B. Bisping et al., TEMPE FERMENTATION - SOME ASPECTS OF FORMATION OF GAMMA-LINOLENIC ACID, PROTEASES AND VITAMINS, Biotechnology advances, 11(3), 1993, pp. 481-493
During a tempe fermentation the concentrations of linoleic, and alpha-
linolenic acids (ALA) decreased while the concentration of oleic acid
increased. During fatty acid synthesis Rhizopus sp. produced only gamm
a-linolenic acid (GLA) instead of ALA. The amount of GLA in tempe were
influenced by varying external parameters. The proteolytic capacity o
f 36 strains of the genus Rhizopus isolated from Indonesian tempe or t
empe inocula was examined. There was a distinct increase in the amount
of free amino acids during tempe fermentation. Fermentations with mix
ed populations of bacteria and Rhizopus yielded a lower level of free
amino acids, but an increase in total amount of amino acids. In compar
ison to intracellular, and extracellular proteases the proteases of th
e cell wall fraction are most responsible for proteolytic capacity of
the different Rhizopus strains. Two isolated strains of Citrobacter fr
eundii were found to be the best vitamin B-12 producers during the soa
king of soybeans. In the solid substrate fermentation the Rhizopus mol
ds formed vitamin B-6, riboflavin, and nicotinic acid. The addition of
bacteria to the solid substrate fermentation resulted in a strong inc
rease of active vitamin B-12 in tempe. In the presence of the Rhizopus
mold, the vitamin B-12 formation by C. freundii was three times highe
r than that of a fermentation without the mold.