Cellulose (C₆H₁₀O₅)n is a polysaccharide consisting of a linear chain of several hundred to over ten thousand β(1→4) linked D-glucose units. It is the most abundant biopolymer in the world, and is foundational to many industries including pulp and paper, textiles, bioenergy, and tissue engineering. This topic will cover the biosynthesis and bio-degradation/bio-conversion of cellulose aiming to facilitate the research and application of cellulose.

Cellulose is biosynthesized mainly in vascular plants at the plasma membrane by rosette terminal complexes (RTCs). However, various microorganisms (algae, fungi, and bacteria) are also able to synthesize cellulose, with notable bacterial cellulose (BC) producers including species of Acetobacter and Achromobacter. BC is distinguished from plant-based cellulose by its high purity, and does not contain any hemicellulose or lignin. BC has the same chemical structure as plant cellulose, but exhibits superior physical and chemical properties, including high mechanical tensile strength, purity, biodegradability and water-holding capacity. Synthesis of BC is a precisely regulated multi-step process, which includes two main operative amphibolic pathways: the pentose phosphate cycle (also known as hexose monophosphate pathway (HMP)) for the oxidation of carbohydrates, and the Krebs cycle (also known as tricarboxylic acid cycle (TCA)) for the oxidation of organic acid with related compounds. Review and original research papers related to cellulose biosynthesis in plants and microorganisms are welcome.

Degradation and conversion of cellulose in lignocellulosic biomass to fuels and chemicals has attracted much momentum due to the concerns of using fossil-based resources. Generally, cellulose is recalcitrant to be degraded by chemical and biological methods, especially the cellulose in the lignocellulosic biomass, due to the complex chemical structure in its interior. From a perspective at the molecular level, there is strong interaction by hydrogen bonds between adjacent chains in the cellulose sheet, as well as weaker hydrophobic interactions between cellulose sheets. Besides, cellulose in plant biomass is buried in a lignin carbohydrates complex (LCC), which makes degradation and conversion of cellulose difficult. Biochemical route involves pretreatment to open up the plant cell wall, enzymatic hydrolysis to convert cellulose/hemicelluloses to fermentable sugars and fermentation of sugars to various fuels and chemicals. Lignocellulosic biomass can also be directly decomposed and converted to fuels and chemicals using cellulolytic microorganisms. We are looking for both review and original research articles that elaborate on change/modification/bio-degradation of cellulose/lignocellulosic materials using biological/microbiological approaches. Articles about thermo-chemical approaches will not be considered unless they include a large portion of biological elements.

We hope that this topic will give deep insights into the fundamentals of biosynthesis, bio-degradation and utilization of cellulose. To encourage work that spans multiple specialties, this topic is being hosted in Microbiotechnology, Ecotoxicology and Bioremediation,
Microbiological Chemistry and Geomicrobiology and Systems Microbiology and welcomes Original Research and Review article submissions through any of these sections.

Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.