Journal articles: 'Impact on microbial community'

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Сhirаnjeeb, Kumаr. "Effect of Climatic Change on Soil Microbial Community." Emerging Trends in Climate Change 1, no. 2 (July 28, 2022): 1–8. http://dx.doi.org/10.18782/2583-4770.106.

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Climate change is the most severe problem that adversely affects crop productivity and negatively impacts soil microbial biodiversity, which is considered the key component of soil fertility indicators. Microbial biodiversity regulates all necessary functions to strengthen and maintain the stability of the ecosystem. Climate change primarily affects the crop microclimate, which in turn destroys the ecological balance and disrupts the ideal growth conditions for the crops and hampers the proliferation of microorganisms in the environment, thus decreasing crop production over a particular region. Climate change conditions such as higher temperature, rainfall and other abrupt conditions destroy the equilibrium between microbes, plants and the environment to a large extent, altering the plant-microbe interactions. Higher Carbon dioxide concentration favours the crop in photosynthesis and helps achieve higher productivity. Microbial respiration also enhances the carbon dioxide concentration in the atmosphere, leading to global warming and other potentially hazardous conditions. Mitigation strategies on crop, soil and land management measures are important to counteract the negative impact of climate change.

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RINGELBERG, D. B., C. M. REYNOLDS, and L. KARR. "Microbial Community Composition Near Depleted Uranium Impact Points." Soil and Sediment Contamination: An International Journal 13, no. 6 (November 2004): 563–77. http://dx.doi.org/10.1080/10588330490519446.

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Jingang, Liang, Luan Ying, Jiao Yue, Sun Shi, Wu Cunxiang, Wu Haiying, Zhang Mingrong, Zhang Haifeng, Zheng Xiaobo, and Zhang Zhengguang. "High-methionine soybean has no significant effect on nitrogen-transforming bacteria in rhizosphere soil." Plant, Soil and Environment 64, No. 3 (March 21, 2018): 108–13. http://dx.doi.org/10.17221/750/2017-pse.

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Transgenic plants may induce shifts in the microbial community composition that in turn alter microbially-mediated nutrient cycling in soil. Studies of how specific microbial groups respond to genetically modified (GM) planting help predict potential impacts upon processes performed by these groups. This study investigated the effect of transgenic high-methionine soybean cv. ZD91 on nitrogen-fixing and ammonia-oxidizing bacterial populations. A difference in nitrogen-fixing or ammonia-oxidizing bacteria community composition was not found, suggesting that cv. ZD91 does not alter the bacterial populations in rhizosphere soil. This study increases our understanding of the potential effect of transgenic soybean on microbial functional groups within soil by suggesting that nitrogen-transforming bacteria may be useful for future investigations on the GM crops impact in the soil ecosystem.

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Matusiak, Katarzyna, Sebastian Borowski, Sebastian Opaliński, Tadeusz Bakuła, Roman Kołacz, and Beata Gutarowska. "Impact of a microbial-mineral biopreparation on microbial community and deodorization of manures." Acta Biochimica Polonica 62, no. 4 (2015): 791–98. http://dx.doi.org/10.18388/abp.2015_1135.

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Tamminen, Manu, Jenny Spaak, Ahmed Tlili, Rik Eggen, Christian Stamm, and Katja Räsänen. "Wastewater constituents impact biofilm microbial community in receiving streams." Science of The Total Environment 807 (February 2022): 151080. http://dx.doi.org/10.1016/j.scitotenv.2021.151080.

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Massana, Ramon, Josep M. Gasol, Klaus J¨rgens, and Carlos Pedròs-Aliò. "Impact of Daphnia pulex on a metalimnetic microbial community." Journal of Plankton Research 16, no. 10 (1994): 1379–99. http://dx.doi.org/10.1093/plankt/16.10.1379.

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Tong, Zhonghua, Marianne Bischoff, Loring Nies, Bruce Applegate, and Ronald F. Turco. "Impact of Fullerene (C60) on a Soil Microbial Community." Environmental Science & Technology 41, no. 8 (April 2007): 2985–91. http://dx.doi.org/10.1021/es061953l.

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An, Lingling. "Accurate Prediction of Death Time via Integrating Microbial Community Dynamics." International Journal of Forensic Sciences 9, no. 1 (2024): 1–9. http://dx.doi.org/10.23880/ijfsc-16000353.

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This study addresses the challenge of accurately estimating Postmortem Interval (PMI), the time since death, employing a data-driven approach. PMI determination is crucial in forensic investigations, and traditional methods often lack precision. We focus on utilizing a data mining approach Regularized Random Forest with cross-validation to enhance PMI prediction accuracy. Unlike conventional methods, our approach incorporates external information about the deceased, recognizing the impact of contextual factors on PMI estimation. Recent advancements have seen statistical methods leveraging dynamic changes in microbial communities to predict PMI. However, accuracy has been hindered by various sources of noise. To overcome this limitation, we propose a novel data mining approach, integrating cross-validation techniques and external information to refine PMI predictions. Through an empirical demonstration, we establish that our approach surpasses existing procedures in terms of accuracy, as validated against published datasets. This research contributes to the advancement of PMI estimation methodologies, emphasizing the importance of incorporating comprehensive data mining techniques and contextual information for more precise forensic applications.

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Ibekwe, A. Mark, Sharon K. Papiernik, Jianying Gan, Scott R. Yates, Ching-Hong Yang, and David E. Crowley. "Impact of Fumigants on Soil Microbial Communities." Applied and Environmental Microbiology 67, no. 7 (July 1, 2001): 3245–57. http://dx.doi.org/10.1128/aem.67.7.3245-3257.2001.

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ABSTRACT Agricultural soils are typically fumigated to provide effective control of nematodes, soilborne pathogens, and weeds in preparation for planting of high-value cash crops. The ability of soil microbial communities to recover after treatment with fumigants was examined using culture-dependent (Biolog) and culture-independent (phospholipid fatty acid [PLFA] analysis and denaturing gradient gel electrophoresis [DGGE] of 16S ribosomal DNA [rDNA] fragments amplified directly from soil DNA) approaches. Changes in soil microbial community structure were examined in a microcosm experiment following the application of methyl bromide (MeBr), methyl isothiocyanate, 1,3-dichloropropene (1,3-D), and chloropicrin. Variations among Biolog fingerprints showed that the effect of MeBr on heterotrophic microbial activities was most severe in the first week and that thereafter the effects of MeBr and the other fumigants were expressed at much lower levels. The results of PLFA analysis demonstrated a community shift in all treatments to a community dominated by gram-positive bacterial biomass. Different 16S rDNA profiles from fumigated soils were quantified by analyzing the DGGE band patterns. The Shannon-Weaver index of diversity,H, was calculated for each fumigated soil sample. High diversity indices were maintained between the control soil and the fumigant-treated soils, except for MeBr (H decreased from 1.14 to 0.13). After 12 weeks of incubation, Hincreased to 0.73 in the MeBr-treated samples. Sequence analysis of clones generated from unique bands showed the presence of taxonomically unique clones that had emerged from the MeBr-treated samples and were dominated by clones closely related to Bacillus spp. andHeliothrix oregonensis. Variations in the data were much higher in the Biolog assay than in the PLFA and DGGE assays, suggesting a high sensitivity of PLFA analysis and DGGE in monitoring the effects of fumigants on soil community composition and structure. Our results indicate that MeBr has the greatest impact on soil microbial communities and that 1,3-D has the least impact.

