Huan jing ke xue= Huanjing kexue最新文献

{"title":"[Effects of Chemical Fertilizer Reduction Combined with Straw Application on Diazotrophic Communities in a Double Rice Cropping System].","authors":"Kai-Peng Chen,&nbsp;Ju-Xian Wei,&nbsp;Dan Chen,&nbsp;Cong Wang,&nbsp;Jian-Lin Shen,&nbsp;Yong Li,&nbsp;Jin-Shui Wu","doi":"10.13227/j.hjkx.202110132","DOIUrl":"https://doi.org/10.13227/j.hjkx.202110132","url":null,"abstract":"<p><p>Based on a three-year field experiment, the effects of reduced chemical fertilizer combined with straw application on paddy yield, soil fertility properties, and community structure of diazotrophs in a double-rice cropping field three years after straw application were examined. Three treatments were applied:conventional fertilizer application (CF), chemical fertilizer reduction combined with a low straw application rate (CFLS, 3 t·hm^-2), and a high straw application rate (CFHS, 6 t·hm^-2). The results showed that CFLS and CFHS did not significantly reduce rice grain yield (<i>P</i>>0.05); significantly neutralized soil acidification; increased soil microbial biomass carbon and nitrogen, dissolved organic carbon, and organic carbon content (<i>P</i><0.05); and significantly reduced soil redox potential, ammonium nitrogen, and nitrate nitrogen contents (<i>P</i><0.05). This was more conducive to improve soil nitrogen use efficiency. Compared with those under the CF treatment, the natural nitrogen fixation functional communities of CFLS and CFHS increased the Shannon, PD, and Evenness indexes (<i>P</i><0.05) due to the improvement of conditions such as the increase in soil carbon storage and the decrease in acidification degree. The relative abundance of microbial communities with nitrogen fixation, carbon fixation, and plant growth promotion functions such as <i>Ferrigenium, Sulfurivermis, Methylomonas, Methylovulum, Ectothiorhodospira</i>, and <i>Nostoc</i> increased significantly (<i>P</i><0.05). In conclusion, the reduction in chemical fertilizer combined with 3 t·hm^-2 and 6 t·hm^-2 straw application was an effective measure to improve the community structure of soil diazotrophs and the potential of soil nitrogen fixation.</p>","PeriodicalId":172067,"journal":{"name":"Huan jing ke xue= Huanjing kexue","volume":"43 10","pages":"4725-4734"},"PeriodicalIF":0.0,"publicationDate":"2022-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33501764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Effects of Long-term Straw Returning on Fungal Community, Enzyme Activity and Wheat Yield in Fluvo-aquic Soil].","authors":"Lei Ma,&nbsp;Yan Li,&nbsp;Jian-Lin Wei,&nbsp;Zi-Shuang Li,&nbsp;Xiao-Lin Zhou,&nbsp;Fu-Li Zheng,&nbsp;Xiao-Bin Wu,&nbsp;Li Wang,&nbsp;Zhao-Hui Liu,&nbsp;De-Shui Tan","doi":"10.13227/j.hjkx.202201210","DOIUrl":"https://doi.org/10.13227/j.hjkx.202201210","url":null,"abstract":"&lt;p&gt;&lt;p&gt;To illustrate the effects of long-term straw returning on the fungal community, soil enzyme activity, and crop yield in a fluvo-aquic soil area typical of the Huang-Huai-Hai Plain, a 10-year field experiment (established in 2010) located in Dezhou City, Shandong province, was performed, including three fertilization regimes (NF, no fertilization control; NPK, fertilization with chemical N, P, and K fertilizers; NPKS, straw returning combined with chemical N, P, and K fertilizers). This study aimed to explore the regulation mechanisms of fungal communities on soil fertility, enzyme activities, and crop yield by employing co-occurrence network and structural equation model analyses. Our results showed that long-term straw returning significantly improved soil nutrients, enzyme activity, and wheat yield. Compared with the NPK and NF treatments, soil organic matter (SOM) increased by 9.20% and 34.75%, alkali-hydrolyzed nitrogen (AN) increased by 12.03% and 39.17%, dehydrogenase (DHA) increased by 37.21% and 50.91%, &lt;i&gt;β&lt;/i&gt;-glucosidase (&lt;i&gt;β&lt;/i&gt;-GC) increased