As of yet ascorbic acid production from glucose is not possible with a single organism, but a variety of organisms can be used The process is possible in two steps with separate organisms (see figure 4 below). Some organisms can do a large proportion of thsee steps, for example mutants of Gluconobacter melanogenous can synthesise 2-keto-l-gulonic acid from D-sorbitol or L-sorbose (Sugisawa et al., 1990), but this has not yet been adopted for industry.