A review on recent taxonomic updates of gut bacteria associated with social bees, with a curated genomic reference database.

Honeybees and bumblebees play a crucial role as essential pollinators. The special gut microbiome of social bees is a key factor in determining the overall fitness and health of the host. Although bees harbor relatively simple microbial communities at the genus level, recent studies have unveiled significant genetic divergence and variations in gene content within each bacterial genus. However, a comprehensive and refined genomics-based taxonomic database specific to social bee gut microbiomes remains lacking. Here, we first provided an overview of the current knowledge on the distribution and function of social bee gut bacteria, as well as the factors that influence the gut population dynamics. We then consolidated all available genomes of the gut bacteria of social bees and refined the species-level taxonomy, by constructing a maximum-likelihood core genome phylogeny and calculating genome-wide pairwise average nucleotide identity. On the basis of the refined species taxonomy, we constructed a curated genomic reference database, named the bee gut microbe genome sequence database (BGM-GDb). To evaluate the species-profiling performance of the curated BGM-GDb, we retrieved a series of bee gut metagenomic data and inferred the species-level composition using metagenomic intra-species diversity analysis system (MIDAS), and then compared the results with those obtained from a prebuilt MIDAS database. We found that compared with the default database, the BGM-GDb excelled in aligned read counts and bacterial richness. Overall, this high-resolution and precise genomic reference database will facilitate research in understanding the gut community structure of social bees.

Deep-sea microbial genetic resources: new frontiers for bioprospecting.

Deep-sea ecosystems are home to a diverse community of microorganisms. These microbes are not only fundamental to ecological processes but also a treasure trove of natural products and enzymes with significant scientific and industrial applications. This forum focuses on the vast diversity of deep-sea microbes and their potential for bioprospecting. It also discusses threats posed by climate change and deep-sea mining to deep-sea microbial genetic resources, and proposes future research directions.

Toll receptor ligand Spätzle 4 responses to the highly pathogenic Enterococcus faecalis from Varroa mites in honeybees.

Honeybees play a major role in crop pollination, which supports the agricultural economy and international food supply. The colony health of honeybees is threatened by the parasitic mite Varroa destructor, which inflicts physical injury on the hosts and serves as the vector for variable viruses. Recently, it shows that V. destructor may also transmit bacteria through the feeding wound, yet it remains unclear whether the invading bacteria can exhibit pathogenicity to the honeybees. Here, we incidentally isolate Enterococcus faecalis, one of the most abundant bacteria in Varroa mites, from dead bees during our routine generation of microbiota-free bees in the lab. In vivo tests show that E. faecalis is only pathogenic in Apis mellifera but not in Apis cerana. The expression of antimicrobial peptide genes is elevated following infection in A. cerana. The gene-based molecular evolution analysis identifies positive selection of genes encoding Späetzle 4 (Spz4) in A. cerana, a signaling protein in the Toll pathway. The amino acid sites under positive selection are related to structural changes in Spz4 protein, suggesting improvement of immunity in A. cerana. The knock-down of Spz4 in A. cerana significantly reduces the survival rates under E. faecalis challenge and the expression of antimicrobial peptide genes. Our results indicate that bacteria associated with Varroa mites are pathogenic to adult bees, and the positively selected gene Spz4 in A. cerana is crucial in response to this mite-related pathogen.

N/O Co-doped hierarchical nanoporous biochar derived from waste polypropylene nonwoven for high-performance supercapacitors.

