The Impact of Orthodontic Adhesive Containing Resveratrol, Silver, and Zinc Oxide Nanoparticles on Shear Bond Strength: An In Vitro Study.

Introduction The goal of orthodontic treatment is to provide patients with esthetic smiles and functional occlusion. Despite best efforts and continuous evolution of materials, white spot lesions present a persistent hindrance to the desired treatment outcome. Nanoparticles have shown efficacy in reducing microbial activity; however, currently, there is a need for natural anti-cariogenic compounds with minimal side effects. Resveratrol is a natural compound belonging to the polyphenol group and has shown promising anti-microbial efficacy. This study aimed to evaluate the influence of dentin bonding agents incorporated with the following three different nanoparticles on shear bond strength: silver nanoparticles (Ag-Np), zinc oxide nanoparticles (ZnO-Np), and resveratrol nanoparticles (RSV-Np). Materials and methods A total of 40 premolar teeth therapeutically extracted were assigned to four equal groups of n=10 each. Groups 1, 2, and 3 used experimental adhesives doped with silver, zinc oxide, and resveratrol nanoparticles, respectively. Group 4 was bonded using unmodified adhesive. The bonded teeth were then subjected to shear bond strength (SBS) testing which was measured using a Universal Testing Machine (model no. UNITEST-10; Pune, India: ACME Engineers). Statistical analyses were performed using SPSS version 21 (Armonk, NY: IBM Corp.), employing one-way ANOVA and Tukey's post-hoc test for pairwise comparisons. Results Shear bond strength testing revealed that the control group with unmodified adhesive (8.6 MPa) had the highest SBS, followed by RSV-Np (7.6 MPa), Ag-Np (6.3 MPa), and ZnO-Np (5.65 MPa). Although the experimental groups demonstrated decreased SBS compared to the control, the values for Ag-Np and RSV-Np fell within the acceptable range. Conclusion Resveratrol nanoparticles had the least impact on shear bond strength among the experimental groups. These findings suggest that the incorporation of resveratrol nanoparticles in dentin bonding agents can provide anti-cariogenic effect without significantly impacting the adhesive's mechanical properties thereby providing a new and promising alternative to synthetic nanoparticles. Further studies are recommended to optimize the balance between anti-microbial efficacy and bond strength in clinical applications.

Parabens as the double-edged sword: Understanding the benefits and potential health risks.

Parabens are globally employed as important preservatives in pharmaceutical, food, and personal care products. Nonetheless, improper disposal of commercial products comprising parabens can potentially contaminate various environmental components, including the soil and water. Residues of parabens have been detected in surface water, ground water, packaged food materials, and other consumer items. Long-term exposure to parabens through numerous consumer products and contaminated water can harm human health. Paraben can modulate hormonal and immune orchestra of the body. Recent findings have correlated paraben use with hypersensitivity, obesity, and infertility. Notably, parabens have also been detected in the samples of breast cancer patients, suggesting a potential cross-talk between parabens and carcinogenesis. Therefore, the present article aims to dissect the significance of parabens as a preservative in several consumer products and their impact of chronic exposure to human health. This review encompasses various facets of paraben, including its sources, mechanism of action at the molecular level, and sheds light on its toxicological implications on human health.

Shelf-life of cooked meat of southern king crab (Lithodes santolla) and false king crab (Paralomis granulosa) during refrigerated storage.

