Spo0A directly controls the switch from acid to solvent production in solvent‐forming clostridia

Ravagnani, Adriana; Jennert, Katrin C. B.; Steiner, Elisabeth; Grünberg, Raik; Jefferies, James R.; Wilkinson, Shane R.; Young, Danielle I.; Tidswell, Edward C.; Brown, David P.; Youngman, Philip; Morris, Jonathan; Young, Michael

doi:10.1046/j.1365-2958.2000.02071.x

Cited by 136 publications

(144 citation statements)

References 80 publications

Supporting

Mentioning

132

Contrasting

Order By: Relevance

“…S-3AÀC), suggesting that strain MF28 is asporogenic and solventogenic, unlike many other wellknown Gram-positive Clostridium species, including C. acetobutylicum (Harris et al, 2002), C. beijerinckii (Ravagnani et al, 2000), and Clostridium sp. strain BOH3 (Li et al, 2014) that initiated sporulation at day 5 of fermentation ( Fig.…”

Section: An Unusual Repressor Controls the Expression Of A Crucial Spmentioning

confidence: 99%

Simultaneous saccharification and fermentation of hemicellulose to butanol by a non-sporulating Clostridium species

2016

Bioresource Technology

View full text Add to dashboard Cite

h i g h l i g h t sSimultaneous saccharification and fermentation of xylan to butanol by new strain MF28. Simultaneous fermentation of glucose and xylose to produce 11.9 g/L butanol. High yields of butanol on xylan and xylooligosaccharide were obtained. No acetone/ethanol byproducts were formed in converting lignocellulose to butanol. Non-sporulating strain MF28 is capable of continuous industrial-scale fermentation. a r t i c l e i n f o t r a c tProduction of lignocellulosic butanol has drawn increasing attention. However, currently few microorganisms can produce biofuels, particularly butanol, from lignocellulosic biomass via simultaneous saccharification and fermentation. Here we report discovery of a wild-type, mesophilic Clostridium sp. strain MF28 that ferments xylan to produce butanol (up to 3.2 g/L) without the addition of saccharolytic enzymes and without any chemical pretreatments. Application of selective pressure from 2-deoxy-Dglucose facilitated isolation of strain MF28, which exhibits inactivation of genes (gid and ccp genes) responsible for carbon catabolite repression, thus allowing strain MF28 to simultaneously ferment a combination of glucose (30 g/L), xylose (15 g/L), and arabinose (15 g/L) to produce 11.9 g/L of butanol. Strain MF28 possesses several unique features: (i) non-sporulating, (ii) no acetone/ethanol, (iii) complete hemicellulose-binding enzymatic domain, and (iv) absence of carbon catabolite repression. These unique characteristics demonstrate the industrial potential of strain MF28 for cost-effective biofuel generation from lignocellulosic biomass.

show abstract

Section: An Unusual Repressor Controls the Expression Of A Crucial Spmentioning

confidence: 99%

Simultaneous saccharification and fermentation of hemicellulose to butanol by a non-sporulating Clostridium species

2016

Bioresource Technology

View full text Add to dashboard Cite

show abstract

“…While an exactly analogous phosphorelay system has not been identified in C. acetobutylicum, Spo0A has been shown to play a major role in differentiation. An activated Spo0A has been recently shown to induce all key solvent formation genes (21,40), thereby mediating many, if not all, possible triggers of solventogenesis.…”

mentioning

confidence: 99%

“…These findings reveal that butanol stress results in increased expression of solvent formation genes and proteins. Regulation of the solvent formation genes has been strongly linked to expression and subsequent activation (by phosphorylation) of spo0A (21,40). The expression pattern of spo0A (Fig.…”

mentioning

confidence: 99%

Transcriptional Analysis of Butanol Stress and Tolerance in Clostridium acetobutylicum

2004

View full text Add to dashboard Cite

The effects of challenges with low (0.25%, vol/vol) and high (0.75%) concentrations of butanol on the growth, glucose metabolism, product formation, and transcriptional program of the solvent-tolerant Clostridium acetobutylicum strain 824(pGROE1) and the plasmid control strain 824(pSOS95del) were used to study solvent tolerance and stress response. Strain 824(pGROE1) was generated by groESL overexpression. The growth of 824(pGROE1) was less inhibited than that of 824(pSOS95del), and 824(pGROE1) was able to metabolize glucose over the entire course of the culture (60 h postchallenge) while glucose metabolism in 824(pSOS95del) lasted 24 h. A comparison of their respective DNA array-based transcriptional profiles identified genes with similar expression patterns (these genes are likely to be part of a general butanol stress response) and genes with opposite expression patterns (these genes are likely to be associated with increased tolerance to butanol). Both strains exhibited a butanol dose-dependent increase in expression of all major stress protein genes, including groES, dnaKJ, hsp18, and hsp90; all major solvent formation genes, including aad, ctfA and -B, adc, and bdhA and -B (an unexpected and counterintuitive finding); the butyrate formation genes (ptb and buk); the butyryl coenzyme A biosynthesis operon genes; fructose bisphosphate aldolase; and a gene with homology to Bacillus subtilis kinA. A dose-dependent decrease in expression was observed for the genes of the major fatty acid synthesis operon (also an unexpected and counterintuitive finding), several glycolytic genes, and a few sporulation genes. Genes with opposite expression kinetics included rlpA, artP, and a gene encoding a hemin permease. Taken together, these data suggest that stress, even when it derives from the solvent product itself, triggers the induction of the solvent formation genes.Metabolically engineered solventogenic clostridia may potentially lead to industrial processes for the production of solvents (such as butanol and acetone), other oxychemicals, and enzymes (30,35,41) or for biotransformation (57). In addition, clostridia can degrade a number of toxic chemicals and have great potential for bioremediation applications (15,16,25,46,54). In all such applications, the ability of cells to withstand "stressful" conditions such as high concentrations of substrates and the accumulation of toxic products without loss of productivity is a most significant goal. The difficulty-but also the intellectual and biotechnological challenge-is that the desirable phenotypic trait may be determined by several genes or a complex regulatory network. Solvents are inherently toxic to bacteria. Solvent tolerance, particularly ethanol tolerance, has been extensively examined in gram-negative organisms (38) but rarely, if at all, in gram-positive organisms. Gram-negative bacteria are generally much more resistant to increasingly polar solvents that gram-positive prokaryotes (27,28,51). The initial effect is disruption of membrane fluidity, and cells may...

show abstract

“…There are Spo0A~P binding sites upstream of the adc and sol promoters of C. acetobutylicum. DNAbinding studies clearly revealed the participation of the phosphorylated transcription factor in regulation of solvent formation (Ravagnani et al, 2000). Spo0A inactivation reduced expression of genes responsible for solventogenesis (Harris et al, 2002).…”

Section: Control Mechanismsmentioning

confidence: 99%

The Past, Present, and Future of Biofuels – Biobutanol as Promising Alternative

Köpke¹,

Steffi²,

Dürre³

2011

Biofuel Production-Recent Developments and Prospects

View full text Add to dashboard Cite

Spo0A directly controls the switch from acid to solvent production in solvent‐forming clostridia

Cited by 136 publications

References 80 publications

Simultaneous saccharification and fermentation of hemicellulose to butanol by a non-sporulating Clostridium species

Simultaneous saccharification and fermentation of hemicellulose to butanol by a non-sporulating Clostridium species

Transcriptional Analysis of Butanol Stress and Tolerance in Clostridium acetobutylicum

The Past, Present, and Future of Biofuels – Biobutanol as Promising Alternative

Contact Info

Product

Resources

About