The piecharts report the fraction of the sequences maintained and the fraction of sequences lost during quality refinement steps. Nucleotide relative frequency distribution along the sequences.
Compare the soil microbial communities between a native tall grass prairie and an annual no-till system. Assess diversity of soil diazotrophs in these systems both across treatments and through the soil profile. Project Methods Soils will be sampled from a preexisting field trial in Kansas where a never-tilled, bottom-land tall grass prairie has been converted to an annual no-till grain system.
Soils will be sampled to 1 m depth in 6 increments and total genomic DNA from soil organisms extracted with a commercial extraction kit. A molecular fingerprinting technique T-RFLP will then be used to compare the structure of microbial communities in the different treatment and correlate these with other measures of system performance.
Three studies were included in this work: Soils were sampled at 10, 20, 30, 40, 60, 80 and cm depth at multiple time points within each season and between years in both the regional and conversion studies. Resulting data were analyzed and included in a broader comparative study of T-RFLP fingerprinting multivariate methods.
Results will also be presented in a series of manuscripts in refereed journals. Steven Culman, Cornell University, graduate student. The Land Institute, Salina, Kansas. Midwest wheat farmers, The Land Institute and its associated target audiences. Nothing significant to report during this reporting period.
Impacts The primary driver of general bacterial community composition at all sites was soil depth. Bacterial communities grouped uniquely by their respective depth of sampling in multivariate analyses. In the recent conversion, no consistent changes in general or nitrogen fixing bacterial community composition were detected between the prairie soil and the no-till system.
Project members analyze bacterial diversity among various environments, geographies and chemistries by sequencing the 16S rRNA gene, a genetic marker specific for bacteria and their relatives. Nov 08, · The purpose of this study was to determine the bacterial diversity in the human subgingival plaque by using culture-independent molecular methods as part of an ongoing effort to obtain full 16S rRNA sequences for all cultivable and not-yet-cultivated species of human oral bacteria. Department Microbial Ecology and Diversity Projects. Evolutionary basis of bacterial diversity - mechanisms of genome evolution, speciation and niche separation. Bacteria and archaea are genetically, phylogenetically and physiologically very diverse. In contrast to human pathogens from the clinical habitat, little is known of the evolutionary.
However, in the long-term study, significant differences in bacterial community composition between no-till agricultural and prairie plots were detected in the first 40 cm at 10 cm, 20 cm and 40 cm of soil, but not at 60, 80 or cm depth.
Free-living nitrogen fixing bacterial community composition was influenced most by management system, as depth was not a consistent driver of composition in the long-term study.
We concluded that converting prairie to annual cropping systems significantly affects extant soil bacterial populations. In addition, three years following the conversion, microbial biomass C MBC and readily-oxidizable carbon ROC were significantly lower in the top 40 cm in the agricultural plots compared to the native prairie.
These data indicate strong relationships between bacterial communities and key soil properties, suggesting that 1 soil fertility is closely linked to soil biological food webs, and 2 decreases in soil fertility namely soil C experienced in annual agricultural systems are driven by plant community composition depth of rooting as well as by tillage.
Overall, we found that soil organic C stocks decline rapidly post-conversion and have estimated a relative rate of soil C loss over time for these systems. Soil microbial community composition in the top 40 cm of soil was significantly affected by land conversion, but these changes occurred more slowly.
This work demonstrates how rapidly soil ecosystem degradation can occur in the absence of extensive perennial root systems and argues for selecting species for agricultural use that can both exploit nutrient resources and contribute to soil C stocks at greater depth than currently used varieties.
Soil microbial dynamics and associative nitrogen fixation in Kansan tallgrass prairies. Journal of Microbiological Methods Perennial grassland agroecosystems have long been recognized for the environmental benefits they provide, such as reduced soil erosion, reduced nitrogen N leaching, and greater carbon C sequestration.
