Short-term Incubation Research Articles

Effects of Ionized Water Irrigation on Organic Nitrogen Mineralization in Saline-Alkali Soil in China

The application of ionized water to irrigation, as a new type of water treatment technology, can improve the spatial distribution of water in soil and increase water utilization efficiency, which may affect the microbiological processes involved in nitrogen transformation and alter soil nitrogen supply capability. However, the effects of ionized water technology on soil organic nitrogen mineralization are still in need of further research. In this study, we investigated the soil organic nitrogen mineralization process with four different water additions: non-ionized fresh water (CK), ionized fresh water (DE), non-ionized brackish water (BCK), and ionized brackish water (BDE). By using a short-term laboratory incubation method, we monitored the changes of the inorganic nitrogen concentration in each treatment during the incubation process. We compared the net nitrogen mineralization and nitrogen mineralization rates in different treatments, and fitted the organic nitrogen mineralization process with three models (One-pool model, Special model, and EATM model). We divided the whole incubation process into three periods based on the differences of the organic nitrogen mineralization trends. The results demonstrated that when DE was compared with CK, the net nitrogen mineralization increased by 21.97% and the nitrogen mineralization rate increased by 20.42% in the latter incubation period. When BDE was compared with BCK, the net nitrogen mineralization decreased by 3.63%, and the nitrogen mineralization rate increased by 21.86% in the latter incubation period. When BCK was compared with CK, brackish water irrigation reduced the organic nitrogen mineralization intensity to a certain extent, with the net nitrogen mineralization decreased by 11.62% and the nitrogen mineralization rate decreased by 41.07% in the whole incubation process. When BDE was compared with DE, the net nitrogen mineralization decreased by 30.09% and the nitrogen mineralization rate decreased by 53.39% in the whole incubation process. The simulation model of the soil organic nitrogen mineralization process showed that the special model and EATM model are superior to the One-pool model. This study provides a theoretical basis for the popularization and application of ionized water irrigation in agricultural production.

Immediate and Sustained Root Caries Prevention of Fluoride Varnish Combined with Toothpastes

The aim of this study was to determine the immediate and sustained effect of a fluoride varnish and its combinations with toothpastes in preventing root caries development using a salivary microcosm in vitro model. Human root dentin specimens (n = 150) were randomly divided into 5 experimental protocols (n = 30): (1) Fluoride Varnish (V); (2) V followed by Paste One (V + PO); (3) V followed by Paste Plus (V + PP); (4) V followed by PO and PP (V + PO + PP); and (5) No treatment (control). One varnish layer was applied on the specimens (except for the control group) and kept for 18 h. Then, the varnish was removed and toothpaste treatments were initiated according to experimental groups. For the short-term incubation model (n = 15), the specimens were also immediately subjected to 7-day cariogenic challenge. For that, human saliva was used as bacterial inoculum and McBain artificial saliva containing 2% sucrose as growth medium. The other half of the specimens (n = 15) were used to study the varnish’s sustained effect by long-term incubation (8 weeks) before cariogenic challenge. The protocols’ anti-caries properties were evaluated by dentin porosity (rhodamine intensity; RI) and mineral density, while their anti-biofilm effects were evaluated using biofilm’s biomass and viability assays. For short- and long-term incubation models, all experimental regimens resulted in statistically significant decreases (p < 0.05) in the RI (up to 180 μm and 120 μm, respectively) as well as higher mineral density compared to No treatment (p < 0.001). V + PO + PP and/or V + PO resulted in statistically lower RI compared to V for some depths (p < 0.05) in both models. There were changes in RI and mineral density within groups over time. All experimental treatments exhibited anti-biofilm effects. All prevention protocols exhibited immediate and sustained anti-caries effect against root caries development. The combination of a fluoride varnish with PO resulted in superior additional anti-caries effects.

Warming exacerbates the impacts of ultraviolet radiation in temperate diatoms but alleviates the effect on polar species.

