Establishment of Strigolactone-Producing Bacterium-Yeast Consortium

Abstract

Strigolactones (SLs) are a class of phytohormones playing diverse roles in plant growth and development, yet the limited access to SLs is largely impeding SL-based foundational investigations and applications. Here, we developed Escherichia coli-Saccharomyces cerevisiae consortia to establish a microbial biosynthetic platform for the synthesis of various SLs, including carlactone, carlactonic acid, 5-deoxystrigol (5DS), 4-deoxyorobanchol (4DO), and orobanchol (OB). The SL-producing platform enabled us to conduct functional identification of CYP722Cs from various plants as either OB or 5DS synthase. It also allowed us to quantitatively compare known variants of plant SL biosynthetic enzymes in the microbial system. The titer of 5DS was further enhanced through pathway engineering to 0.0473 mg/L. This work provides a unique platform for investigating SL biosynthesis and evolution and lays the foundation for developing SL microbial production process.

Ancestral sequence reconstruction of the CYP711 family reveals functional divergence in strigolactone biosynthetic enzymes associated with gene duplication events in monocot grasses

“…The conversion of CL to CLA is a well‐conserved activity reported for all active CYP711As characterized so far. Although it has been speculated that CL was not the native substrate for the P450s ancestral to the CYP711 family (Wu et al ., 2021), it is the substrate for MpaCYP711A, which catalyzes the synthesis of bryosymbiol, an SL discovered in the early land plant M. paleacea (Kodama et al ., 2021) (Fig. 1).…”

“…These resurrected ancestral CYP711As show potential for further development as biocatalysts for diversification of the SLs structure. Such efforts would be augmented by the availability of co‐culture systems for the production of the natural substrates for these enzymes, as demonstrated in an elegant recent study (Wu et al ., 2021). Future analysis using these proteins may provide insights into the exact amino acid changes responsible for specific catalytic activities.…”

“…However, the specific subfamilies, CYP722C and CYP728B, which are involved in SL synthesis, are not conserved throughout the land plant evolutionary tree; for example, the CYP722C subfamily is absent in monocot grasses and Arabidopsis (Wakabayashi et al ., 2021). The characterization of a variety of CYP722Cs heterologously expressed in a bacterium–yeast consortium (Wu et al ., 2021) showed that they possess one of two distinct activities (Fig. 1): direct conversion of CLA into orobanchol (without evidence of 4DO as an intermediate) and CLA conversion to 5‐deoxystrigol (5DS) (Wakabayashi et al ., 2019; Wakabayashi et al ., 2020).…”

Engineering Escherichia coli asymmetry distribution‐based synthetic consortium for shikimate production

“…At the cell level, microbial consortia can affect factory efficiency through the regulation of metabolic division (Zhou et al, 2015), population quality control (Hartline et al, 2020), consortium structure (Liao et al, 2019), and altruism interaction (Honjo et al, 2019). Notably, microbial consortia offer numerous advantages, including diversity in cell environments (Wu, Ma, et al, 2021), reduced metabolic burden (Faust, 2019), optimized consortium structure (T. L. Weiss et al, 2017), elimination of feedback inhibition (Zhou et al, 2015), and high substrate conversion capacity (Ergal et al, 2021).…”

Engineering microbes to synthesize functionalized biopolymers

“…If the volatile is a natural pesticide (such as perillyl alcohol 7,19 ), the cells may be directly added into the soil and programmed to lyse themselves under the environment; if the volatile is a fragrance molecule (e.g., geraniol 18 ), the functionalized polymer may be applied on cloth as a new perfume design. In the agricultural example, if we replace the volatile with plant hormones (e.g., 5-deoxystrigol 20 ), these small molecules can be slowly released to positively regulate plant growth. When any of these applications can be safely implemented without purifying the polymer from the cells, the economic feasibility of the application would be improved substantially.…”