Growth Conditions Research Articles

Sucrose supplements modulate the Pseudomonas chlororaphis-Arabidopsis thaliana interaction via decreasing the production of phenazines and enhancing the root auxin response

Management of the plant microbiome may help support food needs for the human population. Bacteria influence plants through enhancing nutrient uptake, metabolism, photosynthesis, biomass production and/or reinforcing immunity. However, information into how these microbes behave under different growth conditions is missing. In this work, we tested how carbon supplements modulate the interaction of Pseudomonas chlororaphis with Arabidopsis thaliana. P. chlororaphis streaks strongly repressed primary root growth, lateral root formation and ultimately, biomass production. Noteworthy, increasing sucrose availability into the media from 0 to 2.4% restored plant growth and promoted lateral root formation in bacterized seedlings. This effect could not be observed by supplementing sucrose to leaves only, indicating that the interaction was strongly modulated by bacterial access to sugar. Total phenazine content decreased in the bacteria grown in high (2.4%) sucrose medium, and conversely, the expression of phzH and pslA genes were diminished by sugar supply. Pyocyanin antagonized the promoting effects of sucrose in lateral root formation and biomass production in inoculated seedlings, indicating that this virulence factor accounts for growth repression during the plant-bacterial interaction. Defence reporter transgenes PR-1::GUS and LOX2::GUS were induced in leaves, while the expression of the auxin-inducible, synthetic reporter gene DR5::GUS was enhanced in the roots of bacterized seedlings at low and high sucrose treatments, which suggests that growth/defence trade-offs in plants are critically modulated by P. chlororaphis. Collectively, our data suggest that bacterial carbon nutrition controls the outcome of the relation with plants.

Comparing physiological responses of acute and chronically stressed diploid and triploid Atlantic salmon (Salmo salar)

We compared the performance and physiological response of diploid and triploid Atlantic salmon (Salmo salar) following 21 days of either unpredictable chronic stress (UCS) or no disturbance (control). Thereafter, all four groups were challenged with a novel acute stressor consisting of crowding, netting and transfer into another tank. Growth was monitored during the 21-day period, and stress response to the novel acute stress challenge was assessed by blood chemistry parameters and pituitary gene expression. Plasma parameters were analyzed before (0) and 15, 30, 45, 60, 90, 120, 240, and 300 min after acute stress induction, whereas gene expression was analyzed at 0, 30, 60, 120, and 240 min. The results showed: a) similar growth rate and condition factor reductions from UCS in triploids and diploids, b) higher post-stress plasma Acth and cortisol levels in triploids compared with diploids, c) wider post-stress fluctuations in most of the other plasma parameters for triploids compared with diploids, particularly for glucose and lactate, d) pomca1, pomcb, crf-r1a and crf-r1b mRNA levels were more upregulated in control diploids than control triploids, and e) only minor changes in pituitary gene expression from UCS in both diploids and triploids, but with a noticeable upregulation of pomca2 and crf-r1a and crf-r1b in the triploids. Our results suggest that triploid Atlantic salmon have a higher energy cost in response to stress than diploids salmon. This can make them more sensitive to suboptimal conditions and episodes of acute and chronic stress.

Feammox bacterial biofilm formation in HFMB

Nitrogen pollution has been increasing with the development of industrialization. Consequently, the excessive deposition of reactive nitrogen in the environment has generated the loss of biodiversity and eutrophication of different ecosystems. In 2005, a Feammox process was discovered that anaerobically metabolizes ammonium. Feammox with the use of hollow fiber membrane bioreactors (HFMB), based on the formation of biofilms of bacterial communities, has emerged as a possible efficient and sustainable method for ammonium removal in environments with high iron concentrations. This work sought to study the possibility of implementing, at laboratory scale, an efficient method by evaluating the use of HFMB. Samples from an internal circulation reactor (IC) incubated in culture media for Feammox bacteria. The cultures were enriched in a batch reactor to evaluate growth conditions. Next, HFMB assembly was performed, and Feammox parameters were monitored. Also, conventional PCR and scanning electron microscopy (SEM) analysis were performed to characterize the bacterial communities associated with biofilm formation. The use of sodium acetate presented the best performance for Feammox activity. The HFMB operation showed an ammonium (NH4+) removal of 50%. SEM analysis of the fibers illustrated the formation of biofilm networks formed by bacteria, which were identified as Albidiferax ferrireducens, Geobacter spp, Ferrovum myxofaciens, Shewanella spp., and Anammox. Functional genes Archaea/Bacteria ammonia monooxygenase, nrxA, hzsB, nirS and nosZ were also identified. The implementation of HFMB Feammox could be used as a sustainable tool for the removal of ammonium from wastewater produced because of anthropogenic activities.

