I’m always fascinated by how we have fashioned cells into small factories. They produce a great range of products from food and beverage to pharmaceuticals. Recently, it has been about producing packaging and plastics, about destroying and degrading pollutants and about transforming raw materials into useful products. What is so truly fascinating about them is their remarkable ability to perform a wide array of biochemical processes efficiently and precisely. It’s the harnessing of this power which has been driven genetic engineering and the various tools that are now available to effect this. The tools we have now have allowed us to transition from what could best be described as a static design to one where we exercise dynamic control. As others have said, we now ferment microorganisms and for that matter plant and animal cells, turning them into the ultimate mini factory (Jung et al., 2021).
At the heart of this is the cell – be it microbial, plant or animal. All these cells perform complex biochemical reactions, akin to a factory’s production lines. Through metabolism, we have witnessed cells convert substrates into energy and biomass through metabolic pathways. As a result they produce enzymes which catalyze reactions, breaking down or assembling complex molecules. They also produce antibiotics, pigments, and other bioactive compounds which are part of the great collection of secondary metabolites.
To enable manufacture, cells possess genetic machinery that functions like a factory’s control system. They contain DNA which is the blueprint – a genetic code within that DNA that dictates the production of proteins and enzymes. The controlling mechanism is enacted through gene regulation. This is the ability of cells to make use of gene regulation whereby they can turn genes on or off in response to environmental cues, optimizing their production processes.
All metabolic processes require the conversion of energy. Cells are very efficient at this because they can convert energy into one form or another. They do this in two ways. Through respiration and fermentation which are processes that generate ATP, the cell’s energy currency, from organic and inorganic substrates. The other is by photosynthesis. Plant cells and some microbes like cyanobacteria, convert solar energy into chemical energy.
Cells are also very effective at using resources. They are able to transport the nutrients they require across their cell membranes and then use them to fuel both growth and production. They’re also effective at recycling their wastes. All of them without exception can recycle waste products which minimises the need for external agents.
One of the most fascinating features of cell growth is the ability they have for adapting to different environmental conditions. They are vey much like a flexible production line. They can withstand extreme conditions such as high temperatures, acidity, or salinity by adjusting their internal processes. Dealing with and responding to stress is a fascinating condition of their life. Another fascinating aspect is the ability to form symbiotic relationships with each. Some microbes form beneficial relationships with plants and animals, enhancing nutrient exchange and growth.
Advances in synthetic biology now allow for the design of microbial cells with customized capabilities. Through genetic engineering, scientists can introduce new pathways into microbes, enabling the production of novel compounds. In so doing, the dynamic metabolic control strategy has been employed to redistribute resources in the cell and then optimally regulate such metabolic pathways. That has led to metabolic engineering where pathways can be optimized to increase yield and efficiency of desired products. All living cells as factories have to have a balance in metabolism of growth and production. They also have to be able to generate the structural elements which make the hardware as the nuts and bolts of a factory. These cells have already developed their own means for optimising metabolic flux through levels of gene expression. Biotechnologists have however taken these designs further by exploiting genetic engineering tools to fine-tune gene expression, and to regulate genomic nucleic acid as well as mRNA and levels of protein.
On this web-site we have lots of examples of microbial cells and many of them operate like a mini factory. We can discuss Saccharomyces, Lactobacilli and others which are recognised in their natural non-genetically engineered state to be producers of particular chemicals and then become engineered in a such a way that they become our mini- factories of the future. We have also put together a list of all those genetic engineering tools which are by no means comprehensive. You can read about CRISPR-Cas-9 for example.
The concept of the microbial cell as a mini factory highlights the potential of microorganisms to revolutionize various industries by providing sustainable, efficient, and versatile production systems. Advances in biotechnology and genetic engineering continue to expand the capabilities of these microbial factories, paving the way for innovative solutions to global challenges.
References
Jung, S. W., Yeom, J., Park, J. S., & Yoo, S. M. (2021). Recent advances in tuning the expression and regulation of genes for constructing microbial cell factories. Biotechnology Advances, 50, 107767. (Article)
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