Biopolymers Research
Open Access

Bacterial biopolymers, pathogenicity, antimicrobial drug, polysaccharides

Introduction

A wide variety of intracellular and extracellular biopolymers, including polysaccharides, polyamides, polyesters, polyphosphates, extracellular DNA, and proteinaceous components, may be produced by bacteria, which are excellent cell factories capable of converting carbon and nitrogen sources. Bacterial polymers play significant roles in pathogenicity, and they are suited for use in both medicinal and industrial settings due to their wide range of chemical and material characteristics. When created by pathogenic bacteria, the same biopolymers serve as important virulence factors, but when produced by non-pathogenic bacteria, they are transformed into food components or biomaterials. Interdisciplinary research has uncovered new antibacterial medication targets, given information on the molecular principles of bacterial polymer production, and provided guidance for synthetic biology approaches to the development of novel materials.

A wide variety of intracellular and extracellular biopolymers, including polysaccharides, polyamides, polyesters, polyphosphates, extracellular DNA, and proteinaceous components, may be produced by bacteria, which are excellent cell factories capable of converting carbon and nitrogen sources. Bacterial polymers play significant roles in pathogenicity, and they are suited for use in both medicinal and industrial settings due to their wide range of chemical and material characteristics. When created by pathogenic bacteria, the same biopolymers serve as important virulence factors, but when produced by non-pathogenic bacteria, they are transformed into food components or biomaterials. Interdisciplinary research has uncovered new antibacterial medication targets, given information on the molecular principles of bacterial polymer production, and provided guidance for synthetic biology approaches to the development of novel materials. This provides an overview of how bacterial polymers play a role in pathogenesis, their synthesis, and material characteristics, as well as methods for designing cell factories that can produce custom biobased materials that are suited for high-value applications. Processive enzymes that connect building ingredients like sugars, amino acids, or hydroxy fatty acids generate biopolymers, which are high molecular weight compounds produced by living things. Numerous classes of these biopolymers, including polysaccharides (consisting of sugars and/ or sugar acids connected by glycosidic linkages), polyamides (consisting of amino acids connected by peptide bonds), polyesters (consisting of hydroxy fatty acids linked by ester bonds), and polyphosphates (polyPs; consisting of inorganic phosphates connected by anhydride bonds), can be produced by bacteria. Due to their role in the survival and pathogenicity of bacteria, scientists have spent decades studying the production processes of bacterial polymers. These polymeric materials have several roles in bacterial biofilms, which account for 60–80% of all bacterial infections in humans [1-5]. They can be used as storage molecules, protective capsular layers around cells, and important matrix components. Research on the physicochemical characteristics of biopolymers, however, also reveals their usefulness in both industrial and medicinal settings. Innovative biopolymers with uses or potential applications in medicine (for example: hyaluronate as a biomaterial), as additives in cosmetic products, as additives in food (for example: xanthan and dextran), and as biopolyesters in packaging were produced thanks to recent advances in synthetic biology and bioengineering techniques. Research and business interest in the rational design of biopolymer-producing cell factories has grown.

In bacteria, regulatory networks that process environmental inputs and regulate responses through transcriptional and post-translational regulation govern polymer biosynthesis. Transcription factors activate promoters that manage the expression of genes with similar functions at the transcriptional level. Sigma factors, which are RNA polymerase subunits, and regulatory proteins, which bind to DNA areas upstream of biosynthetic genes, are examples of these transcription factors. Antisigma factors bind to some sigma factors, which are then released when exposed to outside stimuli. For instance, the sigma factor AlgU facilitates binding to a particular promoter region upstream of the alginate biosynthetic gene cluster by attaching to the core RNA polymerase. When circumstances are not favourable for the synthesis of alginate, P. aeruginosa85 and probably other pseudomonads sequester AlgU through the membrane-bound anti-sigma factor MucA. AlgU is released and triggers transcription of the alginate biosynthesis gene cluster upon environmental destabilisation of this complex, such as in response to cell envelope stress or on mutation of the mucA gene (for example, adaptive mutation during persistent infection). A designed MucA-inactivated strain86 generated significant quantities of alginate constitutively, which suggests a potential route for improved bacterial alginate synthesis. Furthermore, signal processing and intricate regulatory networks that regulate polymer production in bacteria are regulated by short non-coding RNAs, two-component systems, regulatory RNA-binding proteins, and second messengers (such c-di- GMP and c-di-AMP). Synthetic biology methods for effective polymeric material manufacturing will be informed by improved knowledge of these regulatory complexities through systems biology. Bacteria have the ability to produce polyaminoacids or polyamides, such as secreted poly-L-lysine and poly-D-glutamic acid or the intracellularly produced cyanophycin (copolymer of L-arginine and L-aspartic acid), which can be used as a storage substance as well as a component of biofilm matrix or capsular polymer. Similar to the polysaccharides in the biofilm matrix, polyamide biofilm or capsule is less immunogenic, preventing the human immune system from attacking bacteria like Bacillus anthracis. Numerous non-pathogenic bacteria, including Bacillus megaterium, Bacillus licheniformis, and several cyanobacteria, also manufacture polyamide-based polymers. Polyamides can be polycationic or polyanionic and contain large charges. They are thought to be renewable, biodegradable, and non-toxic. The manufacture of polyamides with increased biological properties is aided by metabolic engineering [6-10]. Chemically manufactured polymers may be replaced by polyamides in industry. For instance, poly-D-glutamic acid can be used to treat wastewater instead of synthetic flocculants like polyacrylamide or polyaluminum chloride. Since it can damage the cross links and compromise the integrity of the membrane, poly- L-lysine, which is employed in antimicrobial coatings, has antibacterial capabilities.

