Characteristics Alcaligenes odorans Bacillus subtilis Corynebacterium propinquum Pseudomonas aeruginosa
Gram staining Negative Positive Positive Negative
Cell shape Bacilli Bacilli Bacilli Bacilli
Motility Motile Motile Non motile Motile
Colony  Thin, irregular Circular Slimy Round, raised
Catalase reaction Positive Positive Positive Positive
Nitrate reduction Negative  Positive Positive Positive
H2S production Positive Negative Negative Negative
Indole production Negative Negative Negative Negative 
Fermentation Tests Negative Negative Negative  Negative
Dextrose Negative   Negative Negative Negative
Lactose Negative Negative Negative Negative
Sucrose Negative Positive Negative Negative
Starch Hydrolysis Positive Positive Negative Positive
Oxidase  Citrate Utilization Negative Positive  Negative Positive
Table 1: Morphological and Biochemical Characteristics of isolates.