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Mlejnková, H., and K. Sovová. "Impact of pollution and seasonal changes on microbial community structure in surface water." Water Science and Technology 61, no. 11 (June 1, 2010): 2787–95. http://dx.doi.org/10.2166/wst.2010.080.

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We studied the differences in a microbial community structure with respect to the water pollution level and seasonal changes. The determination of phylogenetic groups of Bacteria and Archaea was done using fluorescent in situ hybridization (FISH). The total number of microorganisms was determined by direct counting of DAPI (4′,6-diamidino-2-phenylindole) stained samples using a fluorescence microscope. Our results showed that the microbial community structure was significantly dependent on the level of water pollution, both in absolute microbial counts and in relative abundance of phylogenetic groups. For surface water with anthropogenic pollution, the microbial community with significant proportion of Betaproteobacteria and Cytophaga-Flavobacterium was characteristic. Gammaproteobacteria were significant in municipal waste water. In microbial communities with low numbers of microorganisms (e.g. non-polluted water and some industrial waste water) represented the significant component groups Alphaproteobacteria and Archaea. The impact of seasonal changes on the microbial distribution was not significant.

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Gong, Xiao Min, Jie Dong, and Wei Jun Tian. "A Review of Impacts of Agricultural Non-Point Source Pollution on Microbial Community in Riparian Zone." Advanced Materials Research 610-613 (December 2012): 1975–79. http://dx.doi.org/10.4028/www.scientific.net/amr.610-613.1975.

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In recent years, continuous input of exogenous pollutants has changed the original environment of riparian zone, impacting on soil biological community and the stability of ecosystem at the riparian zone. Therefore, it is necessary to study these impacts for environmental protection and providing scientific basis for environmental decision-makers. In this paper, the author took the microbial community of riparian zone as an example and reviewed the relevant literatures at home and abroad published latest years. The impacts of exogenous contamination on microbial community succession in riparian zone were been discussed, and microbial species, microbial biomass and community information were been revealed for understanding the impact of continuous input of exogenous pollutants on micro-ecosystem structure and function and the degree and finding out the leading pollutants in riparian zone. The paper has a great significance to the development of microbial resources and protection of riparian zone.

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Alseth, Ellinor O., Rafael Custodio, Sarah A. Sundius, Rachel A. Kuske, Sam P. Brown, and Edze R. Westra. "The impact of phage and phage resistance on microbial community dynamics." PLOS Biology 22, no. 4 (April 22, 2024): e3002346. http://dx.doi.org/10.1371/journal.pbio.3002346.

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Where there are bacteria, there will be bacteriophages. These viruses are known to be important players in shaping the wider microbial community in which they are embedded, with potential implications for human health. On the other hand, bacteria possess a range of distinct immune mechanisms that provide protection against bacteriophages, including the mutation or complete loss of the phage receptor, and CRISPR-Cas adaptive immunity. While our previous work showed how a microbial community may impact phage resistance evolution, little is known about the inverse, namely how interactions between phages and these different phage resistance mechanisms affect the wider microbial community in which they are embedded. Here, we conducted a 10-day, fully factorial evolution experiment to examine how phage impact the structure and dynamics of an artificial four-species bacterial community that includes either Pseudomonas aeruginosa wild-type or an isogenic mutant unable to evolve phage resistance through CRISPR-Cas. Additionally, we used mathematical modelling to explore the ecological interactions underlying full community behaviour, as well as to identify general principles governing the impacts of phage on community dynamics. Our results show that the microbial community structure is drastically altered by the addition of phage, with Acinetobacter baumannii becoming the dominant species and P. aeruginosa being driven nearly extinct, whereas P. aeruginosa outcompetes the other species in the absence of phage. Moreover, we find that a P. aeruginosa strain with the ability to evolve CRISPR-based resistance generally does better when in the presence of A. baumannii, but that this benefit is largely lost over time as phage is driven extinct. Finally, we show that pairwise data alone is insufficient when modelling our microbial community, both with and without phage, highlighting the importance of higher order interactions in governing multispecies dynamics in complex communities. Combined, our data clearly illustrate how phage targeting a dominant species allows for the competitive release of the strongest competitor while also contributing to community diversity maintenance and potentially preventing the reinvasion of the target species, and underline the importance of mapping community composition before therapeutically applying phage.

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Singer, Esther, Elizabeth M. Carpenter, Jason Bonnette, Tanja Woyke, and Thomas E. Juenger. "Impact of Harvest on Switchgrass Leaf Microbial Communities." Genes 13, no. 1 (December 22, 2021): 22. http://dx.doi.org/10.3390/genes13010022.

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Switchgrass is a promising feedstock for biofuel production, with potential for leveraging its native microbial community to increase productivity and resilience to environmental stress. Here, we characterized the bacterial, archaeal and fungal diversity of the leaf microbial community associated with four switchgrass (Panicum virgatum) genotypes, subjected to two harvest treatments (annual harvest and unharvested control), and two fertilization levels (fertilized and unfertilized control), based on 16S rRNA gene and internal transcribed spacer (ITS) region amplicon sequencing. Leaf surface and leaf endosphere bacterial communities were significantly different with Alphaproteobacteria enriched in the leaf surface and Gammaproteobacteria and Bacilli enriched in the leaf endosphere. Harvest treatment significantly shifted presence/absence and abundances of bacterial and fungal leaf surface community members: Gammaproteobacteria were significantly enriched in harvested and Alphaproteobacteria were significantly enriched in unharvested leaf surface communities. These shifts were most prominent in the upland genotype DAC where the leaf surface showed the highest enrichment of Gammaproteobacteria, including taxa with 100% identity to those previously shown to have phytopathogenic function. Fertilization did not have any significant impact on bacterial or fungal communities. We also identified bacterial and fungal taxa present in both the leaf surface and leaf endosphere across all genotypes and treatments. These core taxa were dominated by Methylobacterium, Enterobacteriaceae, and Curtobacterium, in addition to Aureobasidium, Cladosporium, Alternaria and Dothideales. Local core leaf bacterial and fungal taxa represent promising targets for plant microbe engineering and manipulation across various genotypes and harvest treatments. Our study showcases, for the first time, the significant impact that harvest treatment can have on bacterial and fungal taxa inhabiting switchgrass leaves and the need to include this factor in future plant microbial community studies.

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Wang, Ji Hua, Xue Gong, Jian Fei Guan, and Hui Yan Xing. "The Impact of Reclaimed Water Irrigation on Soil Microbial Community Structure." Advanced Materials Research 955-959 (June 2014): 3635–39. http://dx.doi.org/10.4028/www.scientific.net/amr.955-959.3635.

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The reclaimed water treated in a Harbin recycled water plant has been taken as a target of research, by using microbial traditional culture method and tablet coated counting method, discussing the influence of the reclaimed water irrigation on soil microbial community structure through the method of short-term indoor simulated soil column irrigation. The results shows that the reclaimed water irrigation can significantly increase the quantity of bacteria and actinomycetes in the surface 0-20 cm layer soil, but it has little affect on 20-40 cm and 40-60 cm layer soil. Microbial community structure and diversity were changed relatively with the irrigation of reclaimed water, which embodied the increase or decrease of dominant and subdominant groups, the disappearance of non-dominant groups sensitive to reclaimed water, the appear or disappear of the other part of the occasional groups.

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Mathew, Reji P., Yucheng Feng, Leonard Githinji, Ramble Ankumah, and Kipling S. Balkcom. "Impact of No-Tillage and Conventional Tillage Systems on Soil Microbial Communities." Applied and Environmental Soil Science 2012 (2012): 1–10. http://dx.doi.org/10.1155/2012/548620.