Lithodes santolla (SKC) and Paralomis granulosa (FSKC) are economically important resources exploited in southern South America. The effect of refrigerated storage (4 °C on flake ice) on physico-chemical (pH, thiobarbituric reactive substances (TBARs), total volatile basic nitrogen (TVB-N), water holding capacity (WHC), and water content (WC)), microbiological (total viable mesophilic bacteria (TVMC), psychrotrophic bacteria (TVPC), Staphylococcus spp, coliforms, enterobacteria, molds and yeasts) and sensory (odor, appearance, texture, juiciness, and taste) parameters was analyzed in the cooked SKC and FSKC merus. For each species, cooked merus from 36 animals were randomly distributed into 6 groups, corresponding to 0, 2, 5, 8, 11, and 14 days of storage. On each day, samples were taken for physico-chemical (n = 6), microbiological (n = 3), and sensory (n = 15) analyses. The pH values increased over time (P < 0.01 in both species), the TBARs only increased in FSKC (P = 0.008), whereas the TVB-N significantly rose only in SKC (P = 0.001). The WHC and the WC did not change over time for any of the king crab species (P > 0.05) in all cases. The presence of TVCM, TVCP, and Staphylococcus spp. in both species was observed from day 0. Furthermore, pathogenic microorganisms (S. aureus, coliforms, and enterobacteria) were not detected, and only the TVCP in SFKC reached the suggested microbial limit after 11 days. All sensory scores significantly decreased (P < 0.001) over time, but the quality of both king crab species remained acceptable until the 11th day. These findings suggest that the shelf-life of cooked merus was 11 and 8 days for SKC and SFKC, respectively, when stored at 4 °C with the presence of flake ice. These contributions consist of elucidating the shelf-life of these economically important seafood products and providing insights into their quality maintenance during storage.

Seasonal and spatial variations in concentration, diversity, and antibiotic resistance of ambient bioaerosols in an arid region.

The airborne microbiome significantly influences human health and atmospheric processes within Earth's troposphere and is a crucial focus for scientific research. This study aimed to analyze the composition, diversity, distribution, and spatiotemporal characteristics of airborne microbes in Qatar's ambient air. Air samples were collected using a sampler from ten geographically or functionally distinct locations during a period of one year. Spatial and seasonal variations significantly impacted microbial concentrations, with the highest average concentrations observed at 514 ± 77 CFU/m3 for bacteria over the dry-hot summer season and 134 ± 31 CFU/m3 for fungi over the mild winter season. Bacterial concentrations were notably high in 80% of the locations during the dry-hot summer sampling period, while fungal concentrations peaked in 70% of the locations during winter. The microbial diversity analysis revealed several health-significant bacteria including the genera Chryseobacterium, Pseudomonas, Pantoea, Proteus, Myroides, Yersinia, Pasteurella, Ochrobactrum, Vibrio, and fungal strains relating to the genera Aspergillus, Rhizopus Fusarium, and Penicillium. Detailed biochemical and microscopic analyses were employed to identify culturable species. The strongest antibiotic resistance (ABR) was observed during the humid-hot summer season, with widespread resistance to Metronidazole. Health risk assessments based on these findings indicated potential risks associated with exposure to high concentrations of specific bioaerosols. This study provides essential baseline data on the natural background concentrations of bioaerosols in Qatar, offering insights for air quality assessments and forming a basis for public health policy recommendations, particularly in arid regions.

Assessing the effectiveness of performic acid disinfection on effluents: focusing on bacterial abundance and diversity.

Poorly-treated wastewater harbors harmful microorganisms, posing risks to both the environment and public health. To mitigate this, it is essential to implement robust disinfection techniques in wastewater treatment plants. The use of performic acid (PFA) oxidation has emerged as a promising alternative, due to its powerful disinfection properties and minimal environmental footprint. While PFA has been used to inactivate certain microbial indicators, its potential to tackle the entire microbial community in effluents, particularly resistant bacterial strains, remains largely unexplored. The present study evaluates the efficacy of PFA disinfection on the microbial communities of a WWTP effluent, through microbial resistance mechanisms due to their membrane structure. The effluent microbiome was quantified and identified. The results showed that the number of damaged cells increases with CT, reaching a maximum for CT = 240 mg/L•min and plateauing around 60 mg/L•min, highlighting the optimal conditions for PFA-disinfection against microbial viability. A low PFA level with a 10-min contact time significantly affected the microbial composition. It is worth noting the sensitivity of several bacterial genera such as Flavobacterium, Pedobacter, Massilia, Exiguobacterium, and Sphingorhabdus to PFA, while others, Acinetobacter, Leucobacter, Thiothrix, Paracoccus, and Cloacibacterium, showed resistance. The results detail the resistance and sensitivity of bacterial groups to PFA, correlated with their Gram-positive or Gram-negative membrane structure. These results underline PFA effectiveness in reducing microbial levels and remodeling bacterial composition, even with minimal concentrations and short contact times, demonstrating its suitability for widespread application in WWTPs.

