Effect of a Compound Microbial Fertilizer on Growth， Quality， and Soil Properties of Andrographis paniculata / 中国实验方剂学杂志

ObjectiveTo study the effect of a microbial compound fertilizer on the growth， quality， and soil properties of Andrographis paniculata and provide a basis for its application in the cultivation and production of A. paniculata. MethodThrough five treatment tests in pots， the control group （CK， no fertilization）， the treatment A group （chemical fertilization）， the treatment B group （microbial fertilization at 2.5 g·kg-1 soil）， the treatment C group （microbial fertilization at 7.5 g·kg-1 soil）， and the treatment D group （microbial fertilization at 12.5 g·kg-1 soil） were established. The effects of a compound microbial fertilizer on the agronomic properties， the content of active ingredients， the number of rhizosphere soil bacteria， Actinomycetes， and fungi， and soil physicochemical properties of A. paniculata were studied. ResultAs compared with the CK group and the treatment A group， the plant height， leaf number， leaf area， and above-ground and below-ground fresh weight of A. paniculata were significantly increased after microbial fertilization， with differences in different growth periods. The effect of the compound microbial fertilizer on the content of andrographolide， dehydrated andrographolide， neandrographolide， and 14-deoxyandrographolide differed. The content of andrographolide significantly increased by 26.13% and 13.23% in the treatment C group， respectively， as compared with the CK group and the treatment A group （P<0.05）. The content of neandrographolide increased with the increasing amount of microbial fertilizer， and the content in the treatment D group increased by 9.06% and 50.33%， respectively， as compared with the CK group and the treatment A group （P<0.05）， which was the most obvious. The content of 14-deoxyandrographolide in the treatment B group significantly increased by 42.04% and 1.74%， respectively， as compared with the treatment A group and the CK group （P<0.05）. The content of dehydrated andrographolide content in the treatment B group increased most significantly， significantly increasing by 11.73% and 27.74%， respectively， as compared with the CK group and the treatment A group （P<0.05）. The soil pH of the treatment B， C， and D groups was higher than that of the CK group and the treatment A group. The content of total nitrogen and effective phosphorus increased most significantly in the treatment B group， and the content of fast-acting potassium increased most significantly in the treatment D group. The application of the compound microbial fertilizer increased the number of rhizosphere soil bacteria and Actinomycetes， which was significantly higher than that in the CK group and the treatment A group （P<0.05）， and increased with the increase of applied amount. The number of fungi decreased with the increase of the compound microbial fertilizer application， which was significantly different from that in the CK group （P<0.05）. The fungi/bacteria of all treatment groups were significantly lower than those of the CK group （P<0.05） and increased with the increase of microbial fertilizer application. ConclusionThe application of the compound microbial fertilizer transforms the plant-soil-microbial system in a benign direction， which is beneficial to the growth of A. paniculata and the accumulation of active ingredients.

Status and Prospect of Management Policy and System for High-level Pathogenic Microorganism Laboratories in China / 中山大学学报(医学科学版)

High-level pathogenic microorganism laboratories are strategic scientific and technological forces of national biosafety， so it is significant to improve the policy and system management and strengthen the safety supervision. This paper reviewed the current status of management policy and system of high-level pathogenic microorganism laboratories， summarized the problems and challenges in terms of safety laws and regulations， supervision mechanism， hierarchical and classified management， standards and norms， legal person responsibility system， occupational access system and personnel training system. This paper also proposed targeted policy suggestions that might underlie the biosafety management of high-level pathogenic microorganism laboratories in China.

Advances in the study on brain-gut axis mechanism of common mental disorders and clinical intervention / 四川精神卫生

There are a large number of microbial communities in human intestine， which play an important role in many physiological processes of the body. It has been found that intestinal microorganisms can act on brain diseases through brain-gut axis mechanism. The purpose of this paper is to summarize the mechanism of intestinal microorganisms in schizophrenia， bipolar disorder and depression， and to provide new ideas for the prevention and treatment of psychiatric disorders.

