[Effects of organic fertilizer from traditional Chinese medicine residues on growth and soil microbial community of Salvia miltiorrhiza by metagenomic technique].

Soil microbiome is a key evaluation index of soil health. Previous studies have shown that organic fertilizer from traditional Chinese medicine(TCM)residues can improve the yield and quality of cultivated traditional Chinese medicinal materials. However, there are few reports on the effects of organic fertilizer from TCM residues on soil microbiome. Therefore, on the basis of evaluating the effects of organic fertilizer from TCM residues on the yield and quality of cultivated Salvia miltiorrhiza, the metagenomic sequencing technique was used to study the effects of organic fertilizer from TCM residues on rhizosphere microbiome community and function of cultivated S. miltiorrhiza. The results showed that:(1) the application of organic fertilizer from TCM residues promoted the growth of S. miltiorrhiza and the accumulation of active components, and the above-ground and underground dry weight and fresh weight of S. miltiorrhiza increased by 371.4%, 288.3%, 313.4%, and 151.9%. The increases of rosmarinic acid and salvianolic acid B were 887.0% and 183.0%.(2)The application of organic fertilizer from TCM residues significantly changed the rhizosphere bacterial and fungal community structures, and the microbial community composition was significantly different.(3)The relative abundance of soil-beneficial bacteria, such as Nitrosospira multiformis, Bacillus subtilis, Lysobacter enzymogenes, and Trichoderma was significantly increased by the application of organic fertilizer from TCM residues.(4)KEGG function prediction analysis showed that metabolism-related microorganisms were more easily enriched in the soil environment after organic fertilizer application. The abundance of functional genes related to nitrification and denitrification could also be increased after the application of organic fertilizer from TCM residues. The results of this study provide guidance for the future application of organic fertilizer from TCM residues in the cultivation of traditio-nal Chinese medicinal materials and enrich the content of green cultivation technology of traditional Chinese medicinal materials.

Christensenella minuta interacts with multiple gut bacteria.

Introduction: Gut microbes form complex networks that significantly influence host health and disease treatment. Interventions with the probiotic bacteria on the gut microbiota have been demonstrated to improve host well-being. As a representative of next-generation probiotics, Christensenella minuta (C. minuta) plays a critical role in regulating energy balance and metabolic homeostasis in human bodies, showing potential in treating metabolic disorders and reducing inflammation. However, interactions of C. minuta with the members of the networked gut microbiota have rarely been explored. Methods: In this study, we investigated the impact of C. minuta on fecal microbiota via metagenomic sequencing, focusing on retrieving bacterial strains and coculture assays of C. minuta with associated microbial partners. Results: Our results showed that C. minuta intervention significantly reduced the diversity of fecal microorganisms, but specifically enhanced some groups of bacteria, such as Lactobacillaceae. C. minuta selectively enriched bacterial pathways that compensated for its metabolic defects on vitamin B1, B12, serine, and glutamate synthesis. Meanwhile, C. minuta cross-feeds Faecalibacterium prausnitzii and other bacteria via the production of arginine, branched-chain amino acids, fumaric acids and short-chain fatty acids (SCFAs), such as acetic. Both metagenomic data analysis and culture experiments revealed that C. minuta negatively correlated with Klebsiella pneumoniae and 14 other bacterial taxa, while positively correlated with F. prausnitzii. Our results advance our comprehension of C. minuta's in modulating the gut microbial network. Conclusions: C. minuta disrupts the composition of the fecal microbiota. This disturbance is manifested through cross-feeding, nutritional competition, and supplementation of its own metabolic deficiencies, resulting in the specific enrichment or inhibition of the growth of certain bacteria. This study will shed light on the application of C. minuta as a probiotic for effective interventions on gut microbiomes and improvement of host health.

Core Soil Microorganisms and Abiotic Properties as Key Mechanisms of Complementary Nanoscale Zerovalent Iron and Nitrification Inhibitors in Decreasing Paclobutrazol Residues and Nitrous Oxide Emissions.