by 17.29% and 73.48%, and wheat production increased by 16.22% and 125.53%, respectively. Different long-term fertilization regimes did not significantly change soil fungal &lt;i&gt;α&lt;/i&gt;-diversity but resulted in significant differences in &lt;i&gt;β&lt;/i&gt;-diversity. Available phosphorus (AP), SOM, and AN were the main driving factors of fungal community differentiation based on redundancy analysis and hierarchical partitioning analysis. Different abundance analyses revealed significantly different fungal community compositions among fertilization regimes. The long-term NF treatment resulted in a significant enrichment of phosphate/potassium-solubilizing species (i.e., &lt;i&gt;Mortierella, Aspergillus, Ceriporia&lt;/i&gt;, and &lt;i&gt;Acremonium&lt;/i&gt;) and symbiotic species (i.e., &lt;i&gt;Leohumicola&lt;/i&gt; and &lt;i&gt;Hyalodendriella&lt;/i&gt;). The relative abundance of pathogenic fungi, namely &lt;i&gt;Sarocladium, Fusarium,&lt;/i&gt; and &lt;i&gt;Fusicolla,&lt;/i&gt; increased significantly in the NPK treatment. Long-term straw returning in the NPKS treatment significantly stimulated the growth of plant growth-promoting species (i.e., &lt;i&gt;Pseudogymnoascus&lt;/i&gt; and &lt;i&gt;Schizothecium&lt;/i&gt;) and straw-degrading species (i.e., &lt;i&gt;Trichocladium&lt;/i&gt; and &lt;i&gt;Lobulomyces&lt;/i&gt;). Co-occurrence network analysis showed that the fungal network was composed of four main modules; the cumulative relative abundance of module 2 was significantly increased under the NPKS treatment and showed a positive linear correlation with DHA and &lt;i&gt;β&lt;/i&gt;-GC. The structural equation model further indicated that the wheat yield was mainly regulated by SOM, whereas species of module 2 could indirectly affect SOM and wheat yield by positively regulating DHA and &lt;i&gt;β&lt;/i&gt;-GC. Taken together, long-term straw returning to the fluvo-aquic soil area of the Huang-Huai-Hai Plain could regulate fungal interspecific interactions, stimulate the growth of specific species groups, inhibit the activity of pathoge","PeriodicalId":172067,"journal":{"name":"Huan jing ke xue= Huanjing kexue","volume":"43 10","pages":"4755-4764"},"PeriodicalIF":0.0,"publicationDate":"2022-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33501767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Chemical Component of Particulate Matters and VOCs Characteristics During Vehicle Brake Processes].","authors":"Zheng-Yu Men,&nbsp;Du-You Liu,&nbsp;Quan-You Guo,&nbsp;Jing Zhang,&nbsp;Jian-Fei Peng,&nbsp;Lin Wu,&nbsp;Hong-Jun Mao","doi":"10.13227/j.hjkx.202112127","DOIUrl":"https://doi.org/10.13227/j.hjkx.202112127","url":null,"abstract":"<p><p>Six sets of brake systems were tested using a brake dynamometer, and the brake wear particles (BWPs) and volatile organic compounds (VOCs) were collected during the braking process. In total, 39 elements, 12 water-soluble ions, 7 carbon components, and 18 polycyclic aromatic hydrocarbons (PAHs) in BWPs were extracted and detected, and 74 VOCs in gas samples were analyzed. The average mass fractions of 12 inorganic elements (i.e., Sb, Mg, Cu, Zn, Ti, Ca, Si, Zr, K, Ba, Al, and Fe) with higher contents in PM_2.5 and PM₁₀ were 43.4% and 40.3%, respectively, and the average mass fraction of Fe was the highest, accounting for 16.6% and 13.1% of PM_2.5 and PM₁₀, respectively. The average mass fractions of the 12 water-soluble ions in PM_2.5 and PM₁₀ were 16.5% and 12.6%, respectively, and NO₃^-, SO₄^2-, and Ca²⁺ were the ions with high contents. The average mass fraction of total carbon (TC) in PM_2.5 and PM₁₀ were 21.9% and 18.1%, respectively, and the average mass fraction of organic carbon (OC) was approximately five times that of elemental carbon (EC). There were six types of PAHs with a detection rate greater than 50%, among which naphthalene (Nap) was the most abundant. The average mass concentration of 74 VOCs was 316.04 μg·m^-3, of which the aromatic hydrocarbon had the highest mass concentration. The compositions of BWPs and VOCs emitted by the six sets of brake systems were quite different, which was mainly determined by the brand and raw materials of the brake pads.