Micro-ecological Environment Research Articles

A tale of two old drugs tetracycline and salicylic acid with new perspectives—Coordination chemistry of their Co(II) and Ni(II) complexes, redox activity of Cu(II) complex, and molecular interactions

Extensive use of the broad-spectrum tetracycline antibiotics (TCs) has resulted their wide spread in the environment and drive new microecological balances, including the infamous antibiotic resistance. TCs require metal ions for their antibiotic activity and resistance via interactions with ribosome and tetracycline repressor TetR, respectively, at specific metal-binding sites. Moreover, the Lewis-acidic metal center(s) in metallo-TCs can interact with Lewis-basic moieties of many bioactive secondary metabolites, which in turn may alter their associated chemical equilibria and biological activities. Thus, it is ultimately important to reveal detailed coordination chemistry of metallo-TC complexes. Herein, we report (a) conclusive specific Co2+, Ni2+, and Cu2+-binding of TC revealed by paramagnetic 1H NMR, showing different conformations of the coordination and different metal-binding sites in solution and solid state, (b) significant metal-mediated activity of Cu-TC toward catechol oxidation with different mechanisms by air and H2O2 (i.e., mono- and di-nuclear pathways, respectively), (c) interactions of metallo-TCs with bioactive salicylic acid and its precursor benzoic acid, and (d) noticeable change of TC antibiotic activity by metal and salicylic acid. The results imply that TCs may play broad and versatile roles in maintaining certain equilibria in microecological environments in addition to their well-established antibiotic activity. We hope the results may foster further exploration of previously unknown metal-mediated activities of metallo-TC complexes and other metalloantibiotics.

Faba bean-wheat intercropping controls the occurrence of faba bean Fusarium wilt by improving the microecological environment of rhizosphere soil

BackgroundFusarium wilt is a severe soil-borne disease that affects faba bean production. Faba bean-wheat intercropping is often used to control the occurrence of Fusarium wilt in faba bean. AimsTo evaluate the effects of faba bean-wheat intercropping on the occurrence of faba bean Fusarium wilt and soil microecology. MethodsWe established two planting patterns, faba bean monocropping (M) and faba bean-wheat intercropping (I), to investigate Fusarium wilt occurrence and plant dry weight and assess changes in soil enzyme activities, microbial diversity, and community composition during different stages of disease onset. ResultsIntercropping effectively controlled faba bean Fusarium wilt at the three disease stages and increased the dry weight of faba bean plants. Intercropping promoted the activities of catalase (CAT), urease, sucrase, and acid phosphatase in the rhizosphere soil of faba bean at three disease stages. Bacterial and fungal diversity decreased with disease progression, and intercropping mitigated this trend. Compared with monocropping, intercropping increased the abundance of beneficial bacteria such as Proteobacteria, Actinobacteriota, Gemmatimonadota, Gemmatimonas, Conexibacter, and Sphingomonas, while reducing the abundance of pathogenic fungi such as Alternaria, Cladosporium, and Fusarium. Intercropping also increased the abundance of arbuscular mycorrhiza, soil saprophytes, and undefined saprophytes while decreasing the abundance of plant pathogens. ConclusionFaba bean-wheat intercropping enhanced soil enzyme activities, effective nutrient content, and alpha diversity indices of bacteria and fungi in the rhizosphere soil of faba bean, while promoting the abundance of beneficial bacteria, arbuscular mycorrhizal fungi, as well as both soil and undefined humus. Simultaneously, intercropping reduced the abundance of plant pathogens, facilitated nutrient cycling in the soil, provided sufficient nutrients for crop uptake, and mitigated the toxic effects of hydrogen peroxide on cells. Ultimately, this resulted in a reduced occurrence of Fusarium wilt.

Acetate-producing bacterium Paenibacillus odorifer hampers lung cancer growth in lower respiratory tract: an in vitro study.