Control of inorganic and organic phosphorus molecules on microbial activity, and the stoichiometry of nutrient cycling in soils in an arid, agricultural ecosystem.

Background: The dynamics of carbon (C), nitrogen (N), and phosphorus (P) in soils determine their fertility and crop growth in agroecosystems. These dynamics depend on microbial metabolism, which in turn depends on nutrient availability. Farmers typically apply either mineral or organic fertilizers to increase the availability of nutrients in soils. Phosphorus, which usually limits plant growth, is one of the most applied nutrients. Our knowledge is limited regarding how different forms of P impact the ability of microbes in soils to produce the enzymes required to release nutrients, such as C, N and P from different substrates. Methods: In this study, we used the arable layer of a calcareous soil obtained from an alfalfa cropland in Cuatro Cienegas, México, to perform an incubation experiment, where five different phosphate molecules were added as treatments substrates: three organic molecules (RNA, adenine monophosphate (AMP) and phytate) and two inorganic molecules (calcium phosphate and ammonium phosphate). Controls did not receive added phosphorus. We measured nutrient dynamics and soil microbial activity after 19 days of incubation. Results: Different P molecules affected potential microbial C mineralization (CO2-C) and enzyme activities, specifically in the organic treatments. P remained immobilized in the microbial biomass (Pmic) regardless of the source of P, suggesting that soil microorganisms were limited by phosphorus. Higher mineralization rates in soil amended with organic P compounds depleted dissolved organic carbon and increased nitrification. The C:N:P stoichiometry of the microbial biomass implied a change in the microbial community which affected the carbon use efficiency (CUE), threshold elemental ratio (TER), and homeostasis. Conclusion: Different organic and inorganic sources of P affect soil microbial community structure and metabolism. This modifies the dynamics of soil C, N and P. These results highlight the importance of considering the composition of organic matter and phosphate compounds used in agriculture since their impact on the microbial activity of the soil can also affect plant productivity.

Antimicrobial potential of Streptomyces sp. NP73 isolated from the forest soil of Northeast India against multi-drug resistant Escherichia coli.

This study reports the isolation and characterization of a Streptomyces sp. from soil, capable of producing bioactive secondary metabolites active against a variety of bacterial human pathogens. We targeted the antimicrobial activity against Escherichia coli ATCC-BAA 2469, a clinically relevant strain of bacteria harbouring resistance genes for carbapenems, extended spectrum beta-lactams, tetracyclines, fluoroquinones, etc. Preliminary screening using the spot inoculation technique identified Streptomyces sp. NP73 as the potent strain among the 74 isolated Actinomycetia strain. 16S rRNA gene and whole genome sequencing (WGS) confirmed its taxonomical identity and helped in the construction of the phylogenetic tree. WGS revealed the predicted pathways and biosynthetic gene clusters responsible for producing various types of antibiotics including the isolated compound. Bioactivity guided fractionation and chemical characterization of the active fraction, carried out using liquid chromatography, gas chromatography-mass spectrometry, infra-red spectroscopy, and nuclear magnetic resonance spectroscopy, led to the tentative identification of the active compound as Pyrrolo[1,2-a] pyrazine-1,4-dione, hexahydro-, a diketopiperazine molecule. This compound exhibited excellent antimicrobial and anti-biofilm properties against E. coli ATCC-BAA 2469 with an MIC value of 15.64 µg ml-1, and the low cytotoxicity of the compound identified in this study provides hope for future drug development.

Imidacloprid Uptake and Accumulation in Lettuce Plant (Lactuca sativa L. var. longipolia) and Its Effects on Abundance of Microbial Communities in Cultivated and Non-Cultivated Arid Soil.