Reduced lung function during childhood in identical twins with discordant fetal growth: a cohort study

Fetal growth restriction (FGR) can negatively affect lung development, leading to increased respiratory morbidity and reduced lung function later in life. Studies regarding the impact of FGR on lung function in singletons are influenced by genetic, obstetric, and maternal factors. To overcome these confounding factors, we aim to investigate lung function in identical twins with selective FGR (sFGR). Lung function assessments were performed in identical twins with sFGR born in our centre between March 1, 2002, and December 31, 2017, aged between 5 and 17 years. sFGR was defined as birthweight discordance ≥20%. Outcome measures consisted of forced expiratory volume in 1s (FEV1), forced vital capacity (FVC), and transfer factor for carbon monoxide (DLCO) and were compared between the smaller and larger twin. Thirty-nine twin pairs performed spirometry of sufficient quality. Median gestational age at birth was 34.3 (interquartile range (IQR) 32.1-36.0) weeks with median birthweights of 1500 (IQR 1160-1880) grams and 2178 (IQR 1675-2720) grams for the smaller and larger twin, respectively. Smaller twins had significantly lower z-scores for FEV1 (-0.94 versus-0.41, p=0.0015), FVC (-0.56 versus-0.06, p<0.0001) and DLCO (-0.50 versus 0.00, p<0.0001) compared to larger co-twins. Although being genetically identical, sFGR in identical twins is associated with a reduction in static and dynamic lung volume and a reduction in lung diffusion, even when taking the reduced lung volume into account. This indicates that adverse growth conditions in utero negatively affect lung development and function, potentially contributing to an increase in respiratory morbidities later in life. The Dutch Heart Foundation and The Bontius Foundation.

Optimal growth conditions to enhance Chlorella vulgaris biomass production in indoor phyto tank and quality assessment of feed and culture Stock

Commercial microalgae cultivation is a dynamic field with ongoing efforts to improve efficiency, reduce costs, and explore new applications. We conducted a study to examine how different light exposure periods affect Chlorella vulgaris's growth. We employed a Phyto tank batch system of approximately 3.5 liters with LED light control, controlled airflow, and sterilized bags, maintained at 22.0 ± 2.0°C indoors. Various methods, including spectrophotometry, and cell counter were employed to monitor Chlorella vulgaris growth under different light exposure cycles. Additionally, quality analysis as feed source was employed by proximate, amino acid, beta-glucan, and microbial content analysis. The results revealed significant variations in C. vulgaris biomass production based on light exposure duration. Notably, the 16:8-hour light-dark photoperiod exhibited the highest biomass concentration, reaching 6.48 × 107 ± 0.50 cells/mL with an optical density (OD) of 1.165 absorbance at 682 nm. The 12:12-hour light-dark photoperiod produced the second-highest biomass concentration, with 2.305 × 106 ± 0.60 cells/mL at an OD of 0.489. Proximate analysis of dry algae powder revealed low lipid content (0.48%), high protein content (37.61%), variable ash concentration (average 10.75%), and a significant carbohydrate fraction (51.16%) during extended daylight and shorter dark periods. Amino acid analysis identified nine essential amino acids, with glutamic acid being the most abundant (17.7%) and methionine the least (0.4%). Furthermore, quality analysis and microbiological assays demonstrated that the C. vulgaris biomass is well-suited for fish and livestock use as a feed source and possibility as human nutraceuticals. These findings can be considered more environmentally friendly and ethically sound due to the absence of genetic modification.

Growth charts for use at birth and in the neonatal period: Recommendations of the French Neonatal Society.