Lung cancer accounts for the large majority of cancer incidence and mortality worldwide for decades. The dysbiotic microbiome and its metabolite secretions in the gut have been regarded as the dominant biological factors in oncogenesis, development, and progression, adding probiotic components of which have come to be potential therapeutic regimes. However, there still exists little knowledge about whether probiotic microorganisms in lower airways inhibit lung cancer by lung microenvironment remodulation. In this study, we performed bioinformatics analysis from previous sequencing data and specific microbiome databases to identify the potent protective microbes in lower airways, followed by bacterial cultivation and morphological verifications in vitro. We found that Paenibacillus odorifer was correlated closely with the anti-tumorous by-product acetic acid in lower respiratory tract. Additionally, the enrichment of this microorganism in the health, rather than in lung neoplasms from public data sets, further confirmed its protective activity in preserving pulmonary homeostasis. Colony cultivation of this strain and targeted metabolite analysis indicated that Paenibacillus odorifer proliferation was weakened at 37°C but lasted longer than it did at the optimal temperature. And performing as a candidate origin of acetic acid, this strain was liable to inhibit the growth of lung cancer cells in time- and dose-dependent approaches which was validated by colony formation assays. These results suggested that Paenibacillus odorifer functions as a candidate probiotic in lower airways to restrict lung cancer cell growth by releasing protective molecules, indicating a potential preventive microbial strategy.IMPORTANCEVarious types of microorganisms in lower respiratory tracts protect local homeostasis against oncogenesis. Although extensive efforts engaged in gut microbiome-mediated pulmonary carcinogenesis, emerging evidence suggested the crucial role of microbial metabolites from respiratory tracts in modulating carcinogenesis-related host inflammation and DNA damage in lung cancer, which was still not fully understood in lower respiratory tract microbes and its metabolite-mediated microecological environment homeostasis in preventing or alleviating lung cancer. In this study, we analyzed the lower respiratory tract microbiome and SCFAs expression among different lung segments from the same participants, further identifying that Paenibacillus odorifer was correlated closely with anti-tumorous by-product, acetate acid in lower respiratory tract by multi-omics analysis. And previous experiments showed this strain could inhibit the growth of lung cancer cells in vitro. These findings indicated that Paenibacillus odorifer in lower respiratory tracts might perform as a candidate probiotic against lung carcinogenesis by releasing protective factor acetate, which further presented a promising diagnostic and interventional approach in clinical settings of lung cancer.

Research progress of probiotics regulating intestinal micro-ecological environment in obese patients after bariatric surgery

Bariatric surgery may cause intestinal microecological environment imbalance due to changes in gastrointestinal anatomy. Some patients may have compli-cations, even regain weight. Probiotics can act on intestinal mucosa, epithelium and gut-associated lymphoid tissue to improve the intestinal microecological environment of obese patients after bariatric surgery. Probiotics can promote the production of short-chain fatty acids, stimulate intestinal cells to release glucagon-like peptide-1, peptide tyrosine-tyrosine, insulin and other endocrine hormones, affect the function of the central nervous system through the gut-brain axis, make patients after bariatric surgery feel full, and reduce blood sugar at the same time. Probiotics can produce lactic acid, acetic acid and lactase, to inhibit the growth of harmful bacteria and to improve gastrointestinal symptoms of patients after bariatric surgery. Probiotics can activate the AMP-activated protein kinase signaling pathway, improve lipid metabolism, and promote the recovery of symptom indicators of nonalcoholic fatty liver disease after bariatric surgery. Probiotics can regulate the release of neurotransmitters or metabolites by the microbiota through the gut-brain axis to affect brain activity and behavior, thus helping patients improve negative emotions after bariatric surgery. This article describes the intestinal microecological environment of obese patients and mechanism of the change after bariatric surgery and summarizes the effects and possible mechanisms of probiotics in improving the intestinal microecological environment of obese patients after bariatric surgery, to provide references for promoting the clinical application of probiotics.

