Microbial community composition controls carbon flux across litter types in early phase of litter decomposition.

Leaf litter decomposition is a major carbon input to soil, making it a target for increasing soil carbon storage through microbiome engineering. We expand upon previous findings to show with multiple leaf litter types that microbial composition can drive variation in carbon flow from litter decomposition and specific microbial community features are associated with synonymous patterns of carbon flow among litter types. Although plant litter type selects for different decomposer communities, within a litter type, microbial composition drives variation in the quantity of dissolved organic carbon (DOC) measured at the end of the decomposition period.

Soil Bacterial and Fungal Richness Forecast Patterns of Early Pine Litter Decomposition.

Discovering widespread microbial processes that drive unexpected variation in carbon cycling may improve modeling and management of soil carbon (Prescott, 2010; Wieder et al., 2015a, 2018). A first step is to identify community features linked to carbon cycle variation.

Effects of initial microbial biomass abundance on respiration during pine litter decomposition.

Microbial biomass is one of the most common microbial parameters used in land carbon (C) cycle models, however, it is notoriously difficult to measure accurately. To understand the consequences of mismeasurement, as well as the broader importance of microbial biomass abundance as a direct driver of ecological phenomena, greater quantitative understanding of the role of microbial biomass abundance in environmental processes is needed. Using microcosms, we manipulated the initial biomass of numerous microbial communities across a 100-fold range and measured effects on CO2 production during plant litter decomposition.

Tracking Replicate Divergence in Microbial Community Composition and Function in Experimental Microcosms.

The study of microbial community functions necessitates replicating microbial communities. Variation in community development over time renders this an imperfect process. Thus, anticipating the likely degree of variation among replicate communities may aid in experimental design.

Short-Term Transcriptional Response of Microbial Communities to Nitrogen Fertilization in a Pine Forest Soil.

Numerous studies have examined the long-term effect of experimental nitrogen (N) deposition in terrestrial ecosystems; however, N-specific mechanistic markers are difficult to disentangle from responses to other environmental changes. The strongest picture of N-responsive mechanistic markers is likely to arise from measurements over a short (hours to days) time scale immediately after inorganic N deposition. Therefore, we assessed the short-term (3-day) transcriptional response of microbial communities in two soil strata from a pine forest to a high dose of N fertilization (ca.

A parallel microfluidic channel fixture fabricated using laser ablated plastic laminates for electrochemical and chemiluminescent biodetection of DNA.

Herein is described the fabrication and use of a plastic multilayer 3-channel microfluidic fixture. Multilayer devices were produced by laser machining of plastic polymethylmethacrylate and polyethyleneterapthalate laminates by ablation. The fixture consisted of an array of nine individually addressable gold or gold/ITO working electrodes, and a resistive platinum heating element.

Multiplexed microneedle-based biosensor array for characterization of metabolic acidosis.

The development of a microneedle-based biosensor array for multiplexed in situ detection of exercise-induced metabolic acidosis, tumor microenvironment, and other variations in tissue chemistry is described. Simultaneous and selective amperometric detection of pH, glucose, and lactate over a range of physiologically relevant concentrations in complex media is demonstrated. Furthermore, materials modified with a cell-resistant (Lipidure(®)) coating were shown to inhibit macrophage adhesion; no signs of coating delamination were noted over a 48-h period.

Integrated carbon fiber electrodes within hollow polymer microneedles for transdermal electrochemical sensing.

In this study, carbon fiber electrodes were incorporated within a hollow microneedle array, which was fabricated using a digital micromirror device-based stereolithography instrument. Cell proliferation on the acrylate-based polymer used in microneedle fabrication was examined with human dermal fibroblasts and neonatal human epidermal keratinocytes. Studies involving full-thickness cadaveric porcine skin and trypan blue dye demonstrated that the hollow microneedles remained intact after puncturing the outermost layer of cadaveric porcine skin.