Agrochemical residues and nitrous oxide (N2O) emissions have caused considerable threats to agricultural soil ecology. Nanoscale zerovalent iron (nZVI) and nitrification inhibitors might be complementary to each other to diminish soil agrochemical residues and N2O emissions and enhance soil bacterial community diversities. Compared to the control, the nZVI application declined soil paclobutrazol residues by 5.9% but also decreased the bacterial community co-occurrence network node. Combined nZVI and Dicyandiamide applications significantly decreased soil N2O emission rates and paclobutrazol residues but promoted Shannon diversity of the bacterial community. The increased soil pH, ammonium nitrogen, and Actinobacteriota could promote soil paclobutrazol dissipation. The nZVI generated double-edged sword effects of positively decreasing paclobutrazol residues and N2O emissions but negatively influencing soil multifunctionalities. The nZVI and Dicyandiamide could be complementary to each other in diminishing soil agrochemical residues and N2O emission rates but promoting soil bacterial community diversities simultaneously.

Microbial regulation of plant secondary metabolites: Impact, mechanisms and prospects.

Plant secondary metabolites possess a wide range of pharmacological activities and play crucial biological roles. They serve as both a defense response during pathogen attack and a valuable drug resource. The role of microorganisms in the regulation of plant secondary metabolism has been widely recognized. The addition of specific microorganisms can increase the synthesis of secondary metabolites, and their beneficial effects depend on environmental factors and plant-related microorganisms. This article summarizes the impact and regulatory mechanisms of different microorganisms on the main secondary metabolic products of plants. We emphasize the mechanisms by which microorganisms regulate hormone levels, nutrient absorption, the supply of precursor substances, and enzyme and gene expression to promote the accumulation of plant secondary metabolites. In addition, the possible negative feedback regulation of microorganisms is discussed. The identification of additional unknown microbes and other driving factors affecting plant secondary metabolism is essential. The prospects for further analysis of medicinal plant genomes and the establishment of a genetic operation system for plant secondary metabolism research are proposed. This study provides new ideas for the use of microbial resources for biological synthesis research and the improvement of crop anti-inverse traits for the use of microbial resources.

Spatial distribution characteristics and degradation mechanism of microorganisms in n-hexadecane contaminated vadose zone.

The damage caused by petroleum hydrocarbon pollution to soil and groundwater environment is becoming increasingly significant. The vadose zone is the only way for petroleum hydrocarbon pollutants to leak from surface into groundwater. The spatial distribution characteristics of indigenous microorganisms in vadose zone, considering presence of capillary zones, have rarely been reported. To explore the spatial distribution characteristics of indigenous microorganisms in vadose zone contaminated by petroleum hydrocarbons, a one-dimensional column migration experiment was conducted using n-hexadecane as characteristic pollutant. Soil samples were collected periodically from different heights during experiment. Corresponding environmental factors were monitored online. The microbial community structure and spatial distribution characteristics of the cumulative relative abundance were systematically analyzed using 16S rRNA sequencing. In addition, the microbial degradation mechanism of n-hexadecane was analyzed using metabolomics. The results showed that presence of capillary zone had a strong retarding effect on n-hexadecane infiltration. Leaked pollutants were mainly concentrated in areas with strong capillary action. Infiltration and displacement of NAPL-phase pollutants were major driving force for change in moisture content (θ) and electric conductivity (EC) in vadose zone. The degradation by microorganisms results in a downward trend in potential of hydrogen (pH) and oxidation-reduction potential (ORP). Five petroleum hydrocarbon-degrading bacterial phyla and 11 degradable straight-chain alkane bacterial genera were detected. Microbial degradation was strong in the area near edge of capillary zone and locations of pollutant accumulation. Mainly Sphingomonas and Nocardioides bacteria were involved in microbial degradation of n-hexadecane. Single-end oxidation involved microbial degradation of n-hexadecane (C16H34). The oxygen consumed, hexadecanoic acid (C16H32O2) produced during this process, and release of hydrogen ions (H+) were the driving factors for reduction of ORP and pH. The vadose zone in this study considered presence of capillary zone, which was more in line with actual contaminated site conditions compared with previous studies. This study systematically elucidated vertical distribution characteristics of petroleum hydrocarbon pollutants and spatiotemporal variation characteristics of indigenous microorganisms in vadose zone considered presence of capillary zone. In addition, the n-hexadecane degradation mechanism was elucidated using metabolomics. This study provides theoretical support for development of natural attenuation remediation measures for petroleum-hydrocarbon-contaminated soil and groundwater.

