Enhancement of photosynthesis in Synechococcus bacillaris by sponge-derived Ageladine A.

Ulf Bickmeyer,Silke Thoms,Liliane Petety Mukagatare,Franz Josef Sartoris,Romaston Silalahi,Florian Koch,Frank Melzner

doi:10.1371/journal.pone.0213771

Ulf Bickmeyer, Silke Thoms + Show 5 more

Open Access

https://doi.org/10.1371/journal.pone.0213771

Copy DOI

Abstract

This study is a proof of concept that the sponge derived pyrrole-imidazole alkaloid Ageladine A acts as an additional light harvesting molecule for photosynthesis of symbionts of marine sponges. The absorbance of Ageladine A is in the UV range and fluoresces blue, matching the blue absorbance of chlorophyll a. A joint modeling and experimental approach demonstrates that Ageladine A increases photosynthetic O2 production of Synechococcus bacillaris WH5701 (CCMP1333), when the cells are exposed to UV light, which is marginally used for photosynthesis. Due to the presence of Ageladine A, production of O2 increased 2.54 and 3.1-fold, in the experiments and the model, respectively.

Highlights

Marine sponges harbor many symbionts, such as the cyanobacterium Synechococcus, which constitute a large amount of the sponge’s dry weight [1,2]
Fi and Fs represent the integral of the emitted fluorescence spectra of the probe and standards, whereas fi und fs are factors of the absorption spectra. fx is the fraction of the light impinging on the sample that is absorbed while ni and ns represent refraction indices of the solvent [26]
Cultures were exposed to UV light (370-380nm) and oxygen production, as a proxy for photosynthesis, was assessed with and without the addition of Ageladine A (30 μmolL-1). 90 minutes of exposure to UV light resulted in a highly significant (p

Summary

Introduction

Marine sponges harbor many symbionts, such as the cyanobacterium Synechococcus, which constitute a large amount of the sponge’s dry weight [1,2]. The widely distributed sponges of the genus Agelas (Fig 1a) [6] produce the fluorescing pyrrole imidazole alkaloid Ageladine A. This compound was first detected and described during the search for an antiangiogenic matrixmetalloproteinases inhibitor [7] and later chemically synthetized [8,9,10,11]. With decreasing pH, Ageladine A is protonated twice, and trapped in acidic cellular compartments, where it fluoresces blue when exposed to UV light [12]. These include lysosomes, endosomes and the thylakoid lumen found in photoautotrophic symbionts, like cyanobacteria [14].

Methods

Results

Conclusion