In situ solid-liquid extraction enhances recovery of taxadiene from engineered Saccharomyces cerevisiae cell factories

Microbial cell factories express diverse heterologous pathways for the production of a wide range of valuable natural products. However, the recovery and purification of such compounds is a major bottleneck in commercialization. In this study, a novel in situ solid phase adsorption strategy was investigated for enhanced recovery of taxadiene, a precursor to the blockbuster anticancer drug, paclitaxel, from engineered Saccharomyces cerevisiae. A synthetic adsorbent resin (HP-20) was employed to efficiently sequester taxadiene as it was secreted during growth and a carefully optimized desorption solvent was applied following cultivation to maximize recovery of both secreted and intracellular taxadiene, across a range of scales (2 – 250 mL). Resin concentration was found to have an impact on cellular growth, with the high concentration of 12 % (w/v) resulting in fragmentation of the resin beads, which was detrimental to growth. The optimal resin concentration and desorption solvent combination elucidated at microscale (2 mL) resulted in a two-fold improvement in taxadiene titer to 61 ± 8 mg/L, compared to the traditional liquid-liquid extraction approach (dodecane overlay). Taxadiene was found to be distributed evenly between resin beads and biomass. Performance of the optimal process was subsequently investigated through scale-up using controlled mini-bioreactors (250 mL). Here, a comparable taxadiene titer of 76 ± 19 mg/L was achieved despite a 125-fold scale-up in cultivation volume. This represented a 1.4-fold improvement in taxadiene recovery compared to previous mini-bioreactor scale cultivations using the dodecane overlay extraction approach

Categorical perception of tactile distance

The tactile surface forms a continuous sheet covering the body. And yet, the perceived distance between two touches varies across stimulation sites. Perceived tactile distance is larger when stimuli cross over the wrist, compared to when both fall on either the hand or the forearm. This effect could reflect a categorical distortion of tactile space across body-part boundaries (in which stimuli crossing the wrist boundary are perceptually elongated) or may simply reflect a localised increased in acuity surrounding anatomical landmarks (in which stimuli near the wrist are perceptually elongated). We tested these two interpretations, by comparing a well-documented bias to perceive mediolateral tactile distances across the forearm/hand as larger than proximodistal ones along the forearm/hand at three different sites (hand, wrist, and forearm). According to the ‘categorical’ interpretation, tactile distances should be elongated selectively in the proximodistal axis thus reducing the anisotropy. According to the ‘localised acuity’ interpretation, distances will be perceptually elongated in the vicinity of the wrist regardless of orientation, leading to increased overall size without affecting anisotropy. Consistent with the categorical account, we found a reduction in the magnitude of anisotropy at the wrist, with no evidence of a corresponding specialized increase in precision. These findings demonstrate that we reference touch to a representation of the body that is categorically segmented into discrete parts, which consequently influences the perception of tactile distance

The BIODESERT survey: assessing the impacts of grazing on the structure and functioning of global drylands

Grazing by domestic livestock is both the main land use across drylands worldwide and a major desertification and global change driver. The ecological consequences of this key human activity have been studied for decades, and there is a wealth of information on its impacts on biodiversity and ecosystem processes. However, most field assessments of the ecological impacts of grazing on drylands conducted to date have been carried out at local or regional scales and have focused on single ecosystem attributes (e.g., plant productivity) or particular taxa (mainly aboveground, e.g., plants). Here we introduce the BIODESERT survey, the first systematic field survey devoted to evaluating the joint impacts of grazing by domestic livestock and climate on the structure and functioning of dryland ecosystems worldwide. This collaborative global survey was carried out between 2016 and 2019 and has involved the collection of field data and plant, biocrust, and soil samples from a total of 326 45 m × 45 m plots from 98 sites located in 25 countries from 6 continents. Here we describe the major characteristics and the field protocols used in this survey. We also introduce the organizational aspects followed, as these can be helpful to everyone wishing to establish a global collaborative network of researchers. The BIODESERT survey provides baseline data to assess the current status of dryland rangelands worldwide and the impacts of grazing on these key ecosystems, and it constitutes a good example of the power of collaborative research networks to study the ecology of our planet using much-needed field data.This research has been supported by the European Research Council (ERC grant agreement no. 647038 – BIODESERT) and the Conselleria de Innovación, Universidades, Ciencia y Sociedad Digital, Generalitat Valenciana (grant no. CIDEGENT/2018/041). Nicolas Gross was supported by CAP 20-25 (16-IDEX-0001) and the AgreenSkills+ fellowship program which has received funding from the EU's Seventh Framework Programme under grant agreement no. 996 FP7-609398 (AgreenSkills+ contract). Hugo Saiz is supported by a María Zambrano fellowship funded by the Ministry of Universities and European Union Next Generation plan

Functional Feed Assessment on Litopenaeus vannamei Using 100% Fish Meal Replacement by Soybean Meal, High Levels of Complex Carbohydrates and Bacillus Probiotic Strains