Research progress of occupational hazards in plywood manufacturing / 中华劳动卫生职业病杂志

Occupational disease hazards in plywood manufacturing mainly include wood dust, formaldehyde, phenol, ammonia, noise, terpene, microorganisms, etc. The exposure is complex with multiple factors accompanied or coexisted. In the production process, these factors are exceeded, and mass occupational disease hazard events occurred among workers. Exposure to wood dust, formaldehyde, terpene, etc., put workers at increased risk of cancer. This article provides a review of this issue in order to provide a scientific basis for the prevention and control of occupational disease hazards in plywood manufacturing.

Enhanced nitrogen removal by bioelectrochemical coupling anammox and characteristics of microbial communities / 生物工程学报

To investigate the bioelectrochemical enhanced anaerobic ammonia oxidation (anammox) nitrogen removal process, a bioelectrochemical system with coupled anammox cathode was constructed using a dual-chamber microbial electrolysis cell (MEC). Specifically, a dark incubation batch experiment was conducted at 30 ℃ with different influent total nitrogen concentrations under an applied voltage of 0.2 V, and the enhanced denitrification mechanism was investigated by combining various characterization methods such as cyclic voltammetry, electrochemical impedance spectroscopy and high-throughput sequencing methods. The results showed that the total nitrogen removal rates of 96.9%±0.3%, 97.3%±0.4% and 99.0%±0.3% were obtained when the initial total nitrogen concentration was 200, 300 and 400 mg/L, respectively. In addition, the cathode electrode biofilm showed good electrochemical activity. High-throughput sequencing results showed that the applied voltage enriched other denitrifying functional groups, including Denitratisoma, Limnobacter, and ammonia oxidizing bacteria SM1A02 and Anaerolineaceae, Nitrosomonas europaea and Nitrospira, besides the anammox bacteria. These electrochemically active microorganisms comprised of ammonium oxidizing exoelectrogens (AOE) and denitrifying electrotrophs (DNE). Together with anammox bacteria Candidatus Brocadia, they constituted the microbial community structure of denitrification system. Enhanced direct interspecies electron transfer between AOE and DNE was the fundamental reason for the further improvement of the total nitrogen removal rate of the system.

Live biotherapeutic products: the forefront of innovative drug development driven by biotechnology / 生物工程学报

As human microbiome research advances, a large body of evidence shows that microorganisms are closely related to human health. Probiotics were discovered and used as foods or dietary supplements with health benefits in the last century. Microorganisms have shown broader application prospects in human health since the turn of the century, owing to the rapid development of technologies such as microbiome analysis, DNA synthesis and sequencing, and gene editing. In recent years, the concept of "next-generation probiotics" has been proposed as new drugs, and microorganisms are considered as "live biotherapeutic products (LBP)". In a nutshell, LBP is a living bacterial drug that can be used to prevent or treat certain human diseases and indications. Because of its distinct advantages, LBP has risen to the forefront of drug development research and has very broad development prospects. This review introduces the varieties and research advances on LBP from a biotechnology standpoint, followed by summarizing the challenges and opportunities for LBP clinical implementations, with the aim to facilitate LBP development.

Identification of the metabolites from co-cultures of marine Streptomyces sp. IMB18-531 and Cladosporium sp. IMB19-099 / 药学学报

A new siderophore chelate (1) and 8 known compounds were identified from the liquid co-cultures of the marine-derived Streptomyces sp. IMB18-531 and Cladosporium sp. IMB19-099 by a combination of chromatography methods, including C18 reversed-phase medium pressure chromatography, gel column chromatography and HPLC. Their structures were determined by spectroscopic analysis and chemical methods as aluminioxamine E (1), desferrioxamine E (2), ferrioxamine E (3), terragine E (4), capsimicin (5), cyclo(L-prolinyl-L-tyrosine) (6), anthranilic acid (7), (Z)-14-methylpentadec-9-enoic acid (8), and (Z)-hexadec-8-enoic acid (9). Compound 2 showed inhibitory activities against the expression of liver fibrosis related genes COL1A1, MMP2, and TIMP2. Compounds 5, 8, and 9 displayed antibacterial activities against methicillin-resistant Staphylococcus aureus, S. epidermidis and Bacillus subtilis, with MICs of 16-64 μg·mL-1. Compound 5 showed cytotoxicities against human pancreatic cancer MIA Paca-2 and human colon cancer HT-29 cell lines with IC50 of 2.9 and 6.3 μmol·L-1, respectively.