How to efficiently treat municipal solid waste (MSW) has become one of the critical solutions in response to the call for "carbon neutrality". Here, the waste polypropylene nonwoven fabric of waste diapers was converted into hierarchical nanoporous biochar (HPBC) through pre-carbonization and activation processes as an ideal precursor for supercapacitors (SCs) with excellent performance. The prepared HPBC-750-4 with an ultrahigh specific surface area (3838.04 m2 g-1) and abundant heteroatomic oxygen (13.25%) and nitrogen (1.16%) codoped porous biochar structure. Given its structural advantages, HPBC-750-4 achieved a specific capacitance of 340.9 F g-1 at a current density of 1 A g-1 in a three-electrode system. Its capacitance retention rate was above 99.2% after 10 000 cycles at a current density of 10 A g-1, which indicated an excellent rate capability and long-term cycling stability. Furthermore, the HPBC-750-4//HPBC-750-4 symmetric SC exhibited a superb energy density of 10.02 W h kg-1 with a power density of 96.15 W kg-1 in a 6 M KOH electrolyte. This work not only demonstrates the enormous potential of waste polypropylene nonwoven fabric in the SC industry but also provides an economically feasible means of managing MSW.

In Situ N, O-Dually Doped Nanoporous Biochar Derived from Waste Eutrophic Spirulina for High-Performance Supercapacitors.

Sustainable and high-performance energy storage materials are crucial to address global energy and environmental challenges. In this study, Spirulina platensis was used as the carbon and nitrogen source, and Spirulina-based nanoporous biochar (SNPB) was synthesized through chemical activation using KOH as the activating agent in N2 atmosphere. SNPB-800-4 was characterized by N2 adsorption-desorption and XPS, showing a high specific surface area (2923.7 m2 g-1) and abundant heteroatomic oxygen (13.78%) and nitrogen (2.55%). SNPB-800-4 demonstrated an exceptional capacitance of 348 F g-1 at a current density of 1 A g-1 and a remarkable capacitance retention of 94.14% after 10,000 cycles at a current density of 10 A g-1 in 6 M KOH. Notably, symmetric supercapacitors SNPB-800-4//SNPB-800-4 achieved the maximum energy and power densities of 17.99 Wh kg-1 and 162.48 W kg-1, respectively, at a current density of 0.5 A g-1, and still maintained 2.66 Wh kg-1 when the power density was increased to 9685.08 W kg-1 at a current density of 30 A g-1. This work provides an easily scalable and straightforward way to convert waste algae biomass into in situ N, O-dually doped biochar for ultra-high-power supercapacitors.

In Situ N, O Co-Doped Nanoporous Carbon Derived from Mixed Egg and Rice Waste as Green Supercapacitor.

The conversion of nitrogen-oxygen-rich biomass wastes into heteroatomic co-doped nanostructured carbons used as energy storage materials has received widespread attention. In this study, an in situ nitrogen-oxygen co-doped porous carbon was prepared for supercapacitor applications via a two-step method of pre-carbonization and pyrolytic activation using mixed egg yolk/white and rice waste. The optimal sample (YPAC-1) was found to have a 3D honeycomb structure composed of abundant micropores and mesopores with a high specific surface area of 1572.1 m2 g-1, which provided abundant storage space and a wide transport path for electrolyte ions. Notably, the specific capacitance of the constructed three-electrode system was as high as 446.22 F g-1 at a current density of 1 A g-1 and remained above 50% at 10 A g-1. The capacitance retention was 82.26% after up to 10,000 cycles. The symmetrical capacitor based on YPAC-1 with a two-electrode structure exhibited an energy density of 8.3 Wh kg-1 when the power density was 136 W kg-1. These results indicate that porous carbon materials prepared from mixed protein and carbohydrate waste have promising applications in the field of supercapacitors.

In situ N, O co-doped porous carbon derived from antibiotic fermentation residues as electrode material for high-performance supercapacitors.