Systemic plant protection products, such as neonicotinoids (NIs), are capable of being translocated throughout a plant. Although NIs are less toxic to mammals, fish, and birds, their impact on microbial and non-target insects is of concern. This study investigates the uptake, translocation, and accumulation of the NI, imidacloprid (IMI), in romaine lettuce (Lactuca sativa L. var. longipolia). Exposing 15-day-old seedlings to "10 mg/L" of IMI, the effects on microbial communities in both cultivated (CS) and non-cultivated soil (NCS) were studied along with IMI translocation within plant tissues. The concentrations of IMI in soil varied temporally and between soil types after initial application, with a decrease from 2.0 and 7.7 mg/kg on the first day of sampling to 0.5 and 2.6 mg/kg on the final sampling day (day 35) for CS and NCS, respectively. The half-life of IMI soil was 10.7 and 72.5 days in CS and NCS, respectively, indicating that IMI degraded more quickly in CS, possibly due to smaller grain size, aeration, microbial degradation, and water flow. The accumulated concentrations of IMI in lettuce tissues ranged from 12.4 ± 0.2 and 18.7± 0.9 mg/kg in CS and NCS, respectively. The highest concentration of IMI was found in the shoots, followed by the roots, whereas the soil showed the lowest IMI residuals at the end of the trial. Soil bacteria and fungi were altered by the application of IMI, with a lower abundance index within the bacterial community, indicating a negative impact on the distribution of bacteria in the soil.

Microbial electrosynthesis from CO2 reaches productivity of syngas and chain elongation fermentations.

Carbon-based products are essential to society, yet producing them from fossil fuels is unsustainable. Microorganisms have the ability to take up electrons from solid electrodes and convert carbon dioxide (CO2) to valuable carbon-based chemicals. However, higher productivities and energy efficiencies are needed to reach a viability that can make the technology transformative. Here, we show how a biofilm-based microbial porous cathode in a directed flow-through electrochemical system can continuously reduce CO2 to even-chain C2-C6 carboxylic acids over 248 days. We demonstrate a threefold higher biofilm concentration, volumetric current density, and productivity compared with the state of the art. Most notably, the volumetric productivity (VP) resembles those achieved in laboratory-scale and industrial syngas (CO-H2-CO2) fermentation and chain elongation fermentation. This work highlights key design parameters for efficient electricity-driven microbial CO2 reduction. There is need and room to improve the rates of electrode colonization and microbe-specific kinetics to scale up the technology.

Enrichment of dissolved metal(loid)s and microbial organic matter during transit of a historic mine drainage system.

Water quality degradation by decommissioned mining sites is an environmental issue recognized globally. In the Ore mountains of Central Europe, a wide array of contaminants is released by abandoned under- and aboveground mining sites threatening the quantity and quality of surface and groundwater resources. Here, we focus on the less-explored internal pollution processes within these mines involving organic carbon and microorganisms in trace metal(loid)s mobilization processes. Over an 18-month period, we conducted hydrological and biogeochemical monitoring at the Reiche Zeche mine, a former lead-zinc-silver mine, in Germany, reaching 230 meters below ground, well below the critical zone. Our results show strong seasonal fluctuations in water availability, concentrations of metal(loid)s, pH, and dissolved organic matter (DOM) components across multiple depths. Excess metal(loid) presence during high flow conditions indicated mobilization behavior deviating from conservative dilution. Our findings reveal strong positive correlations between metal(loid) variability and pH (0.894), and between metal(loid) variability and the DOM fluorescent component C2 (-0.910), a proxy for microbial activity. Accordingly, the microbial processes may significantly contribute to the observed metal(loid) composition and fluxes. By elucidating the intricate roles of hydrological and biogeochemical factors in trace metal(loid) mobilization, our research offers a comprehensive framework for improving mine water management and remediation, potentially informing global environmental policies and sustainable mining practices.

