Chemicals involved in plutonium uranium reduction extraction (PUREX) can be released from nuclear reprocessing facilities and accumulate in the environment. We exposed chemically diverse soils to a range of concentrations of key chemicals used in the PUREX process. The responses of soil microbial communities are dependent on soil type, and tributyl phosphate exposure generates the most reproducible changes in microbial communities. We reconstructed the genomes of key bacteria and find several phosphotriesterase genes found only in Rhizobiaceae. The abundance of phosphotriesterase genes is significantly higher in samples exposed to tributyl phosphate. These phosphotriesterase genes may be involved in breakdown of tributyl phosphate, and a means of accessing phosphate for these bacteria.
The convergence of advances in biotechnology with laboratory automation, access to data, and computational biology has democratized biotechnology and accelerated the development of new therapeutics. However, increased access to biotechnology in the digital age has also introduced additional security concerns and ultimately, spawned the new discipline of cyberbiosecurity, which encompasses cybersecurity, cyber-physical security, and biosecurity considerations. With the emergence of this new discipline comes the need for a logical, repeatable, and shared approach for evaluating facility and system vulnerabilities to cyberbiosecurity threats. In this paper, we outline the foundation of an assessment framework for cyberbiosecurity, accounting for both security and resilience factors in the physical and cyber domains. This is a unique problem set, but despite the complexity of the cyberbiosecurity field in terms of operations and governance, previous experience developing and implementing physical and cyber assessments applicable to a wide spectrum of critical infrastructure sectors provides a validated point of departure for a cyberbiosecurity assessment framework. This approach proposes to integrate existing capabilities and proven methodologies from the infrastructure assessment realm (e.g., decision science, physical security, infrastructure resilience, cybersecurity) with new expertise and requirements in the cyberbiosecurity space (e.g., biotechnology, biomanufacturing, genomics) in order to forge a flexible and defensible approach to identifying and mitigating vulnerabilities. Determining where vulnerabilities reside within cyberbiosecurity business processes can help public and private sector partners create an assessment framework to identify mitigation options for consideration that are both economically and practically viable and ultimately, allow them to manage risk more effectively.
Botulinum neurotoxin (BoNT) presents a significant hazard under numerous realistic scenarios. The standard detection scheme for this fast-acting toxin is a lab-based mouse lethality assay that is sensitive and specific, but slow (∼2 days) and requires expert administration. As such, numerous efforts have aimed to decrease analysis time and reduce complexity. Here, we describe a sensitive ratiometric fluorescence resonance energy transfer scheme that utilizes highly photostable semiconductor quantum dot (QD) energy donors and chromophore conjugation to compact, single chain variable antibody fragments (scFvs) to yield a fast, fieldable sensor for BoNT with a 20-40 pM detection limit, toxin quantification, adjustable dynamic range, sensitivity in the presence of interferents, and sensing times as fast as 5 min. Through a combination of mutations, we achieve stabilized scFv denaturation temperatures of more than 60 °C, which bolsters fieldability. We also describe adaptation of the assay into a microarray format that offers persistent monitoring, reuse, and multiplexing.
Methods to assess the quality and performance of protein microarrays fabricated from undefined protein content are required to elucidate slide-to-slide variability and interpolate resulting signal intensity values after an interaction assay. We therefore developed several simple total- and posttranslational modification-specific, on-chip staining methods to quantitatively assess the quality of gel element protein arrays manufactured with whole-cell lysate in vitro protein fractions derived from two-dimensional liquid-phase fractionation (PF2D) technology. A linear dynamic range of at least 3 logs was observed for protein stains and immobilized protein content, with a lower limit of detection at 8 pg of protein per gel element with Deep Purple protein stain and a field-portable microarray imager. Data demonstrate the successful isolation, separation, transfer, and immobilization of putative transmembrane proteins from Yersinia pestis KIM D27 with the combined PF2D and gel element array method. Internal bovine serum albumin standard curves provided a method to assess on-chip PF2D transfer and quantify total protein immobilized per gel element. The basic PF2D array fabrication and quality assurance/quality control methods described here therefore provide a standard operating procedure and basis for developing whole-proteome arrays for interrogating host–pathogen interactions, independent of sequenced genomes, affinity tags, or a priori knowledge of target cell composition.
Protein profiling and characterization of protein interactions in biological samples ultimately require indicator-free methods of signal detection, which likewise offer an opportunity to distinguish specific interactions from nonspecific protein binding. Here we describe a new 3-dimensional protein microchip for detecting biomolecular interactions with matrix-assisted laser desorption-ionization mass spectrometry (MALDI-MS); the microchip comprises a high-density array of methacrylate polymer elements containing immobilized proteins as capture molecules and directly interfaces with a commercially available mass spectrometer. We demonstrated the performance of the chip in three types of experiments by detecting antibody-antigen interactions, enzymatic activity, and enzyme-inhibitor interactions. MALDI-MS biochip-based tumor necrosisfactor alpha (TNF-alpha) immunoassays demonstrated the feasibility of detecting antigens in complex biological samples by identifying molecular masses of bound proteins even at high nonspecific protein binding. By detecting model interactions of trypsin with trypsin inhibitors, we showed that the protein binding capacity of methacrylate polymer elements and the sensitivity of MALDI-MS detection of proteins bound to these elements surpassed that of other 2- and 3-dimensional substrates tested Immobilized trypsin retained functional (enzymatic) activity within the protein microchip and the specificity of macromolecular interactions even in complex biological samples. We believe that the underlying technology should therefore be extensible to whole-proteome protein expression profiling and interaction mapping.