PRODUCTION Of NUTRIENT SOURCES FOR RHIZOBIUM

Table 8. (continued).
Species a
D.polymorphus
(D.phaffii,
P. polymorpha)
P. anomala
(C. pelliculosa)
Amylase(s) Location b
General characteristics
��
- C Two activities (α-Amylase, glucoamylase)
reported, but not separated.
- C Two activities tentatively designated as
glucoamylase.
P. burtonii α-Amylase E Extracellular glucoamylase also reported but
not separated; α-amylase partially cellassociated.
Rh. ingeniosa α-Amylase E Major portion associated with cell; Phadebas
(T. ingeniosa)
substrate hydrolyzed.
Rhodosporidium sp. Glucoamylase E Hydrolyzes raw starch.
Sp. holsaticus E Probably a glucoamylase.
Tr. pullulans α -Amylase,
glucoamylases
E α-Amylase hydrolyzes β-cyclodextrin;
gluco-amylase are glycoproteins with
debranching activity.
aName other than those currently recommerded are shown in parentheses. Abbreviations for genera: C.= Candida; Cr.=
Cryptococcus; D.= Debaryomyces; P.= Pichia; Rh. = Rhodotorula; Sp.= Sporobolomyces; Tr.= Trichosporon; T.= Torulopsis.
bC = cell-associated periplasmic; E = extracellular (secreted in the medium).
cPreliminary identification based on starch hydrolysis pattern.
Source: Varachtert et al. (1990).
1.8 Extracted yeast cell products
Yeasts are rich sources of proteins, nucleic acids, vitamins and minerals but with negligible
levels of triglycerides. When extracted by either acids (to produce hydrolysates) or enzymes
(autolysates) or salt (plasmolysates), yeasts develop characteristic savoury flavours and aromas which
are utilized in numerous processed and convenience foods where a ‘meaty flavour’ is sought, e.g.