Effect of Phytoplankton Feed on Growth and Renieramycin M Producing of a Blue Marine Sponge (Xestospongia Sp.)

Abstract

Objective of the study was to determine growth and the accumulation of an anticancer metabolite, renieramycin M (RM) of the sponge Xestospongia sp. Two phytoplankton, Chaetocerose gracilis and Nannochloropsis sp., were used as live feed. Sponges fed by C. gracilis weighed significantly more than sponges fed by Nannochloropsis sp. and control (2.95 g vs 1.27 and 0.66 g, respectively; P<0.05), respectively. Sponges fed by Nannochloropsis sp. showed maximum RM accumulation (0.32 mg/1500 mg tissue), followed by sponges fed by with C. gracilis (0.19 mg/1500 mg tissue) and the control (0.16 mg/1500 g tissue). RM accumulation was not significantly different among treatment groups, suggesting the type of phytoplankton feed affects the growth of Xestospongia sp. To confirm the existence of sponge associated cyanobacteria (Ca. E. renieramycinifaciens), two renieramycin biosynthetic genes (renC and renJ) belonging to the endosymbiont were amplified. Quantification, purification and sequencing analysis of recombinant DNA revealed the existence of renC and renJ in sponge tissue, with similarities of 99.40% and 99.33% to other isolates in the gene bank suggesting the association of Ca. E. renieramycinifaciens with the sponge. It can conclude that C. gracilis promotes the growth of a blue sponge, while RM was produced by an associated cyanobacterium.