Isolation and Morphological Characterization of Tunicate-Associated Bacterial Colonies from the Shipwreck of Kumbang Karimunjawa, Jepara, Indonesia

Tunicates (Ascidia) are hosts for organisms associated with them which include bacteria, archaea, and fungi.Tunicates and their associated bacteria are able to produce bioactive compounds that have various functions, such as antibacterial, antiviral, antifungal, anticancer, antitumor, and cytotoxic compounds.The selection of appropriate media in the isolation of tunicate-associated bacteria increases the opportunity to obtain pure cultures that have the potential to produce bioactive compounds.In this study, a total of 6 tunicates were identified based on morphological characteristics.Isolation of associated bacteria was conducted by serial dilution method using Zobell and M1 media.Colonies that grew on the surface of the media were characterized based on colony morphology and purified by streak plate method.The isolation results 29 isolates that grew on Zobell 2216 media and 82 isolates on M1 media.Purification left 41% isolates from Zobell 2216 media and 84% isolates from M1 media.The decrease in the number of isolates is due to the unsuitable environmental conditions compared to their natural habitat or the inability of isolates to utilize media nutrients for a long time.M1 media is better than Zobell 2216 media in the percentage of colonies that grow during isolation and the obtaining of pure isolates.