Under global change scenarios, the sea surface temperature is increasing steadily along with other changes to oceanic environments. Consequently, marine diatoms are influenced by multiple ocean global change drivers. We hypothesized that temperature rise mediates the responses of polar and temperate diatoms to UV radiation (UVR) to different extents, and exposed the temperate centric diatoms, Thalassiosira weissflogii and Skeletonema costatum, and a polar pennate diatom Entomoneis sp., to warming (+5°C) for 10 days, then performed short-term incubations under different radiation treatments with or without UVR. The effective quantum yields of the three diatoms were stable during exposure to PAR, but decreased when exposed to PAR + UVR, leading to significant UV-induced inhibition, which was 3% and 9%, respectively, for T. weissflogii and S. costatum under ambient temperature but increased to 12% and 17%, respectively, in the cells acclimated to the warming treatment. In contrast, UVR induced much higher inhibition, by about 45%, in the polar diatom Entomoneis sp. at ambient temperature, and the warming treatment alleviated the UV-induced inhibition, which dropped to 36%. The growth rates were significantly inhibited by UVR in S. costatum under the warming treatment and in Entomoneis sp. under ambient temperature, while there was no significant effect for T. weissflogii. Our results indicate that the polar diatom was more sensitive to UVR though warming could alleviate its impact, whereas the temperate diatoms were less sensitive to UVR but warming exacerbated its impacts, implying that diatoms living in different regions may exhibit differential responses to global changes.

Absence of photophysiological response to iron addition in autumn phytoplankton in the Antarctic sea-ice zone

Abstract. The high nutrient–low chlorophyll condition of the Southern Ocean is generally thought to be caused by the low bioavailability of micronutrients, particularly iron, which plays an integral role in phytoplankton photosynthesis. Nevertheless, the Southern Ocean experiences seasonal blooms that generally initiate in austral spring, peak in summer, and extend into autumn. This seasonal increase in primary productivity is typically linked to the seasonal characteristics of nutrient and light supply. To better understand the potential limitations on productivity in the Antarctic sea-ice zone (SIZ), the photophysiological response of phytoplankton to iron addition (2.0 nM FeCl3) was investigated during autumn along the Antarctic coast off Dronning Maud Land. Five short-term (24 h) incubation experiments were conducted around Astrid Ridge (68∘ S) and along a 6∘ E transect, where an autumn bloom was identified in the region of the western SIZ. Surface iron concentrations ranged from 0.27 to 1.39 nM around Astrid Ridge, and 0.56 to 0.63 nM along the 6∘ E transect. Contrary to expectation, the photophysiological response of phytoplankton to iron addition, measured through the photosynthetic efficiency and the absorption cross-section for photosystem II, showed no significant responses. It is thus proposed that since the autumn phytoplankton in the SIZ exhibited a lack of an iron limitation at the time of sampling, the ambient iron concentrations may have been sufficient to fulfil the cellular requirements. This provides new insights into extended iron replete post-bloom conditions in the typically assumed iron deficient high nutrient–low chlorophyll Southern Ocean.

Labile substrate input weakens the memory effect of soil microbial functions under global warming

The feedback between soil carbon (C) and climate change has the potential to decrease over time, which is mainly due to the thermal acclimation of microbial decomposition of soil organic matter (SOM). The adaption and stabilization mechanisms of microbial functions in response to long-term warming in agroecosystems, however, remain intensive debate. Therefore, we explored the controls of thermal acclimation based on an 8-year field warming (ambient, +1.6 °C, +3.2 °C) in agroecosystem and a short-term incubation at five constant temperature levels (from 5 to 25 °C with 5 °C intervals) under microbial steady-state (without glucose, non-activated microbial community) and activate microbial growth induced by sufficient glucose addition. At the steady-state, field warming (+3.2 °C) increased the specific growth rate whilst decreased the portion of growing microbial biomass as compared to ambient soils. This indicated that 8-year field warming facilitated the consumption of labile organics due to faster microbial growth. Consequently, microbial growth, activities of β-glucosidase and leucine aminopeptidase, as well as microbial respiration acclimated to field warming (+1.6 °C, +3.2 °C) over 8-year, responded up to 40% weaker to further short-term temperature increase (above 15 °C). Also, the temperature sensitivity of enzyme activity decreased with field warming magnitude under higher incubation temperatures, which further indicated enzyme acclimation. Under activation mode, however, the higher enzyme activities suggested that the increased labile C remarkably relieved the substrate limitation of microbial growth and activated dormant microorganisms in field warmed soils, and weaken the thermal acclimation of soil microbial functions. We thus found experimental evidence that the transition between microbial physiological states (i.e., dormant vs. active) owing to variations in C availability is the most plausible explanation for the alterations in temperature sensitivity of enzyme activities and microbial respiration. The compensating effect of the increased labile substrate under climate warming on the thermal acclimation of soil microbe-driven CO2 may thus be larger than that currently predicted, with important consequences for atmospheric CO2 concentrations.