</p>","PeriodicalId":172067,"journal":{"name":"Huan jing ke xue= Huanjing kexue","volume":"43 10","pages":"4348-4356"},"PeriodicalIF":0.0,"publicationDate":"2022-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33502615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Effect of Aging on Adsorption of Tetracycline by Microplastics and the Mechanisms].","authors":"Lin Wang,&nbsp;Shu-Xin Wang,&nbsp;Xiang-Ying Zeng,&nbsp;Yang He,&nbsp;Wen Huang,&nbsp;Shi-Jie Zheng,&nbsp;Jian-Qiang Zhang","doi":"10.13227/j.hjkx.202112299","DOIUrl":"https://doi.org/10.13227/j.hjkx.202112299","url":null,"abstract":"<p><p>As new pollutants, microplastics (MPs) can adsorb antibiotics in the water environment and migrate together as carriers. However, microplastics will age continuously in the environment, and their adsorption capacity and adsorption mechanism will change accordingly. With polyethylene (PE) and polystyrene (PS) as the target MPs, which were irradiated by ultraviolet (UV-254), the changes in the physical and chemical properties of MPs before and after aging, such as the color, surface morphology, and functional groups, were compared, and their effects on the adsorption of tetracycline (TC) as well as the related mechanism were explored. The results showed that the pseudo-second-order model could better fit the adsorption process, the adsorption equilibrium was reached within 24 hours, the adsorption capacity of aged MPs for TC was significantly higher than that of original MPs, and the adsorption capacity of PS was higher than that of PE. Langmuir and Freundlich isothermal adsorption equations could both describe the adsorption isothermal test data, and the adsorption of TC on MPs was a spontaneous and endothermic physical adsorption process, whereas aging had no obvious effect on the adsorption thermodynamic characteristics of MPs. With the increase in pH value, the adsorption capacity first increased and then decreased. The maximum adsorption capacity of MPs before and after aging was reached at pH=5. UV aging increased the specific surface area of MPs, generating oxygen-containing functional groups such as -C＝O, -OH, and O＝C＝O, changing the physical and chemical properties of MPs, and thus changing the adsorption mechanism of MPs for TC. Compared with the original PE MPs, in addition to hydrophobic distribution, van der Waals forces, and electrostatic interactions, pore filling was also an important adsorption mechanism of aged PE. The main adsorption mechanisms of original PS microplastics were hydrophobic distribution, van der Waals forces, electrostatic interaction, and π-π interaction, whereas there was hydrogen bonding for aged PS.</p>","PeriodicalId":172067,"journal":{"name":"Huan jing ke xue= Huanjing kexue","volume":"43 10","pages":"4511-4521"},"PeriodicalIF":0.0,"publicationDate":"2022-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33502929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Effect of Nitrogen on the Phytoremediation of Cd-PAHs Co-contaminated Dumpsite Soil by Alfalfa (<i>Medicago sativa</i> L.) and on the Soil Bacterial Community Structure].","authors":"Yi-Jia Li,&nbsp;Jun-Wei Ma,&nbsp;Yu-Qian Li,&nbsp;Chen Xiao,&nbsp;Xin-Yi Shen,&nbsp;Yun Xiu,&nbsp;Jia-Jun Chen","doi":"10.13227/j.hjkx.202112006","DOIUrl":"https://doi.org/10.13227/j.hjkx.202112006","url":null,"abstract":"<p><p>The key point in facing the demand for the disposal of waste storage in rural areas of China is to manage informal landfills. However, limited studies have been conducted to evaluate the phytoremediation efficiency of heavy metal and polycyclic aromatic hydrocarbon (PAHs) co-contaminated dumpsite soil with high ammonia nitrogen content. In