The use of different growth charts can lead to confusion in discussions between professionals. There are obstetric charts (of fetal growth) and neonatal charts (of measurements at birth and of postnatal growth). These charts can be descriptive (derived from an unselected population) or prescriptive (derived from of a population at low risk and with optimal conditions for growth). (1) To describe available charts for infants at birth and in the neonatal period and compare them, and (2) to recommend one or more charts for use in neonatology in France. Bibliographic research was conducted on MEDLINE and completed by the guidelines of professional societies. Antenatal information about fetal growth restriction (FGR) or fetuses identified as small-for-gestational-age using Intrauterine charts must be integrated into the identification of newborns at risk, but the use of Intrauterine charts to evaluate birthweight is not recommended to allow consistency with postnatal charts used in neonatal practice. Z-score variations using the updated Fenton postnatal charts are the most appropriate for the assessment of birthweight and postnatal growth for infants born preterm. These charts are sex-specific, include the three measurements (length, weight, and head circumference) and enable longitudinal follow-up of growth up to 50 weeks of corrected age and are linked to the WHO charts at term. The French Audipog charts, although are individualized, accessible online and can be used in maternity units to evaluate birthweight for term infants, but do not allow the follow-up of postnatal growth, while Fenton charts may be used to evaluate birthweight and postnatal growth in the first month for hospitalized term infants. The updated Fenton charts are the neonatal charts that best suit the objectives of pediatricians in France for monitoring the growth of preterm newborns. The use of the Audipog charts at term remains an alternative in maternity wards, while Fenton charts can be used for hospitalized term newborns.

Thermal Structure and Millimeter Emission from a Protoplanetary Disk with Embedded Protoplanets from Radiative Transfer Modeling

The discovery of protoplanets and circumplanetary disks provides a unique opportunity to characterize planet formation through observations. Massive protoplanets shape the physical and chemical structure of their host circumstellar disk by accretion, localized emission, and disk depletion. In this work, we study the thermal changes induced within the disk by protoplanet accretion and synthetic predictions through hydrodynamical simulations with postprocessed radiative transfer with an emphasis on radio millimeter emission. We explored distinct growth conditions and varied both planetary accretion rates and the local dust-to-gas mass ratios for a protoplanet at 1200 K. The radiative transfer models show that beyond the effect of disk gaps, in most cases, the circumplanetary disk (CPD) and the planet’s emission locally increase the disk temperature. Moreover, depending on the local dust-to-gas depletion and accretion rate, the presence of the CPD may have detectable signatures in millimeter emission. It also has the power to generate azimuthal asymmetries that are important for continuum subtraction. Thus, if other means of detection of protoplanets are proven, the lack of corresponding evidence at other wavelengths can set limits on their growth timescales through a combined analysis of the local dust-to-gas ratio and the accretion rate.

Length-weight relationship and condition factor of Nile tilapia (Oreochromis niloticus) fed diets supplemented with guava and star gooseberry leaf extract

Background Nile tilapia (Oreochromis niloticus) is predominant cultured species in aquaculture. However, there is a scarcity of literature regarding relationship between guava and star gooseberry leaf extract and the condition factor. Thus, the present study aims to investigate the effect of guava and star gooseberry leaf extract-supplemented diets on the specific growth rate, length-weight relationship, and condition factor of Nile tilapia. Methods Six hundred and thirty Nile tilapia (8.7±0.4 g) were randomly distributed among twenty-one tanks (30 fish per tank) within a recirculation system. Over a 60-day period, the fish were fed diets supplemented with 5g/Kg and 10g/Kg of guava leaf extract (GLE-5, GLE-10), star gooseberry leaf extract (SGLE-5, SGLE-10), and a mixture of both (MxLE-5, MXLE-10). Subsequently, specific growth rate, length-weight relationship, and condition factor were determined. Results After 60 days, the specific growth rate was significantly higher in all the GLE, SGLE, and MxLE groups compared to the control group. The final lengths and weights differed significantly both in the control group and all the GLE, SGLE, and MxLE groups. The analysis of the regression equation indicated a positive correlation (r = 0.970, 0.977, 0.976, 0.974, 0.974, 0.974, and 0.969) between the length and weight of Nile tilapia in the control group and in all the GLE, SGLE, and MxLE groups. The regression exponent "b" values in all the GLE, SGLE, and MxLE groups were &gt;3, indicating a positive allometric growth pattern in Nile tilapia compared to the control (b=2.866), which exhibited a negative allometry. The final condition factor values did not differ significantly in either the control group or any of the plant extract groups. Conclusions Nile tilapia exhibited positive allometric growth patterns and maintained good health when fed with GLE, SGLE, and MxLE groups. Therefore, these plant extracts demonstrate suitability for commercial Nile tilapia production.

Cotton seed cultivar identification based on the fusion of spectral and textural features.