Differential contribution of nitrifying prokaryotes to groundwater nitrification

The ecophysiology of complete ammonia-oxidizing bacteria (CMX) of the genus Nitrospira and their widespread occurrence in groundwater suggests that CMX bacteria have a competitive advantage over ammonia-oxidizing bacteria (AOB) and archaea (AOA) in these environments. However, the specific contribution of their activity to nitrification processes has remained unclear. We aimed to disentangle the contribution of CMX, AOA and AOB to nitrification and to identify the environmental drivers of their niche differentiation at different levels of ammonium and oxygen in oligotrophic carbonate rock aquifers. CMX ammonia monooxygenase sub-unit A (amoA) genes accounted on average for 16 to 75% of the total groundwater amoA genes detected. Nitrification rates were positively correlated to CMX clade A associated phylotypes and AOB affiliated with Nitrosomonas ureae. Short-term incubations amended with the nitrification inhibitors allylthiourea and chlorate suggested that AOB contributed a large fraction to overall ammonia oxidation, while metaproteomics analysis confirmed an active role of CMX in both ammonia and nitrite oxidation. Ecophysiological niche differentiation of CMX clades A and B, AOB and AOA was linked to their requirements for ammonium, oxygen tolerance, and metabolic versatility. Our results demonstrate that despite numerical predominance of CMX, the first step of nitrification in oligotrophic groundwater appears to be primarily governed by AOB. Higher growth yields at lower ammonia turnover rates and energy derived from nitrite oxidation most likely enable CMX to maintain consistently high populations.

From cell membrane to mitochondria: Time-dependent AIE photosensitizer for fluorescence imaging and photodynamic anticancer therapy

Aggregation-induced emission photosensitizers (AIE-PSs) targeting different subcellular organelles with time-dependent manner are highly promising for clinical applications but rarely reported. Herein, we designed and synthesized the near-infrared (NIR) emission AIE-PS (CTQ-S) with broad absorption and excellent type I reactive oxygen species (ROS) generation efficiency that was superior to the widely used PS (Rose Bengal and Chlorine 6). With short-term incubation, CTQ-S anchored on the cell membrane (Rr: 0.843, Rr is for Pearson correlation coefficient) and gradually entered the mitochondria (Rr: 0.937) of cancer cells, showing excellent time-dependent fluorescence fluorescent imaging effect. Furthermore, CTQ-S realized the selective photodynamic therapy (PDT) effect in a time-dependent manner under white light irradiation. This work provided a new way for cancer cells fluorescence imaging and PDT.

Influence of Poultry Litter Biochar on Some Properties and Carbon Mineralization in Acidic Soil

During the last years, biochar (BC) from various organic wastes and its application to soil to improve soil properties have been a very common treatment in agricultural soils. While many studies have been conducted on the effects of biochar on the improvement of alkaline soils, studies on acid soils are limited. An incubation experiment was conducted to investigate the effects of poultry litter biochar (PLBC) on acidic soil properties and C mineralization. Biochar derived from poultry litter (PLBC) through slow pyrolysis was mixed with soil in three different doses (0, 2, and 5%) and subjected to a 120-day incubation period. pH increased from 4.38 to 5.31 at the end of the incubation. Electrical conductivity (EC) values also increased. Carbon dioxide (CO2) emission reached its maximum on the 30th day of the incubation in control and with PLBC applied to the soil. PLBC increased the organic matter (OM) content of the soil. Values were 3.51%, 4.70%, 6.27% for control, PLBC 2% and 5% treatments, respectively. PLBC does have an increasing negative priming effect on the carbon (C) mineralization of the soil. Particulate organic matter (POM) increased the storage of organic carbon (OC) in the POM fraction for both PLBC applications. It is revealed that PLBC showed soil conditioning effect as well as C storage in the soil. This study was on the short-term incubation under controlled conditions, varying results would be obtained in field conditions.