COVID-19 pandemic-related drugs and microplastics from mask fibers jointly affect soil functions and processes.

The COVID-19 pandemic has led to an unprecedented increase in pharmaceutical drug consumption and plastic waste disposal from personal protective equipment. Most drugs consumed during the COVID-19 pandemic were used to treat other human and animal diseases. Hence, their nearly ubiquitous presence in the soil and the sharp increase in the last 3 years led us to investigate their potential impact on the environment. Similarly, the compulsory use of face masks has led to an enormous amount of plastic waste. Our study aims to investigate the combined effects of COVID-19 drugs and microplastics from FFP2 face masks on important soil processes using soil microcosm experiments. We used three null models (additive, multiplicative, and dominative models) to indicate potential interactions among different pharmaceutical drugs and mask MP. We found that the multiple-factor treatments tend to affect soil respiration and FDA hydrolysis more strongly than the individual treatments. We also found that mask microplastics when combined with pharmaceuticals caused greater negative effects on soil. Additionally, null model predictions show that combinations of high concentrations of pharmaceuticals and mask MP have antagonistic interactions on soil enzyme activities, while the joint effects of low concentrations of pharmaceuticals (with or without MP) on soil enzyme activities are mostly explained by null model predictions. Our study underscores the need for more attention on the environmental side effects of pharmaceutical contamination and their potential interactions with other anthropogenic global change factors.

Electric stimulation mitigated the mixed microplastic inhibition to anaerobic digestion during wastewater treatment.

The presence of mixed microplastics (MPs) in anaerobic wastewater treatment processes has been shown to impede fermentation performance by suppressing microbial activity. Microbial electrosynthesis (MES), with its extensive potential, offers a promising solution for refractory substances management and methane recovery, achieved through the enhancement of microbial metabolism and interspecies electron transfer. This study, therefore, delves into the functional impacts and the microbial response to MES in the remediation of wastewater contaminated with mixed-MPs. Results indicated that mixed-MPs could inhibit methane production (-52.38%) and substance removal (-26.59%), and MES could effectively mitigate this inhibitory effect (-22.86%, -19.01%). Concurrently, MES also boosts enzymatic activities pivotal for electron transfer, such as cytochrome c and nicotinamide adenine dinucleotide (NADH), as well as those linked to energy metabolism like adenosine triphosphate (ATP). Furthermore, MES bolsters microbial resistance to mixed-MPs, as evidenced by an increase in extracellular polymeric substances (EPS), albeit with a minor rise in reactive oxygen species (ROS) production and lactate dehydrogenase (LDH) release. Correspondingly, electric stimulation promoted the enrichment of functional microorganisms associated with fermentation, acetate production, electrogenesis, and methanogenesis, and stimulated elevated expression levels of genes related to methane metabolism. Notably, the Methanothrix-mediated acetoclastic pathway emerges as the predominant methanogenic route, succeeded by the Methanobacterium-driven hydrogenotrophic pathway. Lastly, the study underscores the supportive role of applied voltage and carriers in energy metabolism and substance transport, which are associated with methanogenesis. Overall, MES demonstrates efficacy in mitigating the biotoxicity induced by mixed-MPs exposure and in enhancing anaerobic wastewater treatment and methane recovery.

Electrochemical biofilter enhances performance of volatile organic compounds abatement.

An electrochemical biofilter (EBF) was developed for enhancing the removal of volatile organic compounds (VOCs) through current. The removal efficiency (RE) of toluene exhibited a notable increase of 15% while the biomass growth rate exhibited a corresponding decline of 46% under an optimal current intensity of 50 mA. Meanwhile, the efficacy of the EBF system was markedly enhanced upon the removal of n-hexane, styrene, dichloromethane, and diisobutylene. The results indicated that there was an 11% to 49% increase in RE and a 0% to 64% reduction in biomass growth rates under the influence of the current. The current stimulation inhibited the accumulation of microorganisms, thereby alleviating biofilm clogging. The relative abundance of gram-positive phyla, including Firmicutes and Actinobacteria, increased by 15% and 23%, respectively, while the traditionally dominant genera within the Proteobacteria phylum, such as Rhodococcus and Dokdonella, exhibited a decline. In addition, the presence of hydrogen peroxide, free chlorine, and superoxides in the leachate indicated that the oxidative reaction increased in EBF system. This study provides an attractive pathway for current stimulation to enhance degradation of VOCs and alleviate biofilm clogging.

