TY - JOUR
T1 - Sustained high nutrient supply as an allelopathic trigger between Periphytic biofilm and Microcystis aeruginosa
AU - Wu, Yonghong
AU - Tang, Jun
AU - Liu, Junzhuo
AU - Graham, Bruce
AU - Kerr, Philip G
AU - Chen, Hong
N1 - Includes bibliographical references.
PY - 2017/9/5
Y1 - 2017/9/5
N2 - Allelopathy among aquatic organisms, especially microorganisms, has received growing attention in recent years for its role in shaping interactions with bloom-forming algae. Many studies have shown that allelopathy occurs and increases under nutrient limiting conditons. However, to date there is no reported direct evidence to indicate allelopathy occurs under the condition of constant high nutrient supply. Here we report the allelopathic action of periphytic biofilm on bloom-forming cyanobacteria (Microcystis aeruginosa), which was triggered by the stress of high nutrient conditions, and continues while nutrients are sustained at high levels (trophic state index at 159 and 171). The experimental evidence indicates that the electron transport from photosystem II (PS II) to photosystem I (PS I) in M. aeruginosa is interrupted by the identified allelochemicals, (9Z)-Octadec-9-enoic acid and (9Z)-Hexadec-9-enoic acid, leading to the failure of photosynthesis and the subsequent death of M. aeruginosa. Our findings indicate that the nutrient stress of constant high nutrient supply may be a newly recognized trigger causing allelopathy between microbial competitors, and therefore opening a new direction for the better management of ecological processes in cyanobacteria-dominated and hyper-eutrophic waters.
AB - Allelopathy among aquatic organisms, especially microorganisms, has received growing attention in recent years for its role in shaping interactions with bloom-forming algae. Many studies have shown that allelopathy occurs and increases under nutrient limiting conditons. However, to date there is no reported direct evidence to indicate allelopathy occurs under the condition of constant high nutrient supply. Here we report the allelopathic action of periphytic biofilm on bloom-forming cyanobacteria (Microcystis aeruginosa), which was triggered by the stress of high nutrient conditions, and continues while nutrients are sustained at high levels (trophic state index at 159 and 171). The experimental evidence indicates that the electron transport from photosystem II (PS II) to photosystem I (PS I) in M. aeruginosa is interrupted by the identified allelochemicals, (9Z)-Octadec-9-enoic acid and (9Z)-Hexadec-9-enoic acid, leading to the failure of photosynthesis and the subsequent death of M. aeruginosa. Our findings indicate that the nutrient stress of constant high nutrient supply may be a newly recognized trigger causing allelopathy between microbial competitors, and therefore opening a new direction for the better management of ecological processes in cyanobacteria-dominated and hyper-eutrophic waters.
U2 - 10.1021/acs.est.7b01027
DO - 10.1021/acs.est.7b01027
M3 - Article
C2 - 28738143
VL - 51
SP - 9614
EP - 9623
JO - Environmental Science & Technology
JF - Environmental Science & Technology
SN - 0013-936X
ER -