Microbial regulatory mechanisms of disease-resistant tobacco varieties in the prevention and control of bacterial wilt disease

Bacterial wilt disease poses a significant threat to the production and quality of tobacco. Disease-resistant varieties of tobacco are the primary means of preventing bacterial wilt, but the soil microbial mechanisms that alleviate this disease require further in-depth research. In our study, we analyzed the physicochemical and microbial properties of rhizosphere soil in four different disease-resistant varieties of tobacco. The treatments included: T1 (Chang Bo Huang; 100 % infection rate); T2 (Yun Yan 87; 80 % infection rate); T3 (K326; 50 % infection rate) and T4 (YAN YAN 97; 0 % infection rate). Our results showed that the T4 treatment improved the fresh biomass of tobacco by 35.42 % compared to the T1 treatment. In addition, a significant increase in soil pH and soil organic matter (SOM) from 4.98 and 1.24 % under T1 treatment to 5.86 and 1.38 % under T4 treatment, respectively. As the disease resistance of the tobacco variety improved was found, there was a noticeable upward trend in the number of operational taxonomic units (OTUs) in the rhizosphere soil, showing higher sensitivity compared to fungi. Additionally, rhizosphere soil from susceptible varieties exhibited higher levels of metabolites, resulting in the accumulation of acidic substances (6-aminopenicillanic acid, garcinia acid, and 4-decan-4-ylbenzenesulfonic acid). Moreover, these soil metabolites might have attracted certain pathogenic fungi (Monoblepharomycota), contributing to the spread of soil diseases. This study suggests that the rhizosphere soil of disease-resistant tobacco variety provides a better microecological environment which could inhibit accumulation of allelopathic substances and reduce the spread of bacterial wilt disease.

Meta-analysis of gut microbiota biodiversity in patients with polycystic ovary syndrome based on medical images

PCOS is thought to be associated with metabolic disorders, endocrine disorders, and reproductive system problems. By collecting relevant literature and conducting meta-analyses, we integrated data from multiple studies to enhance the reliability of the analysis results. Studies with medical image data were selected to ensure the accuracy and credibility of the studies. A statistical framework was employed to examine the biodiversity indicators associated with the gut microbiota. These findings provide robust support for the notion that PCOS is intricately linked to notable alterations within the gut microbial community. The utilization of a statistical approach and the systematic synthesis of research findings in this meta-analysis contribute to a more comprehensive understanding of the substantial impact of PCOS on the gut microbiota landscape. PCOS patients showed significant changes in the relative abundance of certain bacteria in their gut microbiota. This imbalance will lead to the instability of intestinal microecological environment, and then affect the health of the body.

Effect of different delivery modes on intestinal microbiota and immune function of neonates

Different delivery methods can cause variations in the composition and structure of intestinal microbiota in neonates. However, the impact of the microecological environment on host immune function requires further investigation. In this study, 75 healthy neonates were divided into two groups: vaginal delivery group (n = 36) and cesarean section group (n = 39). Fecal and peripheral blood samples were collected from the 7th to the 10th day. 16S rRNA sequencing technique was performed to investigate the gut microbiota on fecal samples. Levels of immunoglobulins and Th1 and Th2 cells in the peripheral blood of neonates were measured. The abundance of Escherichia, Bifidobacterium, and Bacteroides in neonates in the cesarean section group was significantly lower than that in the vaginal delivery group. Metabolic pathway analysis showed three significantly up-regulated metabolic pathways in the intestinal microbiota of neonates in the cesarean section group. The levels of serum IgG and IL-12p70 in the cesarean section group were lower than those in the vaginal delivery group, and the proportion of IFN-γ/IL-4 was significantly lower in the cesarean section group compared to the vaginal delivery group. The mode of delivery has potential impact on the intestinal microbiota and immune functions of neonates, potentially leading to an imbalance of Th1/Th2 cells in neonates delivered by cesarean section.