With the widespread use of antibiotics, the safe utilization of waste antibiotic fermentation residues has become an urgent issue to be resolved. In this study, in situ N, O co-doped porous carbon was prepared using fresh oxytetracycline fermentation residue under the mild activation of the green activator K2CO3. The optimal sample exhibited a 3D grid carbon skeleton structure, excellent specific surface area (SBET = 948 m2 g-1), and high nitrogen and oxygen content (N = 3.42 wt%, O = 14.86 wt%). Benefiting from its developed morphology, this sample demonstrated excellent electrochemical performance with a high specific capacitance of 310 F g-1 at a current density of 0.5 A g-1 in the three-electrode system. Moreover, it exhibited superior cycling stability with only a 5.32% loss of capacity after 10 000 cycles in 6 M KOH aqueous electrolyte. Furthermore, the symmetric supercapacitor prepared from it exhibited a maximum energy density of 7.2 W h kg-1 at a power density of 124.9 W kg-1, demonstrating its promising application prospects. This study provided a green and facile process for the sustainable and harmless treatment of antibiotic fermentation residues.

Effective CO2 capture by in-situ nitrogen-doped nanoporous carbon derived from waste antibiotic fermentation residues.

It is of great environmental benefit to rationally dispose of and utilize antibiotic fermentation residues. In this study, oxytetracycline fermentation residue was transformed into an in-situ nitrogen-doped nanoporous carbon material with high CO2 adsorption performance by low-temperature pyrolysis pre-carbonization coupled with pyrolytic activation. The results indicated the activation under mild conditions (600 °C, KOH/OC = 2) was able to increase micropores and reduce the loss of in-situ nitrogen content. The developed microporous structure was beneficial for the filling adsorption of CO2, and the in-situ nitrogen doping in a high oxygen-containing carbon framework also strengthened the electrostatic adsorption with CO2. The maximum CO2 adsorption reached 4.38 mmol g-1 and 6.40 mmol g-1 at 25 °C and 0 °C (1 bar), respectively, with high CO2/N2 selectivity (32/1) and excellent reusability (decreased by 4% after 5 cycles). This study demonstrates the good application potential of oxytetracycline fermentation residue as in-situ nitrogen-doped nanoporous carbon materials for CO2 capture.

Effective removal of tetracycline antibiotics from water by magnetic functionalized biochar derived from rice waste.

The effective removal of tetracycline antibiotics (TCs) from water is of great significance and remains a big challenge. In this work, a novel magnetized biochar (magnetic functionalized carbon microsphere, MF-CMS) was prepared by the coupling hydrothermal carbonization and pyrolysis activation of starch-rich rice waste using ZnCl2 and FeCl3 as activators. As the MF-CMS dose was 2.0 g/L, the initial concentration of TCs was 100 mg/L, the removal rates of tetracycline, doxycycline, oxytetracycline, and chlortetracycline were 96.02%, 96.10%, 96.52%, and 85.88%, respectively. The best modeled on pseudo second order, Langmuir adsorption model, and intraparticle diffusion kinetic models suggested that both chemisorption and physisorption occurred in all removal processes, in which chemisorption dominated. TCs were efficiently adsorbed through the combined effects of pore filling, electrostatic attraction, π-π interactions, and complexation reactions of surface functional groups (such as γ-Fe2O3 and FeOOH). The removal rates of TCs after five cycles approximately decreased by 20%. And the cycling and metal ion release experiments of MF-CMS indicated that MF-CMS had good reusability, stability, and safety. The estimated cost of preparing MF-CMS is 5.91 USD per kg, and 1 kg of MF-CMS (consuming 8 kg of waste rice) can approximately treat 0.55 tons of TCs wastewater. Overall, the magnetic biochar derived from starch-rich rice waste as an adsorbent has promising and effective for the removal of TCs from water, but also provides a new idea for the resourceful treatment of solid waste.

Continuous Positive Airway Pressure Reduces Plasma Neurochemical Levels in Patients with OSA: A Pilot Study.