The mixing of cotton seeds of different cultivars and qualities can lead to differences in growth conditions and make field management difficult. In particular, except for yield loss, it can also lead to inconsistent cotton quality and poor textile product quality, causing huge economic losses to farmers and the cotton processing industry. However, traditional cultivar identification methods for cotton seeds are time-consuming, labor-intensive, and cumbersome, which cannot meet the needs of modern agriculture and modern cotton processing industry. Therefore, there is an urgent need for a fast, accurate, and non-destructive method for identifying cotton seed cultivars. In this study, hyperspectral images (397.32 nm-1003.58 nm) of five cotton cultivars, namely Jinke 20, Jinke 21, Xinluzao 64, Xinluzao 74, and Zhongmiansuo 5, were captured using a Specim IQ camera, and then the average spectral information of seeds of each cultivar was used for spectral analysis, aiming to estab-lish a cotton seed cultivar identification model. Due to the presence of many obvious noises in the < 400 nm and > 1000 nm regions of the collected spectral data, spectra from 400 nm to 1000 nm were selected as the representative spectra of the seed samples. Then, various denoising techniques, including Savitzky-Golay (SG), Standard Normal Variate (SNV), and First Derivative (FD), were applied individually and in combination to improve the quality of the spectra. Additionally, a successive projections algorithm (SPA) was employed for spectral feature selection. Based on the full-band spectra, a Partial Least Squares-Discriminant Analysis (PLS-DA) model was established. Furthermore, spectral features and textural features were fused to create Random Forest (RF), Convolutional Neural Network (CNN), and Extreme Learning Machine (ELM) identification models. The results showed that: (1) The SNV-FD preprocessing method showed the optimal denoising performance. (2) SPA highlighted the near-infrared region (800-1000 nm), red region (620-700 nm), and blue-green region (420-570 nm) for identifying cotton cultivar. (3) The fusion of spectral features and textural features did not consistently improve the accuracy of all modeling strategies, suggesting the need for further research on appropriate modeling strategies. (4) The ELM model had the highest cotton cultivar identification accuracy, with an accuracy of 100% for the training set and 98.89% for the test set. In conclusion, this study successfully developed a highly accurate cotton seed cultivar identification model (ELM model). This study provides a new method for the rapid and non-destructive identification of cotton seed cultivars, which will help ensure the cultivar consistency of seeds used in cotton planting, and improve the overall quality and yield of cotton.

Elevated Temperature Effects on Protein Turnover Dynamics in Arabidopsis thaliana Seedlings Revealed by 15N-Stable Isotope Labeling and ProteinTurnover Algorithm

Global warming poses a threat to plant survival, impacting growth and agricultural yield. Protein turnover, a critical regulatory mechanism balancing protein synthesis and degradation, is crucial for the cellular response to environmental changes. We investigated the effects of elevated temperature on proteome dynamics in Arabidopsis thaliana seedlings using 15N-stable isotope labeling and ultra-performance liquid chromatography-high resolution mass spectrometry, coupled with the ProteinTurnover algorithm. Analyzing different cellular fractions from plants grown under 22 °C and 30 °C growth conditions, we found significant changes in the turnover rates of 571 proteins, with a median 1.4-fold increase, indicating accelerated protein dynamics under thermal stress. Notably, soluble root fraction proteins exhibited smaller turnover changes, suggesting tissue-specific adaptations. Significant turnover alterations occurred with redox signaling, stress response, protein folding, secondary metabolism, and photorespiration, indicating complex responses enhancing plant thermal resilience. Conversely, proteins involved in carbohydrate metabolism and mitochondrial ATP synthesis showed minimal changes, highlighting their stability. This analysis highlights the intricate balance between proteome stability and adaptability, advancing our understanding of plant responses to heat stress and supporting the development of improved thermotolerant crops.

Uptake of tire-derived compounds in leafy vegetables and implications for human dietary exposure

