H. Morais et al., Effect of the composition of culture media on the laccase production of Lentinus edodes strains, ACT BIOTECH, 21(4), 2001, pp. 307-320
The effect of charge, ion radii and concentration of cations and fermentati
on time on the laccase production of four Lentinus edodes strains was deter
mined using 28 different fermentation media and 60 days of fermentation tim
e. Samples were taken every 10 days and the laccase activity was determined
by visible spectrophotometry. Principal component analysis (PCA) was used
for the assessment of similarities and dissimilarities between the laccase
activities of the samples. As PCA is not suitable for the separation of the
strength (potency) and selectivity of the effect of various factors (compo
sition of cultures, fermentation time, Lentinus edodes strains) on the lacc
ase production, they were separated by the spectral mapping technique (SPM)
. The dimensionality of the matrices of PC loadings and variables and the s
electivity maps were reduced to two by the lion-linear mapping technique. T
he results of PCA and SPM were compared by calculating linear relationships
among the potency values and the corresponding coordinates of PCA and SPM
maps. It was established that neither the type of the cations nor their con
centration in the fermentation media had a significant effect on the laccas
e production. It was found that the type of the Lentinus edodes strains and
the fermentation time exerts a considerable effect both on the strength an
d on the selectivity of the laccase production. It was further proven that
the results of PCA and SPM were considerably different. Therefore, their si
multaneous application in future quantitative structure activity relationsh
ip (QSAR) studies is highly recommended.