Research progress on health risks of aerosol microorganisms / 上海预防医学

Aerosol microorganisms are important constituents of aerosols. They participate in physical and chemical reactions in the air and are also closely related to disease transmission and human health. With the SARS-CoV-2 pandemic， aerosol microorganisms have become a public health topic of great concern. Studying the composition and influencing factors of the air microbiome therefore has significant public health implications. Due to the limitations of traditional technologies for sampling and determination， the aerosol microbiome has not been fully understood. However， with the development and maturity of high-throughput sequencing technology， the aerosol microbiome has shown promising research prospects. This article reviews the composition， characteristics， detection methods and influencing factors of aerosol microorganisms， providing basic knowledge for further research on the air microbiome. In-depth research on microbial aerosols has significant implications on urban air quality control， national security and public health.

Microbial monitoring of urban drinking water in Jiangxi Province from 2016 to 2020 / 上海预防医学

ObjectiveTo monitor the microbes in urban drinking water in Jiangxi from 2016 to 2020， to analyze the change in microbial qualification rate， and to provide a scientific basis for government decision-making. MethodsAccording to the Standard Examination Method for Drinking Water （GB/T 5750‒2006） and the Standards for Drinking Water Quality （GB 5749‒2006）， the water samples were collected， tested and evaluated for hygienic safety. The chi-square test was used to compare the qualification rates among different water periods， water source types， water supply modes， water samples， treatment processes， and disinfection methods. ResultsA total of 10 584 water samples were collected and examined from 2016 to 2020，with a qualification rate of 97.72%. The qualified rate of the microbiological index increased gradually over the years. There was no statistically significant difference in the microbiological qualification rate of water samples monitored in different water periods （χ2=0.718，P=0.398）， and the qualification rates were 97.85% and 97.60% in dry and abundant water periods respectively. There was a statistically significant difference in the qualification rates of water samples monitored in different water source types （χ2=79.560，P=0.398）， with groundwater having a higher qualification rate of 98.83% than surface water （97.70%）. The microbiological pass rate of water samples differed among different water supply methods （χ2=201.836，P<0.001）. The microbiological pass rates of municipal centralized water supply， self-built centralized water supply and secondary water supply were 97.51%， 88.94% and 96.56% respectively. The microbiological pass rates of water samples differed among different treatment processes. There were differences in the qualification rates of the water samples between different treatment processes（χ2=855.034，P<0.001）， with 98.22%， 67.19%， 95.60% and 53.13% of the conventionally treated， precipitated filtered， disinfected only and untreated water samples， respectively. The differences in the microbiological qualification rates of the monitored water samples between different disinfection methods were statistically significant （χ2=904.993，P<0.001）. Chlorination disinfection， chlorine dioxide disinfection， other disinfection methods and non-disinfected water samples had the pass rates of 98.35%， 98.19%， 84.38% and 60.16%， respectively. ConclusionThe qualified rate of the microbiological index of drinking water in Jiangxi increases year by year， but there are still some drinking water without appropriate disinfectants and water quality treatment processes. There is still a need to strengthen the purification， disinfection and monitoring of drinking water.

