Conspecific cues that induce spore settlement in the biofouling and green tide-forming alga Ulva tepida provide a potential aggregation mechanism. (November 2019)

• Record Type: Journal Article
• Authors: Agusman, ; Qi, Yuxuan; Wu, Zhiwen; He, Jian; Rittschof, Daniel; Su, Pei; Ke, Caihuan; Feng, Danqing
• Is Part Of: International biodeterioration & biodegradation. Volume 145(2019)
• Publication Date: 2019-11
• Subjects: Aggregation -- Di-n-butyl phthalate -- Fatty acids -- Settlement -- Spore -- Ulva; Biodegradation -- Periodicals; Bioremediation -- Periodicals; Biodegradation -- Periodicals; Biodégradation -- Périodiques; Biorestauration -- Périodiques; Electronic journals; 620.11223
• DOI: 10.1016/j.ibiod.2019.104807
• Languages: English
• ISSNs: 0964-8305

Abstract

Abstract: Ulva, an important biofouling and green tide-forming alga, forms aggregations that have adverse economic and ecological impacts. However, little is known regarding the aggregation mechanism of Ulva . Knowledge of Ulva aggregation provides clues for controlling this alga in marine biofouling and green tides. We hypothesized Ulva contains conspecific settlement cue(s). Hexane and dichloromethane extracts of U. tepida fronds were found to induce the settlement of conspecific spores. From these extracts, two bioactive compounds that induce spore settlement in U. tepida were isolated: C16:4 at 5 μg mL −1 and di-n-butyl phthalate at 0.1–10 μg mL −1 . Fatty acids with different carbon chains (C16 –C18 ) and degrees of saturation, C16:1 and C18:2, previously reported to be present in U. tepida fronds, showed significant inducing activity for spore settlement. C16:1, C16:4, C18:2, and di-n-butyl phthalate all triggered dense settlements of U. tepida spores. The results support our hypothesis and provide insight into possible aggregation mechanisms for Ulva. Graphical abstract: Image 1 Highlights: Extracts of Ulva tepida fronds induced conspecific spore settlement. C16:4 and di-n-butyl phthalate were isolated from the active extracts of U. tepida. C16:4 and di-n-butyl phthalate induced spore settlement of U. tepida. Compounds C16:1 and C18:2 previously found in Ulva, induced spore settlement. An aggregation mechanism for green macroalgae based on these findings was suggested.