Synthetic Biology Tools for Genome and Transcriptome Engineering of Solventogenic Clostridium

Abstract

Strains of Clostridium genus are used for production of various value-added products including fuels and chemicals. Development of any commercially viable production process requires a combination of both strain and fermentation process development strategies. The strain development in Clostridium sp. could be achieved by random mutagenesis, and targeted gene alteration methods. However, strain improvement in Clostridium sp. by targeted gene alteration method was challenging due to the lack of efficient tools for genome and transcriptome engineering in this organism. Recently, various synthetic biology tools have been developed to facilitate the strain engineering of solventogenic Clostridium. In this review, we consolidated the recent advancements in toolbox development for genome and transcriptome engineering in solventogenic Clostridium. Here we reviewed the genome-engineering tools employing mobile group II intron, pyrE alleles exchange, and CRISPR/Cas9 with their application for strain development of Clostridium sp. Next, transcriptome engineering tools such as untranslated region (UTR) engineering and synthetic sRNA techniques were also discussed in context of Clostridium strain engineering. Application of any of these discussed techniques will facilitate the metabolic engineering of clostridia for development of improved strains with respect to requisite functional attributes. This might lead to the development of an economically viable butanol production process with improved titer, yield and productivity.

Recent Progress and Trends in the Development of Microbial Biofuels from Solid Waste—A Review

“…Higher alcohol or short-chain chemicals can be used in gasoline as oxygenates or, in certain circumstances, as a complete gasoline replacement. For example, n-butanol, which contains 84% of the calorific value of gasoline, has a lower water solubility and is immiscible in water [16,17]. Wild-type microorganism strains, such as Clostridium acetobutylicum, were assayed for growth on different biomass sources, such as liquefied cornflour11, glycerol, glucose10 (a combination of treated biodiesel derived from fats) [18], and syngas (hydrogen and carbon monoxide mix).…”

“…Even though C. acetobutylicum showed growth and butanol production, the rate of reaction is slow due to the strictly anaerobic reaction and solvent toxicity, making the butanol production no more than 13 g/L. Recently developed synthetic biology tools for the genetic manipulation of the Clostridium genus could potentially engineer strains that can overcome the slow reaction rates and diminish solvent toxicity [17].…”

“…Recently, there has been a successful commercialization of farnesene production [47]. In addition, several authors have recently reported insights on using synthetic biology and engineered microorganisms and enzymes for the production of microbial fuels [9,17,22,42,49].…”

Effect of deregulation of repressor-specific carbon catabolite repression on carbon source consumption in Escherichia coli

“…The production of industrially essential compounds from sustainable biomass is attracting attention as a critical technology for solving serious global problems, including climate change [1][2][3][4]. Escherichia coli strains have been widely used as a host for developing the cell factory to produce chemicals from sustainable biomass [5][6][7][8][9][10].…”

Clostridium acetobutylicum atpG-Knockdown Mutants Increase Extracellular pH in Batch Cultures

“…Clostridium acetobutylicum is a strictly anaerobic, gram-positive bacterium that survives in hostile environments by producing endospores ( Shao et al, 2007 ). C. acetobutylicum possesses industrially applicable metabolic properties, notably including the production of organic solvents, such as acetone, butanol, and ethanol ( Kwon et al, 2020 ; Shin et al, 2021 ). C. acetobutylicum produces the solvents through biphasic pathway, which is divided into an acidogenic phase and a solventogenic phase ( Shao et al, 2007 ; Im et al, 2021 ).…”