No-tillage systems promote bacterial photosynthetic gene expression in low carbon, semi-arid surface soils.

Managing soils in semi-arid agricultural croplands generally focuses on reducing wind erosion, increasing fertility, and storing carbon. Thus, converting conventionally tilled systems to no-tillage and cover-cropped systems are often the first steps towards a conservation management approach across the growing area of semi-arid croplands. From a soil biological perspective, introducing cover crops to semi-arid soils has been shown to alter microbial community structure, which may lead to changes in the biogeochemical pathways expressed in these soils.

Isolation and Characterization of Bacterial Endophytes from Small Nodules of Field-Grown Peanut.

It is evident that legume root nodules can accommodate rhizobial and non-rhizobial bacterial endophytes. Our recent nodule microbiome study in peanuts described that small nodules can harbor diverse bacterial endophytes. To understand their functional role, we isolated 87 indigenous endophytes from small nodules of field-grown peanut roots and characterized them at molecular, biochemical, and physiological levels.

Microbiome analysis revealed distinct microbial communities occupying different sized nodules in field-grown peanut.

Legume nodulation is the powerhouse of biological nitrogen fixation (BNF) where host-specific rhizobia dominate the nodule microbiome. However, other rhizobial or non-rhizobial inhabitants can also colonize legume nodules, and it is unclear how these bacteria interact, compete, or combinedly function in the nodule microbiome. Under such context, to test this hypothesis, we conducted 16S-rRNA based nodule microbiome sequencing to characterize microbial communities in two distinct sized nodules from field-grown peanuts inoculated with a commercial inoculum.

Hurricane Harvey Impacts on Water Quality and Microbial Communities in Houston, TX Waterbodies.

Extreme weather events can temporarily alter the structure of coastal systems and generate floodwaters that are contaminated with fecal indicator bacteria (FIB); however, every coastal system is unique, so identification of trends and commonalities in these episodic events is challenging. To improve our understanding of the resilience of coastal systems to the disturbance of extreme weather events, we monitored water quality, FIB at three stations within Clear Lake, an estuary between Houston and Galveston, and three stations in bayous that feed into the estuary. Water samples were collected immediately before and after Hurricane Harvey (HH) and then throughout the fall of 2017.

Niche Differentiation of Arsenic-Transforming Microbial Groups in the Rice Rhizosphere Compartments as Impacted by Water Management and Soil-Arsenic Concentrations.

Arsenic (As) bioavailability in the rice rhizosphere is influenced by many microbial interactions, particularly by metal-transforming functional groups at the root-soil interface. This study was conducted to examine As-transforming microbes and As-speciation in the rice rhizosphere compartments, in response to two different water management practices (continuous and intermittently flooded), established on fields with high to low soil-As concentration. Microbial functional gene composition in the rhizosphere and root-plaque compartments were characterized using the GeoChip 4.

Increased Antimicrobial and Multidrug Resistance Downstream of Wastewater Treatment Plants in an Urban Watershed.

Development and spread of antimicrobial resistance (AMR) and multidrug resistance (MDR) through propagation of antibiotic resistance genes (ARG) in various environments is a global emerging public health concern. The role of wastewater treatment plants (WWTPs) as hot spots for the dissemination of AMR and MDR has been widely pointed out by the scientific community. In this study, we collected surface water samples from sites upstream and downstream of two WWTP discharge points in an urban watershed in the Bryan-College Station (BCS), Texas area, over a period of nine months.

Elevated Incidences of Antimicrobial Resistance and Multidrug Resistance in the Maumee River (Ohio, USA), a Major Tributary of Lake Erie.

Maumee River, the major tributary in the western basin of Lake Erie, serves as one of major sources of freshwater in the area, supplying potable, recreational, and industrial water. In this study we collected water samples from four sites in the Maumee River Bay between 2016-2017 and was isolated, enumerated, and analyzed for antimicrobial resistance (AMR) and multidrug resistance (MDR). Strikingly, 95% of the total isolates were found to be resistant to at least one antibiotic.

Whole genome sequence analysis reveals high genetic variation of newly isolated Acidithiobacillus ferrooxidans IO-2C.

Acidithiobacillus ferrooxidans, a chemolithoautotrophic bacterium, is well known for its mineral oxidizing properties. The current study combines experimental and whole genome sequencing approaches to investigate an iron oxidizing, extreme acidophilic bacterium, A. ferrooxidans isolate (IO-2C) from an acid seep area near Carlos, TX, USA.

Fungal Community Structural and Microbial Functional Pattern Changes After Soil Amendments by Oilseed Meals of and : A Microcosm Study.

The meals after oil extraction from many oilseed crops have nutrition and biofumigation potential for land application. Oilseed meal (SM) from the dedicated bioenergy crop were implicated to contain compounds that have antibacterial properties on some soil pathogens. However, little is known about its effect on non-targeted soil microbial community, especially on fungi.

Diesel degrading bacterial endophytes with plant growth promoting potential isolated from a petroleum storage facility.

Thirteen (13) endophytic bacterial strains were isolated from (Cockspur grass) and (Bermuda grass) growing in an oil-contaminated site at a petroleum storage and transportation facility. Of the 13 strains assessed for their potential to degrade monoaromatic compounds (phenol, toluene, and xylene) and diesel and for their plant growth promoting (PGP) ability (phosphate solubilization, siderophores and 1-aminocyclopropane-1-carboxylate (ACC) deaminase production), isolate J10 (identified as sp. by 16S rRNA gene sequencing) was found to the best diesel biodegrader with the best PGP traits.