USE OF VERMICOMPOST TO IMPROVE SOIL PROPERTIES AND SPINACH GROWTH IN THE SOIL AFFECTED BY WIND EROSION

Limited nutrient availability and poor soil structure are the major constraints to plant production in the calcareous soils affected by wind erosion. Short-term (90 days) incubation study was carried out to evaluate the impacts of vermicompost on improving crop yield and soil properties in the calcareous soil exposed to wind erosion. Vermicompost was applied at the rate of 0, 1, 2 and 4% (w/w). Significant (P˂0.05) differences in the selected physico-chemical properties were observed when the treatments with vermicompost and no vermicompost were compared; except for soil pH and lime content. Soil properties were improved substantially in parallel with the application rates. When compared to the control, vermicompost application significantly increased the yield, fresh leaf biomass (FLB), fresh root biomass (FRB), dry leaf biomass (DLB), dry root biomass (DRB), leaf number (LN) and leaf chlorophyll content (LCC) values of the spinach plant grown under greenhouse conditions. Conclusively, applying vermicompost improves soil properties and crop performance; however, field study is recommended in order to validate the findings of this study prior to adopting vermicompost as soil management practices in the calcareous soils exposed to wind erosion.

Clinical impacts of the rapid diagnostic method on positive blood cultures.

This study aimed to evaluate the impact of short-term incubation (STI) protocol on clinical outcomes of bloodstream infection (BSI) patients. A total of 1363 positive blood culture records from January 2019 to December 2021 were included. The main clinical outcomes included pathogen identification turnaround time (TAT), antimicrobial susceptibility testing (AST) TAT, and length of total hospital stay. The TAT of pathogen identification and AST significantly decreased after implementing the STI protocol (2.2 vs 1.4 days and 3.4 vs 2.5 days, respectively, with P < .001 for both). Moreover, for patients with Gram-negative bacteria (GNB)-infected BSIs, the length of total hospital stay decreased from 31.9 days to 27.1 days, indicating that these patients could be discharged 5 days earlier after implementing the STI protocol (P < .01). The protocol led to a significant reduction in TAT and improved clinical outcomes, particularly for GNB organisms. The findings suggest that the STI protocol can improve patient outcomes and hospital resource utilization in the management of BSIs.

Importance of Considering Enzyme Degradation for Interpreting the Response of Soil Enzyme Activity to Nutrient Addition: Insights from a Field and Laboratory Study

Soil enzyme activity can be affected by both production and degradation processes, as enzymes can be degraded by proteases. However, the impact of nutrient addition on enzyme activity is often solely attributed to changes in enzyme production without fully considering degradation. In this study, we demonstrate that the activities of β-1,4-glucosidase (BG), β-D-cellobiohydrolase (CBH), β-1,4-xylosidase (BX), and β-1,4-N-acetyl-glucosaminidase (NAG) in two tropical plantations exhibited comparable levels between nitrogen (N)- and phosphorus (P)-fertilized soils and the unfertilized control under field conditions. However, it was observed that the reduction in enzymatic activity was significantly higher in the fertilized soils during short-term laboratory incubation in the acacia plantation. Additionally, the eucalyptus plantation exhibited a similar tendency, although statistical significance was not achieved due to the high variance of the data. The results show that the interruption of the natural, continuous supply of organic matter or non-soil microbial-derived enzymes, which typically occurs under field conditions, leads to a more significant reduction in soil enzyme activities in fertilized soils compared to unfertilized control. This may be attributed to the higher abundance of protease in fertilized soils, resulting in faster enzyme degradation. Interestingly, P fertilization alone did not have a similar effect, indicating that N fertilization is likely the main cause of the larger decreases in enzyme activity during incubation in fertilized soils compared to unfertilized control soils, despite our study site being poor in P and rich in N. These findings highlight the importance of considering enzyme degradation when investigating material dynamics in forest ecosystems, including the impact of nutrient addition on enzyme activity, as enzyme production alone may not fully explain changes in soil enzyme activity.

