scholarly journals Compositional Shift of Bacterial, Archaeal, and Fungal Communities Is Dependent on Trophic Lifestyles in Rice Paddy Soil

2021 ◽  
Vol 12 ◽  
Author(s):  
Hyun Kim ◽  
Jongbum Jeon ◽  
Kiseok Keith Lee ◽  
Yong-Hwan Lee

The soil environment determines plants’ health and performance during their life cycle. Therefore, ecological understanding on variations in soil environments, including physical, chemical, and biological properties, is crucial for managing agricultural fields. Here, we present a comprehensive and extensive blueprint of the bacterial, archaeal, and fungal communities in rice paddy soils with differing soil types and chemical properties. We discovered that natural variations of soil nutrients are important factors shaping microbial diversity. The responses of microbial diversity to soil nutrients were related to the distribution of microbial trophic lifestyles (oligotrophy and copiotrophy) in each community. The compositional changes of bacterial and archaeal communities in response to soil nutrients were mainly governed by oligotrophs, whereas copiotrophs were mainly involved in fungal compositional changes. Compositional shift of microbial communities by fertilization is linked to switching of microbial trophic lifestyles. Random forest models demonstrated that depletion of prokaryotic oligotrophs and enrichment of fungal copiotrophs are the dominant responses to fertilization in low-nutrient conditions, whereas enrichment of putative copiotrophs was important in high-nutrient conditions. Network inference also revealed that trophic lifestyle switching appertains to decreases in intra- and inter-kingdom microbial associations, diminished network connectivity, and switching of hub nodes from oligotrophs to copiotrophs. Our work provides ecological insight into how soil nutrient-driven variations in microbial communities affect soil health in modern agricultural systems.

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254065
Author(s):  
Wenjing Li ◽  
Lamei Jiang ◽  
Yang Zhang ◽  
Dexiong Teng ◽  
Hengfang Wang ◽  
...  

Environmental properties are important factors in structuring soil microbial communities. The primary driving factors vary in different ecosystems. In the present work, we analyzed the microbial communities of rhizosphere and bulk soils associated with the halophyte Alhagi sparsifolia across three salt/water gradients in the desert area around Ebinur Lake Basin, China, using high-throughput sequencing technology. We found that there were significant differences in soil water content (SWC), soil salinity (SAL), total nitrogen (TN), and total phosphorus (TP) contents between the three water/salt gradients. In the L (low water and salt) plot, Actinobacteria was the most abundant bacterial phylum while Ascomycota was the dominant fungal phylum. The relative abundance of Actinobacteria was negatively correlated with soil pH, soil organic carbon (SOC), TP, and available phosphorus (AP). The abundance of Bacteroidetes was significantly positively correlated with soil SOC, SWC, SAL, pH, TN, and TP (P < 0.05). The abundance of fungal phylum Chytridiomycota was significantly positively correlated with pH (P < 0.01), SWC, AP, and sulfate ion (P < 0.05). SOC and nitrate nitrogen were the main factors impacting the bacterial community, while ammonium nitrogen (NH4+) and TP were the main driving forces for the fungal community. Soil nutrients were the main contributors to the dissimilarities in the bacterial and fungal communities, explaining 48.06% and 44.45% of the variation. SWC, SAL, and pH explained only a small percentage of the microbial community dissimilarity. In conclusion, soil microbial community structure was affected by SWC, SAL, pH, and soil nutrients, with soil nutrients as the main driving factors. Nitrogen has a differential effect on the different microbial communities: bacterial communities of Alhagi sparsifolia were mainly affected by nitrate nitrogen, while fungal communities were mainly driven by ammonium nitrogen.


2021 ◽  
Author(s):  
Liuting Zhou ◽  
Jianjuan Li ◽  
Chen Zhang ◽  
Xinlai Guo ◽  
Wei Chu ◽  
...  