Soil Bacterial Community Was Changed after Brassicaceous Seed Meal Application for Suppression of Wilt on Pepper.

Application of Brassicaceous seed meal (BSM) is a promising biologically based disease-control practice but BSM could directly and indirectly also affect the non-target bacterial communities, including the beneficial populations. Understanding the bacterial response to BSM at the community level is of great significance for directing plant disease management through the manipulation of resident bacterial communities. wilt is a devastating disease on pepper.

Within-House Spatial Distribution of Fecal Indicator Bacteria in Poultry Litter.

Land application of poultry litter is often considered to be a major source of water pollutants in poultry-producing regions. However, reported levels of fecal indicator microorganisms in litter vary widely, with considerable variation possible within houses and across farms, depending on management practices. Therefore, a study was conducted to determine the levels and distribution of indicator microorganisms within 12 broiler farms representing three companies.

Biodegradation of phenol and benzene by endophytic bacterial strains isolated from refinery wastewater-fed Cannabis sativa.

The presence of benzene and phenol in the environment can lead to serious health effects in humans and warrant development of efficient cleanup strategies. The aim of the present work was to assess the potential of indigenous endophytic bacterial strains to degrade benzene and phenol. Seven strains were successfully isolated from Cannabis sativa plants irrigated with oil refinery wastewater.

Impacts of Heronries on Water Quality as Evaluated through and Fecal Sterol Analyses.

  The authors used fecal sterol analysis to determine the potential contribution of E. coli from heronries to waterbodies in east-central Texas. They analyzed E.

Hill number as a bacterial diversity measure framework with high-throughput sequence data.

Bacterial diversity is an important parameter for measuring bacterial contributions to the global ecosystem. However, even the task of describing bacterial diversity is challenging due to biological and technological difficulties. One of the challenges in bacterial diversity estimation is the appropriate measure of rare taxa, but the uncertainty of the size of rare biosphere is yet to be experimentally determined.

Soil bacterial and fungal communities respond differently to various isothiocyanates added for biofumigation.

The meals from many oilseed crops have potential for biofumigation due to their release of biocidal compounds such as isothiocyanates (ITCs). Various ITCs are known to inhibit numerous pathogens; however, much less is known about how the soil microbial community responds to the different types of ITCs released from oilseed meals (SMs). To simulate applying ITC-releasing SMs to soil, we amended soil with 1% flax SM (contains no biocidal chemicals) along with four types of ITCs (allyl, butyl, phenyl, and benzyl ITC) in order to determine their effects on soil fungal and bacterial communities in a replicated microcosm study.

Water management impacts on arsenic speciation and iron-reducing bacteria in contrasting rice-rhizosphere compartments.

Rice cultivated on arsenic (As) contaminated-soils will accumulate variable grain-As concentrations, as impacted by varietal differences, soil variables, and crop management. A field-scale experiment was conducted to study the impact of intermittent and continuous flooding on As speciation and microbial populations in rice rhizosphere compartments of soils that were either historically amended with As pesticide or unamended with As. Rhizosphere-soil, root-plaque, pore-water and grain As were quantified and speciated, and microbial populations in rhizosphere soil and root-plaque were characterized.

Dynamics of microbial community composition and function during in situ bioremediation of a uranium-contaminated aquifer.

A pilot-scale system was established to examine the feasibility of in situ U(VI) immobilization at a highly contaminated aquifer (U.S. DOE Integrated Field Research Challenge site, Oak Ridge, TN).

Investigation of intermittent air exposure on four-stage and one-stage anaerobic semi-continuous mixed-acid fermentations.

This study evaluated anaerobic mixed-acid countercurrent fermentations in both strict S (minimal oxygen) and relaxed R (high oxygen) conditions. In relaxed fermentations, filter solids and liquids were exposed to air for 90 min every 56 h. The total acid concentrations for four-stage trains were 23.

Black Box Chimera Check (B2C2): a Windows-Based Software for Batch Depletion of Chimeras from Bacterial 16S rRNA Gene Datasets.

The existing chimera detection programs are not specifically designed for "next generation" sequence data. Technologies like Roche 454 FLX and Titanium have been adapted over the past years especially with the introduction of bacterial tag-encoded FLX/Titanium amplicon pyrosequencing methodologies to produce over one million 250-600 bp 16S rRNA gene reads that need to be depleted of chimeras prior to downstream analysis. Meeting the needs of basic scientists who are venturing into high-throughput microbial diversity studies such as those based upon pyrosequencing and specifically providing a solution for Windows users, the B2C2 software is designed to be able to accept files containing large multi-FASTA formatted sequences and screen for possible chimeras in a high throughput fashion.

Structure and dynamics of the microbial communities underlying the carboxylate platform for biofuel production.

The carboxylate platform utilizes a mixed microbial community to convert lignocellulosic biomass into chemicals and fuels. While much of the platform is well understood, little is known about its microbiology. Mesophilic (40 degrees C) and thermophilic (55 degrees C) fermentations employing a sorghum feedstock and marine sediment inoculum were profiled using 16S rRNA tag-pyrosequencing over the course of a 30-day incubation.