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Soil management practices influence soil physical and chemical characteristics and bring about changes in the soil microbial community structure and function. In this study, the effects of long-term conventional and no-tillage practices on microbial community structure, enzyme activities, and selected physicochemical properties were determined in a continuous corn system on a Decatur silt loam soil. The long-term no-tillage treatment resulted in higher soil carbon and nitrogen contents, viable microbial biomass, and phosphatase activities at the 0–5 cm depth than the conventional tillage treatment. Soil microbial community structure assessed using phospholipid fatty acid (PLFA) analysis and automated ribosomal intergenic spacer analysis (ARISA) varied by tillage practice and soil depth. The abundance of PLFAs indicative of fungi, bacteria, arbuscular mycorrhizal fungi, and actinobacteria was consistently higher in the no-till surface soil. Results of principal components analysis based on soil physicochemical and enzyme variables were in agreement with those based on PLFA and ARISA profiles. Soil organic carbon was positively correlated with most of the PLFA biomarkers. These results indicate that tillage practice and soil depth were two important factors affecting soil microbial community structure and activity, and conservation tillage practices improve both physicochemical and microbiological properties of soil.

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Ksontini, H., F. Kachouri, and M. Hamdi. "Dairy Biofilm: Impact of Microbial Community on Raw Milk Quality." Journal of Food Quality 36, no. 4 (August 2013): 282–90. http://dx.doi.org/10.1111/jfq.12036.

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Alkan, Hakan, Soujatya Mukherjee, and Felix Kögler. "Reservoir engineering of in-situ MEOR; impact of microbial community." Journal of Petroleum Science and Engineering 195 (December 2020): 107928. http://dx.doi.org/10.1016/j.petrol.2020.107928.

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Nemani, Vivek A., Michael J. McKie, Liz Taylor-Edmonds, and Robert C. Andrews. "Impact of biofilter operation on microbial community structure and performance." Journal of Water Process Engineering 24 (August 2018): 35–41. http://dx.doi.org/10.1016/j.jwpe.2018.05.009.

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Eckert, Ester M., Andrea Di Cesare, Marie Therese Kettner, Maria Arias-Andres, Diego Fontaneto, Hans-Peter Grossart, and Gianluca Corno. "Microplastics increase impact of treated wastewater on freshwater microbial community." Environmental Pollution 234 (March 2018): 495–502. http://dx.doi.org/10.1016/j.envpol.2017.11.070.

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Akari, Maiko, and Yoshitaka Uchida. "Survival Rates of Microbial Communities from Livestock Waste to Soils: A Comparison between Compost and Digestate." Applied and Environmental Soil Science 2021 (January 29, 2021): 1–15. http://dx.doi.org/10.1155/2021/6645203.

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Livestock waste-based products, such as composted manure, are often used in crop production systems. The products’ microbial characteristics differ depending on animal waste treatment methods used (e.g., biogas production/composting). The question remains whether different livestock waste-based products differently impact soil microbiota. A pot experiment with five treatments (control, chemical fertilizer, digestate + chemical fertilizer, wheat straw compost + chemical fertilizer, and woodchip compost + chemical fertilizer) was conducted to compare the survival rates of microbial communities from digestate and composted manure, after their application to agricultural soil. Potatoes were planted in each pot. The changes in soil pH, the concentration of ammonium and nitrate, and the microbial community properties were monitored after 1, 6, 10, and 14 weeks of the application of livestock waste-based products. The application of composted manure, especially woodchip compost, showed a relatively more extensive impact on the soil microbial community structure than the other treatments. Woodchip compost contained a relatively more abundant and diverse bacterial community than digestate, and its family-level bacterial community structure was similar to that of the soil. These characteristics might determine the extent of the impact of livestock waste-based products on soil microbial communities. Digestate markedly influenced the inorganic nitrogen concentrations in soils but did not affect the soil microbial community. In conclusion, the survival rate of microbes of livestock waste-based products varies depending on the product type. Further investigation is needed to fully understand their impact on soils’ microbial functions.

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Suwannarach, Nakarin, Jaturong Kumla, Yan Zhao, and Pattana Kakumyan. "Impact of Cultivation Substrate and Microbial Community on Improving Mushroom Productivity: A Review." Biology 11, no. 4 (April 8, 2022): 569. http://dx.doi.org/10.3390/biology11040569.

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Lignocellulosic materials commonly serve as base substrates for mushroom production. Cellulose, hemicellulose, and lignin are the major components of lignocellulose materials. The composition of these components depends upon the plant species. Currently, composted and non-composted lignocellulosic materials are used as substrates in mushroom cultivation depending on the mushroom species. Different substrate compositions can directly affect the quality and quantity of mushroom production yields. Consequently, the microbial dynamics and communities of the composting substrates can significantly affect mushroom production. Therefore, changes in both substrate composition and microbial diversity during the cultivation process can impact the production of high-quality substrates and result in a high degree of biological efficiency. A brief review of the current findings on substrate composition and microbial diversity for mushroom cultivation is provided in this paper. We also summarize the advantages and disadvantages of various methods of mushroom cultivation by analyzing the microbial diversity of the composting substrates during mushroom cultivation. The resulting information will serve as a useful guide for future researchers in their attempts to increase mushroom productivity through the selection of suitable substrate compositions and their relation to the microbial community.

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Lian, Tengxiang, Yinghui Mu, Jian Jin, Qibin Ma, Yanbo Cheng, Zhandong Cai, and Hai Nian. "Impact of intercropping on the coupling between soil microbial community structure, activity, and nutrient-use efficiencies." PeerJ 7 (February 8, 2019): e6412. http://dx.doi.org/10.7717/peerj.6412.

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Sugarcane-soybean intercropping has been widely used to control disease and improve nutrition in the field. However, the response of the soil microbial community diversity and structure to intercropping is not well understood. Since microbial diversity corresponds to soil quality and plant health, a pot experiment was conducted with sugarcane intercropped with soybean. Rhizosphere soil was collected 40 days after sowing, and MiSeq sequencing was utilized to analyze the soil microbial community diversity and composition. Soil columns were used to assess the influence of intercropping on soil microbial activity (soil respiration and carbon-use efficiency: nitrogen-use efficiency ratio). PICRUSt and FUNGuild analysis were conducted to predict microbial functional profiling. Our results showed that intercropping decreased pH by approximately 8.9% and enhanced the soil organic carbon, dissolved organic carbon, and available nitrogen (N) by 5.5%, 13.4%, and 10.0%, respectively. These changes in physicochemical properties corresponded to increased microbial diversity and shifts in soil microbial communities. Microbial community correlated significantly (p < 0.05) with soil respiration rates and nutrient use efficiency. Furthermore, intercropping influenced microbial functions, such as carbon fixation pathways in prokaryotes, citrate cycle (TCA cycle) of bacteria and wood saprotrophs of fungi. These overrepresented functions might accelerate nutrient conversion and control phytopathogens in soil.

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Zou, Xiangbo, Xinyu Jiang, Heng Jiang, Cheng Li, Jiong Cheng, Dongqing Ji, Jin Wang, et al. "Soil Biocrusts May Exert a Legacy Impact on the Rhizosphere Microbial Community of Plant Crops." Agronomy 14, no. 11 (October 30, 2024): 2548. http://dx.doi.org/10.3390/agronomy14112548.