Bacteria can even create a variety of biopolymers that can function as extracellular DNA and proteinaceous components. These biopolymers can be utilised to make biomaterials in addition to being involved in bacterial disease. When a cell is lysed, the intracellular DNA is released, and extracellular DNA is created. In the case of biofilms, a cellular subpopulation lyses to create extracellular DNA, as seen, for instance, in the stalks of P. aeruginosa’s mushroom-like microcolonies. Extracellular DNA plays a variety of roles in the adherence and stability of the biofilm matrix by interacting with cationic polysaccharides (like Pel) and other cations, and it can also act as a source of nutrients during times of starvation, conferring antibiotic resistance. This is due to the extracellular DNA’s high negative charge.

Conclusion

Major virulence factors generated by bacterial pathogens include extracellular polymers. Thus, a technique for the therapy of bacterial infections involves inhibiting their production processes. New approaches to combat bacterial infections are urgently needed due to the increased rates of antibiotic resistance. Understanding the production, secretion, and control of biopolymers will provide novel and precise drug development targets, such as those that compromise bacterial defences against host immunological defences or antimicrobial therapy. Non-pathogenic bacterial polymers are regarded as safe materials for a variety of uses. Challenges persist despite significant advancements in the design of cell factories for improved biopolymer synthesis as well as manufacture of custom biopolymers. It is difficult to rationally develop new GRAS-certified cell factories and biopolymers because complex biological systems have so many interconnected parts and feedback loops. In order to better inform genome-scale metabolic models, metabolic network modelling, and computer simulations of massive data sets that feed into synthetic biology methodologies, it is crucial to minimise this complexity through systems biology. This effort will lay the groundwork for effective bioengineering tactics and precise projections of the evolution of cell factories and bioprocesses.

In addition to producing a large number of biopolymers, non-pathogenic bacteria are also employed in a wide range of biotechnological products for both commercial and medical purposes. Despite making considerable strides in the planning and construction of cell factories for a higher output of natural and custom biopolymers, there are still certain obstacles to overcome, such as their high cost and the need to validate their safety profiles, among other things. Some viable bioengineering solutions for novel GRAS-guaranteed microbial cell factories and biopolymers are still not well investigated since complex bio-systems include a broad range of interplaying components and many feedback loops. To develop metabolic models for genomescaling and metabolic modelling of networks, coupled with computer simulations incorporating vast sets of databases feeding into synthetic biology methodologies, it is required to reduce the complexity through systems biology.

1. Gouveia L, Oliveira AC (2009) Micro algae as a raw material for biofuels production. J Ind Microbiol Biotechnol 36: 269-274.

Indexed at, Google Scholar, Crossref

2. Nakano S, Murakami M (2000) Reciprocal subsidies: Dynamic interdependence between terrestrial and aquatic food webs. Center for Ecological Research 52-2113.

Google Scholar, Crossref

3. Elias E, Weldemariam S, Bereket T, Wondwosen G (2019) Impact of Land Use/Cover Changes on Lake Ecosystem of Ethiopia Central Rift Valley. Cogent Food Agric 5.

Indexed at, Google Scholar, Crossref

4. Osman AI, Hefny M, Maksoud MA, Elgarahy AM, Rooney DW (2020) Recent advances in carbon capture storage and utilisation technologies: a review. Environ Chem Lett 19: 797-849.

Indexed at, Google Scholar, Crossref

5. Koussoroplis AM, Lemarchand C, Bec A, Desvilettes C, Amblard C (2008) From Aquatic to Terrestrial Food Webs: Decrease of the Docosa Hexaenoic Acid/Linoleic Acid Ratio. Lipids 43: 461-466.

Google Scholar, Crossref

6. Homburger F, Russfield AB, Weisburger JH, Lim S, Chak SP, et al.(1975) Aging changes in CD-1 HaM/ICR mice reared under standard laboratory conditions. J Natl Cancer Inst 55(1): 37-45.

Indexed at, Google Scholar

7. Percy DH, Jonas AM (1971) Incidence of spontaneous tumors in CD (R) -1 HaM-ICR mice. J Natl Cancer Inst 46(5): 1045-1065.

Indexed at, Google Scholar

8. Ward JM, Argilan F, Reynolds CW (1983) Immunoperoxidase localization of large granular lymphocytes in normal tissues and lesions of athymic nude rats. J Immunol 131(1): 132-139.

Indexed at, Google Scholar

9. Slaga TJ (1983) Overview of tumor promotion in animals. Environ Health Perspect 50: 3–14.

Indexed at, Google Scholar

10. Deka S, Om PT, Ashish P (2019) Perception-Based Assessment of Ecosystem Services of Ghagra Pahar Forest of Assam, Northeast India. Geol Ecol Landsc 3: 197-209.

Indexed at, Google Scholar, Crossref