IntroductionTire and road wear particles are one of the most abundant types of microplastic entering the environment. The toxicity of tire and road wear particles has been linked to their organic additives and associated transformation products. Tire and road wear particles, and associated tire-derived compounds are introduced to the agricultural environment via atmospheric deposition, irrigation with reclaimed wastewater, and the use of biosolids (treated sewage sludge) as fertilizer. In the agricultural environment, these tire-derived compounds could be taken up by edible plants, leading to human exposure.MethodsSixteen tire-derived compounds were measured in twenty-eight commercial leafy vegetable samples from four countries. Based on the results, the estimated daily intake of these tire-derived compounds was calculated due to leafy vegetable consumption based on local diets under a mean and maximum concentration scenario.ResultsIn commercial leafy vegetables, six tire-derived compounds were detected: benzothiazole (maximum concentration—238 ng/g dry weight), 2-hydroxybenzothiazole (maximum concentration—665 ng/g dry weight), 1,3-diphenylguanidine (maximum concentration—2.1 ng/g dry weight), N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD, maximum concentration—0.4 ng/g dry weight), N-Isopropyl-N-phenyl-4-phenylenediamine (IPPD, maximum concentration—0.1 ng/g dry weight), and N-phenyl-N-cyclohexyl-p-phenylenediamine (CPPD, maximum concentration—0.3 ng/g dry weight). At least one compound was present in 71% of samples analyzed. The estimated daily intake for 1,3-diphenylguanidine ranged from 0.05 ng/person/day in the mean scenario to 4.0 ng/person/day in the maximum scenario; benzothiazole ranged from 12 to 1,296 ng/person/day; 6PPD ranged from 0.06 to 2.6 ng/person/day; IPPD ranged from 0.04 to 1.1 ng/person/day; CPPD ranged from 0.05 to 2.6 ng/person/day.DiscussionStatistical analyses did not reveal correlation between known growth conditions and tire-derived compound concentrations in the leafy vegetable samples. The estimated daily intake via leafy vegetable consumption was generally lower than or comparable to the estimated daily intake via other known sources. However, we show that tire-derived compounds are taken up by foodstuff, and exposure might be higher for other produce. Future studies are needed to uncover pathways of tire-derived compounds from road to food, assess the exposure to transformation products, and investigate the biological effects associated with this exposure.

Stochastic Optimization of the Management Schedule of Korean Pine Plantations

Korean pine is one of the most important tree species in northeastern China, where Korean pine plantations produce timber and edible seeds. Often, seeds create more income than timber. Predicting the timber and cone yields of alternative management schedules of the plantations involves uncertainty because the future climatic conditions for tree growth and cone production are unknown. This study developed a simulation model that generates stochastic variation around the predictions of tree growth and cone yield models, allowing the forest manager to seek cutting schedules that maximize the expected amounts of timber or cones, or the expected economic profit, under uncertain future states of nature. Stochastic analysis also facilitates management optimizations for different risk attitudes. The differential evolution algorithm and the developed stochastic simulation model were used to optimize the management of planted Korean pine. Timber and cone yields of a management schedule were calculated under 100 different scenarios for tree growth and cone production. When the growth and cone yield scenarios were stationary (no temporal trends), the optimal management schedules were similar to those of deterministic optimization. The benefits of stochastic optimization increased when it was assumed that the tree growth scenarios may contain climate-change-induced trends. Non-stationary growth variation led to shorter optimal rotation lengths than stationary growth variation. Increasing risk tolerance shortened optimal rotations.

Influence of Kluyveromyces lactis and Enterococcus faecalis on Obtaining Lactic Acid by Cheese Whey Fermentation

Cheese whey is a byproduct of the cheese industry that causes high levels of pollution in the environment, but its high lactose content means that it can be used as a source to obtain lactic acid. In this study, two strains, one belonging to a yeast and the other one to a bacteria (Kluyveromyces lactis and Enterococcus faecalis), were isolated from cheese whey and molecularly characterized, and the optimal growth conditions were determined. Then, using proteinized and deproteinized cheese whey, batch fermentation was carried out with the strains arranged in suspension and immobilized. The consumption of lactose and the production of lactic acid were measured through Brix degrees and acidity analysis. Afterwards, the lactic acid was purified, and its yield and physical and chemical characteristics were determined. It was proven that there were differences between each of the strains; arranged in free or encapsulated cells, the proteinized and deproteinized cheese wheys, under the same purification conditions, achieved different yields, colors, and densities of lactic acid. Immobilized Enterococcus faecalis had the highest yield (50.61 ± 34.94 g/L) using the deproteinized cheese whey compared to the immobilized Kluyveromyces lactis (35.70 ± 0.15 g/L) using the proteinized cheese whey.