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Biological soil crusts (biocrusts) play important ecological roles in many ecosystems, but their legacy effects in subtropical agricultural systems are poorly understood. This study investigated how biocrusts impact soil properties and subsequent crop rhizosphere microbiomes. Soil with (+BC) and without (−BC) biocrusts was cultivated and used to grow pepper plants in a greenhouse experiment. Soil physicochemical properties and microbial communities in the pre-planting soils, and microbial communities in crop rhizosphere were analyzed. The results showed that soils with biocrust had significantly higher organic matter, total nitrogen, alkaline hydrolyzable nitrogen, total phosphorus, and total potassium content. Microbial community structures differed significantly among treatments, with −BC soils exhibiting higher microbial diversity in pre-planting conditions, while +BC soils showed higher diversity in crop rhizosphere soils. Soil properties, especially extractable potassium, total nitrogen, and organic matter content, were significantly correlated with rhizosphere microbial community structure. Additionally, our results showed that the first principal coordinate (PCoA1) of soil microbial community structure was significantly correlated with rhizosphere microbiota. Multiple regression analysis revealed that pre-planting soil microbial diversity indices and certain soil physicochemical properties could predict crop rhizosphere soil microbial diversity. Our results demonstrate that biocrusts can enhance soil fertility and alter microbial communities in subtropical agricultural soils, with persistent effects on the crop rhizosphere microbiome. This study provides new insights into the ecological legacy of biocrusts in managed subtropical ecosystems and their potential agricultural implications.

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Yu, Jiantao, Suyan Li, Xiangyang Sun, Wenzhi Zhou, Libing He, Guanyu Zhao, Zhe Chen, Xueting Bai, and Jinshuo Zhang. "The Impact and Determinants of Mountainous Topographical Factors on Soil Microbial Community Characteristics." Microorganisms 11, no. 12 (November 28, 2023): 2878. http://dx.doi.org/10.3390/microorganisms11122878.

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Soil bacterial and fungal community communities play significant ecological functions in mountain ecosystems. However, it is not clear how topographic factors and soil physicochemical properties influence changes in microbial community structure and diversity. This study aims to investigate how altitude and slope orientation affect soil physicochemical properties, soil microbial communities, and their contributing factors. The assessment was conducted using Illumina MiSeq sequencing in various altitude gradients and on slopes with different aspects (shady slopes and sunny slopes) in the subalpine meadow of Dongling Mountain, Beijing. Topographical factors had a significant effect on soil physicochemical properties: the primary factors determining the structure of microbial communities are total potassium (TK), ammonium nitrogen (NH4+-N), and soil organic carbon (SOC). There was no significant change in the diversity of the bacterial community, whereas the diversity of the fungal community displayed a single-peaked trend. The effect of slope orientation on microbial communities was not as significant as the effect of elevation on them. The number of bacterial communities with significant differences showed a unimodal trend, while the number of fungal communities showed a decreasing trend. The co-occurrence network of fungal communities exhibits greater intricacy than that of bacterial communities, and bacterial communities are more complex in soils with sunny slopes compared to soils with shady slopes, and the opposite is true for fungal communities. The identification of the main factors that control soil microbial diversity and composition in this study, provided the groundwork for investigating the soil microbial response and adaptation to environmental changes in subalpine meadows.

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Maeda, Tadashi, hiroaki zai, Yuto Fukui, yoshihumi katou, eri kumade, toshiyasu watanabe, Norihiro Furushou, et al. "1223. Impact of Helicobacter pylori Infection on Duodenal Microbial Community Structures and Microbial Metabolic Pathways." Open Forum Infectious Diseases 7, Supplement_1 (October 1, 2020): S632. http://dx.doi.org/10.1093/ofid/ofaa439.1408.

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Abstract Background Recent reports suggest that Helicobacter pylori infection causes extragastric diseases. However, the onset mechanisms of these diseases have not been fully elucidated, and the factors involved in the onset of these extragastric diseases remain obscure. Methods Forty-seven (20 male, 27 female) subjects who underwent gastric cancer screening were enrolled. Aspirated duodenal fluid samples were collected from the descending duodenum. Samples were analyzed by 16S rRNA gene amplicon sequencing to investigate whether the duodenal microbiota and microbial biofunctions were affected by H. pylori infection. Results Thirteen subjects were H. pylori positive while 34 were negative. We observed 1404 bacterial operational taxonomic units from 23 phyla and 253 genera. In the H. pylori positive group, we observed higher abundance of Proteobacteria and lower abundance of Actinobacteria and TM7 than in the H. pylori negative group. The abundance of 10 genera differed significantly between the H. pylori positive and negative groups. Aspects of microbiota in the H. pylori positive group were significantly influenced by 12 taxa primarily belonging to Gammaproteobacteria, compared with those in the H. pylori negative group. Microbial functional annotation collated using the Kyoto Encyclopedia of Genes and Genomes Orthology database showed that 12 microbial metabolic pathways were significantly affected by H. pylori infection. Conclusion 1. pylori infection disrupted the normal bacterial communities in the duodenum and changed aspects of the commensal microbial functions primarily by upregulating the metabolic pathways. This may be one of the principal factors in the development of extragastric diseases. Disclosures All Authors: No reported disclosures

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McNamara, Patrick J., Timothy M. LaPara, and Paige J. Novak. "The Effect of Perfluorooctane Sulfonate, Exposure Time, and Chemical Mixtures on Methanogenic Community Structure and Function." Microbiology Insights 8s2 (January 2015): MBI.S31345. http://dx.doi.org/10.4137/mbi.s31345.

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A plethora of organic micropollutant mixtures are found in untreated municipal wastewater. Anaerobic digesters receive large loadings of hydrophobic micropollutants that sorb to wastewater biosolids. Despite micropollutants being pervasive as mixtures, little research is available to explain the impact that mixtures of compounds, as well as exposure time, have on microbial communities in anaerobic digesters. Perfluorooctane sulfonate (PFOS) was added to anaerobic enrichment cultures in both short-term (14 days) and long-term (140 days) studies to determine the impact of exposure time. Additionally, triclosan was added during the experiments to investigate the impact of mixtures on community structure and function. PFOS did not alter methane production in short-term studies, but in long-term studies, methane production increased, consistent with our hypothesis that PFOS may act as a metabolic uncoupler. The impact of triclosan on methane production was exacerbated when PFOS was already present in the anaerobic enrichment cultures. Triclosan also had greater impacts on microbial community structures in the bottles that had been exposed to PFOS long-term. These results demonstrate that both chemical mixtures and exposure time are important parameters to address when trying to define the impacts of micropollutants on anaerobic microbial communities.

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Bogati, Kalisa, and Maciej Walczak. "The Impact of Drought Stress on Soil Microbial Community, Enzyme Activities and Plants." Agronomy 12, no. 1 (January 13, 2022): 189. http://dx.doi.org/10.3390/agronomy12010189.