Ferric- and calcium-loaded red soil assist colonization of submerged macrophyte for the in-situ remediation of eutrophic shallow lake: From mesocosm experiment to field enclosure application.

Eutrophication and its resulting harmful algal blooms greatly reduce the ecosystem services of natural waters. The use of modified clay materials to assist the phytoremediation of eutrophic water is a promising technique. In this study, ferric chloride and calcium hydroxide were respectively loaded on red soil for algal flocculation and phosphorus inactivation. A two-by-two factorial mesocosm experiment with and without the application of ferric- and calcium- loaded red soil (FA), and with and without planting the submerged macrophyte Vallisneria natans was conducted for the in-situ repair of eutrophic water and sediment. Furthermore, field enclosure application was carried out to verify the feasibility of the technology. At the end of the mesocosm experiment, the total phosphorus, total nitrogen, and ammonia nitrogen concentrations in water were reduced by 81.8 %, 63.3 %, and 62.0 %, respectively, and orthophosphate phosphorus concentration in the sediment-water interface decreased by 90.2 % in the FA + V. natans group compared with those in the control group. The concentration and proportion of chlorophyll-a in cyanobacteria decreased by 89.8 % and 71.2 %, respectively, in the FA + V. natans group. The content of active phosphorus in V. natans decreased and that of inert phosphorus increased in the FA + V. natans group, compared with those in the V. natans alone group, thus may reducing the risk of phosphorus release after decomposing of V. natans. The sediment bacterial diversity index did not change significantly among treatments. Field enclosure application have also been successful, with chlorophyll-a concentration in the water of treated enclosure decreased from above 200 µg/L to below 10 µg/L, and phosphorus concentration in the water decreased from >0.6 mg/L to <0.02 mg/L. These results demonstrated that the FA in combination with submerged macrophyte planting had great potential for the in-situ remediation of eutrophic water, especially those with severe algal blooms.

Efficacy of epigallocatechin gallate (EGCG) and its underlying mechanism in preventing bisphenol-A-induced metabolic disorders in mice.

To investigate the efficacy of epigallocatechin gallate (EGCG) and its underlying mechanism in preventing bisphenol-A-induced metabolic disorders, in this study, a mice model of metabolic disorders induced by BPA was developed to investigate the efficacy and mechanism of EGCG using microbiomes and metabolomics. The results showed that EGCG reduced body weight, liver weight ratio, and triglyceride and total cholesterol levels in mice by decreasing the mRNA expression of genes related to fatty acid synthesis (Elov16) and cholesterol synthesis (CYP4A14) and increasing the mRNA expression of genes related to fatty acid oxidation (Lss) and cholesterol metabolism (Cyp7a1). In addition, EGCG normalized BPA-induced intestinal microbial dysbiosis. Metabolic pathway analysis showed that low-dose EGCG was more effective than high-dose EGCG at affecting the biosynthesis of L-cysteine, glycerophosphorylcholine, and palmitoleic acid. These results provide specific data and a theoretical basis for the risk assessment of BPA and the utilization of EGCG.

Response of antioxidant activity, active constituent and rhizosphere microorganisms of Salvia miltiorrhiza to combined application of microbial inoculant, microalgae and biochar under Cu stress.