Habitat heterogeneity effects on microbial communities of the Gulf of Maine

Many biological and physical variables influence microbes at the sediment-water interface, whose response to those variables affects the overall fate and residence time of organic matter (OM) in the marine environment. In addition to the many ecological roles microbes play in deep-sea sediments, further studies are needed to address microbial community diversity and its influence on seafloor organic matter remineralization rates. We explored microbial diversity, distribution, and associated organic matter remineralization among contrasting habitats and following 24-h experimental phytodetrital enrichment of sediments from Canyon, Inter-Canyon, and Channel habitats of the Gulf of Maine, Northwest Atlantic. Based on multivariate analyses of community composition we found that habitat heterogeneity influenced microbial community composition but not microbial diversity. Similarly, the phytodetrital addition did not translate to significant differences in microbial diversity but altered nitrate flux in Inter-canyon sediments and phosphate flux in Channel sediments. Bacteria were dominant over Archaea and, of the environmental variables we measured, quantity and quality of organic matter best explained overall microbial community variation. Proteobacteria, Bacteroidae, Acidobacteriota, Planctomycetota, and NB1-J Deltaproteobacteria dominated all habitats, but variation in the microbial community at our study sites explained only 7% of nutrient fluxes. Our exploratory study did not suggest a strong contribution of microbial community composition to OM remineralization variation both among contrasting habitats and in response to phytodetrital addition, and thus to this aspect of deep-sea ecosystem functioning, at least over short-term incubations.

Seasonal Upwelling Conditions Modulate the Calcification Response of a Tropical Scleractinian Coral

Natural processes such as upwelling of deeper-water masses change the physical-chemical conditions of the water column creating localized ocean acidification events that can have an impact on the natural communities. This study was performed in a coral reef system of an archetypical bay within the Tayrona National Natural Park (PNNT) (Colombia), and aimed to quantify net calcification rates of a foundational coral species within a temporal context (6 months) taking into account the dynamics of seasonal upwelling that influence the study area. Net calcification rates of coral fragments were obtained in situ by the alkalinity anomaly technique in short-term incubations (~2.5 h). We found a significant effect of the upwelling on net calcification rates (Gnet) (p &lt; 0.05) with an 42% increase in CaCO3 accretion compared to non-upwelling season. We found an increase in total alkalinity (AT) and dissolved inorganic carbon (DIC) with decreased aragonite saturation (Ωara) for the upwelling months, indicating an influence of the Subtropical Under Water mass (SAW) in the PNNT coral community. Significant negative correlations between net calcification with temperature and Ωara, which indicates a positive response of M. auretenra with the upwelling conditions, thus, acting as “enhancer” of resilience for coral calcification.

Abstract LB311: Increased potency of CD8-targeted fusosomes enhances CAR gene delivery to resting primary T cells

