A marine photosynthetic microbial cell factory as a platform for spider silk production

Choon Pin Foong,Keiji Numata,Chonprakun Thagun,Mieko Higuchi-Takeuchi,Ali D Malay,Nur Alia Oktaviani

doi:10.1038/s42003-020-1099-6

Choon Pin Foong, Keiji Numata + Show 4 more

Open Access

https://doi.org/10.1038/s42003-020-1099-6

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Abstract

Photosynthetic microorganisms such as cyanobacteria, purple bacteria and microalgae have attracted great interest as promising platforms for economical and sustainable production of bioenergy, biochemicals, and biopolymers. Here, we demonstrate heterotrophic production of spider dragline silk proteins, major ampullate spidroins (MaSp), in a marine photosynthetic purple bacterium, Rhodovulum sulfidophilum, under both photoheterotrophic and photoautotrophic growth conditions. Spider silk is a biodegradable and biocompatible material with remarkable mechanical properties. R. sulfidophilum grow by utilizing abundant and renewable nonfood bioresources such as seawater, sunlight, and gaseous CO2 and N2, thus making this photosynthetic microbial cell factory a promising green and sustainable production platform for proteins and biopolymers, including spider silks.

Highlights

Photosynthetic microorganisms such as cyanobacteria, purple bacteria and microalgae have attracted great interest as promising platforms for economical and sustainable production of bioenergy, biochemicals, and biopolymers
The introduction of exogenous plasmid DNA into R. sulfidophilum via bacterial conjugation using pCF1010-derived plasmids and E. coli S17-1 as a donor strain was reported[34]. This transformation was achieved based on the RP4/RK2 mating system
We used another broad-host-range vector, pBBR1MCS-2, harboring a kanamycin resistance gene, mob gene and transfer origin, which have been widely used in Gram-negative bacterial conjugation[35,36]

Summary

Introduction

Photosynthetic microorganisms such as cyanobacteria, purple bacteria and microalgae have attracted great interest as promising platforms for economical and sustainable production of bioenergy, biochemicals, and biopolymers. We develop an economical and sustainable marine photosynthetic microbial cell factory using R. sulfidophilum, which is a marine purple nonsulfur bacterium that is capable of producing the hydrophobic repetitive sequence of MaSp1 using small amount of organic substance under photoheterotrophic or photoautotrophic growth conditions.

Results

Conclusion