Salvia miltiorrhiza, a widely used medicinal herb renowned for its properties in promoting blood circulation, removing blood stasis and alleviating pain, is currently facing quality degradation due to excessive heavy metal levels, posing a threat to medication safety. In order to investigate the effects of microbial inoculant, microalgae and biochar on the growth of Salvia miltiorrhiza under copper (Cu) stress, as well as its Cu absorption, antioxidant activity, active component contents and rhizosphere microbial community, a pot experiment was conducted. Salvia miltiorrhiza plants were cultivated in the soil containing 400 mg/kg of Cu for six months and treated with microbial inoculant, microalgae and biochar, either individually or in combination. Almost all soil amendment treatments led to an increase in root biomass. Notably, co-application of microbial inoculant and microalgae had the optimal effect with a 63.07 % increase compared to the group treated solely with Cu. Moreover, when microbial inoculant was applied alone or in combination with microalgae, the Cu content in plant roots was reduced by 19.29 % and 25.37 %, respectively, whereas other treatments failed to show a decreasing trend. Intriguingly, Cu stress increased the active component contents in plant roots, and they could also be enhanced beyond non-stress levels when microbial inoculant and microalgae were applied together or in combination with biochar. Analyses of plant antioxidant activity, soil properties and rhizosphere microorganisms indicated that these amendments may alleviate Cu stress by enhancing peroxidase activity, facilitating plant nutrient absorption, and enriching beneficial microorganisms capable of promoting plant growth and mitigating heavy metal-induced damage. This study suggests that the combined application of microbial inoculant and microalgae can reduce Cu levels in Salvia miltiorrhiza while enhancing its quality under Cu stress.

Microbial community interactions determine the mineralization of soil organic phosphorus in subtropical forest ecosystems.

In subtropical forest ecosystems with few phosphorus (P) inputs, P availability and forest productivity depend on soil organic P (Po) mineralization. However, the mechanisms by which the microbial community determines the status and fate of soil Po mineralization remain unclear. In the present study, soils were collected from three typical forest types: secondary natural forest (SNF), mixed planting, and monoculture forest of Chinese fir. The P fractions, Po-mineralization ability, and microbial community in the soils of different forest types were characterized. In addition, we defined Po-mineralizing taxa with the potential to interact with the soil microbial community to regulate Po mineralization. We found that a higher labile P content persisted in SNF and was positively associated with the Po-mineralization capacity of the soil microbial community. In vitro cultures of soil suspensions revealed that soil Po mineralization of three forest types was distinguished by differences in the composition of fungal communities. We further identified broad phylogenetic lineages of Po-mineralizing fungi with a high intensity of positive interactions with the soil microbial community, implying that the facilitation of Po-mineralizing taxa is crucial for soil P availability. Our dilution experiments to weaken microbial interactions revealed that in SNF soil, which had the highest interaction intensity of Po-mineralizing taxa with the community, Po-mineralization capacity was irreversibly lost after dilution, highlighting the importance of microbial diversity protection in forest soils. In summary, this study demonstrates that the interactions of Po-mineralizing microorganisms with the soil microbial community are critical for P availability in subtropical forests.IMPORTANCEIn subtropical forest ecosystems with few phosphorus inputs, phosphorus availability and forest productivity depend on soil organic phosphorus mineralization. However, the mechanisms by which the microbial community interactions determine the mineralization of soil organic phosphorus remain unclear. In the present study, soils were collected from three typical forest types: secondary natural forest, mixed planting, and monoculture forest of Chinese fir. We found that a higher soil labile phosphorus content was positively associated with the organic phosphorus mineralization capacity of the soil microbial community. Soil organic phosphorus mineralization of three forest types was distinguished by the differences in the composition of fungal communities. The positive interactions between organic phosphorus-mineralizing fungi and the rest of the soil microbial community facilitated organic phosphorus mineralization. This study highlights the importance of microbial diversity protection in forest soils and reveals the microbial mechanism of phosphorus availability maintenance in subtropical forest ecosystems.

