There are a large number of natural microbial communities in nature. Different populations inside the consortia expand the performance boundary of a single microbial population through communication and division of labor, reducing the overall metabolic burden and increasing the environmental adaptability. Based on engineering principles, synthetic biology designs or modifies basic functional components, gene circuits, and chassis cells to purposefully reprogram the operational processes of the living cells, achieving rich and controllable biological functions. Introducing this engineering design principle to obtain structurally well-defined synthetic microbial communities can provide ideas for theoretical studies and shed light on versatile applications. This review discussed recent progresses on synthetic microbial consortia with regard to design principles, construction methods and applications, and prospected future perspectives.
Microbial Consortia/genetics* ; Synthetic Biology ; Microbiota ; Models, Theoretical

In order to clarify dynamic change of microbial community composition and to identify key functional bacteria in the cellulose degradation consortium, we studied several aspects of the biodegradation of filter papers and rice straws by the microbial consortium, the change of substrate degradation, microbial biomass and pH of fermentation broth. We extracted total DNA of the microbial consortium in different degradation stages for high-throughput sequencing of amplicons of bacterial 16 S rRNA genes. Based on the decomposition characteristics test, we defined the 12th, 72nd and 168th hours after inoculation as the initial stage, peak stage and end stage of degradation, respectively. The microbial consortium was mainly composed of 1 phylum, 2 classes, 2 orders, 7 families and 11 genera. With cellulose degradation, bacteria in the consortium showed different growth trends. The relative abundance of Brevibacillus and Caloramator decreased gradually. The relative abundance of Clostridium, Bacillus, Geobacillus and Cohnella increased gradually. The relative abundance of Ureibacillus, Tissierella, Epulopiscium was the highest in peak stage. The relative abundance of Paenibacillus and Ruminococcus did not change obviously in each stage. Above-mentioned 11 main genera all belonged to Firmicutes, which are thermophilic, broad pH adaptable and cellulose or hemicellulose degradable. During cellulose degradation by the microbial consortium, aerobic bacteria were dominant functional bacteria in the initial stage. However, the relative abundance of anaerobic bacteria increased gradually in middle and end stage, and replaced aerobic bacteria to become main bacteria to degrade cellulose.
Bacteria ; classification ; metabolism ; Biodegradation, Environmental ; Cellulose ; metabolism ; DNA, Bacterial ; genetics ; Microbial Consortia ; RNA, Ribosomal, 16S ; genetics

Direct observation of a wide range of natural microorganisms has revealed the fact that the majority of microbes persist as surface-attached communities surrounded by matrix materials, called biofilms. Biofilms can be formed by a single bacterial strain. However, most natural biofilms are actually formed by multiple bacterial species. Conventional methods for bacterial cleaning, such as applications of antibiotics and/or disinfectants are often ineffective for biofilm populations due to their special physiology and physical matrix barrier. It has been estimated that billions of dollars are spent every year worldwide to deal with damage to equipment, contaminations of products, energy losses, and infections in human beings resulted from microbial biofilms. Microorganisms compete, cooperate, and communicate with each other in multi-species biofilms. Understanding the mechanisms of multi-species biofilm formation will facilitate the development of methods for combating bacterial biofilms in clinical, environmental, industrial, and agricultural areas. The most recent advances in the understanding of multi-species biofilms are summarized and discussed in the review.
Animals ; Bacterial Adhesion ; physiology ; Bacterial Typing Techniques ; Biofilms ; growth & development ; Environmental Restoration and Remediation ; Equipment Contamination ; Humans ; Microbial Consortia ; genetics ; physiology ; Microbial Interactions ; physiology ; Microscopy, Confocal ; Models, Biological ; Nucleic Acid Hybridization ; Polymerase Chain Reaction ; Polysaccharides, Bacterial ; chemistry

Bacteria survive in nature by forming biofilms on surfaces and probably most, if not all, bacteria (and fungi) are capable of forming biofilms. A biofilm is a structured consortium of bacteria embedded in a self-produced polymer matrix consisting of polysaccharide, protein and extracellular DNA. Bacterial biofilms are resistant to antibiotics, disinfectant chemicals and to phagocytosis and other components of the innate and adaptive inflammatory defense system of the body. It is known, for example, that persistence of staphylococcal infections related to foreign bodies is due to biofilm formation. Likewise, chronic Pseudomonas aeruginosa lung infections in cystic fibrosis patients are caused by biofilm growing mucoid strains. Gradients of nutrients and oxygen exist from the top to the bottom of biofilms and the bacterial cells located in nutrient poor areas have decreased metabolic activity and increased doubling times. These more or less dormant cells are therefore responsible for some of the tolerance to antibiotics. Biofilm growth is associated with an increased level of mutations. Bacteria in biofilms communicate by means of molecules, which activates certain genes responsible for production of virulence factors and, to some extent, biofilm structure. This phenomenon is called quorum sensing and depends upon the concentration of the quorum sensing molecules in a certain niche, which depends on the number of the bacteria. Biofilms can be prevented by antibiotic prophylaxis or early aggressive antibiotic therapy and they can be treated by chronic suppressive antibiotic therapy. Promising strategies may include the use of compounds which can dissolve the biofilm matrix and quorum sensing inhibitors, which increases biofilm susceptibility to antibiotics and phagocytosis.
Animals ; Antibiotic Prophylaxis ; Biofilms ; drug effects ; growth & development ; Chronic Disease ; Cystic Fibrosis ; microbiology ; Drug Resistance, Microbial ; physiology ; Foreign Bodies ; microbiology ; Humans ; Microbial Consortia ; drug effects ; genetics ; immunology ; Phagocytosis ; Pseudomonas Infections ; microbiology ; Pseudomonas aeruginosa ; drug effects ; genetics ; physiology ; Quorum Sensing ; drug effects ; genetics