Bidirectional interaction between heavy metals and intestinal microorganisms / 环境与职业医学

There is a bidirectional interactive relationship between heavy metals and intestinal microorganisms. Single exposure to common heavy metals (Cd, Cr, As, Pb, etc.) may cause intestinal microecological damage and related diseases by losing the diversity and relative abundance of intestinal microorganisms. However, heavy metals in the environment are usually mixed exposure and an overall toxic effect is presented. Published studies have suggested a synergistic effect between most heavy metals, so the impact of mixed exposure on intestinal microorganisms is expected to be more significant than that of single exposure. Intestinal microorganisms are the first line of defense against heavy metals entering the body, and can reduce inflammation and oxidation caused by heavy metals via changing protein synthesis, intestinal PH, enzyme activity, etc. At the same time, the colonization of oral probiotics in the intestinal tract has a significant detoxification effect on heavy metals entering the body through synergy with intestinal microorganisms, which can promote the elimination of heavy metals, reduce the production of oxides and inflammatory mediators, reverse the changes in the relative abundance of intestinal microorganisms, and then reduce the damage of heavy metals to intestinal microecology. Therefore, probiotics may have better prospects than traditional heavy metal antidotes. In the future, more in-depth research on the mechanism of bidirectional interactive relationship between heavy metals and intestinal microorganisms is needed to provide new ideas for clinical heavy metal detoxification.

Research progress of human surface microbiota and ocular surface diseases / 国际眼科杂志(Guoji Yanke Zazhi)

The ocular surface microbiota is a part of the human ocular surface microenvironment and is critical to its stability. Many studies have explored the composition of the ocular surface microbiota in health and disease, but the research results are different based on internal and external factors, and the relationship between microorganism dysbiosis and diseases also remains unclear. As the research on intestinal microorganisms and systemic diseases has intensified in recent years, ophthalmic researchers have been inspired to further explore the relationship between ocular surface microbiota and non-infectious ocular surface diseases. Therefore, this article will review the core microbiota of the normal ocular surface as well as alterations in ocular surface microbiota in ocular and systemic diseases, and discuss the possible mechanisms of diseases caused by microorganism dysbiosis, hoping to provide a reference for future studies in ocular surface microbiota.

Etiological diagnosis value of metagenomic next generation sequencing in the patients with spinal infection / 中华传染病杂志

Objective:To investigate the efficacy of metagenomic next generation sequencing (mNGS) in the etiological diagnosis of patients with spinal infection, so as to provide reference for timely diagnosis and treatment.Methods:A total of 40 patients with suspected spinal infection admitted to the Department of Infectious Diseases in Henan Provincial People′s Hospital from January 2020 to July 2022 were included. The results of tissue culture, histopathological examination and tissue mNGS detection were analyzed retrospectively. According to the clinical diagnose, the patients were divided into the spinal infection group (28 cases) and the non-spinal infection group (12 cases). The positive rate, sensitivity and specificity of mNGS and tissue culture in the pathogen detection of patients with spinal infection were compared. McNemar test was used for statistical analysis.Results:There were 23 males and 17 females in 40 patients. The positive rate of mNGS was higher than that of tissue culture (75.0%(30/40) vs 12.5%(5/40)), and the difference was statistically significant ( χ2=0.08, P<0.001). Based on clinical diagnostic criteria, the sensitivity of mNGS in the diagnosis of spinal infection was higher than that of tissue culture (82.1% vs 17.9%), with a statistically significant difference ( χ2=0.02, P<0.001), while the specificity compared to the tissue culture (33.3% vs 100.0%), the difference was not statistically significant ( P>0.05). Conclusions:mNGS has a high pathogen detection rate and sensitivity in the etiological diagnosis of patients with spinal infection, which could provide clinical guidance for the diagnosis and treatment of patients with spinal infection.

Research progress of microbes in subway air / 环境与职业医学

Accumulating studies suggest that, as the subway is one of the important means of transport in cities, airborne microorganisms in its system have potential effects on human health, but previous studies have mainly focused on some foreign cities. We reviewed the spatio-temporal distribution characteristics of airborne microorganisms in subway stations in different cities, including diurnal, weekly, and seasonal variations, and the distribution of microorganisms in different regions of the world. The factors affecting airborne microorganisms, such as human activities, temperature and humidity, ventilation, and particulate matter, were presented. The potential health effects were described. Although there was no significant risk of infection from using subway, many pathogens do exist in the air. The influence of microorganisms in subway air on health has become a public health problem that cannot be ignored.