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Nowadays, the most significant consequence of climate change is drought stress. Drought is one of the important, alarming, and hazardous abiotic stresses responsible for the alterations in soil environment affecting soil organisms, including microorganisms and plants. It alters the activity and functional composition of soil microorganisms that are responsible for crucial ecosystem functions and services. These stress conditions decrease microbial abundance, disturb microbial structure, decline microbial activity, including enzyme production (e.g., such as oxidoreductases, hydrolases, dehydrogenase, catalase, urease, phosphatases, β-glucosidase) and nutrient cycling, leading to a decrease in soil fertility followed by lower plant productivity and loss in economy. Interestingly, the negative effects of drought on soil can be minimized by adding organic substances such as compost, sewage slugs, or municipal solid waste that increases the activity of soil enzymes. Drought directly affects plant morphology, anatomy, physiology, and biochemistry. Its effect on plants can also be observed by changes at the transcriptomic and metabolomic levels. However, in plants, it can be mitigated by rhizosphere microbial communities, especially by plant growth-promoting bacteria (PGPB) and fungi (PGPF) that adapt their structural and functional compositions to water scarcity. This review was undertaken to discuss the impacts of drought stress on soil microbial community abundance, structure and activity, and plant growth and development, including the role of soil microorganisms in this process. Microbial activity in the soil environment was considered in terms of soil enzyme activities, pools, fluxes, and processes of terrestrial carbon (C) and nitrogen (N) cycles. A deep understanding of many aspects is necessary to explore the impacts of these extreme climate change events. We also focus on addressing the possible ways such as genome editing, molecular analysis (metagenomics, transcriptomics, and metabolomics) towards finding better solutions for mitigating drought effects and managing agricultural practices under harsh condition in a profitable manner.

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Chomiak, Kristina M., Wendy A. Owens-Rios, Carmella M. Bangkong, Steven W. Day, Nathan C. Eddingsaas, Matthew J. Hoffman, André O. Hudson, and Anna Christina Tyler. "Impact of Microplastic on Freshwater Sediment Biogeochemistry and Microbial Communities Is Polymer Specific." Water 16, no. 2 (January 20, 2024): 348. http://dx.doi.org/10.3390/w16020348.

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Plastic debris is a growing threat in freshwater ecosystems and transport models predict that many plastics will sink to the benthos. Among the most common plastics found in the Laurentian Great Lakes sediments are polyethylene terephthalate (especially fibers; PET), polyvinylchloride (particles; PVC), and styrene-butadiene rubber resulting from tire wear (“crumb rubber”; SBR). These materials vary substantially in physical and chemical properties, and their impacts on benthic biogeochemistry and microbial community structure and function are largely unknown. We used a microcosm approach to evaluate the impact of these three plastics on benthic-pelagic coupling, sediment properties, and sediment microbial community structure and function using sediments from Irondequoit Bay, a major embayment of Lake Ontario in Rochester, New York, USA. Benthic metabolism and nitrogen and phosphorous cycling were all uniquely impacted by the different polymers. PET fibers and PVC particles demonstrated the most unique effects, with decreased ecosystem metabolism in sediments containing PET and greater nutrient uptake in sediments with PVC. Microbial diversity was reduced in all treatments containing plastic, but SBR had the most substantial impact on microbial community function, increasing the relative importance of metabolic pathways such as hydrocarbon degradation and sulfur metabolism. Our results suggest that individual polymers have unique impacts on the benthos, with divergent implications for ecosystem function. This provides deeper insight into the myriad ways plastic pollution may impact aquatic ecosystems and will help to inform risk assessment and policy interventions by highlighting which materials pose the greatest risk.

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Christaki, U., F. Van Wambeke, D. Lefevre, A. Lagaria, L. Prieur, M. Pujo-Pay, J. D. Grattepanche, et al. "The impact of anticyclonic mesoscale structures on microbial food webs in the Mediterranean Sea." Biogeosciences Discussions 8, no. 1 (January 10, 2011): 185–220. http://dx.doi.org/10.5194/bgd-8-185-2011.

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Abstract. The abundance and activity of the major members of the heterotrophic microbial community – from viruses to ciliates – were studied along a longitudinal transect across the Mediterranean Sea in the summer of 2008. The Mediterranean Sea is characterized by a west to the east gradient of deepening of DCM (deep chlorophyll maximum) and increasing oligotrophy reflected in gradients of heterotrophic microbial biomass and production. However, within this longitudinal trend, hydrological mesoscale features exist and likely influence microbial dynamics. We show here the importance of mesoscale structures by a description of the structure and function of the microbial food web through an investigation of 3 geographically distant eddies within a longitudinal transect. Three selected sites each located in the center of an anticyclonic eddy were intensively investigated: in the Algero-Provencal Basin (St. A), the Ionian Basin (St. B), and the Levantine Basin (St. C). The 3 geographically distant eddies showed the lowest values of the different heterotrophic compartments of the microbial food web, and except for viruses in site C, all stocks were higher in the neighboring stations outside the eddies. During our study the 3 eddies showed equilibrium between GCP (Gross Community Production) and DCR (Dark Community Respiration); moreover, the west-east (W-E) gradient was evident in terms of heterotrophic biomass but not in terms of production. Means of integrated PPp values were higher at site B (~190 mg C m−2 d−1) and about 15% lower at sites A and C (~160 mg C m−2 d−1). Net community production fluxes were similar at all three stations exhibiting equilibrium between gross community production and dark community respiration.

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Kim, Lavane, Eulyn Pagaling, Yi Y. Zuo, and Tao Yan. "Impact of Substratum Surface on Microbial Community Structure and Treatment Performance in Biological Aerated Filters." Applied and Environmental Microbiology 80, no. 1 (October 18, 2013): 177–83. http://dx.doi.org/10.1128/aem.03001-13.

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ABSTRACTThe impact of substratum surface property change on biofilm community structure was investigated using laboratory biological aerated filter (BAF) reactors and molecular microbial community analysis. Two substratum surfaces that differed in surface properties were created via surface coating and used to develop biofilms in test (modified surface) and control (original surface) BAF reactors. Microbial community analysis by 16S rRNA gene-based PCR-denaturing gradient gel electrophoresis (DGGE) showed that the surface property change consistently resulted in distinct profiles of microbial populations during replicate reactor start-ups. Pyrosequencing of the bar-coded 16S rRNA gene amplicons surveyed more than 90% of the microbial diversity in the microbial communities and identified 72 unique bacterial species within 19 bacterial orders. Among the 19 orders of bacteria detected,BurkholderialesandRhodocyclalesof theBetaproteobacteriaclass were numerically dominant and accounted for 90.5 to 97.4% of the sequence reads, and their relative abundances in the test and control BAF reactors were different in consistent patterns during the two reactor start-ups. Three of the five dominant bacterial species also showed consistent relative abundance changes between the test and control BAF reactors. The different biofilm microbial communities led to different treatment efficiencies, with consistently higher total organic carbon (TOC) removal in the test reactor than in the control reactor. Further understanding of how surface properties affect biofilm microbial communities and functional performance would enable the rational design of new generations of substrata for the improvement of biofilm-based biological treatment processes.

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Matsui, Kazuaki, and Takeshi Miki. "Microbial community composition and function in an urban waterway with combined sewer overflows before and after implementation of a stormwater storage pipe." PeerJ 11 (January 12, 2023): e14684. http://dx.doi.org/10.7717/peerj.14684.

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When the wastewater volume exceeds the sewer pipe capacity during extreme rainfall events, untreated sewage discharges directly into rivers as combined sewer overflow (CSO). To compare the impacts of CSOs and stormwater on urban waterways, we assessed physicochemical water quality, the 16S rRNA gene-based bacterial community structure, and EcoPlate-based microbial functions during rainfall periods in an urban waterway before and after a stormwater storage pipe was commissioned. A temporal variation analysis showed that CSOs have significant impacts on microbial function and bacterial community structure, while their contributions to physicochemical parameters, bacterial abundance, and chlorophyll a were not confirmed. Heat map analysis showed that the impact of CSO on the waterway bacterial community structure was temporal and the bacterial community composition in CSO is distinct from that in sewers. Hierarchical clustering analysis revealed that the waterway physicochemical water qualities, bacterial community composition, and microbial community function were distinguishable from the upper reach of the river, rather than between CSO and stormwater. Changes in the relative abundance of tetracycline resistance (tet) genes—especially tet(M)—were observed after CSOs but did not coincide with changes in the microbial community composition, suggesting that the parameters affecting the microbial community composition and relative abundance of tet genes differ. After pipe implementation, however, stormwater did not contribute to the abundance of tet genes in the waterway. These results indicate that CSO-induced acute microbial disturbances in the urban waterway were alleviated by the implementation of a stormwater storage pipe and will support the efficiency of storage pipe operation for waterway management in urban areas.