Functional feed supplemented with alternative-economic nutrient sources (protein, carbohydrates, lipids) and probiotics are being considered in shrimp/fish aquaculture production systems as an option to increase yield and profits and to reduce water pollution. In this study the probiotic potential to formulate functional feeds have been evaluated using four dietary treatments: Treatment 1 (B + Bs); Bacillus subtilis potential probiotic strain was supplemented to a soybeanmeal (SBM)—carbohydrates (CHO) basal feed. Treatment 2 (B + Bm); Bacillus megaterium potential probiotic strain was supplemented to the same SBM-CHO basal feed. In Treatment 3 (B); SBM-CHO basal feed was not supplemented with probiotic strains. Treatment 4 (C); fishmeal commercial feed (FM) was utilized as positive control. Feeding trials evaluated the survival, growth, and food conversion ratio and stress tolerance of juvenile Litopenaeus vannamei (Boone) Pacific white shrimp. Best overall shrimp performance was observed for animals fed with Treatment 1 (B+Bs); additionally, stress tolerance and hemolymph metabolites also showed the best performance in this treatment. SBM-CHO basal feed not supplemented with probiotic strains (B) presented smaller growth and lower feed conversion ratio (FCR). Shrimps fed with the fishmeal commercial feed (C) presented the lowest stress tolerance to high ammonia and low oxygen levels. Specifically selected B. subtilis strains are recommended to formulate functional and economical feeds containing high levels of vegetable; protein and carbohydrates as main dietary sources in L. vannamei cultures

Relict periglacial soils on Quaternary terraces in the central Ebro Basin (NE Spain)

Pedofeatures associated with ancient cold climatic conditions have been recognized in soils on terraces in the Monegros area (central Ebro Basin, Spain), at a latitude of 41°49′N and an altitude of 300 m a.s.l. Eleven soil profiles were described on fluvial deposits corresponding to the most extensive terrace (T5) of the Alcanadre River, Middle Pleistocene in age (MIS8–MIS7). Each soil horizon was sampled for physical, chemical, mineralogical and micromorphological analyses. Macromorphological features related to pedocryogenic processes were described: involutions, jacked stones, shattered stones, detached and vertically oriented carbonatic pendents, fragmented carbonatic crusts, laminar microstructures, succitic fabric, silt cappings on rock fragments and aggregates, and irregular, broken, discontinuous and deformed gravel and sandy pockets. Accumulations of Fe–Mn oxides, dissolution features on the surface of carbonatic stones, and calcitic accumulations were identified related to vadose–phreatic conditions. The observed periglacial features developed under cold environmental conditions in exceptional geomorphic and hydrological conditions. This soil information may have potential implications in studies of paleoclimate in the Ebro Valley as well as in other Mediterranean areas

Functional rarity and evenness are key facets of biodiversity to boost multifunctionality

The functional traits of organisms within multispecies assemblages regulate biodiversity effects on ecosystem functioning. Yet how traits should assemble to boost multiple ecosystem functions simultaneously (multifunctionality) remains poorly explored. In a multibiome litter experiment covering most of the global variation in leaf trait spectra, we showed that three dimensions of functional diversity (dispersion, rarity, and evenness) explained up to 66% of variations in multifunctionality, although the dominant species and their traits remained an important predictor. While high dispersion impeded multifunctionality, increasing the evenness among functionally dissimilar species was a key dimension to promote higher multifunctionality and to reduce the abundance of plant pathogens. Because too-dissimilar species could have negative effects on ecosystems, our results highlight the need for not only diverse but also functionally even assemblages to promote multifunctionality. The effect of functionally rare species strongly shifted from positive to negative depending on their trait differences with the dominant species. Simultaneously managing the dispersion, evenness, and rarity in multispecies assemblages could be used to design assemblages aimed at maximizing multifunctionality independently of the biome, the identity of dominant species, or the range of trait values considered. Functional evenness and rarity offer promise to improve the management of terrestrial ecosystems and to limit plant disease risks.This work was funded by the British Ecological Society (SR17\1297 grant, PI: P.G.-P.) and by the European Research Council (ERC Grant Agreement #647038, BIODESERT, PI: F.T.M.). Y.L.B.-P. was supported by a Marie Sklodowska-Curie Actions Individual Fellowship within the European Program Horizon 2020 (DRYFUN Project #656035). H.S. was supported by a Juan de la Cierva-Formación grant from the Spanish Ministry of Economy and Competitiveness (FJCI-2015-26782). F.T.M. and S.A. were supported from the Generalitat Valenciana (CIDEGENT/2018/041). M.D. was supported by a Formación del Profesorado Universitario (FPU) fellowship from the Spanish Ministry of Education, Culture and Sports (FPU-15/00392). S.A. was supported by the Spanish MINECO for financial support via the DIGGING_DEEPER project through the 2015 to 2016 BiodivERsA3/FACCE‐JPI joint call for research proposals. B.K.S. research on biodiversity-ecosystem functions was supported by the Australian Research Council (DP170104634 and DP190103714). P.G.-P. was supported by a Ramón y Cajal grant from the Spanish Ministry of Science and Innovation (RYC2018-024766-I). R.M. was supported by MINECO (Grants CGL2014-56567-R and CGL2017-83855-R)

MINERvA neutrino detector response measured with test beam data

The MINERvA collaboration operated a scaled-down replica of the solid scintillator tracking and sampling calorimeter regions of the MINERvA detector in a hadron test beam at the Fermilab Test Beam Facility. This article reports measurements with samples of protons, pions, and electrons from 0.35 to 2.0 GeV/c momentum. The calorimetric response to protons, pions, and electrons are obtained from these data. A measurement of the parameter in Birks' law and an estimate of the tracking efficiency are extracted from the proton sample. Overall the data are well described by a Geant4-based Monte Carlo simulation of the detector and particle interactions with agreements better than 4%, though some features of the data are not precisely modeled. These measurements are used to tune the MINERvA detector simulation and evaluate systematic uncertainties in support of the MINERvA neutrino cross section measurement program.Comment: as accepted by NIM

Gain of MYC underlies recurrent trisomy of the MYC chromosome in acute promyelocytic leukemia

The leukemogenic effects of Myc drive recurrent trisomy in a mouse model of acute myeloid leukemia