Isolation and Characterization of Microbes of Different Kinds of Street Food and Determination of Antibiotic Susceptibility of the Isolates

Aim: Improper personal hygiene can facilitate the transmission of the pathogenic microorganisms found in environment and on people抯 hands via food to humans. The present study was undertaken to investigate the microbiological quality of different street food and determining the antibiotic susceptibility of the isolated microorganisms. Study Design: Collection of food samples for isolation of Pathogenic Microorganisms, to identify them by using Biochemical test, molecular test (16sr RNA typing), Antibiotic susceptibility was done by using different antibiotics against the isolates. Place and Duration of Study: Food samples were collected from street vendors of Sainkpuri area, work was done from December 2020 to April 2021 at Microbiology Department, St. Francis College for Women, Hyderabad. Methodology: Five samples of street food were collected in sterilized bottles, tested for the presence of microorganisms by following standard microbiological method used for isolation of microorganisms. The organisms were identified by carrying out various biochemical test according to Bergey抯 Manual of Systematic Bacteriology. The Molecular characterization was done based on 16sr RNA typing. Determining the sensitivity of the isolates against different Antibiotics by employing Kirby Bauer technique. Results: The organisms isolated from Manchuria and Ragada samples: Lactobacillus delbrueckii; Lactobacillus casei, Klebsiella pneumonia, Enterococcus faecalis and Vibrio spp respectively; Samosa and bonda: Staphylococcus aureus, Lactobacillus delbrueckii and Pantoea dispersa; Pani puri water: Staphylococcus aureus and Providencia vermicola. Antibiotic susceptibility tests showed that most of the isolated microorganisms were sensitive to Ciproflaxin. Conclusion: Hence the quality of street food is found to be low due to following factor: lack hygiene conditions in the food preparation, ingredients may also affect quality of the food, and presence of air borne microorganisms in the surrounding areas of service points.

Rhizosphere Exudate-mediated Synergistic Harm of Soil Microorganisms to Medicinal Plants in Continuous Cropping / 中国实验方剂学杂志

Continuous cropping obstacle is the bottleneck of medicinal plant cultivation, which seriously affects the quality and yield of medicinal materials. The research on the mechanism of continuous cropping obstacle has evolved from soil physical and chemical properties and allelopathy in the 1970s to the changes of rhizosphere microenvironment and plant response mechanism at present. According to the available studies in this field and our previous research work, we systematically analyzed the mechanism of rhizosphere exudate-mediated microbial community reconstruction in the soil of the medicinal plants in continuous cropping. Specifically, rhizosphere exudates, providing the carbon source and energy for microbial growth, act as inducers or repellents to induce microbial growth or transfer, thereby changing the physicochemical properties (such as acidity) of rhizosphere soil and further altering the structure of rhizosphere microbial community. Further, we comprehensively discussed the ways of synergism between rhizosphere exudates and soil microorganisms in causing harm to the medicinal plants in continuous cropping. That is, rhizosphere exudates mediate the infection of the rhizosphere by pathogenic microorganisms, increase the susceptibility of the nearby plants, inhibit the defense of the host plants, and protect the pathogens to occupy the dominant niche. The synergistic interaction results in the release of more pathogenic factors such as mycotoxins by rhizosphere pathogens, enhanced toxicity of rhizosphere allelochemicals, and deterioration of soil physical and chemical properties. This paper summarizes the role of interaction between rhizosphere exudates and soil microorganisms in the formation of continuous cropping obstacles, aiming to provide a new research idea for revealing the formation mechanism as well as the theoretical support for overcoming continuous cropping obstacles of medicinal plants.