Isolation, Identification and Characterization of Leptosphaerulina trifolii, the Causative Agent of Alfalfa Leptosphaerulina Leaf Spot in Inner Mongolia, China

Leptosphaerulina leaf spot, caused by Leptosphaerulina trifolii, is a major disease of alfalfa (Medicago sativa), leading to noticeable losses. From 2022 to 2023, we collected samples of alfalfa with symptoms of the disease from different locations in Inner Mongolia, China. Nine fungal isolates recovered from these samples were identified through morphological traits and a maximum likelihood phylogeny based on concatenated partial sequences of ITS, 28S, and rpb2. A pathogenicity test on alfalfa confirmed the pathogenicity of the isolates on alfalfa. Analysis of physiological traits of L. trifolii revealed optimal mycelium growth at 20 °C and a pH range of 5 to 7, with soluble starch as the preferred carbon source and yeast extract as the optimal nitrogen source. The pathogen thrived in V8-juice agar and oat agar media. This study confirms L. trifolii as the causative agent of Leptosphaerulina leaf spot of alfalfa in Inner Mongolia and provides valuable insights into its optimal growth conditions. These findings enhance the understanding and management of this disease in alfalfa fields.

Thiourea improves yield and quality traits of Brassica napus L. by upregulating the antioxidant defense system under high temperature stress

High temperature stress influences plant growth, seed yield, and fatty acid contents by causing oxidative damage. This study investigated the potential of thiourea (TU) to mitigate oxidative stress and restoring seed oil content and quality in canola. The study thoroughly examined three main factors: (i) growth conditions—control and high temperature stress (35 °C); (ii) TU supplementation (1000 mg/L)—including variations like having no TU, water application at the seedling stage, TU application at seedling stage (BBCH Scale-39), water spray at anthesis stage, and TU application at anthesis stage (BBCH Scale-60); (iii) and two canola genotypes, 45S42 and Hiola-401, were studied separately. High temperature stress reduced growth and tissue water content, as plant height and relative water contents were decreased by 26 and 36% in 45S42 and 27 and 42% Hiola-401, respectively, resulting in a substantial decrease in seed yield per plant by 36 and 38% in 45S42 and Hiola-401. Seed oil content and quality parameters were also negatively affected by high temperature stress as seed oil content was reduced by 32 and 35% in 45S42 and Hiola-401. High-temperature stress increased the plant stress indicators like malondialdehyde, H2O2 content, and electrolyte leakage; these indicators were increased in both canola genotypes as compared to control. Interestingly, TU supplementation restored plant performance, enhancing height, relative water content, foliar chlorophyll (SPAD value), and seed yield per plant by 21, 15, 30, and 28% in 45S42; 19, 13, 26, and 21% in Hiola-401, respectively, under high temperature stress as compared to control. In addition, seed quality, seed oil content, linoleic acid, and linolenic acid were improved by 16, 14, and 22% in 45S42, and 16, 11, and 23% in Hiola-401, as compared to control. The most significant improvements in canola seed yield per plant were observed when TU was applied at the anthesis stage. Additionally, the research highlighted that canola genotype 45S42 responded better to TU applications and exhibited greater resilience against high temperature stress compared to genotype Hiola-401. This interesting study revealed that TU supplementation, particularly at the anthesis stage, improved high temperature stress tolerance, seed oil content, and fatty acid profile in two canola genotypes.

Lipschitz Regularity for a Priori Bounded Minimizers of Integral Functionals with Nonstandard Growth

AbstractWe establish the Lipschitz regularity of the a priori bounded local minimizers of integral functionals with non autonomous energy densities satisfying non standard growth conditions under a bound on the gap between the growth and the ellipticity exponent that is reminiscent of the sharp bound already found in [16].

Improving Epitaxial Growth of γ‐Al2O3 Films via Sc2O3/Y2O3 Oxide Buffers

Heteroepitaxial growth of γ‐Al2O3 on Sc2O3/Y2O3/Si (111) is achieved with oxygen plasma‐assisted molecular beam epitaxy in order to prevent polycrystalline grain boundary formation caused by lattice mismatch. Substrate temperature as well as oxygen flow are adjusted to optimize epitaxial growth conditions around 715–760 °C and 1.9 sccm, respectively. Epitaxial growth is monitored in situ by reflection high‐energy diffraction, while surface morphology is studied by scanning electron microscopy ex‐situ. X‐ray diffraction indicates epitaxial out‐of‐plane 111 orientation with oxygen flow above 0.6 sccm. However, transmission electron microscopy shows stacking fault formation for high oxygen flows. Finally, nanobeam electron diffraction confirms Smrčok model of a spinel‐like γ‐Al2O3 crystal structure.