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Klein, Robert, Michael Schlömann, Yun Zeng, Bernd Wacker, Franz Glombitza, Eberhard Janneck, and Martin Mühling. "Impact of the Hydraulic Retention Time on the Performance of a Sulfidogenic Bioreactor." Advanced Materials Research 825 (October 2013): 392–95. http://dx.doi.org/10.4028/www.scientific.net/amr.825.392.

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Treatment of acidic Fe (II)- and sulfate-rich mine waters represents a major problem in many areas of the world. Therefore, a process was developed which utilises naturally occurring sulfate-reducing microorganisms for the elimination of sulfate and of part of the acidity from the acidic mine water. In order to improve the performance of this biological sulfate reduction process an in-depth analysis of the microbial diversity and activity in dependence of the hydraulic retention time (HRT) and other process parameters used to run the bioreactors was undertaken. This comparison demonstrated a positive correlation between shorter HRT and increasing sulfate reduction rates. The improvement in performance with decreasing HRT was paralleled by an increase of the total enzymatic activity (measured as hydrolase activity) of the microbial community and of the biomass (measured as protein concentration) in the bioreactors. A partial taxonomic identification of the microbial community in the bioreactors was achieved via nucleotide sequence analysis of a clone library of PCR-amplified 16S rRNA gene fragments prepared from a sample of the microbial biofilm in the bioreactor. Additionally, the genetic fingerprint technique T-RFLP was used to assess temporal changes of the microbial community in the biofilm within the reactor.

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Liu, Qianqian, Wensui Li, Hui Nie, Xiaorui Sun, Lina Dong, Liu Xiang, Jinchi Zhang, and Xin Liu. "The Effect of Human Trampling Activity on a Soil Microbial Community at the Urban Forest Park." Forests 14, no. 4 (March 28, 2023): 692. http://dx.doi.org/10.3390/f14040692.

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Soil degradation resulting from human trampling in urban forest parks can negatively impact the taxonomic diversity and function of soil microbial communities. In this study, we established long-term, fixed large plots in Zijin Mountain Urban Forest Park in Nanjing, China, to assess the level of trampling pressure. Soil samples were collected from depths of 0–10 cm, 10–20 cm, and 20–30 cm for light trampling (LD), moderate trampling (MD), severe trampling (SD), extreme trampling (ED), and a no-trampling control (CK). The effects of different trampling pressures on soil were studied, including soil nutrient indices, microbial biomass, and the taxonomic diversity of fungi and bacteria. ANOVA and structural equation modeling (SEM) were employed to investigate the impacts of human trampling on the microbial community structure and function. The results indicated that soil organic carbon, ammonium, and acid phosphatase activity were the primary driving factors of microbial community change. Soil microbial diversity initially increased and then decreased with increasing trampling intensity. The changes in soil microbial function and classification were found to be associated with the intensity of trampling. Moderate trampling could enhance the diversity of the soil microbial community. The succession pattern of the fungi and bacteria communities was distinct, and the composition of the bacteria community remained relatively stable. Trampling impacts vegetation and soil structure, which then affects the structure and function of the microbial community. This study provides an essential foundation for the restoration of compacted soil in urban forest parks through targeted monitoring and management efforts.

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Gu, Fu Guang, Zhao Bo Chen, Xiao Yu Wang, Hong Cheng Wang, and Jin Yang Hao. "The Study on the Impact of Microbial Community Structure by the Different Intermediate Concentration of Pharmaceutical Wastewater." Advanced Materials Research 647 (January 2013): 430–33. http://dx.doi.org/10.4028/www.scientific.net/amr.647.430.

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There is a certain amount of intermediate and other ingredient in pharmaceutical wastewater .These pharmaceutical will have a big effect on microorganism in sewage treatment plant. So this article discussed the study one impact of microbial community structure by the different intermediate concentration of Pharmaceutical waste water .The study shows that Microbial community structure are diversity in the pharmaceutical wastewater treatment plant.With the change of the environment some microbes are reduced or even disappear and some microbes are gradually produce. The microbes which have a big effect by different environment have adapt to 7-ACA, won the resistance and become a part of microbial community in stationary phase.

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Seghers, Dave, Lieven Wittebolle, Eva M. Top, Willy Verstraete, and Steven D. Siciliano. "Impact of Agricultural Practices on the Zea mays L. Endophytic Community." Applied and Environmental Microbiology 70, no. 3 (March 2004): 1475–82. http://dx.doi.org/10.1128/aem.70.3.1475-1482.2004.

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ABSTRACT Agricultural practices are known to alter bulk soil microbial communities, but little is known about the effect of such practices on the plant endophytic community. We assessed the influence of long-term applications (20 years) of herbicides and different fertilizer types on the endophytic community of maize plants grown in different field experiments. Nested PCR-denaturing gradient gel electrophoresis (DGGE) analyses targeting general bacteria, type I or II methanotrophs, actinomycetes, and general fungi were used to fingerprint the endophytic community in the roots of Zea mays L. Low intraplant variability (reproducible DGGE patterns) was observed for the bacterial, type I methanotroph, and fungal communities, whereas the patterns for endophytic actinomycetes exhibited high intraplant variability. No endophytic amplification product was obtained for type II methanotrophs. Cluster and stability analysis of the endophytic type I methanotroph patterns differentiated maize plants cultivated by using mineral fertilizer from plants cultivated by using organic fertilizer with a 100% success rate. In addition, lower methanotroph richness was observed for mineral-fertilized plants than for organically fertilized plants. The use of herbicides could not be traced by fingerprinting the endophytic type I methanotrophs or by evaluating any other endophytic microbial group. Our results indicate that the effect of agrochemicals is not limited to the bulk microbial community but also includes the root endophytic community. It is not clear if this effect is due to a direct effect on the root endophytic community or is due to changes in the bulk community, which are then reflected in the root endophytic community.

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Sacristán-Soriano, Oriol, and Mikel A. Becerro. "Publication impact in sponge chemical and microbial ecology." Scientia Marina 80, no. 4 (November 22, 2016): 555. http://dx.doi.org/10.3989/scimar.04466.04a.

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It is well known that sponges constitute one of the most prevalent groups in marine benthic communities based on their challenging structural organization, abundance and diversity, and their functional roles in natural communities. The evolutionary success of this group may be explained by the close interaction between sponges and microbes, which dates back to the Precambrian era. This particular symbiosis has become a key factor within sponge research and is an emerging topic of two scientific disciplines: chemical and microbial ecology. This mini-review evaluates the influence of these two disciplines on the general scientific community using a series of bibliometric indicators to ensure objectivity. Our analyses showed that, although sponge chemical ecology has a greater overall impact on the scientific community, both disciplines are cited equally and more frequently than expected. Both research areas show a great impact on applied sciences, but the ecological perspectives of sponge chemistry and microbiology may fall outside the interests of a broader ecological audience. Moreover, we highlight some research topics (e.g. effects of environmental stress) that may require further attention. Hence, sponge chemical and microbial ecology have the opportunity to contribute to broader ecological issues in topics that make sponges particularly important, such as symbiosis.

