Innovating carbon-capture biotechnologies through ecosystem-inspired solutions

Rising atmospheric carbon concentrations affect global health, the economy, and overall quality of life. We are fast approaching climate tipping points that must be addressed, not only by reducing emissions but also through new innovation and action toward carbon capture for sequestration and utilization (CCSU). In this perspective, we delineate next-generation biotechnologies for CCSU supported by engineering design principles derived from ecological processes inspired by three major biomes (plant-soil, deep biosphere, and marine). These are to interface with existing industrial infrastructure and, in some cases, tap into the carbon sink potential of nature. To develop ecosystem-inspired biotechnology, it is important to identify accessible control points of CO2 and CH4 within a given system as well as value-chain opportunities that drive innovation. In essence, we must supplement natural biogeochemical carbon sinks with new bioengineering solutions

Metabolic Engineering of Bacillus methanolicus MGA3 for Production of Acetoin

Being a pure, inexpensive, non-food chemical that can be sustainably produced, methanol has attracted great interest as a carbon feedstock for microbial production of commodity/specialty chemicals. In this thesis, methanol-based production of acetoin was achieved by recombinant Bacillus methanolicus MGA3 strains. The alsSD operons from Bacillus licheniformis DSM13 and Bacillus subtilis 168 were cloned into expression vector pTH1mp and heterologously expressed in B. methanolicus MGA3, creating two acetoin-producing strains with different growth characteristics, MGA3 (pTH1mpLacO-alsSD_Bl(GTG)) and MGA3 (pTH1mpLacO-alsSD_Bs(GTG)), respectively. The potential of B. methanolicus MGA3 as an acetoin producer was evaluated by assessing acetoin tolerance and by functionally assaying the activity of recombinant enzymes produced. MGA3 (pTH1mpLacO-alsSD_Bl(GTG)) achieved the highest acetoin titer of 1.48 ± 0.24 g/L with yield of 0.23 ± 0.04g/L gacetoin/gmethanol, growing on methanol as sole carbon source. The relatively narrow engineering effort performed in this thesis highlights the potential of B. methanolicus MGA3 as a candidate for industrial production of acetoin. Parameters such as productivity, rate of methanol consumption, etc. are yet to be determined, which leaves room for future engineering strategies to further optimize yield. In addition, potential production of 2,3-butanediol, of which acetoin is the direct precursor, in B. methanolicus MGA3 was investigated

Revealing the Host-Dependent Nature of an Engineered Genetic Inverter in Concordance with Physiology

Broad-host-range synthetic biology is an emerging frontier that aims to expand our current engineerable domain of microbial hosts for biodesign applications. As more novel species are brought to “model status,” synthetic biologists are discovering that identically engineered genetic circuits can exhibit different performances depending on the organism it operates within, an observation referred to as the “chassis effect.” It remains a major challenge to uncover which genome-encoded and biological determinants will underpin chassis effects that govern the performance of engineered genetic devices. In this study, we compared model and novel bacterial hosts to ask whether phylogenomic relatedness or similarity in host physiology is a better predictor of genetic circuit performance. This was accomplished using a comparative framework based on multivariate statistical approaches to systematically demonstrate the chassis effect and characterize the performance dynamics of a genetic inverter circuit operating within 6 Gammaproteobacteria. Our results solidify the notion that genetic devices are strongly impacted by the host context. Furthermore, we formally determined that hosts exhibiting more similar metrics of growth and molecular physiology also exhibit more similar performance of the genetic inverter, indicating that specific bacterial physiology underpins measurable chassis effects. The result of this study contributes to the field of broad-host-range synthetic biology by lending increased predictive power to the implementation of genetic devices in less-established microbial hosts

Innovating carbon-capture biotechnologies through ecosystem-inspired solutions

Rising atmospheric carbon concentrations affect global health, the economy, and overall quality of life. We are fast approaching climate tipping points that must be addressed, not only by reducing emissions but also through new innovation and action toward carbon capture for sequestration and utilization (CCSU). In this perspective, we delineate next-generation biotechnologies for CCSU supported by engineering design principles derived from ecological processes inspired by three major biomes (plant-soil, deep biosphere, and marine). These are to interface with existing industrial infrastructure and, in some cases, tap into the carbon sink potential of nature. To develop ecosystem-inspired biotechnology, it is important to identify accessible control points of CO2 and CH4 within a given system as well as value-chain opportunities that drive innovation. In essence, we must supplement natural biogeochemical carbon sinks with new bioengineering solutions