Influence of different culture media on the antimicrobial activity of Pediococcus pentosaceus ST65ACC against Listeria monocytogenes.

Pediococcus pentosaceus ST65ACC is a bacteriocinogenic lactic acid bacteria (LAB) isolated from Brazilian artisanal cheese that is capable of inhibiting different food pathogens, mainly Listeria monocytogenes. The production of bacteriocins can be influenced by several growth conditions, such as temperature, pH, and medium composition. This study aimed to evaluate the effect of different culture media on the production of bacteriocins and antimicrobial activity of P. pentosaceus ST65ACC on L. monocytogenes Scott A. The strains were inoculated alone and in coculture in four different media: BHI broth, MRS broth, meat broth, and reconstituted skim milk (RSM) 10% (w/v). The culture media were then incubated at 37°C for 96h, and count analysis, pH measurement, and bacteriocin production were performed at 0, 24, 48, 72 and 96h. L. monocytogenes was inhibited to nondetectable levels in coculture with P. pentosaceus ST65ACC in MRS broth within 96h, consistent with the high production of bacteriocin throughout the analysis period (3,200-12,800 AU/mL). However, lower inhibitory activities of P. pentosaceus ST65ACC on L. monocytogenes Scott A were recorded in BHI, RSM, and meat broth, with low or no production of bacteriocins at the analyzed times. The composition of these culture media may have repressed the production and activity of bacteriocins and, consequently, the antagonist activity of P. pentosaceus ST65ACC on L. monocytogenes Scott A. The results showed that the antimicrobial activity was more effective in MRS broth, presenting greater production of bacteriocins and less variability when compared to the other media analyzed.

Labeling of methyl groups: a streamlined protocol and guidance for the selection of 2H precursors based on molecular weight.

A streamlined one-day protocol is described to produce isotopically methyl-labeled protein with high levels of deuterium for NMR studies. Using this protocol, the D2O and 2H-glucose content of the media and protonation level of ILV labeling precursors (ketobutyrate and ketovalerate) were varied. The relaxation rate of the multiple-quantum (MQ) state that is present during the HMQC-TROSY pulse sequence was measured for different labeling schemes and this rate was used to predict upper limits of molecular weights for various labeling schemes. The use of deuterated solvents (D2O) or deuterated glucose is not required to obtain 1H-13C correlated NMR spectra of a 50kDa homodimeric protein that are suitable for assignment by mutagenesis. High quality spectra of 100-150kDa proteins, suitable for most applications, can be obtained without the use of deuterated glucose. The proton on the β-position of ketovalerate appears to undergo partial exchange with deuterium under the growth conditions used in this study.

Comparison of the transcriptome, lipidome, and c-di-GMP production between BCGΔBCG1419c and BCG, with Mincle- and Myd88-dependent induction of proinflammatory cytokines in murine macrophages

We have previously reported the transcriptomic and lipidomic profile of the first-generation, hygromycin-resistant (HygR) version of the BCGΔBCG1419c vaccine candidate, under biofilm conditions. We recently constructed and characterized the efficacy, safety, whole genome sequence, and proteomic profile of a second-generation version of BCGΔBCG1419c, a strain lacking the BCG1419c gene and devoid of antibiotic markers. Here, we compared the antibiotic-less BCGΔBCG1419c with BCG. We assessed their colonial and ultrastructural morphology, biofilm, c-di-GMP production in vitro, as well as their transcriptomic and lipidomic profiles, including their capacity to activate macrophages via Mincle and Myd88. Our results show that BCGΔBCG1419c colonial and ultrastructural morphology, c-di-GMP, and biofilm production differed from parental BCG, whereas we found no significant changes in its lipidomic profile either in biofilm or planktonic growth conditions. Transcriptomic profiling suggests changes in BCGΔBCG1419c cell wall and showed reduced transcription of some members of the DosR, MtrA, and ArgR regulons. Finally, induction of TNF-α, IL-6 or G-CSF by bone-marrow derived macrophages infected with either BCGΔBCG1419c or BCG required Mincle and Myd88. Our results confirm that some differences already found to occur in HygR BCGΔBCG1419c compared with BCG are maintained in the antibiotic-less version of this vaccine candidate except changes in production of PDIM. Comparison with previous characterizations conducted by OMICs show that some differences observed in BCGΔBCG1419c compared with BCG are maintained whereas others are dependent on the growth condition employed to culture them.