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Rasheela, Abdul Rashid P., Muhammad Fasih Khalid, Dana A. Abumaali, Juha M. Alatalo, and Talaat Ahmed. "Impact of Abiotic Stressors on Soil Microbial Communities: A Focus on Antibiotics and Their Interactions with Emerging Pollutants." Soil Systems 9, no. 1 (December 26, 2024): 2. https://doi.org/10.3390/soilsystems9010002.

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Soil is a complex and dynamic ecosystem containing a diverse array of microorganisms, and plays a crucial and multifaceted role in various functions of the ecosystem. Substantial fluctuations in the environmental conditions arise from diverse global changes. The microbial shifts in the soil in concordance with the changing environmental factors, or a combination of these factors, are of high significance. Exploring the contribution of global change drivers to the microbial community to improve the predictions of the response of the microbial community to the functioning of the ecosystem is of prime importance. Promoting the health of soil microorganisms maintains the overall health and fertility of the soil, which in turn supports the health of terrestrial ecosystems and agricultural systems. The current review aims to assemble different abiotic factors or stressors that exist in the environment that affect the microbial community. More focus will be given to one of the stressors—antibiotics, a recent emerging pollutant. The effects on the soil microbial community and the future of soil health due to the presence of antibiotics will be addressed. The scope of the interaction of antibiotics with other pollutants like plastics and heavy metals (HMs) will be examined.

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Dunfield, Kari E., and James J. Germida. "Seasonal Changes in the Rhizosphere Microbial Communities Associated with Field-Grown Genetically Modified Canola (Brassica napus)." Applied and Environmental Microbiology 69, no. 12 (December 2003): 7310–18. http://dx.doi.org/10.1128/aem.69.12.7310-7318.2003.

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ABSTRACT The introduction of transgenic plants into agricultural ecosystems has raised the question of the ecological impact of these plants on nontarget organisms, such as soil bacteria. Although differences in both the genetic structure and the metabolic function of the microbial communities associated with some transgenic plant lines have been established, it remains to be seen whether these differences have an ecological impact on the soil microbial communities. We conducted a 2-year, multiple-site field study in which rhizosphere samples associated with a transgenic canola variety and a conventional canola variety were sampled at six times throughout the growing season. The objectives of this study were to identify differences between the rhizosphere microbial community associated with the transgenic plants and the rhizosphere microbial community associated with the conventional canola plants and to determine whether the differences were permanent or depended on the presence of the plant. Community-level physiological profiles, fatty acid methyl ester profiles, and terminal amplified ribosomal DNA restriction analysis profiles of rhizosphere microbial communities were compared to the profiles of the microbial community associated with an unplanted, fallow field plot. Principal-component analysis showed that there was variation in the microbial community associated with both canola variety and growth season. Importantly, while differences between the microbial communities associated with the transgenic plant variety were observed at several times throughout the growing season, all analyses indicated that when the microbial communities were assessed after winter, there were no differences between microbial communities from field plots that contained harvested transgenic canola plants and microbial communities from field plots that did not contain plants during the field season. Hence, the changes in the microbial community structure associated with genetically modified plants were temporary and did not persist into the next field season.

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Epelde, Lur, JosÃ¯Â¿Â½ M. Becerril, George A. Kowalchuk, Ye Deng, Jizhong Zhou, and Carlos Garbisu. "Impact of Metal Pollution and Thlaspi caerulescens Growth on Soil Microbial Communities." Applied and Environmental Microbiology 76, no. 23 (October 8, 2010): 7843–53. http://dx.doi.org/10.1128/aem.01045-10.

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ABSTRACT Soil microorganisms drive critical functions in plant-soil systems. As such, various microbial properties have been proposed as indicators of soil functioning, making them potentially useful in evaluating the recovery of polluted soils via phytoremediation strategies. To evaluate microbial responses to metal phytoextraction using hyperaccumulators, a microcosm experiment was carried out to study the impacts of Zn and/or Cd pollution and Thlaspi caerulescens growth on key soil microbial properties: basal respiration; substrate-induced respiration (SIR); bacterial community structure as assessed by PCR-denaturing gradient gel electrophoresis (DGGE); community sizes of total bacteria, ammonia-oxidizing bacteria, and chitin-degrading bacteria as assessed by quantitative PCR (Q-PCR); and functional gene distributions as determined by functional gene arrays (GeoChip). T. caerulescens proved to be suitable for Zn and Cd phytoextraction: shoots accumulated up to 8,211 and 1,763 mg kg−1 (dry weight [DW]) of Zn and Cd, respectively. In general, Zn pollution led to decreased levels of basal respiration and ammonia-oxidizing bacteria, while T. caerulescens growth increased the values of substrate-induced respiration (SIR) and total bacteria. In soils polluted with 1,000 mg Zn kg−1 and 250 mg Cd kg−1 (DW), soil bacterial community profiles and the distribution of microbial functional genes were most affected by the presence of metals. Metal-polluted and planted soils had the highest percentage of unique genes detected via the GeoChip (35%). It was possible to track microbial responses to planting with T. caerulescens and to gain insight into the effects of metal pollution on soilborne microbial communities.

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Romano, Salvatore. "Bioaerosols: Composition, Meteorological Impact, and Transport." Atmosphere 14, no. 3 (March 20, 2023): 590. http://dx.doi.org/10.3390/atmos14030590.

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The characterization and the main properties of biogenic airborne particles (or bioaerosols) comprising both living and dead microorganisms (such as bacteria, fungi, viruses, pollen, and microbial fragments) are currently of increasing interest in the scientific community [...]

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Wu, Yanru, Wenquan Yang, Qinyao Li, Qianluo Qiao, Shuai Zhao, Yangcan Zhang, Yanghua Yu, Shengxiang Zhang, Xilai Li, and Jiancun Kou. "Microbial Community Response to Alpine Meadow Degradation and Its Impact on Soil Nutrient Cycling." Agronomy 14, no. 1 (January 16, 2024): 195. http://dx.doi.org/10.3390/agronomy14010195.

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The degradation of alpine meadows on the Qinghai–Tibet Plateau is a major issue affecting both the ecology and the economy. Microorganisms play an important role in soil nutrient cycling and the regulation of ecosystem function. This study aimed to investigate the species composition and diversity of microbial communities and understand the response of microbial communities to changes in physicochemical properties resulting from meadow degradation. In this study, the soil bacterial and fungal communities’ composition and diversity of alpine meadows of degradation gradient were sequenced by high-throughput sequencing. During the process of grassland degradation, there were 59 bacterial taxa and 29 fungal taxa showing significant differences. The relative abundance of meadow pathogenic fungi significantly increased (p < 0.05). PICRUSt2 analysis showed a decrease in synthesis-related functional gene abundance and an increase in metabolism-related functional gene abundance. FUNGuild analysis showed that symbiotic and saprophytic nutrient fungi decreased significantly (p < 0.05). The soil nutrient cycling was mainly influenced by the beta diversity of microbial communities. Grassland degradation affects soil structure, thereby affecting the diversity of soil microbial composition and functional soil nutrient content. This work reveals the response of microbial communities to the degradation of alpine meadows and their impact on nutrient cycling, providing theoretical support for the protection and sustainable development of alpine meadows.

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Zhang, Shuyan, Yanling Yang, Xing Li,, and Wei Bian. "Impact of organic matter on biofilm growth and microbial community diversity." DESALINATION AND WATER TREATMENT 66 (2017): 10–16. http://dx.doi.org/10.5004/dwt.2017.0234.