Study on the ameliorative effect of honeysuckle on DSS-induced ulcerative colitis in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Honeysuckle, first documented in the Miscellaneous Records of Famous Physicians, is known for its ability to expel toxin and cool blood to stop diarrhea. Modern pharmacological research has shown that honeysuckle has anti-inflammatory, antibacterial, antioxidant, and immune-regulating effects and is widely used in clinical practice. However, the effect of honeysuckle on ulcerative colitis (UC) is still not fully understood, which presents challenges for quality control, research and development. AIM OF THE STUDY: This study aimed to determine the anti-inflammatory properties and mechanism of action of aqueous extracts of honeysuckle in the treatment of ulcerative colitis. MATERIALS AND METHODS: The dextran sodium sulfate (DSS) induced-ulcerative colitis mouse model was established, and the mice were divided into five groups: the control group, the model group, and the low, medium, and high dose honeysuckle treatment groups. RESULTS: All dose groups of honeysuckle were found to significantly reduce IL-6 and TNF-α levels and regulate DSS-induced mRNA levels of CLDN4, COX-2, IL-6, INOS, MUC-2, occludin and NLRP3. The high-dose group displayed the most effective inhibition, and a differentially expressed mRNA detection indicated abnormal mRNA expression. The 16sRNA sequencing revealed that the honeysuckle was able to significantly upregulate the abundance of beneficial bacteria and downregulate the abundance of harmful bacteria. The study of short-chain fatty acids revealed that the levels of acetic, propionic, isobutyric, valeric and isovaleric acids were significantly increased after administering honeysuckle at medium and high doses. CONCLUSION: Honeysuckle reduces the production of pro-inflammatory cytokines, increases the content of short-chain fatty acids and restores the intestinal ecological balance, resulting in better therapeutic effects.

Combining dredging with modified zeolite thin-layer capping to control nitrogen release from eutrophic lake sediment.

Dredging is widely used to control internal sediment nitrogen (N) pollution during eutrophic lake restoration. However, the effectiveness of dredging cannot be maintained for long periods during seasonal temperature variations. This study used modified zeolite (MZ) as a thin-layer capping material to enhance dredging efficiency during a year-long field sediment core incubation period. Our results showed that dredging alone more effectively reduced pore water N, N flux, and sediment N content than MZ capping but showed more dramatic changes during the warm seasons. The N flux in dredged sediment in summer was 1.8 and 2.5 times that in spring and autumn, respectively, indicating a drastic N regeneration process in the short term. In contrast, the combination method reduced the extra 10% pore water N, 22% N flux, and 8% sediment organic N content compared with dredging alone and maintained high stability during seasonal changes. The results indicated that the addition of MZ to the surface of dredged sediment not only enhanced the control effect of dredging by its adsorption capacity but may also smooth the N regeneration process via successive accumulation (in the channel of the material) and activation of bacteria for months, which was evidenced by the variation in microbial diversity in the MZ treatment. As a result, the combination of dredging with modified zeolite simultaneously enhanced the efficiency and stability of the single dredging method in controlling sediment N content and its release, exhibiting great prospects for long-term application in eutrophic lakes with severe pollution from internal N loading.

Isolation of hitherto-uncultivated microorganisms- Application of radical scavengers.

The culture filtrates of the predominant bacterial strains isolated from soil samples have been shown to increase the microbial colony counts on agar plates used for the isolation of uncultured bacteria. One of the factors in the culture filtrates responsible for this increase was identified to be superoxide dismutase (SOD). The generation of reactive oxygen species (O2-, H2O2, and ・OH) was detected from conventional laboratory agar media. The use of agar media supplemented with radical scavengers (SOD, catalase, ascorbic acid, or rutin) effectively increased the colony counts and kinds of microbial strains that grew from soil samples. Taxonomical studies on these isolates revealed new taxa for phylum Actinomycetota; one family, three genera, and nine species were newly described. One of the strains, Patulibacter minatonensis KV-614T belonging to the new family Patulibacteraceae, was isolated on agar medium supplemented with SOD. P. minatonensis KV-614T represents a novel lineage within the phylum Actinomycetota. A polymerase chain reaction (PCR) study using specific primers for the detection of strains related to the genus Patulibacter, order Solirubrobacterales, showed a high distribution frequency, with detection in over 70% of the soil samples tested. These data suggest that the use of radical scavengers may facilitate the isolation of some hitherto-uncultivated microorganisms widely distributed in soil.

Effect of white jade snail secretion on antioxidant capacity and intestinal microbial diversity in mouse model of acute gastric ulcer.

