10 million single nucleotide polymorphisms and short indels with potential use as genetic markers were identified. Transposable elements correspond to 2.3% of the A. darlingi genome. Genes associated with hematophagy, immunity and insecticide resistance, directly involved in vectorhuman and vectorparasite interactions, were identified and discussed. This study represents the first effort to sequence the genome of a neotropical malaria vector, and opens a new window through which we can contemplate the evolutionary history of anopheline mosquitoes. It also provides valuable information that may lead to novel strategies to reduce malaria transmission on the South American continent. The A. darlingi genome is accessible at www.labinfo.lncc.br/index.php/anopheles- darlingi. © 2013 The Author(s)

Optimizing the Self-Healing Efficiency of Hydrogel Encapsulated Bacteria in Concrete

Calcium carbonate precipitation through microbial means is a promising pathway for concrete self-healing technologies, mainly for its microcrack sealing attributes. The main goal of this project was to study and optimize the crack healing efficiency of hydrogel encapsulated bacteria in concrete. To achieve this purpose, Bacillus pseudiformus was implemented as the bacteria strain at a concentration of 108 cells/ml. This bacterium strain along with yeast extract was combined along with three different mineral precursors corresponding to magnesium acetate, calcium lactate, and sodium lactate. All these three precursors were evaluated at two concentrations (67.76 mM/l and 75 mM/l). For each combination, three sets of mortar cubes along with three sets of mortar beams were prepared. Furthermore, the mechanical properties of these specimens were characterized by compressive and flexural strength tests. Moreover, once the beams were cracked after the flexural strength test, they were subjected to 28 days of wet/dry cycles in which the corresponding crack width was monitored. Once the wet/dry cycles finished, the specimens were retested to determine the strength recovery of the samples. As for the compressive strength tests, the samples that displayed the most promising results were the ones in which calcium lactate at a concentration of 75 mM/l along with bacteria and yeast extract were implemented. This specimen also displayed the best results in terms of self-healing efficiency. As for the flexural strength recovery, no significant difference was found among the specimens. Moreover, the healing products of this specimen were characterized under scanning electron microscopy (SEM) and energy X-ray dispersive spectroscopy (EDS). These analyses revealed a high presence of calcium rich crystals (i.e., calcium carbonate or calcium hydroxide crystals) proper of the bacterial activities. After, the results from the mortar specimens were analyzed, a scale-up concrete study was performed based on the best performing mortar samples ( the ones in which calcium lactate at a concentration of 75 mM/l along with bacteria and yeast extract were implemented) and compared to a control sample of plain concrete. The results from the concrete analysis indicated that the addition of calcium lactate favors both concrete’s compressive and flexural strength. Nevertheless, the plain concrete control specimen displayed better healing efficiency after being subjected to wet/dry cycles. The reason for this behavior is that these samples experimented significantly narrower cracks after the flexural testing. Nevertheless, the results from the samples containing calcium lactate and bacteria were very promising since they substantially outperformed the results from previous studies. SEM/EDS analysis was finally conducted in both specimens, revealing the presence of calcium rich crystals as the healing product of the specimens. Finally, a cost analysis on the direct costs of bioconcrete was performed revealing that the bioconcrete costs 28.5% more than conventional concrete

Evaluation of Novel Jointless Engineered Cementitious Composites Ultrathin Whitetopping (ECC-UTW)

Ultrathin Whitetopping (UTW) is a rehabilitation technique that consists of placing a thin layer of concrete over a damaged asphalt pavement. While UTWs have demonstrated satisfactory performance in field tests, the inherent brittleness of concrete has led to the appearance of distresses. To address these distresses, Engineered Cementitious Composites (ECC) have been proposed for UTW applications, thanks to their exceptional attributes, including tensile ductility, flexural performance, and fatigue resistance. In this study, an ECC-UTW was constructed to investigate its potential as a viable solution. The project comprised two 18.3 m ECC sections with different thicknesses, namely 63.5 mm and 101.6 mm, both designed to be completely jointless. Additionally, a 101.6 mm jointed concrete section was included for comparison. Once the project was built, compressive, uniaxial, flexural performance, failing weight deflectometer, and interlayer shear tests were performed to determine the in-situ properties of the overlays. Moreover, accelerated loading was applied to these UTWs to assess their performance. The results revealed that the 63.5 mm ECC jointless section failed after enduring 76,378 passes of 40 kN (representative of a dual tire half axle load of 80 kN), which corresponds to 76,378 ESALs. Similarly, the 101.6 mm jointless ECC-UTW failed at 151,454 passes of 40 kN and 14,310 passes of 71.2 kN, which represents 331,488 ESALs. The 101.6 mm jointed concrete UTW, in contrast, failed at 150,094 passes of 40 kN and 35,299 passes of 71.2 kN, which represents 594,191 ESALs. Furthermore, finite element modeling was conducted to determine the critical stresses upon loading. Finally, these stresses were integrated to an existing ECC fatigue model to develop a performance prediction model, which determines the cycles to failure based on the material thickness. This model was validated with the in-situ results yielding a difference of 5.09% between the experimental and the computational data

Effects of hydrogel-encapsulated bacteria on the healing efficiency and compressive strength of concrete

Microbial-induced calcium carbonate precipitation is a promising technology for self-healing concrete due to its capability to seal microcracks. The main goal of this study was to evaluate the effects of adding hydrogel-encapsulated bacteria on the compressive strength and the self-healing efficiency of concrete. To achieve this objective, 12 sets of mortar samples were prepared, including three different mineral precursors (magnesium acetate, calcium lactate, and sodium lactate), at two concentrations (67.76 and 75.00 ​mM/L), and under two different biological conditions (with and without bacteria). In addition, a set of plain mortar samples was prepared to serve as a control. For each sample set, three mortar cubes and three beams were prepared and subjected to compression and flexural strength tests. From the compression tests, it was found that the sample containing calcium lactate along with yeast extract and bacteria displayed the best results. As for the flexural tests, once cracked, the beams were subjected to 28 ​d of wet/dry cycles (16 ​h of water immersion and 8 ​h of drying), where the bottom crack width was monitored (at 0, 3, 7, 14, 28 ​d of wet/dry cycles). Once the sample with the highest healing efficiency was identified (the one containing calcium lactate and hydrogel-encapsulated bacteria), the study was scaled up to concrete specimens. Two sets of concrete cylinders (consisting of three control samples and three samples with bacteria along with calcium lactate) were tested under compression in order to evaluate the effect of the bacteria-precursor combination on the concrete mechanical properties. The samples that yielded the greatest compressive strength were the ones containing calcium lactate and bacteria, displaying an improvement of 17% as compared to the control specimen. Furthermore, a flexural strength recovery analysis was performed on the concrete specimens revealing that the control showed better flexural strength recovery than the bacteria-containing variant (41.5% vs. 26.1%) after 28 ​d of wet/dry cycles. A healing efficiency analysis was also performed on the cracked samples, revealing that the control displayed the best results. These results are due to the fact that the control specimen showed a narrower crack width in comparison to the bacteria-containing samples