ATP, adenosine triphosphate; CSDB, Carbohydrate Structure Database; DO, dissolved oxygen; FDA, Food and Drug administration; GAG, glycosaminoglycan; GRAS, generally recognized as safe; Glc, glucose; GlcpA, glucuronic acid; GlcpNAc, N-acetylglucosamine; Gram-positive bacteria; HA, hyaluronic acid; HAS, hyaluronic acid synthase; HW HA, high-molecular weight hyaluronic acid; HYBID, hyaluronan-binding protein involved in HA depolymerization; Hyaluronic acid; LW HA, low-molecular weight hyaluronic acid; MMP-2, matrix metalloproteinase 2; MW, molecular weight; Microbial fermentation; MurNAc, N-acetylmuramic acid; ND, no data; RHAMM, receptor for hyaluronic acid mediated motility; Recombinant organism; SNFG, symbol nomenclature for glycans; UDP, uridine 5'-trihydrogen diphosphate; UMP, 5'-uridylic acid; UTP, uridine-5'-triphosphate; amyE, α-amylase (B. subtilis); aprE, subtilisin E (B. subtilis); araR, repressor of arabinose operons; cat, acetyl-CoA:CoA transferase; dcas9, dead Cas9 (derived from S. pyogenes); eglS, endoglucanase (B. subtilis); epr, minor extracellular protease (B. subtilis); galR, HTH-type transcriptional regulator GalR (E. coli); galS, HTH-type transcriptional regulator GalS (E. coli); galU, UTP-glucose-1-phosphate uridylyltransferase; glmM, phosphoglucosamine mutase; glmS, l-glutamine-d-fructose-6-phosphate aminotransferase; glmU, bifunctional UDP-N-acetylglucosamine diphosphorylase/glucosamine-1-phosphate N-acetyltransferase (Corynebacterium glutamicum); kfiD, UDP-glucose 6-dehydrogenase; lacA (ganA), ß-galactosidase (B. subtilis); ldh, lactate dehydrogenase; mazF, endoribonuclease (E. coli); mpr, extracellular metalloprotease (B. subtilis); nprB, neutral protease B (B. subtilis); nprE, bacillolysin (B. subtilis); pfkA, ATP-dependent 6-phosphofructokinase (E. coli); pgcA, phosphoglucomutase; poxB, pyruvate:quinone oxidoreductase; pta-ackA operon, phosphate acetyltransferase and acetate kinase; sigF, RNA polymerase sigma-F factor (B. subtilis); thrC, threonine synthase (B. subtilis); tuaD, UDP-glucose 6-dehydrogenase (1); udgA, UDP-glucose 6-dehydrogenase (2); upp, uracil phosphoribosyltransferase (B. subtilis); vHMW HA, very-high-molecular weight hyaluronic acid; wprA, cell wall associated protease (B. subtilis); xylR, xylose operon repressor (B. megaterium); zwf, glucose-6-phosphate 1-dehydrogenase