production was increased by increasing the tetracycline concentrations (Yang et al.
2019).
6.12 Heterologous Biofuel Production
A heterologous KdcA gene is integrated into the chromosome or can be integrated
into plasmid of Z. mobilis for the isobutanol synthesis (Yang et al. 2019). Two
recombinant strains ZMQ1 and ZMQ2 were made for stable isobutanol production
by the introduction of kdcA gene either into the chromosome locus or into the native
plasmid locus. This integration basically shifts the production of ethanol to the
isobutanol. A1s gene reduces ethanol production and enhances the isobutanol
production. Such plasmid were constructed that shifts the carbon flux for the ethanol
production to isobutanol (Yang et al. 2016a, b). Different studies reveal the
overexpression of kdcA gene and Als-ilvC-ilvD operon that shifts the ethanol
production to the isobutanol biosynthesis. These studies give the strategy to use
metabolic pathway of valine so that biofuels can be synthesized from pyruvate.
6.13 Conclusion
Z. mobilis is a natural anaerobic ethanologenic gram-negative bacterium with many
desirable industrial characteristics. For example, Z. mobilis is generally considered
safe (GRAS), shows high tolerance for ethanol up to 16% (v/v), and can produce
ethanol at a wide pH range (3.5–7.5, especially low pH). Advances in gene sequencing technologies and especially next-generation sequencing (NGS) techniques provide new opportunities for gaining a basic understanding of Z. mobilis strains.
References
Agrawal M, Chen RR (2011) Discovery and characterization of a xylose reductase from
Zymomonas mobilis ZM4. Biotechnol Lett 33(11):2127
Agrawal M, Wang Y, Chen RR (2012) Engineering efficient xylose metabolism into an acetic acidtolerant Zymomonas mobilis strain by introducing adaptation-induced mutations. Biotechnol
Lett 34(10):1825–1832
Agrawal M, Dunn KL, Rao CV (2017) Zymomonas mobilis for the conversion of lignocellulosic
biomass to fuels and chemicals. In: Engineering of microorganisms for the production of
chemicals and biofuels from renewable resources. Springer, pp 67–92
Amarendran AP, Chatterjee T, Yuan Y, Yongtao L (2016) Deriving encryption rules based on file
content. Google Patents
Amutha R, Gunasekaran P (2001) Production of ethanol from liquefied cassava starch using
co-immobilized cells of Zymomonas mobilis and Saccharomyces diastaticus. J Biosci Bioeng
92:560–564
176
M. Khalid et al.
2019).
6.12 Heterologous Biofuel Production
A heterologous KdcA gene is integrated into the chromosome or can be integrated
into plasmid of Z. mobilis for the isobutanol synthesis (Yang et al. 2019). Two
recombinant strains ZMQ1 and ZMQ2 were made for stable isobutanol production
by the introduction of kdcA gene either into the chromosome locus or into the native
plasmid locus. This integration basically shifts the production of ethanol to the
isobutanol. A1s gene reduces ethanol production and enhances the isobutanol
production. Such plasmid were constructed that shifts the carbon flux for the ethanol
production to isobutanol (Yang et al. 2016a, b). Different studies reveal the
overexpression of kdcA gene and Als-ilvC-ilvD operon that shifts the ethanol
production to the isobutanol biosynthesis. These studies give the strategy to use
metabolic pathway of valine so that biofuels can be synthesized from pyruvate.
6.13 Conclusion
Z. mobilis is a natural anaerobic ethanologenic gram-negative bacterium with many
desirable industrial characteristics. For example, Z. mobilis is generally considered
safe (GRAS), shows high tolerance for ethanol up to 16% (v/v), and can produce
ethanol at a wide pH range (3.5–7.5, especially low pH). Advances in gene sequencing technologies and especially next-generation sequencing (NGS) techniques provide new opportunities for gaining a basic understanding of Z. mobilis strains.
References
Agrawal M, Chen RR (2011) Discovery and characterization of a xylose reductase from
Zymomonas mobilis ZM4. Biotechnol Lett 33(11):2127
Agrawal M, Wang Y, Chen RR (2012) Engineering efficient xylose metabolism into an acetic acidtolerant Zymomonas mobilis strain by introducing adaptation-induced mutations. Biotechnol
Lett 34(10):1825–1832
Agrawal M, Dunn KL, Rao CV (2017) Zymomonas mobilis for the conversion of lignocellulosic
biomass to fuels and chemicals. In: Engineering of microorganisms for the production of
chemicals and biofuels from renewable resources. Springer, pp 67–92
Amarendran AP, Chatterjee T, Yuan Y, Yongtao L (2016) Deriving encryption rules based on file
content. Google Patents
Amutha R, Gunasekaran P (2001) Production of ethanol from liquefied cassava starch using
co-immobilized cells of Zymomonas mobilis and Saccharomyces diastaticus. J Biosci Bioeng
92:560–564
176
M. Khalid et al.