Chemistry Reference
In-Depth Information
Table 5.5.
(Continued )
Reactive
linkage and
initial
product
Strain name or
trade name/s (if
available)
Reference
(see
below)
Optimum
pH
Optimum
temp., 8C
Microbial species
Saccharopolyspora
rectivirgula
SAM 1400
19
6.0-7.5
50-55
?
Escherichia coli
20
7.0
40-45
1. Burvall et al., 1979; Asp et al., 1980; Prenosil et al., 1987b; 2. Toba and Adachi, 1978; Mahoney et al., 1975;
Mahoney and Whitaker, 1978; Prenosil et al., 1987b; 3. Toba et al., 1985; Prenosil et al., 1987b; 4. Toba and
Adachi, 1978; Prenosil et al., 1987b; 5. Griffiths and Muir, 1978; Mozaffar et al., 1984; Nakanishi et al., 1983;
Usui et al., 1993; Yanahira et al., 1995; 6. Griffiths and Muir, 1978; Sienkiewicz and Riedel, 1990; 7. Greenberg
and Mahoney, 1982, 1983; Smart, 1991; Linko et al., 1992; 8. Toba et al., 1981; Kobayashi et al., 1990; 9. Rabiu
et al., 2001; Tzortzis et al., 2005a; 10. Ohtsuka et al., 1990; Ozawa et al., 1991; 11. Gorin et al., 1964; Shin et al.,
1995; Shin et al., 1998; Cho et al., 2003; Ishikawa et al., 2005; 12. Onishi and Tanaka, 1995; Onishi et al., 1995;
13. Onishi and Tanaka, 1996; 14. Onishi et al., 1995; 15. Onishi et al 1996; Onishi and Tanaka, 1997; 16.
Akiyama et al., 2001; Grogan, 1991; Pisani et al., 1990; She et al., 2001; 17.Jiet al., 2005; 18. Choi et al., 2004a;
19. Nakayama et al., 1992, 1993; Nakao et al., 1994; 20. Sienkiewicz and Riedel, 1990, p256; Saito et al., 1992.
5.4.1.3.
Some Suppliers of -Galactosidases (EC 3.2.1.23)
Examples of some suppliers of the enzyme are listed in Table 5.6.
Generally, the fungal lactases function optimally at low pH and a relatively
high temperature, whereas the yeast lactases perform best at neutral pH and a
lower temperature. The yeast lactases respond to nutrient additions of mag-
nesium and potassium ions.
5.4.1.4.
Investigations of the Major Transgalactosylation Enzyme
Sources
Kluyveromyces marxianus syn. K. fragilis and syn. Candida pseudotropicalis is an
anamorph of Candida kefyr.
and
Kluyveromyces lactis syn. K. marxiansus var. lactis. is an anamorph of
Candida sphaerica (NCBI, 2007)
These two yeasts were described in earlier years as belonging to the
genus Saccharomyces and also have a number of synonymous names. Sac-
charomyces is still used sometimes as the generic name for these species. The
-galactosidase in these species is intracellular, and production is inducible.
Thus, enzyme activity increases rapidly in the presence of carbohydrate
sources, such as lactose, galactose or lactobionic acid. The activity is
growth-associated and displays optimal activity at neutral pH and a tempera-
ture of about 408C. The regulation of enzyme activity in these yeasts is
