Butanol Tolerance in a Selection of Microorganisms

Abstract

Butanol tolerance is a critical factor affecting the ability of microorganisms to generate economically viable quantities of butanol. Current Clostridium strains are unable to tolerate greater than 2% 1-butanol thus membrane or gas stripping technologies to actively remove butanol during fermentation are advantageous. To evaluate the potential of alternative hosts for butanol production, we screened 24 different microorganisms for their tolerance to butanol. We found that in general, a barrier to growth exists between 1% and 2% butanol and few microorganisms can tolerate 2% butanol. Strains of Escherichia coli, Zymomonas mobilis, and non-Saccharomyces yeasts were unable to surmount the 2% butanol growth barrier. Several strains of Saccharomyces cerevisiae exhibit limited growth in 2% butanol, while two strains of Lactobacillus were able to tolerate and grow in up to 3% butanol.

Engineering alternative butanol production platforms in heterologous bacteria

“…Additionally, stresses caused by butanol toxicity 60 have been attributed to the loss of pSOL1, a mega-plasmid encoding several essential 61 solvent-forming genes (Borden and Papoutsakis, 2007). Furthermore, the metabolic shift 62 from acidogenesis to solventogenesis in Clostridium presents additional complications 63 al., 2008; Knoshaug and Zhang, 2008). Thus, it is anticipated that modest inhibitory 110 thresholds of these strains will ultimately limit their achievable outputs as their 111 productivity is further engineered to that which is required of production-level strains.…”

Genetic Engineering In BioButanol Production And Tolerance

“…Membrane composition shows similarity with a strain of Staphylococcus haemolyticus which has shown tolerance to increased solvent concentration 6 . However limited growth in butanol was found in S.cerevisiae upto 2% but some microbe shows tolerance to 3% butanol while simulation results showed maximum tolerance of 4% by C.acetobutylicum 73,91,95,96,98,99 . Shuttle vector pCAC1839 due gene have similarity with the xenobiotic responsive element and it shows an increase in tolerance of 13 to 81% on introduction to C.acetobutylicum ATCC 824 6,68 .…”

“…67,[72][73][74] . In addition to HSPs gene, mar-sol regulon genes which are responsible for solvent tolerance, mmsB, zwf a member of mar-sol was used for the ethanol tolerance.…”

Lignocellulosic Biomass Utilization Toward Biorefinery Using Meshophilic Clostridial Species

“…The choice between using or engineering natural function versus importing biosynthetic function has been reviewed [16]. Commonly used host strains include Escherichia coli and Saccharomyces cerevisiae that are relatively easy to genetically manipulate but do not tolerate more than 2% 1-butanol [17]. In addition, these strains do not display broad substrate ranges and cannot compete with natural or engineered clostridia for the production of 1-butanol from a broad range substrates including pentose sugars and sugars derived from cellulosic feedstocks.…”