Cellulose is one of the most abundant organic macromolecules on Earth, playing a crucial role in the carbon cycle and plant cell structure. Bacteria such as *Acetobacter xylinum* produce cellulose, a fibrous polymer with a highly ordered structure. This review discusses the biosynthesis of cellulose in bacteria, focusing on *A. xylinum* as a model organism. The process involves the synthesis of glucose polymers, the assembly of cellulose fibrils, and regulation by the cyclic dinucleotide c-di-GMP. The cellulose synthase enzyme is central to this process, catalyzing the polymerization of glucose into β-1,4-glucan chains. The synthesis is tightly regulated by c-di-GMP, which acts as an allosteric effector, enhancing the activity of the cellulose synthase. The regulation involves positive control through diguanylate cyclase and negative control through c-di-GMP phosphodiesterase. The structure of cellulose fibrils is highly ordered, with β-1,4-glucan chains arranged in parallel or antiparallel configurations. The synthesis of cellulose in *A. xylinum* is influenced by various metabolic pathways, and the enzyme's activity is dependent on the availability of UDP-glucose. The cellulose synthase is a complex enzyme, possibly composed of multiple subunits, and its activity is regulated by various factors. The study of cellulose biosynthesis in bacteria has important implications for biotechnology and the development of new materials. The regulation of cellulose synthesis by c-di-GMP is a unique mechanism that allows for precise control of the process, ensuring the formation of structured cellulose fibrils. The understanding of cellulose biosynthesis in bacteria provides insights into the broader mechanisms of polymerization and regulation in biological systems.Cellulose is one of the most abundant organic macromolecules on Earth, playing a crucial role in the carbon cycle and plant cell structure. Bacteria such as *Acetobacter xylinum* produce cellulose, a fibrous polymer with a highly ordered structure. This review discusses the biosynthesis of cellulose in bacteria, focusing on *A. xylinum* as a model organism. The process involves the synthesis of glucose polymers, the assembly of cellulose fibrils, and regulation by the cyclic dinucleotide c-di-GMP. The cellulose synthase enzyme is central to this process, catalyzing the polymerization of glucose into β-1,4-glucan chains. The synthesis is tightly regulated by c-di-GMP, which acts as an allosteric effector, enhancing the activity of the cellulose synthase. The regulation involves positive control through diguanylate cyclase and negative control through c-di-GMP phosphodiesterase. The structure of cellulose fibrils is highly ordered, with β-1,4-glucan chains arranged in parallel or antiparallel configurations. The synthesis of cellulose in *A. xylinum* is influenced by various metabolic pathways, and the enzyme's activity is dependent on the availability of UDP-glucose. The cellulose synthase is a complex enzyme, possibly composed of multiple subunits, and its activity is regulated by various factors. The study of cellulose biosynthesis in bacteria has important implications for biotechnology and the development of new materials. The regulation of cellulose synthesis by c-di-GMP is a unique mechanism that allows for precise control of the process, ensuring the formation of structured cellulose fibrils. The understanding of cellulose biosynthesis in bacteria provides insights into the broader mechanisms of polymerization and regulation in biological systems.