Obstructive sleep apnea (OSA) is a risk factor for neurodegenerative diseases. This study determined whether continuous positive airway pressure (CPAP), which can alleviate OSA symptoms, can reduce neurochemical biomarker levels. Thirty patients with OSA and normal cognitive function were recruited and divided into the control (n = 10) and CPAP (n = 20) groups. Next, we examined their in-lab sleep data (polysomnography and CPAP titration), sleep-related questionnaire outcomes, and neurochemical biomarker levels at baseline and the 3-month follow-up. The paired t-test and Wilcoxon signed-rank test were used to examine changes. Analysis of covariance (ANCOVA) was performed to increase the robustness of outcomes. The Epworth Sleepiness Scale and Pittsburgh Sleep Quality Index scores were significantly decreased in the CPAP group. The mean levels of total tau (T-Tau), amyloid-beta-42 (Aß42), and the product of the two (Aß42 × T-Tau) increased considerably in the control group (ΔT-Tau: 2.31 pg/mL; ΔAß42: 0.58 pg/mL; ΔAß42 × T-Tau: 48.73 pg2/mL2), whereas the mean levels of T-Tau and the product of T-Tau and Aß42 decreased considerably in the CPAP group (ΔT-Tau: -2.22 pg/mL; ΔAß42 × T-Tau: -44.35 pg2/mL2). The results of ANCOVA with adjustment for age, sex, body mass index, baseline measurements, and apnea-hypopnea index demonstrated significant differences in neurochemical biomarker levels between the CPAP and control groups. The findings indicate that CPAP may reduce neurochemical biomarker levels by alleviating OSA symptoms.

Stably transmitted defined microbial community in honeybees preserves Hafnia alvei inhibition by regulating the immune system.

The gut microbiota of honeybees is highly diverse at the strain level and essential to the proper function and development of the host. Interactions between the host and its gut microbiota, such as specific microbes regulating the innate immune system, protect the host against pathogen infections. However, little is known about the capacity of these strains deposited in one colony to inhibit pathogens. In this study, we assembled a defined microbial community based on phylogeny analysis, the 'Core-20' community, consisting of 20 strains isolated from the honeybee intestine. The Core-20 community could trigger the upregulation of immune gene expressions and reduce Hafnia alvei prevalence, indicating immune priming underlies the microbial protective effect. Functions related to carbohydrate utilization and the phosphoenolpyruvate-dependent sugar phosphotransferase system (PTS systems) are represented in genomic analysis of the defined community, which might be involved in manipulating immune responses. Additionally, we found that the defined Core-20 community is able to colonize the honeybee gut stably through passages. In conclusion, our findings highlight that the synthetic gut microbiota could offer protection by regulating the host immune system, suggesting that the strain collection can yield insights into host-microbiota interactions and provide solutions to protect honeybees from pathogen infections.

Screening for Obstructive Sleep Apnea Risk by Using Machine Learning Approaches and Anthropometric Features.

Obstructive sleep apnea (OSA) is a global health concern and is typically diagnosed using in-laboratory polysomnography (PSG). However, PSG is highly time-consuming and labor-intensive. We, therefore, developed machine learning models based on easily accessed anthropometric features to screen for the risk of moderate to severe and severe OSA. We enrolled 3503 patients from Taiwan and determined their PSG parameters and anthropometric features. Subsequently, we compared the mean values among patients with different OSA severity and considered correlations among all participants. We developed models based on the following machine learning approaches: logistic regression, k-nearest neighbors, naïve Bayes, random forest (RF), support vector machine, and XGBoost. Collected data were first independently split into two data sets (training and validation: 80%; testing: 20%). Thereafter, we adopted the model with the highest accuracy in the training and validation stage to predict the testing set. We explored the importance of each feature in the OSA risk screening by calculating the Shapley values of each input variable. The RF model achieved the highest accuracy for moderate to severe (84.74%) and severe (72.61%) OSA. The level of visceral fat was found to be a predominant feature in the risk screening models of OSA with the aforementioned levels of severity. Our machine learning models can be employed to screen for OSA risk in the populations in Taiwan and in those with similar craniofacial structures.

Specific Strains of Honeybee Gut Lactobacillus Stimulate Host Immune System to Protect against Pathogenic Hafnia alvei.

