Zhongtian Zhang

North Carolina State University | NCSU · Department of Microbiology

Bioproduction of renewable chemicals is considered as an urgent solution for fossil energy crisis. However, despite tremendous efforts, it is still challenging to generate microbial strains that can produce target biochemical to high levels. Here, we report an example of biosynthesis of high-value and easy-recoverable derivatives built upon natural...

Background: Clostridium saccharoperbutylacetonicum N1-4 (HMT) is a strictly anaerobic, spore-forming Gram-positive bacterium capable of hyper-butanol production through the well-known acetone-butanol-ethanol fermentation process. Recently, five putative RRNPP-type QSSs (here designated as QSS1 to QSS5) were predicted in this bacterial strain, each...

Clostridium saccharoperbutylacetonicum N1-4 (HMT) is known as a hyper acetone-butanol-ethanol (ABE) producing strain. Within its genome, there is an endogenous megaplasmid (Csp_135p) of 136 kb, which contains 104 protein-encoding genes and two pseudogenes. Till now, the function of the megaplasmid is unknown; meanwhile the existence of the megaplas...

CRISPR-Cas9 has been explored as a transformative genome engineering tool for many eukaryotic organisms. However, its utilization in bacteria remains limited and ineffective. This chapter, taking Clostridium beijerinckii as an example, describes the use of Streptococcus pyogenes CRISPR-Cas9 system guided by the single chimeric guide RNA (gRNA) for...

Although CRISPR-Cas9/Cpf1 have been employed as powerful genome engineering tools, heterologous CRISPR-Cas9/Cpf1 are often difficult to introduce into bacteria and archaea due to their severe toxicity. Since most prokaryotes harbor native CRISPR-Cas systems, genome engineering can be achieved by harnessing these endogenous immune systems. Here, we...

Objectives: Clostridium difficile is a notorious pathogenic species that can cause severe gastrointestinal infections in humans and animals. C. difficile infection (CDI) resulted in thousands of deaths worldwide every year. The elucidation of related mechanisms of CDI and exploration of potential therapeutic strategies are largely delayed due to t...

Butyl butyrate (BB) is a valuable chemical that can be used as flavor, fragrance, extractant, etc. in various industries. Meanwhile, BB can also be used as a fuel source with excellent compatibility as gasoline, aviation kerosene and diesel components. The conventional industrial production of BB is highly energy-consuming and generates various env...

Effects of radio frequency (RF) heating as a biomass pretreatment process to generate hydrolysates for polyhydroxybuyrate (PHB) were evaluated in all production steps from pretreatment to enzymatic hydrolysis to fermentation. Switchgrass was pretreated under alkaline conditions with RF-assisted heating (traditional water bath (WB) heating as contro...

Radio frequency (RF) heating assisted alkaline pretreatment was evaluated as an emerging technology to generate hydrolysates for acetone–butanol–ethanol (ABE) fermentation. Traditional water bath (WB) heating was utilized as a control. ABE fermentation was conducted with Clostridium beijerinckii 8052 using the hydrolysates as carbon sources with or...

CRISPR-Cas9 has been explored as a powerful tool for genome engineering for many organisms. Meanwhile, dCas9 which lacks endonuclease activity but can still bind to target loci has been engineered for efficient gene transcription repression. Clostridium beijerinckii, an industrially significant species capable of biosolvent production, is generally...

CRISPR-Cas9 has been demonstrated as a transformative genome engineering tool for many eukaryotic organisms; however, its utilization in bacteria remains limited and ineffective. Here we explored Streptococcus pyogenes CRISPR-Cas9 for genome editing in Clostridium beijerinckii (industrially significant but notorious for being difficult to metabolic...