The isolated bacteria were observed by light microscope. It is clear
that the bacteria was gram positive, rod shaped coccobacilli,
occurring singly or in chains. The gram staining results indicated
that the isolated bacteria could be identified as lactobacilli [14].
Hanging-drop wet method showed that the isolated bacteria were
nonmotile. In the other hand, Carigie’s technique also showed that
the bacteria grew only along the stab line in the medium. Therefore,
these methods conformed that the bacteria under investigation was
nonmotile. The nonmotile behavior is a characteristic of L.
acidophilus [24].
The catalase test is one of the most useful diagnostic tests for the
recognition of bacteria due to their simplicity. In performing catalase
test, no bubble was observed indicating that the isolated bacterium
is catalase negative and could not mediate the decomposition of
H2O2 to produce O2. It is well known that Lactobacillus acidophilus is
catalase negative [25, 26].
The main task of Carbohydrate fermentation test is to investigate the
ability of bacteria to ferment different types of carbohydrate. Phenol
red broth base medium was used as an indicator to differentiate the
bacteria according to their patterns of carbohydrate utilization.
Table 1 show that the isolated bacteria could ferment maltose,
lactose, sucrose and glucose, but not sorbitol and arabinose. No
bubble was detected from the glucose inserted with Durham tube
indicating that no gas production could be associated with the
growth. Thus, the results obtained coincided with L. acidophilus
strain characteristic [14, 27].