Vaginal microbiome differences between patients with adenomyosis with different menstrual cycles and healthy controls

BackgroundAdenomyosis is a commonly observed benign gynecological disease that affects the quality of life and social psychology of women of childbearing age. However, because of the unknown etiology and incidence of adenomyosis, its pathophysiological mechanism remains unclear; further, because no noninvasive, accurate, and individualized diagnostic methods are available, treatment and efficacy evaluations are limited. Notably, the interaction between the changes in the microecological environment of the female reproductive tract and human immunity, endocrine, and other links leads to the occurrence and development of diseases. In addition, the vaginal microbiome differs in different menstrual cycles; therefore, assessing the differences between the microbiomes of patients with adenomyosis and healthy individuals in different menstrual cycles will improve the understanding of the disease and provide references for the search for noninvasive diagnosis and individualized precision treatment of adenomyosis. This study aimed to explored the data of individuals in different menstrual cycles.ResultsDifferences in the vaginal microbiome between patients with adenomyosis and healthy individuals were observed. At phylum level, the relative abundance of Firmicutes in the adenomyosis group was higher than that in the control group, which contributed the most to the species difference between the two groups. At the genus level, Lactobacillus was the most dominant in both groups, Alpha-diversity analysis showed significant differences in the adenomyosis and control group during luteal phase (Shannon index, p = 0.0087; Simpson index, p = 0.0056). Beta-diversity index was significantly different between the two groups (p = 0.018). However, based on Weighted Unifrac analysis, significant differences were only observed throughout the luteal phase (p = 0.0146). Within the adenomyosis group, differences between women with different menstrual cycles were also observed. Finally, 50 possible biomarkers including were screened and predicted based on the random forest analyse.ConclusionsThe vaginal microbiome of patients with adenomyosis and healthy individuals differed during menstrual periods, especially during the luteal phase. These findings facilitate the search for specific biological markers within a limited range and provide a more accurate, objective, and individualized diagnostic and therapeutic evaluation method for patients with adenomyosis, compared to what is currently available.

Effects of uranium mining on the rhizospheric bacterial communities of three local plants on the Qinghai-Tibet Plateau.

In this study, we used 16S high-throughput sequencing to investigate the effects of uranium mining on the rhizospheric bacterial communities and functions of three local plant species, namely, Artemisia frigida, Acorus tatarionwii Schott., and Salix oritrepha Schneid. The results showed that uranium mining significantly reduced the diversity of rhizospheric bacteria in the three local plant species, including the Shannon index and Simpson index (P < 0.05). Interestingly, we found that Sphingomonas and Pseudotrichobacter were enriched in the rhizosphere soil of the three local plants from uranium mining areas, indicating their important ecological role. The three plants were enriched in various dominant rhizospheric bacterial populations in the uranium mining area, including Vicinamidobacteriaceae, Nocardioides, and Gaiella, which may be related to the unique microecological environment of the plant rhizosphere. The rhizospheric bacterial community of A. tatarionwii plants from tailings and open-pit mines also showed a certain degree of differentiation, indicating that uranium mining is the main factor driving the differentiation of plant rhizosphere soil communities on the plateau. Functional prediction revealed that rhizospheric bacteria from different plants have developed different functions to cope with stress caused by uranium mining activities, including enhancing the translational antagonist Rof, the translation initiation factor 2B subunit, etc. This study explores for the first time the impact of plateau uranium mining activities on the rhizosphere microecology of local plants, promoting the establishment of effective soil microecological health monitoring indicators, and providing a reference for further soil pollution remediation in plateau uranium mining areas.

Optimizing Split-reduced drip fertigation schemes of Arabica coffee based on soil microcosms, bean yield, quality and flavor in dry-hot region of southwest China