Microbial characteristics of domestic waste in a typical residential community of Shanghai / 环境与职业医学

Background Domestic waste classification is one of the major livelihood projects in China. With the introduction of the Shanghai Household Waste Management Regulation in 2019, the work of domestic waste classification has been carried out nationwide, yet its potential risks especially those derived from microorganisms are not clear. Objective To investigate the microbial characteristics of the domestic waste in typical residential areas in Shanghai, and provide a theoretical basis for health protection during the domestic waste classification process in Shanghai and throughout China. Methods Dry and wet waste from a typical residential community in Shanghai were collected during 2019–2020. Microbial colonies were counted in domestic waste and analyzed for growth patterns. Then through 16S rRNA sequencing using lllumina PE250, hierarchical clustering analysis was conducted to reveal the similarity and dissimilarity of community compositions in different domestic waste groups, alpha diversity was estimated to reflect the richness and diversity of bacterial communities, principal co-ordinates analysis of unweighted UniFrac distance was performed to estimate the beta diversity, and linear discriminant analysis effect size (LEfSe) was used to find features differentially represented among domestic waste groups. Results In the chosen typical residential community of this study, the numbers of microorganisms in waste were quite different, with lower numbers of microorganisms in dry waste than the numbers in wet waste. In addition, different growth curves of microorganisms were shown for different seasons, and the peak baterial colony numbers were 200 CFU·cm−2, 6×105 CFU·mL−1, 10 CFU·cm−2, and 2×106 CFU·mL−1 for summer dry waste, summer wet waste, winter dry waste, and winter wet waste, respectively. The results of 16S RNA demonstrated significant differences in α and β diversity indicators among different waste groups, and the difference in waste classifications was larger than the difference of the same classification of waste in different seasons. The main compositions of bacterial colonies in domestic waste was Proteobacteria, followed by Firmicute and Bacteroidota. The clustering analysis showed that the microbial composition in summer dry waste was close to that in winter dry waste, while other groups were quite different. In total 48 differential bacterial taxa were found at the level of genus including Pseudomonas and Pantoea. Conclusion Different seasons and different classifications of domestic waste present varied microbial characteristics, with different potential pathogenic microorganisms. Together with other related studies, we suggest that different measures should be taken for different domestic wastes to prevent and control the health hazards associated with waste classification.

Etiological diagnostic value of cerebrospinal fluid metagenomic next-generation sequencing in central nervous system infection / 中华急诊医学杂志

Objective:To investigate the etiological diagnostic value of metagenomic sequencing in central nervous system (CNS) infectious diseases.Methods:A total of 170 patients with central nervous system infection admitted to the First Affiliated Hospital of Zhengzhou University from January 2018 to June 2020 were selected as the study subjects according to inclusion and exclusion criteria. General clinical data and pathogen test results were collected. All included patients underwent routine examination and mNGS test, and were divided into the conventional method test group and mNGS test group according to the test results. The measurement data conforming to normal distribution were represented by ± s; The measurement data that did not conform to normal distribution were represented by median and interquartile range. The classification data were expressed by the number of cases and percentage( n,%), and were compared by χ2 test or Fisher's exact test. Consistency test was represented by Kappa value. The detection of pathogenic microorganisms by the two methods and the rule of pathogen spectrum were compared and analyzed. Results:The overall positive rate of mNGS in CNS infectious diseases was higher than that of conventional methods (58.23% vs. 18.82%), and the difference was statistically significant ( P<0.01). Among the 20 samples which were both positive by the two methods, 10 cases were completely pathogenic, 5 cases were partially consistent and 5 cases were completely inconsistent. In the detection of tuberculous nervous system infection, the positive rates were 66.7%, 53.8%, 44.0%, 40.0%, 4.0% in blood T-SPOT, cerebrospinal fluid mNGS, ADA, Mycobacterium tuberculosis DNA and tuberculous specific antibody, respectively. The positive rate of acid-fast staining was 0. The positive rate of mNGS combined with conventional method was 80.8%. Conclusions:The detection rate of mNGS in CNS infection is better than that of conventional methods. However, it does not show obvious superiority in the detection rate of Mycobacterium tuberculosis associated nervous system infection. In general, mNGS detection of pathogenic bacteria is more extensive, which is conducive to a thorough and comprehensive understanding of the bacterial characteristics of central nervous system infection. The combination of the two methods can make up for the deficiency of clinical routine detection to a certain extent, and can maximize the detection rate.