this study, we selected the tolerant plant legume alfalfa (<i>Medicago sativa</i> L.) for a pot experiment to investigate the effects of nitrogen (N) (0, 10, and 50 mg·kg^-1) on plant growth, the removal of pollutants, and soil bacterial community structure in Cd-PAHs co-contaminated soil, so as to evaluate the role of N in the process of phytoremediation of dumpsite soil. The results showed that the biomass of alfalfa under high co-contamination conditions (Cd:10 mg·kg^-1 and PAHs:400 mg·kg^-1) increased with N supply and was 6.0 and 6.3 times higher than that of the treatment without N supply, respectively. Furthermore, the lower N level promoted the growth of alfalfa in the low-contamination group (Cd:1 mg·kg^-1 and PAHs:100 mg·kg^-1), but the difference was not significant, and a high concentration of N significantly inhibited its growth. In addition, the phytoremediation efficiency for Cd in the low-contamination group ranged from 5.58% to 7.49%, and N significantly increased the efficiency in the high co-contamination group from 0.95% to 3.02%. Compared with the removal of phenanthrene, N had a stronger influence on the removal of pyrene. Meanwhile, alfalfa could promote the removal of them in soil, among which the degradation of PAHs by microorganisms was dominant, whereas the contribution of the plant uptake pathway was less than 0.21%. As reflected by distance-based redundancy analysis (db-RDA), PAHs and Cd were the main factors affecting the structure of the microbial community; moreover, N had a greater effect on bacterial community composition in the single Cd-contamination and high co-contamination groups, promoting genera with bioremediation effects as the dominant soil bacterial communities, including <i>Arthrobacter, Microbacterium</i>, and <i>Novosphingobium</i>. This study will provide a theoretical basis for the remediation of dumpsites as well as informal landfills with contaminated soil.</p>","PeriodicalId":172067,"journal":{"name":"Huan jing ke xue= Huanjing kexue","volume":"43 10","pages":"4779-4788"},"PeriodicalIF":0.0,"publicationDate":"2022-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33526056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Accumulation Characteristics and Sources of PAEs in Agricultural Soils in Gansu Province].","authors":"Yu-Yu Chen,&nbsp;Guang-Quan Zhang,&nbsp;Yang Zhang,&nbsp;Ming-Kai Li,&nbsp;Jia-Xin Hao,&nbsp;You-Cai Xiong,&nbsp;Chong-Xiao Li,&nbsp;Jing Cao","doi":"10.13227/j.hjkx.202111310","DOIUrl":"https://doi.org/10.13227/j.hjkx.202111310","url":null,"abstract":"<p><p>In order to understand the composition and accumulation characteristics of phthalates esters (PAEs) in agricultural soils in Gansu province, a total of 41 soil samples from four agricultural soils in Gansu province were collected, and the content of six PAEs compounds was analyzed using a gas chromatography-single quadrupole mass spectrometer (GC-MS). The results showed that the average value of PAEs compounds in agricultural soils in Gansu province was 432.4 μg·kg^-1. The detection rates of DMP, DEP, DnBP, DEHP, and DNOP in the soil were 100%, and BBP was not detected. The order of the average value of PAEs content in the four agricultural soils in Gansu province was:greenhouse>farmland (open field)>forest>grassland. The exceeding rates of dibutyl phthalate (DnBP), dimethyl phthalate (DMP), and dimethyl phthalate (DEP) were 94%, 28%, and 27%, and the remaining three did not exceed the standard. The composition of PAEs in different agricultural soils was different due to their different sources. DEHP and DnBP components in the six different PAEs monomers accounted for a higher proportion and were the main pollutants of PAEs in agricultural soils in Gansu province. In this study, the contents of soil PAEs and DEHP were significantly positively correlated with the residual amount of mulch film in the farmland (<i>P</i><0.05). In general, the content of soil PAEs in the Hexi area of Gansu province was significantly higher than that in the Longdong area.