A challenge of the sustainable bioeconomy is to replace petrochemical or other non-renewables as feedstock for biotechnology, and also to avoid the use of renewables that do have competing uses in the feed and food industries. Current biotechnological production of bulk chemicals using microbial cell factories mostly relies on the use of sugar-containing raw materials and agricultural products. For those raw materials, biotechnology competes with food and feed industries, which erodes food security. Addressing food and global resource shortages requires a replacement of the current mode of industrial biotechnology. That results in the increase of search for possible alternative raw material sources for chemical production. Therefore, the production of biological metabolites from one-carbon (C1) feedstocks offers one such opportunity for biotechnological industry to overcome that challenge.
In the MCM4SB project, we focus on C1 compound methanol as carbon and energy source to sustain growth of our microbial cell factories, and the C1 compounds methylamine and CO2 to support production of value-added chemicals. Methanol (CH3OH) and methylamine (CH3NH2) are reduced forms of carbon dioxide (CO2). For biotechnological applications, methanol is a cheap, readily biodegradable, non-food feedstock. As a sugar co-substrate, methanol can enhance the yields of fine chemicals. Renewable methanol can be produced by catalytic CO2 reduction using hydrogen gas and it can be converted to methylamines using ammonia. Methylamine occurs in nature, e.g., at low levels in the urine of man and animals and is a significant source of carbon and nitrogen for microbial growth in marine environments. The emission and accumulation of CO2 is one of the key players in climate change. The synthesis of methanol by catalytic CO2 reduction as well as the catalytic conversion of CO2 to methylamine are ways of CO2 capture. We aim to combine utilization of methanol with CO2 and methylamine for production of the bulk chemical L-malate (market demand of about 70,000 tons per annum) and the specialty chemical N-methyl-L-glutamate. In order to achieve this ambitious goal, two different methylotrophic microorganisms will be used. Bacillus methanolicus is a thermophilic methylotroph that utilizes methanol and is not able to use methylamine as carbon source; on the other hand, Methylobacterium extorquens utilizes methylamine as carbon source for growth. The planned goals will be achieved by combining systems and synthetic biology approaches. The techno-economic assessment will help to steer the bioprocess design by assessing the economic feasibility, bottlenecks, and operation targets for process improvement and identify possible trade-offs during early stages of design and development. Furthermore, Responsible Research and Innovation will be a cross-cutting and integrated research activity in MCM4SB with a focus on sustainable bioeconomy based on renewable feedstocks.
The MCM4SB project aims to replace sugar-based feedstocks for bioprocesses with one carbon (C1) compounds, namely methanol (CH3OH), carbon dioxide (CO2) and methylamine (CH3NH2) in order to establish a novel, sustainable production within a low-fossil-fuel bio-economy. We will combine utilization of methanol with CO2 and/or methylamine for production of the bulk chemical L-malate and the specialty chemical N-methyl-L-glutamate, by using two different methylotrophic organisms Bacillus methanolicus and Methylobacterium extorquens. The application of two diverse hosts has a double impact on the establishment of novel biotechnological processes – on the metabolic engineering level, different genetic targets will be selected based on the flux balance analysis and on the technological level, different cultivation conditions such as medium components and temperature. B. methanolicus utilizes ribulose monophosphate cycle to assimilate methanol and is not able to use methylamine as carbon source while M. extorquens utilizes methylamine via the N-methyl-L glutamate pathway. This project combines systems and synthetic biology approaches. Specifically, target identification for strain development will be guided by the genome-scale metabolic models, which will be iteratively fine-tuned based on experimental test results, and the newly developed strains will be characterized on the transcriptome level in order to detect the bottlenecks in the metabolism, which will subsequently be relieved to steer the next round of strain development. The techno-economic assessment will help to steer the bioprocess design by assessing the economic feasibility, bottlenecks, and operation targets for process improvement and identify possible trade-offs during early stages of design and development. Responsible Research and Innovation will be a cross-cutting and integrated research activity in MCM4SB with a focus on sustainable bioeconomy based on renewable feedstocks.