Biology subjects

Verduzco, R.

Publications and source records attributed to Verduzco, R..

4 recordsLinked to original sources

bioRxiv2025

A Bioelectrochemical Crossbar Architecture Screening Platform (BiCASP) for Extracellular Electron Transfer

Electroactive microbes can be used as components in electrical devices to leverage their unique behavior for biotechnology, but they remain challenging to engineer because the bioelectrochemical systems (BES) used for characterization are low-throughput. To overcome this challenge, we describe the development of the Bioelectrochemical Crossbar Architecture Screening Platform (BiCASP), which allows for samples to be arrayed and characterized in individually addressable microwells. This device reliably reports on the current generated by electroactive bacteria on the minute time scale, decreasing the time for data acquisition by several orders of magnitude compared to conventional BES. Also, this device increased the throughput of screening engineered biological components in cells, quickly identifying mutants of the membrane protein wire MtrA in Shewanella oneidensis that retain the ability to support extracellular electron transfer (EET). BiCASP is expected to enable the design of new components for bioelectronics by supporting directed evolution of electroactive proteins. The bigger pictureDevices that interface microbes and materials, known as bioelectronics, can be used to sense environmental chemicals in real time, generate energy from sugars, and synthesize chemicals. While these devices leverage the unique capabilities of living systems as components in devices, such as their ability to convert chemical information in the environment into electrical information at the cell surface, it remains challenging to engineer these cellular components and their biomolecules for new applications, largely because commercially available bioelectrochemical systems for monitoring current generated by electroactive microbes are costly and require large culture volumes, needs continuous monitoring for days to obtain stable signals, and multichannel potentiostats to monitor multiple microbes in parallel. To overcome these challenges, we created the Bioelectrochemical Crossbar Architecture Screening Platform or BiCASP that is easy to fabricate, enables parallel analysis of microbial samples in flexible arrayed formats, and yields a stable signal on the minute time scale. This device is expected to enable the application of combinatorial protein engineering methods, such as directed evolution, to proteins that control microbial current production, by allowing for fast screening of cells expressing protein mutant libraries. As a proof-of-concept, we demonstrate that this device can screen for cells that express mutants of decaheme cytochromes that retain the ability to electrically connect cells to electrodes. This device will simplify the engineering of cells and proteins that function as electrical switches as well as the diversification of bioelectronic devices for real-time sensing of chemicals in the environment. Furthermore, BiCASP is promising as a high-throughput screening (HTS) platform, enabling rapid, parallel analysis of cellular and molecular interactions of diverse biological systems through label-free electrochemical methods. Such capabilities could transform drug discovery, personalized medicine, and functional genomics, supporting systematic genetic and chemical screens even at single-cell resolution. HighlightsO_LIA high-throughput screening platform with individual addressability C_LIO_LIA device with a flexible crossbar architecture that simplifies current analysis C_LIO_LIReproducible detection of real-time cellular current on the minute time scale C_LIO_LIThe device can be used to screen a library for cells with functional protein wires C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=187 HEIGHT=200 SRC="FIGDIR/small/663982v1_ufig1.gif" ALT="Figure 1"> View larger version (57K): org.highwire.dtl.DTLVardef@c451d1org.highwire.dtl.DTLVardef@d7a50corg.highwire.dtl.DTLVardef@194e986org.highwire.dtl.DTLVardef@16f7af9_HPS_FORMAT_FIGEXP M_FIG C_FIG