</p>","PeriodicalId":172067,"journal":{"name":"Huan jing ke xue= Huanjing kexue","volume":"43 10","pages":"4622-4629"},"PeriodicalIF":0.0,"publicationDate":"2022-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33500854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Spatial Distribution and Sources of Heavy Metals in Soil of a Typical Lead-Zinc Mining Area, Yangshuo].","authors":"Meng Chen,&nbsp;Yong-Xing Pan,&nbsp;Yi-Xiang Huang,&nbsp;Xiao-Tong Wang,&nbsp;Rui-Dong Zhang","doi":"10.13227/j.hjkx.202201127","DOIUrl":"https://doi.org/10.13227/j.hjkx.202201127","url":null,"abstract":"<p><p>Taking a typical lead-zinc mining area in Yangshuo county, Guangxi as the research object, the contents of 10 metal elements (Cr, Mn, Ni, Cu, Zn, As, Cd, Sb, Hg, and Pb) in the surface soil of Sidihe River basin in Yangshuo were analyzed and determined. Pearson correlation analysis, principal component analysis (PCA), positive definite matrix factorization (PMF), and other methods were comprehensively used to quantitatively analyze their contributions and identify pollution sources. In total, 168 surface soil samples were collected across the study area. The mean concentrations of Zn, Cd, Hg, and Pb in the soils were higher than the National Environmental Quality Standards for Soils in China. The mean contents of Sb, Cd, Cu, Pb, and Zn were higher than their corresponding local background values by approximately 1.01, 5.50, 3.29, 9.11, and 10.67 times, respectively, indicating that heavy metals have been enriched in topsoil. The <i>I</i>_geo showed that the major pollutant element in the soils was Hg, followed by Pb, Zn, and Mn. Correlation analysis and principal component analysis showed that the sources of metal pollution in surface soil in the study area were complex and mainly from human activities. Cu, Zn, Cd, Sb, As, and Pb were mainly derived from mining activities; Hg, Cr, and Ni were controlled by soil parent material sources; and Mn and Cd were mainly derived from mining activities and agricultural activities. PMF model analysis results showed that the metal pollution sources in the surface soil were jointly affected by these three sources. Mining activities, natural sources, and a mixed source of mining activities and agricultural activities were the main sources of heavy metal pollution in the soils, accounting for 58.0%, 13.5%, and 28.6% of the total heavy metal accumulation, respectively. Ni, Cu, Zn, As, Sb, Hg, and Pb were derived mainly from mining activities. Cr, Ni, and Hg were mainly attributed to natural sources, such as soil parent materials and rainfall erosion (44.6%, 23.2%, and 21.0%, respectively), and Mn and Cd were associated with a mixed source of mining activities and agricultural activities (75.4% and 70.4%).</p>","PeriodicalId":172067,"journal":{"name":"Huan jing ke xue= Huanjing kexue","volume":"43 10","pages":"4545-4555"},"PeriodicalIF":0.0,"publicationDate":"2022-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33501413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Effects of Nutrients on the Growth of <i>Microcystis aeruginosa</i> and Bacteria in the Phycosphere].","authors":"Ping Lü,&nbsp;Hui-Li Li,&nbsp;Yong Xu,&nbsp;Xiao-Xu Zheng,&nbsp;Zhen-Hua Huang,&nbsp;Cong Wang,&nbsp;Sheng-Jun Xu,&nbsp;Xu-Liang Zhuang","doi":"10.13227/j.hjkx.202201159","DOIUrl":"https://doi.org/10.13227/j.hjkx.202201159","url":null,"abstract":"<p><p>The \"bacteria-algae\" system plays an important role in water ecosystems. The effects of bacteria in phycospheres on the growth of <i>Microcystis aeruginosa</i> under in-situ nutrient stimulation were studied to explore the bacteria-algae interaction during a cyanobacteria bloom. The results showed that LB medium could inhibit the growth of <i>M. aeruginosa</i>, and the algicidal rate was 86.49%. Sodium acetate, glucose, and sodium citrate could