*Review* **Jellyfish-Associated Microbiome in the Marine Environment: Exploring Its Biotechnological Potential**

### **Tinkara Tinta 1,2,\*, Tjaša Kogovšek 2, Katja Klun 2, Alenka Malej 2, Gerhard J. Herndl 1,3 and Valentina Turk 2**


Received: 9 January 2019; Accepted: 29 January 2019; Published: 1 February 2019

**Abstract:** Despite accumulating evidence of the importance of the jellyfish-associated microbiome to jellyfish, its potential relevance to blue biotechnology has only recently been recognized. In this review, we emphasize the biotechnological potential of host–microorganism systems and focus on gelatinous zooplankton as a host for the microbiome with biotechnological potential. The basic characteristics of jellyfish-associated microbial communities, the mechanisms underlying the jellyfish-microbe relationship, and the role/function of the jellyfish-associated microbiome and its biotechnological potential are reviewed. It appears that the jellyfish-associated microbiome is discrete from the microbial community in the ambient seawater, exhibiting a certain degree of specialization with some preferences for specific jellyfish taxa and for specific jellyfish populations, life stages, and body parts. In addition, different sampling approaches and methodologies to study the phylogenetic diversity of the jellyfish-associated microbiome are described and discussed. Finally, some general conclusions are drawn from the existing literature and future research directions are highlighted on the jellyfish-associated microbiome.

**Keywords:** Cnidaria; Ctenophora; biodiversity; bioactive compounds; microbial communities; blue biotechnology