These ecosystem services are commonly thought to come as a trade off for lower productivity relative to their annual grassland counterparts - the cereals.
However, some recent studies have shown that perennial grasslands are equally or more capable than annual croplands at providing food, fiber and fuel. This study was part of a larger collaborative effort with the Land Institute and had two objectives: Soils were sampled by depth 10, 20, 40, 60, 80, cm within and between seasons from our Kansas field sites.
Changes in i soil microbial community biomass, activity and diversity, ii nematode numbers and trophic structure, iii soil aggregate stability and iv organic C contents were used to document changes in soil quality in these systems over time.
General bacterial and nitrogen-fixing bacterial community composition were assessed by terminal restriction fragment length polymorphism T-RFLP analysis. Free-living, nitrogen-fixing bacterial community composition was influenced most strongly by treatment prairie vs annual croppingrather than soil depth in the long-term study.
In addition, three years following the conversion, water stable soil aggregation and readily-oxidizable C significantly decreased in the top 40 cm in agricultural plots compared to the native prairie and changes in nematode community composition were also observed.
Data collected thus far suggest that there is a strong relationship between bacterial and nematode communities and key soil properties, in that i changes in soil fertility appears to be closely associated with changes in the soil biological food webs, ii declines in soil fertility experienced in the annually cropped plots appear more strongly related to the lack of a perennial root system and its associated rhizosphere communities than to agricultural management practices per se namely tillage.
From this work, relative estimates of rates of change in soil fertility and soil microbial populations are being gained. This information will help to deepen our understanding of how quickly soil ecosystem degradation occurs in the absence of extensive perennial roots when prairie lands are converted to crop lands.
Exploring microbial diversity in natural systems agriculture. Land management systems that simulate natural processes have the potential to improve soil quality while simultaneously preserving yield and the capacity of lands to sustain yields over time.
Changes in soil microbial community biomass, activity and diversity can serve as indicators of soil quality change over time. The purpose of this study was to investigate changes in microbial communities as native, perennial prairie was converted to an annual, no-till system.
The primary driver of changes in bacterial community composition was depth in the soil profile, as bacterial communities grouped uniquely with their respective depth of sampling. However, secondary changes in bacterial community structure related to system conversion were detected in the first 40 cm at 10cm, 20 cm and 40cm of soil depth two years after agricultural conversion.
Changes in bacterial community structure at 60, 80 and cm depth were not detected after two years.View Lab Report - Bacterial Diversity Project from BIOLOGY at University of Iowa. Bacterial Diversity Project: The Techniques and Analyzes to Identify a Bacterial Species September Nov 08, · The purpose of this study was to determine the bacterial diversity in the human subgingival plaque by using culture-independent molecular methods as part of an ongoing effort to obtain full 16S rRNA sequences for all cultivable and not-yet-cultivated species of human oral bacteria.
Sep 04, · In this study, the evaluation of soil characteristics was coupled with a pyrosequencing analysis of the V2-V3 16S rRNA gene region in order to investigate the bacterial community structure and diversity in the A horizon of a natural saline soil located in Sicily (Italy).
This data article describes the bacterial diversity of the deep sea shark,. The data was acquired by metabarcoding using 16S rDNA., a deep sea shark found at depths below m was sampled during Sagar Sampada cruise no in the Indian Ocean and metagenomic DNA was isolated from the gut contents using QIAamp DNA stool minikit.
Department Microbial Ecology and Diversity Projects. Evolutionary basis of bacterial diversity - mechanisms of genome evolution, speciation and niche separation. Bacteria and archaea are genetically, phylogenetically and physiologically very diverse. In contrast to human pathogens from the clinical habitat, little is known of the evolutionary.
Bacterial Diversity Project John FreesackSection A24 Kim Daffer, John Chang September 23, Introduction: Bacteria are everywhere. Some can be seen with the naked eye and some require a microscope but how do we distinguish one kind of bacteria from another?