Combined Therapy of Lung and Intestine in Treatment of Lung Diseases： A Review / 中国实验方剂学杂志

The theoretical origin of the combined therapy of lung and intestine can be traced back to the Inner Canon of Huangdi （《黄帝内经》）， which explains the physiological and pathological interaction between the lung and the large intestine. In recent years， researchers have investigated the scientific essence of the "lung-intestine axis" theory from many aspects， which enriches the relevant theoretical basis， and applied it to the treatment of COVID-19， acute lung injury， and other lung diseases. The close relation between lung and intestine in many aspects embodies the holistic conception of traditional Chinese medicine and explains the holistic theory of interrelation between organs， which correlate to each other physiologically and pathologically. Intestinal microecological disorders can affect lung immune function and cause respiratory diseases， and respiratory diseases are usually accompanied by gastrointestinal symptoms. Lung diseases can be prevented and treated by regulating intestinal flora. According to histoembryology， the epithelial tissue of the lung and intestine comes from primitive foregut. In immunology， both lung and intestine contain mucosa-associated lymphoid tissue， and the pathological changes of the respiratory tract are also closely related to intestinal microorganisms. The tissue origin of lung and large intestine， the correlation of mucosal immunity， and the synchronization of ecological changes provide a scientific basis for the combined therapy of lung and intestine. Therefore， this paper summarizes the theoretical origin， modern research mechanism， and clinical application of combined therapy of lung and intestine， in order to provide a new direction for its application in clinical and scientific research.

A dynamically evolving war between autophagy and pathogenic microorganisms / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Autophagy is an intracellular degradation process that maintains cellular homeostasis. It is essential for protecting organisms from environmental stress. Autophagy can help the host to eliminate invading pathogens, including bacteria, viruses, fungi, and parasites. However, pathogens have evolved multiple strategies to interfere with autophagic signaling pathways or inhibit the fusion of autophagosomes with lysosomes to form autolysosomes. Moreover, host cell matrix degradation by different types of autophagy can be used for the proliferation and reproduction of pathogens. Thus, determining the roles and mechanisms of autophagy during pathogen infections will promote understanding of the mechanisms of pathogen‍‒‍host interactions and provide new strategies for the treatment of infectious diseases.

Transformation mechanism of carbon tetrachloride and the associated micro-ecology in landfill cover, a typical functional layer zone / 生物工程学报

Landfill is one of the important sources of carbon tetrachloride (CT) pollution, and it is important to understand the degradation mechanism of CT in landfill cover for better control. In this study, a simulated landfill cover system was set up, and the biotransformation mechanism of CT and the associated micro-ecology were investigated. The results showed that three stable functional zones along the depth, i.e., aerobic zone (0-15 cm), anoxic zone (15-45 cm) and anaerobic zone (> 45 cm), were generated because of long-term biological oxidation in landfill cover. There were significant differences in redox condition and microbial community structure in each zone, which provided microbial resources and favorable conditions for CT degradation. The results of biodegradation indicated that dechlorination of CT produced chloroform (CF), dichloromethane (DCM) and Cl- in anaerobic and anoxic zones. The highest concentration of dechlorination products occurred at 30 cm, which were degraded rapidly in aerobic zone. In addition, CT degradation rate was 13.2-103.6 μg/(m2·d), which decreased with the increase of landfill gas flux. The analysis of diversity sequencing revealed that Mesorhizobium, Thiobacillus and Intrasporangium were potential CT-degraders in aerobic, anaerobic and anoxic zone, respectively. Moreover, six species of dechlorination bacteria and eighteen species of methanotrophs were also responsible for anaerobic transformation of CT and aerobic degradation of CF and DCM, respectively. Interestingly, anaerobic dechlorination and aerobic transformation occurred simultaneously in the anoxic zone in landfill cover. Furthermore, analysis of degradation mechanism suggested that generation of stable anaerobic-anoxic-aerobic zone by regulation was very important for the harmless removal of full halogenated hydrocarbon in vadose zone, and the increase of anoxic zone scale enhanced their removal. These results provide theoretical guidance for the removal of chlorinated pollutants in landfills.