Abstract Introduction: Fusosomes are viral vectors pseudotyped with modified paramyxovirus envelopes targeting specific cell types. A CD8-targeted fusosome delivering CD19CAR transgene has the potential to provide an off-the-shelf therapeutic approach to generate CD19-directed chimeric antigen receptor (CAR) T cells in patients after direct intravenous delivery or extracorporeal delivery (ECD), i.e., a short-term exposure of apheresis product to fusosome before re-infusion into the patient. Here, we demonstrate that an improved manufacturing process resulted in higher fusosome titer and quality, increasing the potency of CAR T generation from resting CD8 T cells. This potency is also observed when fusosomes are evaluated in a clinically relevant mock ECD approach. Methods: Fusosome titer was quantified by ddPCR directly for physical titer (vector genomes, GQA) or after infections of SupT1 cells for functional titer (IU/mL). Transduction of CD8 T cells was measured by flow cytometry and vector copy number analysis after short-term (1-4 hour) incubation of PBMCs with fusosome followed by wash and culture in resting or CD3/CD28-activated conditions. To assess CD19CAR T cell generation at a mock clinical setting and scale, a healthy donor was apheresed to collect PBMCs, fusosome was administered into the apheresis bag and PBMCs were sampled from the bag over a 2.5-hour time course for further analysis. In vivo anti-tumor efficacy of the fusosome was measured in immune-deficient NSG mice engrafted intravenously with Nalm6, then PBMCs followed by fusosome one day later. Tumor growth was monitored by bioluminescence imaging. Results: Fusosomes produced by the improved process had both a higher functional concentration (&amp;gt;14-fold higher IU/mL) and better infectivity (&amp;gt;10-fold higher IU/GQA) in comparison to fusosomes produced by the original process. Exposure of PBMCs to fusosomes produced by the improved process led to increased fusosome binding to CD8 T cells at high IU/PBMC doses and higher transduction efficiency in CD8 T cells at the same calculated dose per cell compared to fusosomes produced by the original process (&amp;gt;3-fold higher mean CAR+ percentage after 2-hour exposure to 2 IU/PBMC, n=8). Furthermore, fusosomes produced by the improved process generated higher frequencies of CAR+ CD8 T cells and resulted in increased ability to control tumor growth at lower doses in vivo in a Nalm6 model. Importantly, the ECD approach translated well to a mock clinical setting, resulting in successful generation of CAR T cells (12.6% of CD8 T cells after a 2.5-hour incubation). Conclusion: CD8-targeted fusosome encoding a CD19CAR transgene represents a potential novel therapeutic approach for cancer. This study demonstrates that improvements in the manufacturing process can significantly increase the potency of the fusosome in T cells, and we intend to move forward to clinical trials using this improved process. Citation Format: Jesse Green, Brian Granger, Ouwen Liang, Jesus Moreno, Andrew Tucker, Aesha Vakil, Reuben Burch, Nicholas Mozdzierz, Matthew Scott-Skandera, Stephanie Riofrio, Mike DeCosta, Amey Gaikwad, Sanket Phadke, Kaely Gallagher, Adam Charlton, Sarah Miller, Hosein Kouros-Mehr, Misha Shamashkin, Neal Van Hoeven, Kutlu Elpek, Terry Fry. Increased potency of CD8-targeted fusosomes enhances CAR gene delivery to resting primary T cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB311.

Soil phosphorus availability and fractionation in response to different phosphorus sources in alkaline and acid soils: a short-term incubation study

Using agricultural wastes as an alternative phosphorus (P) source has great prospects to improve soil P status. A 70-day incubation experiment was carried out to investigate the effects of superphosphate (SSP), poultry manure (PM), cattle manure (CM), maize straw (MS), and cattle bone meal (CB) with the same total P input on soil P availability and fractions in typical acidic (red soil) and alkaline (fluvo-aquic soil) soils. The results showed that in both fluvo-aquic and red soils, CM out-performed other P sources in improving soil P availability. Changes in soil Olsen-P (ΔOlsen-P) were greater in fluvo-aquic soils with SSP, PM and CM additions than in red soils. Among the different P sources used, only CM has increased the labile soil P fractions to levels similar to that with SSP. Compared with SSP, more monoester P and inositol hexakisphosphate were detected in soils amended with PM and CM. A structural equation model (SEM) analysis suggested that soil pH had a direct positive effect on the labile P fractions in the acidic red soil amended with different P sources. In summary, CM is a superior P source for increasing plant available soil P, with considerable practical implications for P recycling.

In Vitro Effect of Enzymes and Human Milk Oligosaccharides on FODMAP Digestion and Fecal Microbiota Composition

Fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) cause intestinal discomfort in patients with irritable bowel syndrome (IBS). An enzyme mix (2500 SU invertase, 2400 GalU α-galactosidase, 10,000 ALU β-galactosidase) optimized for FODMAP digestion, and/or human milk oligosaccharides (HMO) (2'-FL, DFL, and LNnT), were evaluated for effects on microbial community activity and composition in short-term colonic incubations using the fecal microbiota of four patients with IBS-D symptoms under the following test conditions: (i) FODMAP, (ii) pre-digested (with enzyme mix) FODMAP, (iii) FODMAP + HMO, and (iv) pre-digested FODMAP + HMO. Pre-digested FODMAP reduced short-chain fatty acid (SCFA) production versus FODMAP; HMO restored this. A 10-day experiment with the simulator of the human intestinal microbial ecosystem (SHIME®), using fecal samples from two patients with IBS-D, further evaluated these findings. FODMAP resulted in decreased microbial diversity versus blank. Pre-digestion with the enzyme mix restored microbial diversity, improved FODMAP digestibility, and reduced gas pressure versus undigested FODMAP; however, SCFA production decreased. HMO restored SCFA production along with an increase in gas pressure and increased abundance of Lachnospiraceae. When used in combination, the FODMAP enzyme mix and HMO may resolve FODMAP-related IBS symptoms while maintaining a healthy gut microbiome via prebiotic activity.