As a characteristic cash crop in Yunnan Province, China, Arabica coffee ranks first in the country in terms of cultivation area and production, but has always suffered from poor soil nutrient management and a lack of scientific basis for fertilization. It is not clear how to improve the soil microecological environment using split-reduced drip fertigation at different reproductive stages of Arabica coffee to improve bean yield and quality. Therefore, a two-year (2020–2022) field experiment was conducted on 5-year-old Arabica coffee trees in a dry-hot region with five split-drip fertigation patterns, F450, F600, F750, F900 and F1050. Using the local conventional fertilization (Fertilizer of 900 kg ha−1 year−1 only in berry expansion, and no fertilization in early flowering and berry ripening) as the control (CK). The effects of different fertilization modes on soil microecological environment, bean yield, nutritional quality and characteristic flavor were studied, and a comprehensive benefit evaluation model to assess bean yield and nutritional quality under different fertilization modes was established. The results showed that F900 significantly increased soil nitrate nitrogen, available phosphorus, available potassium, microbial population and enzyme activities at early flowering and berry ripening stages compared to CK, while F900 reduced soil nitrate nitrogen, available phosphorus and available potassium but increased soil enzyme activity and microbial population at the berry expansion stage. Compared with CK, F450 decreased bean yield, caffeine and chlorogenic acid content by 31.83 %, 23.73 % and 13.48 %, respectively, while F750 increased two-year average yield, raw bean fat, caffeine and chlorogenic acid content by 20.52 %, 12.37 %, 5.48 % and 11.17 %, respectively. The two-year average yield of F600 showed less difference from CK. Marginal yield was positive and then negative with increasing fertilizer application. Dry bean yield decreased at a total fertilizer application of 900 kg ha−1 year−1. Correlation analyses showed a positive correlation between soil microbial environment and nutrient quality of coffee beans, while different correlations were found between nutrients and volatiles at dark and medium roasting levels. Cluster analysis revealed that the relative contents of aldehydes, alcohols, phenols, pyridines, and pyrroles were higher under dark roasted condition, while the relative contents of ketones, esters, acids, and pyrazines were higher under medium roasted condition. Based on the Entropy weight-TOPSIS method, F750 had the highest combined benefits in terms of yield increase and quality improvement, and the total fertilizer application decreased by 16.67 % compared to CK, thus F750 treatment was the most suitable split-drip fertigation strategy for Arabica coffee in the dry-hot region of Yunnan. This study provided a reference for drip fertigation systems of Arabica coffee in dry and hot regions.

Effect of a topical traditional Chinese herbal medicine on skin microbiota in mouse model of atopic dermatitis

This study aims to explore the impact of the herbal ointment Chushi Zhiyang Ruangao (CSZYRG) on the skin's microecological environment in a mouse model of atopic dermatitis (AD) and to understand the underlying mechanisms involved. The AD model was established in C57 mice using calpolitol (a hypocalcemic analog of vitamin D3; MC903). Medication-free matrix ointment, CSZYRG, and mometasone furoate cream (positive control group) were applied to the injured areas. The skin lesions of AD model mice were photographed. Skin lesions were applied for the hematoxylin and eosin (H&E) staining to observe any pathological changes. Serum immunoglobulin IgE was detected by enzyme-linked immunosorbent assay (ELISA). The changes in the expression of inflammation-related factors TNF-α, IL-1β, and IL-6 in mice were detected using ELISA and qRT-PCR. Skin microflora samples were taken for 16S rDNA sequencing and analyzed for changes in the skin flora diversity, abundance, and dominant flora in mice. It was concluded that CSZYRG effectively alleviates skin lesions, serum IgE, and levels of TNF-α, IL-1β, and IL-6 in AD model mice. However, CSZYRG did not affect the skin microbial diversity of AD model mice but could exert an effect on the skin microbial community in AD mice and the relative abundance of the dominant microflora. CSZYRG may play a therapeutic role in AD by affecting the skin microbial community and relative abundance of dominant microflora in AD mice.

Ecological Characteristics of Culturable Myxobacteria in the Rhizosphere Soil of Saline-Tolerant Plants in the Ebinur Saline Wetlands