Abstract The aim of this study was to explore the soil microbial variability within different forest ecosystems (evergreen broad-leaf forest (EBF), coniferous forest (CF), subalpine dwarf forest (SDF) and alpine meadow (AM) at different altitudes in mid-subtropics of China. The phospholipid fatty acid (PLFA) method was used to analyze the microbial communities in rhizosphere soil under different forest types. The relationships were also analyzed between the microbial diversity and soil nutrients. A total of 27 PLFA biomarkers were detected and the PLFA concentrations decreased in the sequence of bacteria > fungus > actinomycete > protozoa in all forest types. The microbial communities in the soil under all forest types were distinct. The predominant microflora in all soils were 18:1ω9c, 16:1ω7c, cy19:0, a17:0 and 18:0. The indexes of Simpson, Shannon-Wiener and Brillouin of soil microbial community diversity in these four forest types all showed a trend of EBF > CF > SDF > AM. According to principal component analyses (PCA), the variable variances of principal components 1 and 2, which were related to the PLFA biomarkers of soil microorganisms, were 67.67% and 17.91%, respectively. Furthermore, the total PLFAs of different soil microbial groups showed a correlation with soil nutrients and enzyme activities in all forest types. The soil microbial diversity gradually decreased in the order of EBF > CF > SDF > AM in the Daiyun Mountains. Different vegetation types affect soil microbial community composition and diversity by changing the soil physicochemical properties and enzyme activity.


2020 ◽  
Author(s):  
Meiqing Lu ◽  
Xin Luo ◽  
Jiu Jimmy Jiao ◽  
Hailong li ◽  
Xingxing Kuang ◽  
...  

&lt;p&gt;The information of microorganisms in aquifers can advance the understanding of the aquifer environments. Ranwu Lake is a proglacial lake located at the headwaters of Parlung Zangbo River in the Qinghai-Tibet Plateau (QTP). The information of microbial communities along the littoral gradient of Ranwu Lake can be a good indicator of water chemistry exchange between groundwater and surface water in proglacial environments. The study investigates the vertical distribution of microbial diversity and compositions in five sediment columns (two onshore, two offshore and one at the shoreline) taken from a cross section along the littoral gradient of Ranwu Lake. Along the cross section, the microbial diversity decreases toward the lake, becomes lowest in the column at the shoreline, then increases slightly in the two offshore columns. This is probably ascribed to the transition of redox conditions. Vertically, the diversity of the microbes is highest at the top and bottom of the columns. The sequencing results from the samples present 19 phyla, 38 classes, and 44 genera. Proteobacteria, Chloroflexi, and Acidobacteria are the three largest phyla. Except the offshore most column, the abundance of Proteobacteria shows a consistent pattern, while the abundance of Chloroflexi presents an inverse pattern in related to the microbial diversity. Their diversity, compositions, and abundance of microbes show a significant variation along the vertical direction and littoral gradient of the glacial lake, likely regulated by both the exchange between groundwater and surface water, and the hydrogeological properties. The variable distribution of microbial community in turn affects the physio-chemical properties of sediments and waters.&lt;/p&gt;


Author(s):  
Mariane Beatriz Sordi ◽  
Ariadne Cristiane Cabral da Cruz ◽  
Águedo Aragones ◽  
Mabel Mariela Rodríguez Cordeiro ◽  
Ricardo de Souza Magini

The aim of this study was to synthesize, characterize, and evaluate degradation and biocompatibility of poly(lactic-co-glycolic acid) + hydroxyapatite / β-tricalcium phosphate (PLGA+HA/βTCP) scaffolds incorporating simvastatin (SIM) to verify if this biomaterial might be promising for bone tissue engineering. Samples were obtained by the solvent evaporation technique. Biphasic ceramic particles (70% HA, 30% βTCP) were added to PLGA in a ratio of 1:1. Samples with SIM received 1% (m:m) of this medication. Scaffolds were synthesized in a cylindric-shape and sterilized by ethylene oxide. For degradation analysis, samples were immersed in PBS at 37 °C under constant stirring for 7, 14, 21, and 28 days. Non-degraded samples were taken as reference. Mass variation, scanning electron microscopy, porosity analysis, Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetry were performed to evaluate physico-chemical properties. Wettability and cytotoxicity tests were conducted to evaluate the biocompatibility. Microscopic images revealed the presence of macro, meso, and micropores in the polymer structure with HA/βTCP particles homogeneously dispersed. Chemical and thermal analyses presented very similar results for both PLGA+HA/βTCP and PLGA+HA/βTCP+SIM. The incorporation of simvastatin improved the hydrophilicity of scaffolds. Additionally, PLGA+HA/βTCP and PLGA+HA/βTCP+SIM scaffolds were biocompatible for osteoblasts and mesenchymal stem cells. In summary, PLGA+HA/βTCP scaffolds incorporating simvastatin presented adequate structural, chemical, thermal, and biological properties for bone tissue engineering.


