GLUCOSE ISOMERASE (IMMOBILIZED) FROM STREPTOMYCES OLIVOCHROMOGENES
EXPLANATION
This substance has not been previously evaluated by the Joint
FAO/WHO Expert Committee on Food Additives.
BIOLOGICAL DATA
Biochemical aspects
No information available.
Toxicological studies
Acute toxicity
No information available.
Short-term studies
Rats
Groups of 15 male and 15 female Charles-River albino rats were
fed 0, 1, 3, or 10% of a preparation of whole S. olivochromogenes
cells in the diet for 90 days. Harvesting of the cells for the feeding
studies was performed by the addition of 36 g/litre of Perlite to the
fermentation media followed by filtration and washing. (A semipurified
enzyme preparation from lysed cells - no Perlite added - is used in
the actual commercial production of high fructose corn syrup.) An
additional group of 15 males and 15 females were fed a diet containing
7.5% Perlite for 90 days. Clinical chemistry, haematology, urinalysis,
and microscopic pathology were conducted on 10 animals/sex from the
control, Perlite, and high-dose groups.
There was a small decrease in liver to body-weight ratio in all
treatment groups and in the Perlite groups. The decreases were not
dose-related. Spleen to body-weight ratios were decreased in mid- and
high-dose females, but the magnitude of the effect was small. There
was an increase in ovary to body-weight ratio in low- and high-dose
females, but there was an inverse dose relationship and the magnitude
of the effect was small. No treatment-related changes were reported
with respect to body-weight gain, food consumption, haematology,
clinical chemistry, urinalysis, or gross or microscopic pathology
(Smith, 1972).
Dogs
Groups of 4 male and 4 female beagle dogs were fed diets
containing 0, 1, 3, or 10% of a S. olivochromogenes whole-cell
preparation similar to that described above in the rat study. An
additional group of 4 males and 4 females were fed a diet containing
7.5% Perlite. A significant reduction in body-weight gain was observed
in the male high-dose group. No statistically-significant effects of
treatment on food consumption were reported, but there appeared to be
a dose-related trend toward lower food consumption in females. An
increased brain to body-weight ratio in high-dose and diluent-control
males was probably due to the reduced body-weight gain in these
groups. No significant treatment-related changes were reported with
respect to haematology, clinical chemistry, urinalysis, or gross or
microscopic pathology (Burtner, 1972).
Comments
Short-term feeding studies in rats and dogs showed no significant
toxicological effects. Although the preparation fed in these studies
differs from that used in commercial preparations, the high levels of
whole cells fed (up to 10% of the diet) plus the use of a Perlite
control provide adequate information for evaluating the safety of the
preparation derived from lysed cells.
EVALUATION
Level causing no toxicological effect
Rat: 10% (100,000 ppm) in the diet, equivalent to 10,000 mg/kg
b.w./day.
Estimate of acceptable daily intake for man
Acceptable for use in food processing when used as a component in an
immobilized system.
REFERENCES
Burtner, B.R. (1972). Ninety-day subacute oral toxicity study with
XSO-1228 in Beagle dogs. Unpublished report of Industrial
BIO-TEST Laboratories, Inc. Submitted to the World Health
Organization by CPC International, Inc. (validated study).
Smith, P.S. (1972). Ninety-day subacute oral toxicity study with XSO
1228 in albino rats. Unpublished report of Industrial BIO-TEST
Laboratories, Inc. Submitted to the World Health Organization by
CPC International, Inc. (validated study).