2A) reveal slime attaching to the bacterial cells. The filaments
are noticeably thicker for milk kefir grains than for soymilk
kefir grains (Figure 2B). At least a quarter of the dry material
of the kefir grains consists of a capsular polysaccharide usually
denominated by kefiran (La Riviere and others 1967),
which is considered a result of the metabolism of capsular
bacteria such as Lactobacillus kefir (La Riviere and others
1967) and Lactobacillus kefiranofaciens (Toba and others
1987). Carbon source has a considerable influence on lactic
acid bacterial exopolysaccharide yield (Cerning and others
1992). The major carbohydrates present in soymilk are sucrose,
raffinose and stachyose, whereas in milk it is lactose
that is predominant (Pinthong and others 1980). It is likely
that carbohydrates in soymilk are not conducive to the synthesis
of kefiran.