T his study investigated the ecological distribution of myxobacteria in the saline environment of the Ebinur Lake Wetland, in China, which provides a unique microecological environment for their survival. Culturable myxobacteria were isolated using traditional methods including Escherichia coli DH5α, rabbit feces, and filter paper flakes as food sources. Molecular identification along with physiological, biochemical assays and morphological characterization was carried out for the classification and identification of myxobacteria. Associations between soil environmental factors and myxobacterial diversity were analyzed using redundancy analysis. This study involved collecting rhizosphere soil from 15 species of salt-tolerant plants, ultimately yielding 15 strains of myxobacteria from eight of these species. Fifteen strains of myxobacteria were taxonomically placed by analyzing 16S rRNA homology, seven strains were closely related to Myxococcus virescens, six strains were closely related to Myxococcus fulvus and two strains were closely related to Myxococcus xanthus. Myxococcus virescens, the dominant cultivable species of myxobacteria in the Ebinur Lake Wetland, was isolated from various sampling sites using traditional methods. Analysis of antibiotic resistance revealed that myxobacterial strains M2, M6, M9, M13, and M15 are resistant to gentamicin. Furthermore, predation assays demonstrated that myxobacterial strain M14 exhibits the broadest spectrum of predation against both bacterial and fungal prey. The limited culturable myxobacterial diversity observed in the Ebinur Lake Wetland could potentially result from variations in soil physicochemical properties, vegetation type, and employed isolation methods. These findings enhance our comprehension of the myxobacterial resources within this specific salt desert ecosystem.

Research progress and future trends of early-onset gastric cancer

Early onset gastric cancer (EOGC), defined as gastric cancer occurring at a younger age. Early-onset gastric cancer tends to be poorly differentiated and highly malignant. Genetic material and environmental exposure factors may be the main causes of early occurrence of gastric cancer. Prolonging the survival and improving the quality of life of patients with early-onset gastric cancer is our main research goal in the future. This article aims to elaborate on the current research status and progress of EOGC in terms of its clinicopathological characteristics, molecular genetics, microecological environment, prediction methods, treatment plans, and prognosis, while also exploring potential avenues for future research.

The Improvement and Related Mechanism of Microecologics on the Sports Performance and Post-Exercise Recovery of Athletes: A Narrative Review.

The diversity and functionality of gut microbiota may play a crucial role in the function of human motor-related systems. In addition to traditional nutritional supplements, there is growing interest in microecologics due to their potential to enhance sports performance and facilitate post-exercise recovery by modulating the gut microecological environment. However, there is a lack of relevant reviews on this topic. This review provides a comprehensive overview of studies investigating the effects of various types of microecologics, such as probiotics, prebiotics, synbiotics, and postbiotics, on enhancing sports performance and facilitating post-exercise recovery by regulating energy metabolism, mitigating oxidative-stress-induced damage, modulating immune responses, and attenuating bone loss. Although further investigations are warranted to elucidate the underlying mechanisms through which microecologics exert their effects. In summary, this study aims to provide scientific evidence for the future development of microecologics in athletics.

Effects of soil microbial ecology on ginsenoside accumulation in Panax ginseng across different cultivation years

The quality of ginseng is greatly influenced by ecological factors, especially soil factors. However, there are few reports on the association between the physicochemical properties of ginseng rhizosphere soil, enzyme activity, microbial bacterial community, and ginsenoside content accumulation in ginseng planted at different ages. In order to investigate the relationship between the soil microbial ecology of ginseng and the content of ginsenosides, this study compared the differences in the rhizosphere soil microecological environment and ginsenoside accumulation between ginseng planted for one, two, and three years, using soil without ginseng cultivation as a control. The results showed that monomer saponins Ro, Re, Rf, Rb1, and total ginsenoside content increased significantly (P < 0.05), while monomer saponins Rb2, Rd, Rh2, and Rg3 content decreased significantly in three-year-old ginseng, (P < 0.05). And soil pH, soil bulk weight and soil enzyme activity in ginseng rhizosphere soils altered the abundance and diversity of rhizosphere soil bacterial community. Redundancy analysis and Pearson correlation analysis revealed that soil pH, soil bulk density, soil urease, and protease were the primary factors influencing the bacterial community in the soil around roots of one, two, three years old ginseng. Co-occurrence network visualization analysis indicated that seven bacterial communities, Planctomycetota, Methylomirabilota, Verrucomicrobiota and Acidobacteriota at the phylum level, Vicinamibacterales_unclassified, Vicinamibacteraceae_unclassified and Candidatus_Udaeobacter at the genus level, had a significant effect on the synthesis of ginsenosides. In summary, soil urease, pH, and soil bulk density in agricultural soils can regulate soil physicochemical properties, soil enzymatic activities, and soil bacterial community abundance. These factors are key drivers of the ginseng soil microbial ecology in ginseng cultivation. These studies will provide a scientific basis for subsequent optimization of soil improvement techniques for cultivated ginseng in farmland by improving the soil microbial ecology.