Honeybee gut microbiota plays an important role in host physiology and metabolism. Recent studies have shown that the influence of the resident microorganisms in the regulation of honeybee immune system is profound, which protects against the pathogen Serratia marcescens. However, only few of the core gut members in the regulation of immune functions have been studied. Here, we explored how different bee gut bacterial species aided in the clearance of the pathogenic Hafnia alvei, which causes bee septicemia with a high mortality rate. We found that both Gilliamella apicola W8136 and Lactobacillus apis W8172 protect honeybees from the opportunistic pathogen, while two other strains from Gilliamella and Lactobacillus did not affect the invasion of H. alvei. Transcriptomic analysis revealed that gut species induced different expression profiles in the gut. Specifically, two regulator genes from the Toll pathway, PGRP-S3 recognizing Gram-positive and Spätzle that bind to the Toll protein for the downstream signal transduction, were elevated by L. apis. Correspondingly, multiple genes encoding antibacterial proteins were also stimulated by L. apis. Interestingly, we found an increased expression of apidaecin, which also exhibited a high in vitro inhibitory effect on H. alvei. To elucidate the difference of strains in the host's immune regulation, comparative genomic analyses indicate that the S-layer proteins unique to L. apis are potentially involved in honeybee Toll signaling and the activation of antibacterial protein production. IMPORTANCE Honeybees are essential pollinators supporting global agricultural economies and food supplies. Recent honeybee decline has been linked to several factors, while pathogen infection is considered one of the most significant contributing factors. Although a limited number of bacterial pathogens have been identified, Hafnia alvei is one of the pathogens causing septicemia in adult bees. In this study, we showed that two bee gut members, Gilliamella and Lactobacillus, can clear H. alvei from invasion. Mono-colonization of specific strains can stimulate the host Toll signaling pathway and the downstream expression of AMPs. Specifically, apidaecin upregulated by the gut symbionts is more effective against the pathogen. Moreover, our genomic analysis suggests that the surface-layer proteins specific to Lactobacillus strains are an important driver of Toll signaling, highlighting the variation of bee gut strains in regulating the host immune system.

Microalgal bioremediation of heavy metal pollution in water: Recent advances, challenges, and prospects.

With the rapid economy development and population surge, the water resources available for direct use on the earth have been in shortage. Therefore, water pollution remediation inevitably becomes the focus of global attention. Aside from their capacity to fix and effectively control the emission of carbon dioxide thus achieve negative carbon emission, microalgae and its products modified by genetic engineering and other technologies also have a broad prospect in sewage treatment such as efficiently removing all kinds of pollutants in water and producing high-quality biofuels after use. Therefore, research on these organisms has gradually deepened in recent years. This paper summarizes the bioremediation mechanism of heavy metal ions in water by using microalgae and their modified products. The relevant research progresses since 2015 are critically reviewed and discussed. Challenges and prospects are also put forward for their industrial implementation.

A review on solid acid catalysis for sustainable production of levulinic acid and levulinate esters from biomass derivatives.

Biomass is a kind of renewable and abundant resource that can be seen as an important candidate to solve the energy crisis. Levulinic acid (LA) and levulinate esters (LEs) have been widely researched as biomass-based platform compounds. In recent years, efficient, green, and environment-friendly solid acid catalysts have been developed for the fast production and resolution of the problems, such as low yield, high equipmental requirements, and difficulty in product separation, in the preparation of LA and LE from biomass. In this paper, the preparation routes of LA and LEs from various raw materials are introduced, and the solid acid catalysts involved in their production are emphatically reviewed. The challenges and prospects in LA and LE production from biomass are proposed to achieve a more economical and energy efficient process with the concept of sustainable development in the future.

Characterization of Bifidobacterium apousia sp. nov., Bifidobacterium choladohabitans sp. nov., and Bifidobacterium polysaccharolyticum sp. nov., three novel species of the genus Bifidobacterium from honey bee gut.

