Figure 3.

Schematic representation of biocatalytic pathways for trehalose synthesis. The traditional trehalose phosphate synthase/phosphorylase (TPS/TPP) route (a); the malto-oligosyltrehalose synthase/hydrolase (MTS/MTH)-coupled route (b); the TreS-type trehalose synthase route (c); the TreT-like trehalose synthase route (d); and the inverting (e) or retaining (f) trehalose phosphorylase (TP) routes coupled with other glycoside phosphorylases, i.e., maltose phosphorylase (MP) and sucrose phosphorylase (SP), respectively. The latter three pathways (d–f) are also amenable to trehalose analogue synthesis. NDP = nucleoside diphosphate.