FastCCLasso: a fast and efficient algorithm for estimating correlation matrix from compositional data.

The composition and structure of microbial communities on the body surface are closely related to human health. The interaction relationship among microbes can help us understand the formation of the microecological environment and the biological mechanism by which microorganisms influence host health. With the help of high-throughput sequencing technologies, microbial abundances in a natural environment can be directly measured without the isolation of microorganisms in culture. Sequencing experiments in microbiome studies can measure the relative abundance of microbes, which is called compositional data. Although there are already many methods for correlation analysis for compositional data, the computation time or accuracy still needs to be improved for current microbiome studies. We develop a fast and efficient algorithm, called fastCCLasso, based on a penalized weighted least squares for inferring the correlation structure of microbes from compositional data in microbiome studies. We perform a large number of numerical experiments and the simulation results show that fastCCLasso outperforms its competitors in edge detection for inferring the correlation network. We also apply fastCCLasso for estimating microbial networks in microbiome studies and fastCCLasso provides a conservative network with comparable false discovery counts that are derived from shuffled data. FastCCLasso is open source and freely available from https://github.com/ShenZhang-Statistics/fastCCLasso under GNU LGPL v3.

Construction of biochar-based organohalide-respiring bacterial agent for remediation of 2,4,6-trichlorophenol contaminated soil

Construction of an efficient bio-reductive dechlorination system remains challenging due to the narrow ecological niche and low-growth rate of organohalide-respiring bacteria during field remediation. In this study, a biochar-based organohalide-respiring bacterial agent was obtained, and its performance and effects on indigenous microbial composition, diversity, and inter-relationship in soil were investigated. A well-performing material, Triton X-100 modified biochar (BC600-TX100), was found to have the superior average pore size, specific surface area and hydrophicity, compared to other materials. Interestingly, Pseudomonas aeruginosa CP-1, which is capable of 2,4,6-TCP dechlorination, showed a 348 times higher colonization cell number on BC600-TX100 than that of BC600 after 7 d. Meanwhile, the dechlorination rate in soil showed the highest (0.732 d−1) in the BC600-TX100 bacterial agent than in the other agents. The long-term performance of the BC600-TX100 OHRB agent was also verified, with a stable dechlorination activity over six cycles. Soil microbial community analysis found the addition of the BC600-TX100 OHRB agent significantly increased the relative abundance of genus Pseudomonas from 1.53 % to 11.2 %, and Pseudomonas formed a close interaction relationship with indigenous microorganisms, creating a micro-ecological environment conducive to reductive dechlorination. This study provides a feasible bacterial agent for the in-situ bioremediation of soil contaminated organohalides. Environmental ImplicationHalogenated organic compounds are a type of toxic, refractory, and bio-accumulative persistent compounds widely existed in environment, widely detected in the air, water, and soil. In this study, we provide a feasible bacterial agent for the in-situ bioremediation of soil contaminated halogenated organic compounds. The application of biochar provides new insights for “Turning waste into treasure”, which meets with the concept of green chemistry.