2020 ◽  
Vol 27 (28) ◽  
pp. 4584-4592 ◽  
Author(s):  
Avik Khan ◽  
Baobin Wang ◽  
Yonghao Ni

Regenerative medicine represents an emerging multidisciplinary field that brings together engineering methods and complexity of life sciences into a unified fundamental understanding of structure-property relationship in micro/nano environment to develop the next generation of scaffolds and hydrogels to restore or improve tissue functions. Chitosan has several unique physico-chemical properties that make it a highly desirable polysaccharide for various applications such as, biomedical, food, nutraceutical, agriculture, packaging, coating, etc. However, the utilization of chitosan in regenerative medicine is often limited due to its inadequate mechanical, barrier and thermal properties. Cellulosic nanomaterials (CNs), owing to their exceptional mechanical strength, ease of chemical modification, biocompatibility and favorable interaction with chitosan, represent an attractive candidate for the fabrication of chitosan/ CNs scaffolds and hydrogels. The unique mechanical and biological properties of the chitosan/CNs bio-nanocomposite make them a material of choice for the development of next generation bio-scaffolds and hydrogels for regenerative medicine applications. In this review, we have summarized the preparation method, mechanical properties, morphology, cytotoxicity/ biocompatibility of chitosan/CNs nanocomposites for regenerative medicine applications, which comprises tissue engineering and wound dressing applications.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 831
Author(s):  
Andrea Dodero ◽  
Sonia Scarfi ◽  
Serena Mirata ◽  
Alina Sionkowska ◽  
Silvia Vicini ◽  
...  

Chitosan nanofibrous membranes are prepared via an electrospinning technique and explored as potential wound healing patches. In particular, the effect of a physical or chemical crosslinking treatment on the mat morphological, mechanical, water-related, and biological properties is deeply evaluated. The use of phosphate ions (i.e., physical crosslinking) allows us to obtain smooth and highly homogenous nanofibers with an average size of 190 nm, whereas the use of ethylene glycol diglycidyl ether (i.e., chemical crosslinking) leads to rougher, partially coalesced, and bigger nanofibers with an average dimension of 270 nm. Additionally, the physically crosslinked mats show enhanced mechanical performances, as well as greater water vapour permeability and hydrophilicity, with respect to the chemically crosslinked ones. Above all, cell adhesion and cytotoxicity experiments demonstrate that the use of phosphate ions as crosslinkers significantly improves the capability of chitosan mats to promote cell viability owing to their higher biocompatibility. Moreover, tuneable drug delivery properties are achieved for the physically crosslinked mats by a simple post-processing impregnation methodology, thereby indicating the possibility to enrich the prepared membranes with unique features. The results prove that the proposed approach may lead to the preparation of cheap, biocompatible, and efficient chitosan-based nanofibers for biomedical and pharmaceutical applications.


Author(s):  
Ishowriya Yumnam

In this review article the usage of waste sewage sludge and the biomass ash for improving the engineering and non-engineering properties’ of both concrete and soil are discussed in detail. Numerous past research works were studied in detail so as to predict the behavior of biomass ash and waste sewage sludge when used for the stabilization process of soil and concrete. Past studies related to the usage of stabilized sewage sludge and biomass ash were studied in a detailed manner and depending upon the past studies several conclusions has been drawn which are discussed further. Several studies related to the usage of the waste sewage sludge for improving soil physical, chemical and biological properties showed that the usage of waste sewage sludge improve the physical properties, chemical properties, macro-nutriential properties and micro-nutriential properties up to a great extent. Depending upon the results of the past studies it can be concluded that the usage of sewage sludge has positive impact over all the properties of soil and this waste should be utilized in improving the properties of soil rather than dumping. Numerous studies related to the usage of the biomass ash showed that biomass ash has positive impact over both soil as well as concrete. Studies related to the usage of the biomass ash in soil showed that there was a positive response of the stabilized soil after its stabilization with the biomass ash. Studies related to the usage of the biomass ash in concrete showed that the biomass ash can be used up to 10 percent replacement of the ordinary Portland cement so as to attain maximum strength results from it.


2021 ◽  
Author(s):  
Anastasia Arturovna Semenova ◽  
◽  
Yulia Konstantinovna Yushina ◽  
Maria Alexandrovna Grudistova ◽  
Elena Viktorovna Zaiko ◽  
...  

The article discusses the results of a study of the microbial diversity of objects in the production environment of two meat processing enterprises, including antibiotic resistance, isolated strains of pathogenic microorganisms and their ability to biofilm formation.


Sign in / Sign up

Export Citation Format

Share Document