synthetic biology↗

bioRxiv2024

Gender, interdisciplinary graduate training, and confidence working in teams

Teamwork is recognized as critical to solving complex societal challenges related to energy, health, and sustainability. With graduate education, students often gain teamwork experience through a problem-focused approach where they are brought into existing collaborations to pursue research that is focused on studying questions that have already been identified. Here, we describe an interdisciplinary educational program where graduate students were tasked with leading team formation, problem identification, and research formulation. This "team-first" training approach used a two-year curriculum to bring together students enrolled in diverse engineering and science graduate programs and provided students with a pedagogical understanding of interdisciplinarity, nurtured the development of student communication skills across disciplines, fostered student-led team formation and idea development, and empowered students to forge new connections between research groups. Assessment of three cohorts immediately following curriculum completion (n = 36) revealed significant gains in confidence in teamwork (p < 0.001) when compared to a control group of academic peers (n = 74). These gains varied across demographic groups, with women in science, technology, engineering, and mathematics presenting the strongest gains. This finding illustrates the importance of exploring how interdisciplinary team curricula in graduate school could support overcoming the gender gap in confidence. SignificancePedagogical models for graduate education often neglect the importance of teamwork training. Here, we describe an interdisciplinary training program that was developed to bring together doctoral students from diverse science, technology, engineering, and mathematics disciplines for a two-year curriculum that focused on teamwork training through student-led team formation, problem identification, and research formulation. Following program participation, we measured participant confidence in teamwork relative to a peer group. Our findings reveal gains with confidence in teamwork, with women presenting the strongest increases without negative effects on other groups. This pedagogical approach represents a strategy to close gender gaps in professional role confidence while complementing the benefits of traditional disciplinary training approaches.

scientific communication and education↗

bioRxiv2022

A high-throughput approach to identify reproductive toxicants among environmental chemicals using an in vivo evaluation of gametogenesis in budding yeast Saccharomyces cerevisiae

BackgroundEnvironmental chemical exposures are likely making important contributions to current levels of infertility and its increasing incidence. Yet the US produces high volumes of industrial chemicals for which there is limited data on their potential human reproduction toxicity. Current assays typically used in policy and regulatory settings involve costly and timeconsuming whole-animal rodent tests which limit the rapidity with which one can assess the thousands of chemicals yet to be tested. ObjectiveOur aim was to develop a fast and reliable strategy to evaluate a large number of chemicals for reproductive toxicity by developing a high-throughput toxicity assessment using the yeast S. cerevisiae. MethodsYeast are chronically exposed to each environmental chemical at two doses, 30 M and 100 M, in a 96-well plate-based format throughout gametogenesis. Non-gametes are removed and chemicals are washed away before gamete viability is measured using absorbance at 600 nm to produce growth curves. The difference in time at half-maximal saturation with and without exposure is used to determine the extent of reproductive toxicity. ResultsWe validated our assay using bisphenol A (BPA), a well-established mammalian reproductive toxicant. We find that BPA in yeast has similar detrimental effects in meiosis as shown in worms and mammals. Competition assays with BPA analogs reveal that two of out of 19 BPA analogs examined (bisphenol E and 17{beta}-estradiol) show synergistic effects with BPA at doses tested and none show antagonistic effects. Out of 179 additional environmental chemicals, we designated 57 chemicals as reproductively toxic. Finally, by comparing chemicals in our cohort that have been evaluated for reproductive toxicity in mammalian studies, we find a statistically significant association between toxic chemicals in yeast and mammals. ConclusionWe show that a high-throughput assay using yeast may be a useful approach for rapidly and reliably identifying chemicals that pose a reproductive risk.

pharmacology and toxicology↗

bioRxiv2020

Recombination of 2Fe-2S ferredoxins reveals differences in the inheritance of thermostability and midpoint potential

ABSTRACTHomologous recombination can be used to create enzymes that exhibit distinct activities and stabilities from proteins in nature, allowing researchers to overcome component limitations in synthetic biology. To investigate how recombination affects the physical properties of an oxidoreductase that transfers electrons, we created ferredoxin (Fd) chimeras by recombining distantly-related cyanobacterial and cyanomyophage Fds that present similar midpoint potentials but distinct thermostabilities. Fd chimeras having a wide range of amino acid substitutions retained the ability to coordinate an iron-sulfur cluster, although their thermostabilities varied with the fraction of residues inherited from each parent. The midpoint potentials of chimeric Fds also varied. However, all of the synthetic Fds exhibited midpoint potentials outside of the parental protein range. Each of the chimeric Fds could also be used to build synthetic pathways that support electron transfer between Fd-NADP reductase and sulfite reductase in Escherichia coli, although the chimeric Fds varied in the expression required to support similar levels of cellular electron transfer. These results show how recombination can be used to rapidly diversify the physical properties of protein electron carriers and reveal differences in the inheritance of thermostability and electrochemical properties. Furthermore, they illustrate how electron transfer efficiencies of chimeric Fds can be rapidly evaluated using a synthetic electron transfer pathway.Competing Interest StatementThe authors have declared no competing interest.View Full Text

synthetic biology↗