Effects of Mineral on Taxonomic and Functional Structures of Microbial Community in Tengchong Hot Springs via in-situ cultivation

Diverse mineralogical compositions occur in hot spring sediments, but the impact of minerals on the diversity and structure of microbial communities remains poorly elucidated. In this study, different mineral particles with various chemistries (i.e., hematite, biotite, K-feldspar, quartz, muscovite, aragonite, serpentine, olivine, barite, apatite, and pyrite) were incubated for ten days in two Tengchong hot springs, one alkaline (pH ~ 8.34) with a high temperature (~ 82.8 °C) (Gumingquan, short as GMQ) and one acidic (pH ~ 3.63) with a relatively low temperature (~ 43.3 °C) (Wenguangting, short as WGT), to determine the impacts of minerals on the microbial communities taxonomic and functional diversities. Results showed that the mineral-associated bacterial taxa differed from those of the bulk sediment samples in the two hot springs. The relative abundance of Proteobacteria, Euryarchaeota, and Acidobacteria increased in all minerals, indicating that these microorganisms are apt to colonize on solid surfaces. The α-diversity indices of the microbial communities on the mineral surfaces in the WGT were higher than those from the bulk sediment samples (p < 0.05), which may be caused by the stochastically adhering process on the mineral surface during 10-day incubation, different from the microbial community in sediment which has experienced long-term environmental and ecological screening. Chemoheterotrophy increased with minerals incubation, which was high in most cultured minerals (the relative contents were 5.8 − 21.4%). Most notably, the sulfate respiration bacteria (mainly related to Desulfobulbaceae and Syntrophaceae) associated with aragonite in the acidic hot spring significantly differed from other minerals, possibly due to the pH buffering effect of aragonite providing more favorable conditions for their survival and proliferation. By comparison, aragonite cultured in the alkaline hot spring highly enriched denitrifying bacteria and may have promoted the nitrogen cycle within the system. Collectively, we speculated that diverse microbes stochastically adhered on the surface of minerals in the water flows, and the physicochemical properties of minerals drove the enrichment of certain microbial communities and functional groups during the short-term incubation. Taken together, these findings thereby provide novel insights into mechanisms of community assembly and element cycling in the terrestrial hydrothermal system associated with hot springs.

T-cell activation-induced marker assays in health and disease.

Activation-induced marker (AIM) assays have proven to be an accessible and rapid means of antigen-specific T-cell detection. The method typically involves short-term incubation of whole blood or peripheral blood mononuclear cells with antigens of interest, where autologous antigen-presenting cells process and present peptides in complex with major histocompatibility complex (MHC) molecules. Recognition of peptide-MHC complexes by T-cell receptors then induces upregulation of activation markers on the T cells that can be detected by flow cytometry. In this review, we highlight the most widely used activation markers for assays in the literature while identifying nuances and potential downfalls associated with the technique. We provide a summary of how AIM assays have been used in both discovery science and clinical studies, including studies of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunity. This review primarily focuses on AIM assays using human blood or peripheral blood mononuclear cell samples, with some considerations noted for tissue-derived T cells and nonhuman samples. AIM assays are a powerful tool that enables detailed analysis of antigen-specific T-cell frequency, phenotype and function without needing to know the precise antigenic peptides and their MHC restriction elements, enabling a wider analysis of immunity generated following infection and/or vaccination.

