Isolation and Identification of Cadmium-Reducing Bacteria from Contaminated Coastal Sediment in the Northern Coast of Indramayu, Indonesia.

Abstract

<b>Background and Objective:</b> Cadmium (Cd) is one of the heavy metal pollutants and its accumulation impacts the sustainability of marine organisms. Current research aimed to isolate and identify the cadmium-reducing bacteria from contaminated coastal sediment in Karangsong Port, Indramayu, Indonesia. The isolates were investigated for their potential to reduce cadmium and showed the cadmium reduction drastically up to 50% at 6 hrs treated under different cadmium concentrations of 0, 5, 1 and 1.5 ppm, respectively. <b>Materials and Methods:</b> Morphological characteristics were observed in most of the isolates. Out of 8 isolates, two selected strains such as Karangsong Cd 3 and Cd 7 were identified by 16S rRNA sequencing as <i>Pseudoalteromonas issachenkonii</i> strain KMM 3549 (Acc. No. NR 025139.1) and <i>Pseudoalteromonas tetraodonis</i> GFC strain IAM 14160 (Acc. No. NR 041787.1), respectively. <b>Results:</b> The cadmium resistance profile showed that the selected isolates were resistant to various concentrations of cadmium (Cd). The isolates reduced the concentration of cadmium drastically up to 50% at 6 hrs. The results demonstrated the two bacteria are possible to remove the cadmium from seawater containing cadmium. The gram staining showed bacterial colony morphology were diplobacilli and coccobacillus. <b>Conclusion:</b> These results suggested that the Karangsong Cd 3 and Cd 7 could facilitate the new references of future microbial applications for bioremediation efforts.