Abstract
While assaying lipase with emulsified substrate, an investigation was made of the stability of the substrate and coefficient of variation (C.V.) affected by the lot and mixing ratio of poly (vinyl alcohol) (PVA) using Mucor lipase and Rhizopus lipase.
The residual activity of lipase (represented as relative activity against the value assayed immediately following substrate preparation) in the use of [PVA 117+PVA 205] was for Mucor lipase, 92.5% and for Rhizopus lipase, 100%. This shows the substrate to be essentially stable. Whereas the residual activity when using PVA 117 to be 67% and 80% respectively. Thus, the substrate is unstable.
C.V. 96 h after the substrate preparation gave a higher value than that assayed immediately following substrate preparation in both [PVA 117+PVA 205] and PVA 117. C.V. of the former PVA (below 10) was lower than that of the latter PVA (above 10). Furthermore, the effect of PVA on C.V. differed according to the lipase.