BACKGROUND: In the present work, acute gastric ulcer models were constructed by administering hydrochloric acid/ethanol. The mice ingested white jade snail secretion (WJSS) through gastric infusion. Ulcer areas in gastric tissue were recorded, and malondialdehyde (MDA) and superoxide dismutase (SOD) were also measured. Notably, high-throughput 16S rDNA analysis of intestinal flora and determination of amino acid composition in feces were performed to understand the effect of WJSS on model mice. RESULTS: Compared with the control group, the ulcer area in the WJSS low-, medium- and high-concentration groups declined by 28.02%, 39.57% and 77.85%, respectively. MDA content decreased by 24.71%, 49.58% and 64.25%, and SOD relative enzyme activity fell by 28.19%, 43.37% and 9.60%, respectively. The amounts of amino acids in the low-, medium- and high-concentration groups were slightly lower, and probiotic bacteria such as Bacteroidetes and Lactobacillales increased in different-concentration WJSS groups. Adding WJSS contributes to the establishment of beneficial intestinal flora and the absorption of amino acids. CONCLUSION: Our results showed that WJSS has a beneficial effect on inhibiting hydrochloric acid-ethanolic gastric ulcers, suggesting that WJSS has excellent potential as a novel anti-ulcer agent. Combined with ulcer area, MDA content, SOD content, gut probiotics and other indicators, a high concentration of WJSS had the best protective effect on acute gastric ulcer. © 2023 Society of Chemical Industry.

Phosphorus fertiliser application mitigates the negative effects of microplastic on soil microbes and rice growth.

Soil microplastics (MPs) have attracted widespread attention recently. Most studies have explored how soil MPs affect the soil's physicochemical parameters, matter circulation, and soil microbial community assembly. Similarly, a key concern in agricultural development has been the use of phosphorus (P) fertiliser, which is essential for plant health and development. However, the relationship between MPs and phosphate fertilisers and their effects on the soil environment and plant growth remains elusive. This study assessed the influence of adding low-density polyethylene MPs (1%) with different phosphate fertiliser application rates on microbial communities and rice biomass. Our results showed that MPs changed the structure of soil bacterial and phoD-harbouring microbial communities in the treatment with P fertiliser at the same level and suppressed the interactions of phoD-harbouring microorganisms. In addition, we found that MPs contamination inhibited rice growth; however, the inclusion of P fertiliser in MP-contaminated soils reduced the inhibitory action of MPs on rice growth, probably because the presence with P fertiliser promoted the uptake of NO3--N by rice in MP-contaminated soils. Our results provide further insights into guiding agricultural production, improving agricultural management, and rationally applying phosphate fertilisers in the context of widespread MPs pollution and global P resource constraints.

[Functional Genomics Analysis of Nitrogen and Phosphorus Transformation in Maize Rhizosphere Microorganisms].

Fertilizer reduction and efficiency improvement is an important basis for ensuring the safety of the agricultural ecological environment. Microorganisms are the key driving force for regulating the soil nitrogen and phosphorus cycle. Studying the nitrogen and phosphorus transformation function of rhizosphere microorganisms can provide a microbiological regulation approach for further improving the use efficiency of soil nitrogen and phosphorus. Based on the field micro-plot experiments of three typical farmland soils(phaeozem, cambisol, and acrisol), metagenomic sequencing technology was used to study the differences in functional genes and regulatory factors of maize rhizosphere microorganisms during soil nitrogen and phosphorus transformation. The results showed that the functional diversity of maize rhizosphere microorganisms was affected by soil type. The functional diversity of rhizosphere microorganisms in phaeozem and cambisol was mainly affected by water content and nutrient content, and that in acrisol was affected by total phosphorus(TP) and available phosphorus(AP). For soil nitrogen transformation, the gene abundance of related enzymes in the pathway of nitrogen transformation was the highest in the urease gene(ureC) and glucose dehydrogenase gene(gdh), which were 7.25×10-5-12.88×10-5 and 4.47×10-5-7.49×10-5, respectively. The total abundance of assimilatory nitrate reduction functional genes in acrisol was higher than that in phaeozem and cambisol, and the total abundance of functional genes related to other processes was the highest in cambisol. The abundance of functional genes encoding enzymes related to nitrogen metabolism was mainly driven by soil bacterial richness, total potassium(TK), and TP. For soil phosphorus transformation, the number of alkaline phosphatase genes(phoD) catalyzing organic phosphorus mineralization was 1093, and the number of acid phosphatase genes(PHO) was 42. The abundance of phoD was two orders of magnitude higher than that of PHO. In addition, fertilization had no significant effect on the abundance of phoD and PHO in the same soil type. Random forest analysis showed that the abundances of phoD and PHO were significantly affected by soil moisture, organic matter(OM), and total nitrogen(TN), but AP content had the greatest impact on PHO abundance. These results clarified the nitrogen and phosphorus transformation characteristics of maize rhizosphere microorganisms at the functional genomic level and enriched the molecular biological mechanism of the microbial nitrogen and phosphorus transformation function.