Effects of sulfur nanoparticles on rhizosphere microbial community changes in oilseed rape plantation soil under mercury stress

In the present study, experiments were conducted to assess the influence of nanoscale sulfur in the microbial community structure of metallophytes in Hg-contaminated rhizosphere soil for planting rapeseed. The results showed that the richness and diversity of the rhizobacteria community decreased significantly under Hg stress, but increased slightly after SNPs addition, with a reduction in the loss of Hg-sensitive microorganisms. Moreover, all changes in the relative abundances of the top ten phyla influenced by Hg treatment were reverted when subjected to Hg + SNPs treatment, except for Myxococcota and Bacteroidota. Similarly, the top five genera, whose relative abundance decreased the most under Hg alone compared to CK, increased by 19.05%–54.66% under Hg + SNPs treatment compared with Hg alone. Furthermore, the relative abundance of Sphingomonas, as one of the dominant genera for both CK and Hg + SNPs treatment, was actively correlated with plant growth. Rhizobacteria, like Pedobacter and Massilia, were significantly decreased under Hg + SNPs and were positively linked to Hg accumulation in plants. This study suggested that SNPs could create a healthier soil microecological environment by reversing the effect of Hg on the relative abundance of microorganisms, thereby assisting microorganisms to remediate heavy metal-contaminated soil and reduce the stress of heavy metals on plants.

New clues for postbiotics to improve host health: a review from the perspective of function and mechanisms.

Strain activity and stability severely limit the beneficial effects of probiotics in modulating host health. Postbiotics have emerged as a promising alternative as they can provide similar or even enhanced efficacy to probiotics, even under inactivated conditions. This review introduces the ingredients, preparation, and identification techniques of postbiotics, focusing on the comparison of the advantages and limitations between probiotics and postbiotics based on their mechanisms and applications. Inactivation treatment is the most significant difference between postbiotics and probiotics. We highlight the use of emerging technologies to inactivate probiotics, optimize process conditions to maintain the activity of postbiotics, or scale up their production. Postbiotics have high stability which can overcome unfavorable factors, such as easy inactivation and difficult colonization of probiotics after entering the intestine, and are rapidly activated, allowing continuous and rapid optimization of the intestinal microecological environment. They provide unique mechanisms, and multiple targets act on the gut-organ axis, co-providing new clues for the study of the biological functions of postbiotics. We summarize the mechanisms of action of inactivated lactic acid bacteria, highlighting that the NF-κB and MAPK pathways can be used as immune targeting pathways for postbiotic modulation of host health. Generally, we believe that as the classification, composition, and efficacy mechanism of postbiotics become clearer they will be more widely used in food, medicine, and other fields, greatly enriching the dimensions of food innovation. © 2024 Society of Chemical Industry.

Exploring the Impact of Coconut Peat and Vermiculite on the Rhizosphere Microbiome of Pre-Basic Seed Potatoes under Soilless Cultivation Conditions.

Soilless cultivation of potatoes often utilizes organic coconut peat and inorganic vermiculite as growing substrates. The unique microbial communities and physicochemical characteristics inherent to each substrate significantly influence the microecological environment crucial for potato growth and breeding. This study analyzed environmental factors within each substrate and employed Illumina sequencing alongside bioinformatics tools to examine microbial community structures, their correlation with environmental factors, core microbial functions, and the dynamics of microbial networks across various samples. These included pure coconut peat (CP1) and pure vermiculite (V1), substrates mixed with organic fertilizer for three days (CP2 and V2), and three combinations cultivated with potatoes for 50 days (CP3, V3, and CV3-a 1:1 mix of coconut peat and vermiculite with organic fertilizer). Vermiculite naturally hosts a more diverse microbial community. After mixing with fertilizer and composting for 3 days, and 50 days of potato cultivation, fungal diversity decreased in both substrates. Coconut peat maintains higher bacterial diversity and richness compared to vermiculite, harboring more beneficial bacteria and fungi, resulting in a more complex microbial network. However, vermiculite shows lower bacterial diversity and richness, with an accumulation of pathogenic microorganisms. Among the 11 environmental factors tested, water-soluble nitrogen (WSN), total nitrogen (TN), available potassium (AK), total organic carbon (TOC) and air-filled porosity (AFP) were significantly associated with microbial succession in the substrate.The nutritional type composition and interaction patterns of indigenous microorganisms differ between vermiculite and coconut peat. Adding abundant nutrients significantly affects the stability and interaction of the entire microbial community, even post-potato cultivation. When using vermiculite for soilless cultivation, precise control and adjustment of nutrient addition quantity and frequency are essential.