Cell-directed-assembly: directing the formation of nano/bio interfaces and architectures with living cells.

Background: The desire to immobilize, encapsulate, or entrap viable cells for use in a variety of applications has been explored for decades. Traditionally, the approach is to immobilize cells to utilize a specific functionality of the cell in the system.

Scope Of Review: This review describes our recent discovery that living cells can organize extended nanostructures and nano-objects to create a highly biocompatible nano//bio interface [1].

Cell-directed integration into three-dimensional lipid-silica nanostructured matrices.

We report a unique approach in which living cells direct their integration into 3D solid-state nanostructures. Yeast cells deposited on a weakly condensed lipid/silica thin film mesophase actively reconstruct the surface to create a fully 3D bio/nano interface, composed of localized lipid bilayers enveloped by a lipid/silica mesophase, through a self-catalyzed silica condensation process. Remarkably, this integration process selects exclusively for living cells over the corresponding apoptotic cells (those undergoing programmed cell death), via the development of a pH gradient, which catalyzes silica deposition and the formation of a coherent interface between the cell and surrounding silica matrix.

Confinement-induced quorum sensing of individual Staphylococcus aureus bacteria.

It is postulated that in addition to cell density, other factors such as the dimensions and diffusional characteristics of the environment could influence quorum sensing (QS) and induction of genetic reprogramming. Modeling studies predict that QS may operate at the level of a single cell, but, owing to experimental challenges, the potential benefits of QS by individual cells remain virtually unexplored. Here we report a physical system that mimics isolation of a bacterium, such as within an endosome or phagosome during infection, and maintains cell viability under conditions of complete chemical and physical isolation.

Cell-directed localization and orientation of a functional foreign transmembrane protein within a silica nanostructure.

A simple procedure for introducing functional exogenous membrane-bound proteins to viable cells encapsulated within a lipid templated silica nanostructure is described. In one method, bacteriorhodopsin (bR) was added directly to a Saccharomyces cerevisiae solution along with short zwitterionic diacylphosphatidylcholines (diC(6) PC) and mixed with equal volumes of a sol precursor solution. Alternatively, bR was first incorporated into liposomes (bR-proteoliposomes) and then added to an S.

A multifunctional thin film Au electrode surface formed by consecutive electrochemical reduction of aryl diazonium salts.

A multifunctional thin film surface capable of immobilizing two diverse molecules on a single gold electrode was prepared by consecutive electrodeposition of nitrophenyl and phenylboronic acid pinacol ester (PBA-PE) diazonium salts. Activation of the stacked film toward binding platinum nanoparticles (PtNPs) and yeast cells occurred via chemical deprotection of the pinacol ester followed by electroreduction of nitro to amino groups. FTIR spectral analysis was used to study and verify film composition at each stage of preparation.

Cell-directed assembly of bio/nano interfaces-a new scheme for cell immobilization.

When lipid-directed assembly of silicic acid precursors is conducted in the presence of living cells, the cells intervene, surrounding themselves with a fluid, multilayered lipid vesicle that interfaces coherently with an ordered silica mesophase. This bio/nano interface is unique in that its uniform nanostructure prevents excessive drying of water, maintaining cell viability, yet provides accessibility of the cell surface to small molecules. In comparison to existing immobilization schemes, such as encapsulation within sol-gel matrices, we show this interface to form by an active interplay between the living cell and surrounding matrix, which we refer to as cell-directed assembly (CDA).

Cell-directed assembly of lipid-silica nanostructures providing extended cell viability.

Amphiphilic phospholipids were used to direct the formation of biocompatible, uniform silica nanostructures in the presence of Saccharomyces cerevisiae and bacterial cell lines. The cell surfaces organize multilayered phospholipid vesicles that interface coherently with the silica host and help relieve drying stresses that develop with conventional templates. These host structures maintain cell accessibility, addressability, and viability in the absence of buffer or an external fluidic architecture.