**5.2 Isolation of carbazole degrading bacteria and gram staining**

The **Figure 5** below shows the growth of bacteria isolated from second and third enrichment plates which was cultured on MSM broth supplemented with 0.1% carbazole as sole carbon source. It could be observed that IM2 and IM3 turned to dark yellow while IM6 is cloudier but still turned yellow in color. IM1, IM3 and IM5 became light yellow in color compared to control from **Table 6**.

After isolating six different bacteria by streaking on MSM double layer agar plates supplemented with 0.1% carbazole, it could be observed that not all of them produce clear or hollow zones. Despite that, all the isolates showed growth on agar plate proving that carbazole was utilized efficiently by the bacteria. Next, gram staining was done for all isolates to distinguish between Gram positive and Gramnegative groups of bacteria before proceeding with DNA extraction and sequencing (**Table 7**).

**Figure 5.** *Six bacteria isolated, from right, IM1, IM2, IM3, IM4, IM5 and IM6.*

**Table 7.** *Table of isolated bacteria and gram staining results.*

**Figure 6.** *Clear band on IM1 and IM4 genomic DNA fragment at 1500 bp.*