Anti-quorum Sensing of Terminalia catappa and Murraya koenigii Against Streptococcus mutans.

Introduction Dental biofilm constitutes micro-organisms existing in an intercellular matrix containing organic and inorganic materials derived from saliva, gingival crevicular fluid, and bacterial products. Dental plaque biofilm inhibition by certain herbs and medicinal plants has been used as a treatment modality for the prevention of white spot lesions in orthodontic subjects. The aim of this study was to evaluate the anti-quorum sensing and anti-biofilm activity of Terminalia catappa and Murraya koenigiiagainst Streptococcus mutans. Materials and methods Samples of dental plaque were taken from patients receiving orthodontic care. The colonies of the S. mutans were isolated and biochemical characterization was done. Leaf extracts of Terminalia catappa and Murraya koenigii were used in the study. Methanolic extracts were subjected to evaluation of minimum inhibitory concentration (MIC) using the broth microdilution (two-fold) method and anti-biofilm activity using the crystal violet staining method. Results  The MIC of methanol leaf extracts of Murraya koenigii against S. mutans was noted at 0.62 mg/ml and Terminalia catappa at 1.25 mg/ml. At the lowest concentration of 0.03 mg and 0.01 mg methanol extract of Murraya koenigii had remarkably inhibited biofilm formation of 57.6% and 43.6% against S. mutans, respectively. Terminalia catappa leaf extracts did not show any anti-biofilm activity when the organisms were grown in the presence of S. mutans. Conclusion  Both Murraya koenigii and Terminalia catappa had antibacterial effects against S. mutans and Murray koenigii remarkably inhibited biofilm formation by S. mutans.

Yeast culture repairs rumen epithelial injury by regulating microbial communities and metabolites in sheep.

This study delves into the impact of yeast culture (YC) on rumen epithelial development, microbiota, and metabolome, with the aim of investigating YC's mechanism in regulating rumen fermentation. Thirty male lambs of Hu sheep with similar age and body weight were selected and randomly divided into three groups with 10 lambs in each group. Lambs were fed a total mixed ration [TMR; rough: concentrate (R:C) ratio ≈ 30:70] to meet their nutritional needs. The experiment adopted completely randomized design (CRD). The control group (CON) was fed the basal diet with high concentrate, to which 20 g/d of YC was added in the low dose YC group (LYC) and 40 g/d of YC in the high dose YC group (HYC). The pretrial period was 14 days, and the experimental trial period was 60 days. At the end of a 60-day trial, ruminal epithelial tissues were collected for histomorphological analysis, and rumen microorganisms were analyzed by 16S rDNA sequencing and rumen metabolites by untargeted liquid chromatography-mass spectrometry (LC-MS) metabolomics techniques. The results showed that YC improved rumen papilla development and increased rumen papilla length (p < 0.05), while decreased cuticle thickness (p < 0.05). The 16S rDNA sequencing results showed that YC reduced the relative abundance of Prevotella_1 (p < 0.05), while significantly increased the relative abundance of Ruminococcaceae_UCG-005, uncultured_bacterium_f_Lachnospiraceae, and Ruminococcus_1 genus (p < 0.05). Metabolomics analysis showed that YC changed the abundance of metabolites related to amino acid metabolism, lipid metabolism and vitamin metabolism pathways in the rumen. In summary, YC might maintain rumen health under high-concentrate diet conditions by changing rumen microbiota structure and fermentation patterns, thereby affecting rumen metabolic profiles and repairing rumen epithelial injury.

Microorganism Test on Biscuits Combined With Red Algae Extract (Eucheuma denticulatum) and Tempeh (Glycine max).