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Oh, Sung-Dug, Jong-Bum Kim, Jung-Jin Lee, Min-Kyeong Kim, Byung-Ohg Ahn, Soo-In Sohn, Jong-Sug Park, Tae-Hun Ryu, Hyun-Suk Cho, and Kijong Lee. "Impact of Virus-resistant Trigonal Cactus Cultivation on Soil Microbial Community." Korean Journal of Environmental Agriculture 32, no. 2 (June 30, 2013): 148–54. http://dx.doi.org/10.5338/kjea.2013.32.2.148.

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Sutton, Nora B., Farai Maphosa, Jose A. Morillo, Waleed Abu Al-Soud, Alette A. M. Langenhoff, Tim Grotenhuis, Huub H. M. Rijnaarts, and Hauke Smidt. "Impact of Long-Term Diesel Contamination on Soil Microbial Community Structure." Applied and Environmental Microbiology 79, no. 2 (November 9, 2012): 619–30. http://dx.doi.org/10.1128/aem.02747-12.

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ABSTRACTMicrobial community composition and diversity at a diesel-contaminated railway site were investigated by pyrosequencing of bacterial and archaeal 16S rRNA gene fragments to understand the interrelationships among microbial community composition, pollution level, and soil geochemical and physical properties. To this end, 26 soil samples from four matrix types with various geochemical characteristics and contaminant concentrations were investigated. The presence of diesel contamination significantly impacted microbial community composition and diversity, regardless of the soil matrix type. Clean samples showed higher diversity than contaminated samples (P< 0.001). Bacterial phyla with high relative abundances in all samples includedProteobacteria,Firmicutes,Actinobacteria,Acidobacteria, andChloroflexi. High relative abundances ofArchaea, specifically of the phylumEuryarchaeota, were observed in contaminated samples. Redundancy analysis indicated that increased relative abundances of the phylaChloroflexi,Firmicutes, andEuryarchaeotacorrelated with the presence of contamination. Shifts in the chemical composition of diesel constituents across the site and the abundance of specific operational taxonomic units (OTUs; defined using a 97% sequence identity threshold) in contaminated samples together suggest that natural attenuation of contamination has occurred. OTUs with sequence similarity to strictly anaerobicAnaerolineaewithin theChloroflexi, as well as toMethanosaetaof the phylumEuryarchaeota, were detected.AnaerolineaeandMethanosaetaare known to be associated with anaerobic degradation of oil-related compounds; therefore, their presence suggests that natural attenuation has occurred under anoxic conditions. This research underscores the usefulness of next-generation sequencing techniques both to understand the ecological impact of contamination and to identify potential molecular proxies for detection of natural attenuation.

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Kong, C. H., P. Wang, H. Zhao, X. H. Xu, and Y. D. Zhu. "Impact of allelochemical exuded from allelopathic rice on soil microbial community." Soil Biology and Biochemistry 40, no. 7 (July 2008): 1862–69. http://dx.doi.org/10.1016/j.soilbio.2008.03.009.

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Cheema, Simrita, Meeta Lavania, and Banwari Lal. "Impact of petroleum hydrocarbon contamination on the indigenous soil microbial community." Annals of Microbiology 65, no. 1 (May 2, 2014): 359–69. http://dx.doi.org/10.1007/s13213-014-0868-1.

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Zhang, Changpeng, Jun Xu, Xingang Liu, Fengshou Dong, Zhiqiang Kong, Yu Sheng, and Yongquan Zheng. "Impact of imazethapyr on the microbial community structure in agricultural soils." Chemosphere 81, no. 6 (October 2010): 800–806. http://dx.doi.org/10.1016/j.chemosphere.2010.06.079.

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Gebert, Julia, and Mirjam Perner. "Impact of preferential methane flow through soil on microbial community composition." European Journal of Soil Biology 69 (July 2015): 8–16. http://dx.doi.org/10.1016/j.ejsobi.2015.03.006.

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Liu, LinShu, Karley K. Mahalak, Jamshed T. Bobokalonov, Adrienne B. Narrowe, Jenni Firrman, Johanna M. S. Lemons, Kyle Bittinger, Weiming Hu, Steven M. Jones, and Ahmed M. Moustafa. "Impact of Ivermectin on the Gut Microbial Ecosystem." International Journal of Molecular Sciences 24, no. 22 (November 9, 2023): 16125. http://dx.doi.org/10.3390/ijms242216125.

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Ivermectin is a an anti-helminthic that is critical globally for both human and veterinary care. To the best of our knowledge, information available regarding the influence of ivermectin (IVM) on the gut microbiota has only been collected from diseased donors, who were treated with IVM alone or in combination with other medicines. Results thus obtained were influenced by multiple elements beyond IVM, such as disease, and other medical treatments. The research presented here investigated the impact of IVM on the gut microbial structure established in a Triple-SHIME® (simulator of the human intestinal microbial ecosystem), using fecal material from three healthy adults. The microbial communities were grown using three different culture media: standard SHIME media and SHIME media with either soluble or insoluble fiber added (control, SF, ISF). IVM introduced minor and temporary changes to the gut microbial community in terms of composition and metabolite production, as revealed by 16S rRNA amplicon sequencing analysis, flow cytometry, and GC-MS. Thus, it was concluded that IVM is not expected to induce dysbiosis or yield adverse effects if administered to healthy adults. In addition, the donor’s starting community influences the relationship between IVM and the gut microbiome, and the soluble fiber component in feed could protect the gut microbiota from IVM; an increase in short-chain fatty acid production was predicted by PICRUSt2 and detected with IVM treatment.

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Gardner, Terrence G., Juan P. Frene, Shaneka S. Lawson, Niall D. Lue Sue, Jeffery Handy, and Ralph H. Crawford. "The Impact of Tree Species on Microbial Community Structure and Soil Function on Forest Plantations in the Central Hardwoods Region (CHR)." Forests 14, no. 5 (April 22, 2023): 859. http://dx.doi.org/10.3390/f14050859.

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Interactions between above- and below-ground monoculture forest plantation components are critical to tree growth and development. Within the Central Hardwoods Region (CHR), synergistic relationships between tree species and soil microbial community structure and function have received limited research attention. Soil microbes are integral to forest ecosystems as their activities intrinsically promote soil organic matter decomposition, nutrient cycling, and ecosystem functioning. Here, we examined soils from two perfectly aligned stands of black walnut (BW, Juglans nigra L.) and Northern red oak (RO, Quercus rubra L.) trees. Measurements of selected soil chemical properties, microbial community structure using ester-linked fatty acid methyl ester (EL-FAME), and soil enzyme activities (EAs) were used. Analysis of modifications within microbial communities showed a significant positive response to BW based upon soil EAs and microbial indicators, compared to RO. Seasonal comparisons predictably revealed higher microbial activities during summer. Fungi dominated the soil microbial community structure with a fungal/bacterial ratio of 2:1. Gram-positive rather than Gram-negative bacteria or actinomycetes dominated the bacterial community. The activity of the soil enzymes ß-glucosidase and arylsulfatase increased, but ß-glucosaminidase and acid phosphatase decreased. Additionally, acid phosphatase and arbuscular mycorrhizal fungi revealed strong correlations. The differences observed in biological properties, specifically microbial communities and EAs, highlight the varied responses to BW and RO soil biology and subsequent soil ecosystem functions. These results indicate that variations in microbial abundance and soil functions occur throughout the course of an entire year.

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Journal articles on the topic 'Impact on microbial community'

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