Antimicrobial Potential of Pomegranate and Lemon Extracts Alone or in Combination with Antibiotics against Pathogens.

Amidst the growing concern of antimicrobial resistance as a significant health challenge, research has emerged, focusing on elucidating the antimicrobial potential of polyphenol-rich extracts to reduce reliance on antibiotics. Previous studies explored the antifungal effects of extracts as potential alternatives to conventional therapeutic strategies. We aimed to assess the antibacterial and antifungal effects of standardised pomegranate extract (PE) and lemon extract (LE) using a range of Gram-negative and Gram-positive bacteria and two yeast species. Additionally, we assessed the antimicrobial activities of common antibiotics (Ciprofloxacin, Imipenem, Gentamicin, and Ceftazidime), either alone or in combination with extracts, against Staphylococcus aureus and Escherichia coli. PE displayed substantial antibacterial (primarily bactericidal) and antifungal effects against most pathogens, while LE exhibited antibacterial (mostly bacteriostatic) and antifungal properties to a lesser extent. When compared with antibiotics, PE showed a greater zone of inhibition (ZOI) than Ciprofloxacin and Ceftazidime (p < 0.01) and comparable ZOI to Gentamicin (p = 0.4) against Staphylococcus aureus. However, combinations of either PE or LE with antibiotics exhibited either neutral or antagonistic effects on antibiotic activity against Staphylococcus aureus and Escherichia coli. These findings contribute to the existing evidence regarding the antimicrobial effects of PE and LE. They add to the body of research suggesting that polyphenols exert both antagonistic and synergistic effects in antimicrobial activity. This highlights the importance of identifying optimal polyphenol concentrations that can enhance antibiotic activity and reduce antibiotic resistance. Further in vivo studies, starting with animal trials and progressing to human trials, may potentially lead to recommendation of these extracts for therapeutic use.

Fertilization Type Differentially Affects Barley Grain Yield and Nutrient Content, Soil and Microbial Properties.

The use of artificial fertilizers follows the intensification of agricultural production as a consequence of population growth, which leads to soil depletion, loss of organic matter, and pollution of the environment and production. This can be overcome by increasing the use of organic fertilizers in agriculture. In the present study, we investigated the effect of using vermicompost, biochar, mineral fertilizer, a combination of vermicompost and mineral fertilizer, and an untreated control on alluvial-meadow soil on the development of fodder winter barley Hordeum vulgare L., Zemela cultivar. We used a randomized complete block design of four replications per treatment. Barley grain yield, number of plants, and soil and microbiological parameters were studied. We found statistically proven highest grain yield and grain protein values when applying vermicompost alone, followed by the combined treatment and mineral fertilizer. The total organic carbon was increased by 70.2% in the case of vermicompost and by 44% in the case of combined treatment, both compared to the control. Thus, soil microbiome activity and enzyme activities were higher in vermicompost treatment, where the activity of ß-glucosidase was 29.4% higher in respect to the control, 37.5% to the mineral fertilizer, and 24.5% to the combined treatments. In conclusion, our study found the best overall performance of vermicompost compared to the rest of the soil amendments.

Soil fertility and plant nutrition in an organic olive orchard after 5 years of amendment with compost, biochar or their blend.