Differential susceptibility of Red Sea Pocilloporidae corals to UVB highlights photoacclimation potential

Despite being exposed to extreme water temperatures and solar irradiances, Red Sea corals are relatively resistant to bleaching. While their thermal tolerance is well described, little is known about their resistance to ultraviolet-B radiation (UVB). Here, we performed a short-term (2 days) UVB-removal incubation with Stylophora pistillata, and in situ measurements with Pocillopora verrucosa complemented by a long-term (46 days) transplantation and UVB-removal experiment. Using a suite of physiological parameters (effective quantum yield (Fv’/Fm’), oxidative stress (lipid peroxidation, LPO), and primary production), we assessed the impacts of UVB on the physiology and acclimation capacity of Red Sea corals. Shielding S. pistillata from UVB did not change the gross primary production or Fv’/Fm’, and respiration and LPO in the host remained unaffected. In situ, P. verrucosa exhibited less varying and significantly higher Fv’/Fm’ in 8 m depth (0.61 ± 0.04) than in 4 m (0.52 ± 0.06), 2 m (0.51 ± 0.09), and 0.5 m (0.50 ± 0.11), where water temperatures ranged from 30.5–33.4, 30.6–34.0, 30.8–34.5, 30.6–37.3°C and daily UVB exposures averaged 0.9, 2.9, 11.8 and 21.4 kJ m-2, respectively. Fv’/Fm’ correlated the strongest with UVB (-0.57), followed by PAR (-0.54) and temperature (-0.40), suggesting that UVB is a key determinant of photosynthetic efficiency. Fv’/Fm’ of upward transplanted specimens (T 1m) was initially decreased but gradually increased and reached the same values as shallow corals (1 m) after 44 days. UVB removal significantly increased the Fv’/Fm’ of transplanted corals in the first 20 days. Oxidative stress was initially highest in T 1m samples under full sunlight but equalized with 1 m specimens by day 46, whereas oxidative stress was significantly reduced by day 4 in T 1m corals sheltered from UVB. Overall, UVB-removal generally had little impact on the physiology of shallow-water S. pistillata and P. verrucosa but considerably accelerated the acclimation of upward transplanted corals. Our study highlights that UVB is a crucial stressor governing the photoacclimation capacity of these Red Sea coral species.

Serotonin-induced stereospecific formation and bioactivity of the eicosanoid 17,18-epoxyeicosatetraenoic acid in the regulation of pharyngeal pumping of C. elegans

17,18-Epoxyeicosatetraenoic acid (17,18-EEQ), the most abundant eicosanoid generated by cytochrome P450 (CYP) enzymes in C. elegans, is a potential signaling molecule in the regulation of pharyngeal pumping activity of this nematode. As a chiral molecule, 17,18-EEQ can exist in two stereoisomers, the 17(R),18(S)- and 17(S),18(R)-EEQ enantiomers. Here we tested the hypothesis that 17,18-EEQ may function as a second messenger of the feeding-promoting neurotransmitter serotonin and stimulates pharyngeal pumping and food uptake in a stereospecific manner. Serotonin treatment of wildtype worms induced a more than twofold increase of free 17,18-EEQ levels. As revealed by chiral lipidomics analysis, this increase was almost exclusively due to an enhanced release of the (R,S)-enantiomer of 17,18-EEQ. In contrast to the wildtype strain, serotonin failed to induce 17,18-EEQ formation as well as to accelerate pharyngeal pumping in mutant strains defective in the serotonin SER-7 receptor. However, the pharyngeal activity of the ser-7 mutant remained fully responsive to exogenous 17,18-EEQ administration. Short term incubations of well-fed and starved wildtype nematodes showed that both racemic 17,18-EEQ and 17(R),18(S)-EEQ were able to increase pharyngeal pumping frequency and the uptake of fluorescence-labeled microspheres, while 17(S),18(R)-EEQ and also 17,18-dihydroxyeicosatetraenoic acid (17,18-DHEQ, the hydrolysis product of 17,18-EEQ) were ineffective. Taken together, these results show that serotonin induces 17,18-EEQ formation in C. elegans via the SER-7 receptor and that both the formation of this epoxyeicosanoid and its subsequent stimulatory effect on pharyngeal activity proceed with high stereospecificity confined to the (R,S)-enantiomer.