Culture of a blue marine sponge, Xestospongia sp., in semi-circulate close system stressed with calcium and magnesium concentration

The goal of this research was to stimulate renieramycin M (RM) production and the growth performance of a blue marine sponge, Xestospongia sp., in response to different concentration of calcium/magnesium (Ca/Mg).The sponge’s pieceswere exposed to various concentrations of Ca/Mg in natural seawater at salinity 35ppt. Results showed that a Ca/Mg concentration at 430/1,230 ppm (T3)stimulated in maximum RM accumulation in sponge tissue (1.74mg/1,500mg tissue), while 410/1,170 (T1),420/1,200 (T2), and a pure seawater control were 0.33, 0.92, and 0.32 mg/1,500mg tissue, respectively. The mean values calculation revealed that there was statistical difference of RM accumulation between T3and control at 95% confidence interval.Sponges supplemented with Ca/Mg at a level of 410/1,170 showed the most growth (3.77g), while 420/1,200, 430/1,230, and the control were 2.36, 2.44, and 1.70g, respectively. The analysis revealed statistically significant growth differentials between T1 and control at the 95% confidence interval. The resultssuggested the Ca/Mg levels are stressor activate secondary metabolites synthesisand promote the growth of a blue marine sponge, Xestospongia sp.