Bifidobacterium is one of the dominating bacterial genera in the honey bee gut, and they are the key degrader of diet polysaccharides for the host. Previous genomic analysis shows that they belong to separate phylogenetic clusters and exhibited different functional potentials in hemicellulose digestion. Here, three novel strains from the genus Bifidobacterium were isolated from the guts of the honey bee (Apis mellifera). Phylogenomic analysis showed that the isolates could be grouped into four phylogenetic clusters. The average nucleotide identity values between strains from different clusters are <95%, while strains in Cluster IV belong to the characterized species Bifidobacterium asteroides. Carbohydrate-active enzyme annotation confirmed that the metabolic capacity for carbohydrates varied between clusters of strains. Cells are Gram-positive rods; they grew both anaerobically and in a CO2-enriched atmosphere. All strains grew at a temperature range of 20-42 °C, with optimum growth at 35 °C. The pH range for growth was 5-9. Strains from different phylogenetic clusters varied in multiple phenotypic and chemotaxonomic characterizations. Thus, we propose three novel species Bifidobacterium apousia sp. nov. whose type strain is W8102T (=CGMCC 1.18893 T = JCM 34587 T), Bifidobacterium choladohabitans sp. nov., whose type strain is B14384H11T (=CGMCC 1.18892 T = JCM 34586 T), and Bifidobacterium polysaccharolyticum sp. nov. whose type strain is W8117T (=CGMCC 1.18894 T = JCM 34588 T).

Point-of-use sensors and machine learning enable low-cost determination of soil nitrogen.

Overfertilization with nitrogen fertilizers has damaged the environment and health of soil, but standard laboratory testing of soil to determine the levels of nitrogen (mainly NH4+ and NO3-) is not performed regularly. Here we demonstrate that point-of-use measurements of NH4+, combined with soil conductivity, pH, easily accessible weather and timing data, allow instantaneous prediction of levels of NO3- in soil (R2 = 0.70) using a machine learning model. A long short-term memory recurrent neural network model can also be used to predict levels of NH4+ and NO3- up to 12 days into the future from a single measurement at day one, with [Formula: see text] and [Formula: see text], for unseen weather conditions. Our machine-learning-based approach eliminates the need for dedicated instruments to determine the levels of NO3- in soil. Nitrogenous soil nutrients can be determined and predicted with enough accuracy to forecast the impact of climate on fertilization planning and to tune timing for crop requirements, reducing overfertilization while improving crop yields.

Entomomonas moraniae gen. nov., sp. nov., a member of the family Pseudomonadaceae isolated from Asian honey bee gut, possesses a highly reduced genome.

The honey bee gut microbiota contains many bacterial lineages that are specific to this ecosystem. Apis cerana, raised across the Asian continent, is of great significance to the maintenance and development of ecology and agriculture in Asia. Here, we report the isolation and characterization of strain QZS01T from the gut of Apis cerana from Pingwu County, Sichuan Province, PR China. The results of phylogenetic analysis based on 16S rRNA sequences showed that strain QZS01T forms a monophyletic group together with clone sequences derived from variable insect hosts, and it shows 92% sequence similarity to its closest relative, Pseudomonas knackmussii. Strain QZS01T possesses a reduced genome (3.3 Mbp; G+C content, 38.05 mol%) compared to all other Pseudomonas species, and the whole-genome based phylogenetic reconstruction showed that strain QZS01T represents a novel genus within the family Pseudomonadaceae. Strain QZS01T is a Gram-stain-negative facultative anaerobe. It grows on brain heart infusion agar and the energy sources utilized for growth are very limited. Based on the results of genotypic and phenotypic analyses, we propose a novel genus and species, Entomomonas moraniae gen. nov., sp. nov., with the type strain QZS01T (=CGMCC 1.13498T=KCTC 62495T).