The agronomic use of compost and biochar as soil amendments may exhibit contrasting results in terms of soil fertility and plant nutrition. The effects of the biennial application of biochar, compost and a blend of compost:biochar (90:10; % dw:dw) on the agronomical performance of an organically managed and well established 25-year-old olive orchard was assessed 5 years after the initial application. The agronomical evaluation was based on the assessment of the soil physical, chemical, and biological characteristics, and the assessment of the soil fertility by both crop production and nutritional status of the orchard, and the bioassay with olive plantlets. Biochar mainly benefited the physical properties (bulk density, total porosity, aeration, water retention capacity) of soil, especially in the top 0-5 cm. Compost and its blend with biochar improved microbial activity, soil nutritional status (increasing the content of soluble organic C, N, and P) and favoured the formation of aggregates in soil. The bioassay conducted with young plantlets confirmed the enhanced soil fertility status in the three amended treatments, particularly in the case of biochar and its blend with compost. However, this effect was not significantly observed in the adult plants after 5 years of application, reflecting the slow response of adult olive trees to changes in fertilization. Based on these results, alongside the desirable long-residence time of biochar in soil and the ready availability of compost, the blend of biochar with compost assayed in this study is defined as a valid strategy for preparing high quality soil organic amendments.

Study of alginate-encapsulated phycoerythrin in promoting the biological activity of synbiotic ice cream with Lactobacillus casei.

This study examines the effect of phycoerythrin (PE) from a cyanobacterial Nostoc strain encapsulated with alginate as a potential prebiotic to produce synbiotic ice cream products with Lactobacillus casei. It was found that the addition of the encapsulated PE affected, mostly favourably, the physicochemical properties, antioxidant activity, probiotic survival, volatile compound contents, and sensory acceptability of the synbiotic ice cream samples before and after aging at the freezing periods of one day to eight weeks. Thus, it confirms the prebiotic potential of PE for synbiotic ice creams with L. casei.

Sucralose Influences the Productive Performance, Carcass Traits, Blood Components, and Gut Microflora Using 16S rRNA Sequencing of Growing APRI-Line Rabbits.

This study investigated how sucralose influenced rabbit intestine and caecal microbial activity, blood parameters, growth performance, carcass characteristics, and digestibility. In total, 160 5-week-old rabbits from the APRI line weighing 563.29 gm were randomly assigned to four experimental groups with four replicates-5 males and 5 females in each. Four experimental groups were used, as follows: SUC1, SUC2, and SUC3 got 75, 150, and 300 mg of sucralose/kg body weight in water daily, while the control group ate a basal diet without supplements. The results showed that both the control and SUC1 groups significantly (p < 0.05) increased daily weight gain and final body weight. Sucralose addition significantly improved feed conversion ratio (p < 0.05) and decreased daily feed intake (gm/d). The experimental groups do not significantly differ in terms of mortality. Furthermore, nutrient digestibility was not significantly affected by sucralose treatment, with the exception of crud protein digestion, which was significantly reduced (p < 0.05). Additionally, without altering liver or kidney function, sucralose administration dramatically (p < 0.05) decreased blood serum glucose and triglyceride levels while increasing total lipids, cholesterol, and malonaldehyde in comparison to the control group. Furthermore, the addition of sucrose resulted in a significant (p < 0.05) increase in the count of total bacteria, lactobacillus, and Clostridium spp., and a decrease in the count of Escherichia coli. Further analysis using 16S rRNA data revealed that sucralose upregulated the expression of lactobacillus genes but not that of Clostridium or E. Coli bacteria (p < 0.05). Therefore, it could be concluded that sucralose supplementation for rabbits modifies gut microbiota and boosts beneficial bacteria and feed conversion ratios without side effects. Moreover, sucralose could decrease blood glucose and intensify hypercholesterolemia and should be used with caution for human consumption.

Effects of corn grain processing and phosphorus content in calf starters on intake, growth performance, nutrient digestibility, blood metabolites, and urinary purine derivatives.

