Methanol as carbon substrate in the bio‐economy: Metabolic engineering of aerobic methylotrophic bacteria for production of value‐added chemicals

Abstract

Bacteria are widely used as cell factories for production of enzymes and chemicals, mostly from sugars. Methylotrophic bacteria can utilize the one‐carbon compound methanol as sole carbon source for growth, and metabolic engineering is being used to develop bioprocesses based on these organisms for conversion of methanol into value‐added chemicals. Methylotrophic model strains include both Gram‐positive and Gram‐negative bacteria and in all cases methanol metabolism proceeds via the cell‐toxic intermediate formaldehyde. Thus, understanding the genetics, biochemistry, and regulation of methylotrophic pathways is crucial for successful strain development and for their concomitant fermentations. Also, such basic knowledge has proven useful for design of strategies and approaches for the rational transfer of methylotrophy into non‐methylotrophic bacteria. In the current review we highlight the best studied methylotrophic model organisms, with particular focus on the Gram‐positive Bacillus methanolicus and the Gram‐negative Methylobacterium extorquens, including their genetics and physiology. We present successful metabolic engineering examples leading to the construction of recombinant strains for the production of amino acids, platform chemicals, terpenoids and dicarboxylic acids derivatives from methanol as sole carbon source. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd

Structure and function of the lanthanide-dependent methanol dehydrogenase XoxF from the methanotroph Methylomicrobium buryatense 5GB1C

“…Besides serving as the primary biological sink for methane and other methylated greenhouse gases, methylotrophs have been targeted as vehicles for bioremediation and production of fuels and chemicals [3, 4]. In these organisms, methanol is oxidized by methanol dehydrogenase (MDH) enzymes that use pyrroloquinoline quinone (PQQ) as a cofactor.…”

Biological conversion of methanol by evolved Escherichia coli carrying a linear methanol assimilation pathway

“…Owning to its cost advantage and biocompatibility, methanol is regarded as an attractive feedstock for production of biochemicals and biofuels (Pfeifenschneider et al 2017). Although native methylotrophs are capable of using C1 resources including methanol as carbon and energy sources, they are more challenging to engineer than genetically tractable hosts due to inefficient genetic-transfer systems and editing tools (Whitaker et al 2015).…”

“…Synthetic methylotrophs have been constructed by heterogenous expressing MDH and RuMP genes (Pfeifenschneider et al 2017). RuMP cycle depends on regenerating the formaldehyde acceptor Ru5P, which requires high coordination of many enzymes involved in formaldehyde assimilation and PP pathway (Whitaker et al 2015).…”

Biotechnology and Bioprocesses: Their Contribution to Sustainability

“…Our conclusions confirm that biotechnology is firmly positioned as an emerging knowledge area. Its dynamics, development, and outcomes during the study period reflect a substantial number of studies and technologies focused on the creation of knowledge aimed at improving economic development, environmental protection, and social welfare.Processes 2020, 8, 436 2 of 11 and the production of hematopoietic stem cells (HSCs) for therapeutic purposes [7][8][9]; the development of microorganisms for the processing and transformation of biomass into fuels [10][11][12]; the production of raw materials based on fermentation processes, such as ethanol, butanol [13][14][15], and other products traditionally derived from chemical sources, such as aliphatic, aromatic, and other macromolecules using bioprocesses, such as (a) separate hydrolysis and fermentation (SHF), (b) simultaneous saccharification and fermentation (SSF), and (c) consolidated bioprocessing (CBP) [16]; and the construction of bioelectronic devices for applications in multivariate data analysis, experiment design, mathematical models, sensors, and biosensors whose data are processed by software to monitor and optimize processes [17][18][19][20][21][22].Other important bioprocesses involve the large-scale production of secondary metabolites relevant for the food, cosmetics, pharmaceutical [23], wastewater treatment, and bioremediation industries (all of these are high-value processes) using bacteria and plant cells produced in vitro to protect endangered or scarce plants or to obtain metabolites [24,25] and enzymes produced by filamentous fungi, leveraging the advances of genetic engineering and molecular biology [26]; the development of cells that can be used in the production of new drugs [27]; the application of enzymatic processes to treat textiles [28]; the use of bacteria for the production of enzymes and various chemical products [29]; the use of nanotechnology, for instance, the nano-encapsulation of bioactive compounds, intelligent packaging systems in food production, biocatalysts and biosensors, and microbiological identification [30,31]; the collection and commercialization of recyclable and biodegradable biopolymers such as PLA (polylactide) [32]; and the development of regenerative medicine solutions…”

“…Other important bioprocesses involve the large-scale production of secondary metabolites relevant for the food, cosmetics, pharmaceutical [23], wastewater treatment, and bioremediation industries (all of these are high-value processes) using bacteria and plant cells produced in vitro to protect endangered or scarce plants or to obtain metabolites [24,25] and enzymes produced by filamentous fungi, leveraging the advances of genetic engineering and molecular biology [26]; the development of cells that can be used in the production of new drugs [27]; the application of enzymatic processes to treat textiles [28]; the use of bacteria for the production of enzymes and various chemical products [29]; the use of nanotechnology, for instance, the nano-encapsulation of bioactive compounds, intelligent packaging systems in food production, biocatalysts and biosensors, and microbiological identification [30,31]; the collection and commercialization of recyclable and biodegradable biopolymers such as PLA (polylactide) [32]; and the development of regenerative medicine solutions [33].…”