promote <i>M. aeruginosa</i>, and the growth rate was more than 50%. The addition of nutrients in <i>M. aeruginosa</i> could have changed the biocoenosis in the phycosphere and increased the species richness by 16S rRNA gene sequencing, and the number of bacteria in the phycosphere increased dramatically in the LB medium and peptone groups. The physiological and biochemical responses showed that algae suffered serious lipid peroxidation, and superoxide dismutase (SOD) and catalase (CAT) activities first increased significantly and subsequently decreased under the oxidative stress of LB medium or peptone. Scanning electron microscopy (SEM) indicated that the surface of algae cells appeared wrinkled, invaded, and atrophied under LB medium stimulation, whereas bacteria in the phycosphere significantly increased. Furthermore, six strains of algicidal bacteria were isolated from the LB medium and peptone groups, and the algicidal rate of <i>Bacillus</i> sp. A1 was 97.55%, which confirmed that the phycosphere of <i>M. aeruginosa</i> included algicidal bacteria. Therefore, appropriate external nutrient stimulation can produce algicidal bacteria in situ to prevent cyanobacterial blooms.</p>","PeriodicalId":172067,"journal":{"name":"Huan jing ke xue= Huanjing kexue","volume":"43 10","pages":"4502-4510"},"PeriodicalIF":0.0,"publicationDate":"2022-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33502928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Effect of Antibiotic-Degrading Bacteria on Maturity and Bacterial Community Succession During Pig Manure Composting].","authors":"Wei-Lin Li,&nbsp;Xin Zhang,&nbsp;Jun-Wei Ma,&nbsp;Wan-Chun Sun,&nbsp;Qi-Lu Cheng,&nbsp;Hui Lin","doi":"10.13227/j.hjkx.202111253","DOIUrl":"https://doi.org/10.13227/j.hjkx.202111253","url":null,"abstract":"<p><p>The inoculation of antibiotic-degrading bacteria into manure could promote the removal of antibiotics during composting. However, knowledge on the impact of inoculating these antibiotic-degrading bacteria on the composting process and indigenous microbial community succession is still limited. This study assessed the antibiotic removal efficiency in pig manure after inoculating a microbial inoculum with antibiotic-degrading bacteria as the key component. The effect of inoculating this microbial inoculum on the physicochemical dynamics and the succession of the manure bacterial community during composting was also analyzed. The results showed that the antibiotic degradation in pig manure reached 81.95% after inoculating the microbial inoculum. When compared with that in the control, the total concentration of antibiotic residues in manure with the microbial agent inoculated was decreased by 42.18%. During composting, inoculating the microbial inoculum accelerated the temperature rise of compost, favored water loss, and alleviated the release of NH₃ and H₂S. Moreover, the total nutrient content (nitrogen, phosphorus, and potassium) in the final compost and the germination index of radish seeds increased by 6.80% and 68.33%, respectively, after inoculating this microbial inoculum. Furthermore, inoculating the microbial inoculum increased the content of stable organic carbon in the final compost and decreased the content of recalcitrant substances such as cellulose and hemicellulose. The analysis of the manure bacterial community showed that inoculating the microbial inoculum increased the relative abundances of Actinomycetes and Firmicutes in the compost. In particular, the thermophilic bacteria that was positively related to the compost temperature was increased significantly (<i>P</i><0.01) after inoculating the microbial inoculum, whereas the relative abundance of pathogenic bacteria was correspondingly decreased. Network analysis of the bacterial coexistence pattern showed that inoculating this microbial inoculum also changed the interaction pattern of indigenous manure bacterial communities, which greatly reduced the complexity and connectivity of the bacterial interaction and improved the ecological relationship between beneficial bacteria and other bacterial communities. The effect of this microbial inoculum on the interaction with manure bacterial community laid a foundation for the establishment of a new and healthier composting bacterial community. This study provides a scientific basis for the application and development of multifunctional antibiotic-degrading microbial agents in manure treatments.