The study of how microbial cell architecture, development, and metabolism function in live creatures is referred to as microbial physiology. The study of pathogens such as viruses, bacteria, fungus, and parasites is included. It is sometimes referred to as the study of microbial cell functions, which encompasses the study of microbial growth, microbial metabolism, and the structure of microbial cells. Both the discipline of metabolic engineering and the field of functional genomics recognise the significance of microbial physiology.

Define Microbial Physiology

The natural geochemical cycles of carbon, nitrogen, and sulphur all depend on strict anaerobes to function properly. Utilising the reactions that are catalysed by these anaerobes, such as in the synthesis of chemicals and fuels from waste streams, is the primary motivation behind our research.

The Microbial Physiology group investigates the physiology of anaerobic microorganisms and anaerobic microbial communities, whether they are natural or manufactured, that either play an essential role or have the potential to be applied in sustainable circular economy techniques. This includes the following, for instance:

• Isolation, characterization, and application of novel anaerobes with biotechnological application potential study of metabolic microbial interactions in natural systems (such as syntrophy in anaerobic digesters) and in constructed synthetic communities microbial conversions of one-carbon compounds (CO2, CO, formate, methanol, CH4) to added-value products anoxic respiration with sulphur compounds for metal recovery chemolithotrophic processes on solid surfaces isolation, characterization, and application of novel
• Combining several methods of culture with analysis of the proteome and transcriptome helps researchers gain a comprehensive understanding of the metabolic pathways

The Significance of the Physiology of Microorganisms

The study of microbial physiology has historically been accorded a high level of significance in both fundamental research and the practical application of microbes in industry. The traditional method in microbial physiology has always consisted of examining the part that each component, be it genes or proteins, plays in the overall function of the cell. The process of optimising industrial fermentations through the introduction of directed genetic modification is referred to as metabolic engineering. This technique became possible as a result of advancements in molecular biology and is now in widespread use. In addition, as a result of extensive sequencing projects, the full genome sequence is now accessible for a growing number of different microorganisms. Because of this, a substantial amount of research effort has been put into assigning function to all of the open reading frames that have been identified. This field of study is known as functional genomics. There is a movement toward applying a macroscopic view on cell function in both metabolic engineering and functional genomics. This leads to an expanded role for the traditional method that is used in the study of microbial physiology. With an improved understanding of the molecular mechanisms, it is anticipated that in the not-too-distant future it will be possible to describe the interaction between all of the components in the system (the cell), also at the quantitative level. This is the objective of the field of systems biology. Clearly, this will have a profound impact on both the physiology of microorganisms and the engineering of their metabolic pathways.

The Path Forward for Taxonomy

Since Ferdinand Cohn in the 1870s, the capacity to classify microorganisms has been based on the physiology of the microorganisms, the pathogenicity of the microorganisms, the products that they make, and the appearance of the bacteria themselves. This was remedied in the future when the Committee on Bacterial Classification and Nomenclature of the Society of American Bacteriologists started incorporating additional criteria, such as growth conditions, to assist with genus descriptions (Logan, 1994). Bergey’s manual of determinative bacteriology was first released in 1923 with the intention of offering a classification system that was determined by phenetic features, biochemical profiles, morphological traits, and dietary requirements. This became the first edition of a total of eight that were subsequently released after this one (Logan, 1994). However, after the eighth edition was published in 1974, it was discovered that the system that had been constructed was not acceptable, which led to groupings of microbes that were not realistic at all (Logan, 1994). As a result of this, the International Journal of Systematic Bacteriology, which is now known as the International Journal of Systematic and Evolutionary Microbiology, made the decision to allow proposals of new bacterial names to be validly published or their descriptive publications to be approved. These decisions were made in the journal. This publication is considered the “cornerstone” of the field of microbial systematics and follows all of the rigorous standards outlined in the Bacteriological Code.

Conclusion

Based on the foregoing discussion, we conclude that, despite being a classic discipline, microbial physiology continues to play an important role in both application-driven research (metabolic engineering) and fundamental biological research (functional genomics), as it is often necessary to consider the effect of specific genetic modifications at the macroscopic level. In fact, there is a trend in metabolic engineering and functional genomics toward examining the entire system, and systems biology holds a lot of potential here. Returning to our basic definition of microbial physiology, it is evident that the goal of systems biology – to characterise the interaction between all the components in a system at a quantitative level – is quite similar to that of microbial physiology.