<b>Background and Objective:</b> Biscuits are snacks that are widely circulated in the market but do not meet Indonesian National standards so they are harmful to consumer health. This study aims to determine the total plate count (TPC) value of bacteria and mold/yeast and determine the presence or absence of bacterial contamination of <i>Staphylococcus aureus </i>and <i>Escherichia coli</i> in biscuit products. <b>Materials and Methods:</b> This study is descriptive in nature using three different sample types. Total plate count (TPC) value testing was carried out using the pour plate method. Meanwhile, to determine the presence or absence of <i>Staphylococcus aureus</i> bacteria using MSA (mannitol salt agar) media with the spread plate technique. The <i>Escherichia coli</i> test uses EMBA (eosin methylene blue agar) media with a streak plate technique. <b>Results:</b> Three samples of biscuit formula obtained ALT of bacteria in sample A) 2.2×10⁷ colonies/g, sample B) 1.9×10⁷ colonies/g and sample C) 4.1×10⁷ colonies/g. Mold/khamir obtained in sample A) 7.7×10⁵ colonies/g, sample B) 5.1×10⁶ colonies/g and sample C) 1.1×10⁶ colonies/g. In the <i>Staphylococcus aureus</i> bacteria test, the results were not overgrown with <i>Staphylococcus aureus</i> bacteria and in the <i>Escherichia coli</i> bacteria test, the results were easily purplish red in color. <b>Conclusion:</b> It can be concluded that only formula C samples meet the requirements of the SNI quality standards. In the pathogenic microbial test, there was no growth of <i>Staphylococcus aureus</i> and <i>Escherichia coli</i> microbes in the three biscuit formula samples.

A Review on Rhizosphere Microbiota of Tea Plant (Camellia sinensis L): Recent Insights and Future Perspectives.

Rhizosphere microbial colonization of the tea plant provides many beneficial functions for the host, But the factors that influence the composition of these rhizosphere microbes and their functions are still unknown. In order to explore the interaction between tea plants and rhizosphere microorganisms, we summarized the current studies. First, the review integrated the known rhizosphere microbial communities of tea tree, including bacteria, fungi, and arbuscular mycorrhizal fungi. Then, various factors affecting tea rhizosphere microorganisms were studied, including: endogenous factors, environmental factors, and agronomic practices. Finally, the functions of rhizosphere microorganisms were analyzed, including (a) promoting the growth and quality of tea trees, (b) alleviating biotic and abiotic stresses, and (c) improving soil fertility. Finally, we highlight the gaps in knowledge of tea rhizosphere microorganisms and the future direction of development. In summary, understanding rhizosphere microbial interactions with tea plants is key to promoting the growth, development, and sustainable productivity of tea plants.

Impact of nitrogen application and crop stage on epiphytic microbial communities on silage maize leaf surfaces.

This study aimed to examine the impact of nitrogen (N) fertilization on phyllosphere microorganisms in silage maize (Zea mays) to enhance the production of high-quality silage. The effects of different N application rates (160, 240, and 320 kg ha-1) and maturity stages (flowering and dough stages) on microbial diversity, abundance and physiochemical properties of the leaf surfaces were evaluated in a field experiment. The results showed that N application rates did not significantly impact the abundance of lactic acid bacteria (LAB), aerobic bacteria (AB), yeasts, or molds on the leaf surfaces. However, these microbes were more abundant during the flowering stage compared to the dough stage. Furthermore, the N application rate had no significant impact on inorganic phosphorus, soluble sugar, free amino acids, total phenolic content, and soluble protein concentrations, or pH levels on the leaf surfaces. Notably, these chemical indices were lower during the dough stage. The abundance of Pantoea decreased with higher N application rates, while that of other microorganisms did not changes significantly. The abundance of AB, LAB, yeasts, and molds were positively correlated with soluble sugar, soluble protein, inorganic phosphorus, free amino acids, and total phenolic concentrations on leaf surfaces. Moreover, water loss was negatively correlated with the abundance of AB, LAB, yeasts, and molds, whereas water retention capacity and stomatal density were positively correlated with microbial abundance. We recommend applying an optimal N rate of 160 kg ha-1 to silage maize and harvesting at the flowering stage is recommended.