Positioning Bacillus subtilis as terpenoid cell factory

Abstract

Increasing demands for bioactive compounds have motivated researchers to employ microorganisms to produce complex natural products. Currently, Bacillus subtilis has been attracting lots of attention to be developed into terpenoids cell factories due to its generally recognized as safe status and high isoprene precursor biosynthesis capacity by endogenous methylerythritol phosphate (MEP) pathway. In this review, we describe the up-to-date knowledge of each enzyme in MEP pathway and the subsequent steps of isomerization and condensation of C5 isoprene precursors. In addition, several representative terpene synthases expressed in B. subtilis and engineering steps to improve corresponding terpenoids production are systematically discussed. Furthermore, the current available genetic tools are mentioned as well as promising strategies to improve terpenoids in B. subtilis, hoping to inspire future directions in metabolic engineering of B. subtilis for further terpenoids cell factory development.

Bacillus subtilis as a host for natural product discovery and engineering of biosynthetic gene clusters

“…However, over the past 15 years, signicant advances have been made in the development of synthetic biology and genome engineering tools for Bacillus species. 11,14 With the growing availability of such tools, Bacillus is now gaining increasing interest as a heterologous host for natural product biosynthesis. 11 Heterologous expression is particularly valuable when tools for the genetic manipulation of the native host are limited or unknown, e.g., for metagenome-derived gene clusters.…”

“…and a subset of Actinobacteria, such as Streptomyces, utilize both the MVA and MEP pathway. 14,[154][155][156][157][158][159][160] As B. subtilis is recognized for its ability to produce signicant quantities of isoprene, it has long been considered a promising microbial platform for terpenoid production. However, the progress in developing B. subtilis as a robust terpenoid cell factory has lagged behind that of E. coli and S. cerevisiae, primarily due to the slower development of molecular tools tailored specically for B. subtilis.…”

Promoter engineering enables precise metabolic regulation towards efficient β-elemene production in Ogataea polymorpha

“…Microbial cell factories have been regarded as an ecologically-friendly, sustainable, and effective way for production of chemicals. Efficient production of biofuels [ [1] , [2] , [3] ], terpenoids [ [4] , [5] , [6] , [7] ] and other valuable chemicals [ 8 , 9 ] have been achieved in model microbes, such as Escherichia coli , Saccharomyces cerevisiae and Bacillus subtilis . Chemicals with long and complex pathways require precise metabolic modulation, including compartmentalization [ 10 ], modular pathway engineering [ 11 ], and promoter engineering [ 12 ].…”

Engineering of Multiple Modules to Improve Amorphadiene Production in Bacillus subtilis Using CRISPR-Cas9

“…By introducing relevant terpene synthases and metabolic engineering optimization, B. subtilis is able to produce multiple terpenoids, with the production levels ranging from 1.43 to 416 mg/L. − …”

“…However, most of the strategies to improve terpenoids’ production rely on the overexpression of rate-limiting or all enzymes of the MEP pathway, selection of suitable expression vectors for terpene synthases, and optimization of fermentation conditions such as cultivation temperature and medium. ,, Very little work has been done to explore the effects of other related pathways on terpenoids’ production. For example, the competing branch pathways can limit the availability of IPP and DMAPP, and the central metabolic pathways might directly or indirectly impact the supply of cofactors required by the MEP pathway.…”