</p>","PeriodicalId":172067,"journal":{"name":"Huan jing ke xue= Huanjing kexue","volume":"43 10","pages":"4789-4800"},"PeriodicalIF":0.0,"publicationDate":"2022-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33526057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Historical Antibiotic Stress Changed the Effects of Sulfamethoxazole and Trimethoprim on Activated Sludge: ARGs and Potential Hosts].","authors":"Zhong-Xing Zhang,&nbsp;Xiao-Yan Fan,&nbsp;Xing Li,&nbsp;Yu-Xi Gao,&nbsp;Jun-Ru Zhao","doi":"10.13227/j.hjkx.202201136","DOIUrl":"https://doi.org/10.13227/j.hjkx.202201136","url":null,"abstract":"<p><p>The co-exposure of antibiotics has important effects on antibiotic resistance genes (ARGs) and microbial community aggregation in wastewater treatment plants (WWTPs). However, it is unclear whether differences in historical antibiotic exposure stress can determine responses of microbes and ARGs to combined antibiotics. By selecting a high concentration (30 mg·L^-1) of sulfamethoxazole (SMX) and trimethoprim (TMP) as historical exposure stress conditions, the effects of SMX and TMP-combined pollution on ARGs, bacterial communities, and their interactions were explored in short-term experiments. Based on high-throughput quantitative PCR, a total of 13 ARGs were detected, and the absolute abundance was 2.21-5.42 copies·μL^-1 (logarithm, DNA, the same below). Among them, <i>sul2, ermB, mefA</i>, and <i>tetM-01</i> were the main subtypes in the samples, and the absolute abundance was between 2.95 and 5.40 copies·μL^-1. The combined contamination of SMX and TMP could cause the enrichment of ARGs and mobile genetic elements (MGEs); however, their effects on each subtype were different, and the historical legacy effect of SMX was higher than that of TMP. Under the different exposure histories, the co-occurrence and co-exclusion patterns existed between ARGs. Moreover, MGEs (especially <i>intI-1</i>) were significantly correlated with sulfonamides (<i>sul1</i> and <i>sul2</i>), tetracyclines[<i>tet(32)</i>], and macrolide-lincosamide-streptogramin (MLSB) resistance genes (<i>ermB</i>). Based on the full-scale classification of microorganisms, it was found that the microbial community structure of various groups responded differently to combined pollution, and the conditionally abundant taxa (CAT) were obviously enriched. <i>Thauera, Pseudoxanthomonas,</i> and <i>Paracoccus</i> were the dominant resistant bacterial genera. Furthermore, a total of 31 potential hosts of ARGs were identified with network analysis, which were dominated with conditionally rare taxa (CRT). Particularly, <i>Candidatus_Alysiosphaera</i> and <i>Fusibacter</i> were positively correlated with most of the ARGs, being the common protentional hosts. Importantly, some rare genera (RT, <i>Variibacter, Aeromonas, Cloacibacterium</i>, etc.) were potential hosts of transposon <i>IS613</i>, which played an important role in the proliferation and spread of ARGs. In conclusion, this study revealed the legacy effects of historical antibiotic stress on ARGs and their hosts, which could provide new ideas and theoretical basis for reducing ARGs pollution in WWTPs.</p>","PeriodicalId":172067,"journal":{"name":"Huan jing ke xue= Huanjing kexue","volume":"43 10","pages":"4536-4544"},"PeriodicalIF":0.0,"publicationDate":"2022-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33501412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}