How can microorganisms make industrial processes more sustainable?

Metabolic diversity and rapid microbial growth are characteristics with enormous potential for application in the industry. There are so many possibilities that a field dedicated solely to studying microbial processes of industrial interest is called Industrial Microbiology. Being a branch of Environmental Microbiology, its objective is to apply knowledge about microorganisms to benefit humans, specifically in the industry. The fundamental aspect of industrial microbiology is bioprocess, which refers to industrial processes conducted by the activity of microorganisms (or plant and animal cells) or by substances produced by them. In this article, you will learn how microorganisms can be applied in the industry and why these bioprocesses represent essential factors in sustainability. Basic operations of a bioprocess.

A bioprocess corresponds to all the necessary operations in transforming raw materials into a product. Includes the treatment of raw materials and waste and the procedures involved in controlling these processes. It requires the selection of the most appropriate biocatalysts (the microorganisms) and suitable media for their growth and bioreactor. Besides, it depends on the process for purifying the bioproduct. A suitable catalyst is capable of converting substrates quickly and with high efficiency. Additionally, the biocatalyst needs to be stable under environmental variations since many factors, such as pH and temperature, may vary during production as an inherent part of the process. Also, toxic substances resulting from microbial metabolism can alter the conditions. Once properly selected and improved, biocatalysts move to the bioreactor, where the bioprocesses occur. There are various bioreactors types, and the choice depends on the type of cell and the reactions that need to happen. Finally, it is necessary to recover the product of interest. The processes involved should achieve the highest degrees of purity and the required final form (e.g., concentrated liquid or lyophilized). An essential part of the success of bioproduct production corresponds to bioprocess control. The control involves the observation of physical-chemical and biological variables. In addition to observing the microorganisms involved in the process, management also involves inhibiting contamination by other microorganisms.

Biotechnological Applications of Microorganisms.

Bacteria, archaea, fungi, and algae have valuable potential for the industry. Applying them to produce medicines, foods, fertilizers, pigments, and many other products is possible. Bioactive compounds such as antimicrobials and relevant enzymes are obtained by using bacteria. Fungi can be easily applied in the biodegradation of pollutants (like industrial waste) and the production of enzymes and foods. Yeasts, single-celled fungi, also stand out in producing bioethanol and industrially relevant molecules such as lipids, carotenoids, aromatic compounds, and probiotics. What are the microbial characteristics behind these bioprocesses? Rapid growth and metabolic versatility. Due to their small size, microorganisms have easy development. The greater surface-to-volume ratio allows for quick nutrient exchange with the environment. These characteristics have a direct impact on one another. For example, since they can proliferate faster, they will undergo more cell divisions, which may lead to mutations during genome duplication. Moreover, microorganisms can exchange genetic material with others, whether they are closely related or distantly phylogenetically. These factors represent a greater metabolic diversity that helps industries achieve a more extensive product catalogue.

Biorefinery: An example of sustainability in bioprocess-based industries.

What does all of this have to do with sustainability? A remarkable characteristic of these processes is the sustainability they promote by employing renewable raw materials and producing low-toxicity waste. Besides offering alternatives to problems faced by industries, bioprocesses also encompass other aspects of interest beyond technological ones, such as mitigating environmental and social impacts. In recent decades, new technologies have facilitated the expansion of biorefineries, innovation in fermentative processes, and increased product shelf life. Furthermore, genetically modified organisms allow the development of an immense portfolio of chemical compounds, transforming resource scarcity into a solution. In biorefinery, defined as the sustainable processing of biomass into bio-based products and bioenergy, the goal is to avoid using first-generation biomasses and seek solutions based on residual materials (e.g., agricultural waste). In this context, microorganisms and their metabolic versatility can handle compounds of diverse natures, bringing economic and environmental benefits. Moreover, according to Enrica Pessione, the ability of microorganisms to establish reciprocal relationships is also an essential factor to explore as a strategy to address the environmental crisis. Bacteria serve as excellent models of sustainable living, optimizing resources, recycling, sharing metabolites, and using the same molecule for various functions. In the biorefinery, microbial consortia, microbial communities containing species of interest, represent another step towards sustainability. Compared to pure cultures, consortia enable complete substrate utilization, produce various products based on a single compound, and are less costly since they do not require sterilization. In bioethanol production, the degradation of lignocellulose results in several toxic products, such as phenol. Additionally, it is composed of a mixture of carbohydrates that pure cultures of Saccharomyces cerevisiae, commonly employed for this purpose, cannot efficiently convert. On the other hand, recent studies demonstrate the effectiveness of natural consortia in degrading different types of lignocelluloses, as they can produce various kinds of cellulases. Microorganisms present significant potential for transforming industrial processes; however, there is still much to discover. Molecular techniques show that we have only isolated a small portion of microbial diversity. Advancements in these methodologies, as well as in computational sciences and synthetic biology, will be indispensable for the future of biotechnology and sustainability in the industry.