Corn grain with a high phosphorus (P) content (mainly in the form of phytate-P) may need to be processed to improve the digestibility of nutrients for young calves. Processing corn grains can improve the accessibility of phytate-P to the rumen enzymes and increase the bioavailability of P, which benefits the growth and development of calves. The objective of this study was to investigate the effects of feeding starter diets with steam-flaked corn (SFC) compared with ground corn (GC) with 2 P contents of 0.4% and 0.7% DM basis on intake, growth performance, nutrient digestibility, blood metabolites and urinary purine derivatives in dairy calves. A total of 48 female Holstein dairy calves (3 d old; average initial weight 39.7 ± 3.9 kg) were randomly assigned to a 2 × 2 factorial arrangement of treatments (12 calves/treatment) in a randomized complete block design. The treatment groups were: 1) a starter diet of GC with 0.4% P (GC-0.4P); 2) a starter diet of GC with 0.7% P (GC-0.7P); 3) a starter diet of SFC with 0.4% P (SFC-0.4P); 4) a starter diet of SFC with 0.7% P (SFC-0.7P). Calves received 6 L/d of transition milk on d 2-3 and 5 L/d of whole milk on d 4-30, which was increased to 7 L/d on d 31-45, then decreased to 5 L/d on d 46-60 and reduced to a single feeding of 2 L on d 61-62. All calves had free access to starter feed and water. All calves were weaned on d 63 and remained in the study until d 83. Rumen fluid samples were collected on d 38 (pre-weaning) and d 76 (post-weaning). Blood samples were collected on d 40 and 80 and urine samples were collected on 4 consecutive days from d 79 to 82 to analyze urinary excretion of PD. The phytate-P content ranged from 0.23 to 0.17 for GC and SFC, respectively. In particular, the interaction between corn processing method and P content showed that the SFC-0.7P diets had a greater intake of starter feed during the pre- and post-weaning periods compared with the other experimental groups. In addition, calves fed the SFC-0.7P diet had greater average daily gain, body weight, withers height at weaning, better organic matter digestibility, higher blood ß-hydroxybutyrate levels and higher microbial protein synthesis compared with all other groups. Feeding the SFC diet also resulted in improved feed efficiency, improved P digestibility and a tendency toward a lower rumen pH, albeit with a tendency toward an increase in blood glucose concentration during the pre-weaning period. In addition, the inclusion of 0.7% P to the starter diet resulted in increased fiber digestibility and a slight improvement in growth performance, which was particularly evident in hip height. Overall, the inclusion of SFC in the calf starter diet, especially in combination with a 0.7% DM basis P supplement, improved growth performance and nutrient utilization in dairy calves compared with GC.

Responses of soil organic carbon compounds to phosphorus addition between tropical monoculture and multispecies forests.

Tropical forests are sensitive to nitrogen (N) and phosphorus (P) availability, and under nutrient application the variation of soil organic carbon (SOC) preserving mechanism remains to be explored. To reveal the forest-specific SOC preservation via biochemical selection in response to nutrient application, we investigated a monoculture (Acacia plantation) and a multispecies forest both with chronic fertilization in subtropical regions, and measured specific fingerprints of plant- and microbial-derived C compounds. In addition, to quantify the effect of P application on SOC content among tropical forests, we conducted a meta-analysis by compiling 125 paired measurements in field experiments from 62 studies. In our field experiment, microbial community composition and activity mediated forest-specific responses of SOC compounds to P addition. The shift of community composition from fungi towards Gram-positive bacteria in the Acacia plantation by P addition led to the consumption of microbial residual C (MRC) as C source; in comparison, P addition increased plant species with less complex lignin substrates and induced microbial acquisition for N sources, thus stimulated the decomposition of both plant- and microbial-derived C. Same with our field experiment, bulk SOC content had neutral response to P addition among tropical forests in the meta-analysis, although divergences could happen among experimental durations and secondary tree species. Close associations among SOC compounds with biotic origins and mineral associated organic C (MAOC) in the multispecies forest suggested contributions of both plant- and microbial-derive C to SOC stability. Regarding that fungal MRC closely associated with MAOC and consisted of soil N pool which tightly coupled to SOC pool, the reduce of fungal MRC by chronic P addition was detrimental to SOC accumulation and stability in tropical forests.