Comparative metabolomics analysis of Elodea nuttallii and Cladophora sp. in aquaculture systems

Elodea nuttallii is widely planted in shrimp and crab aquaculture ponds. However, the simultaneous growth of Cladophora causes a number of problems, such as niche occupation, nutrient depletion, and disruption of the pond ecosystem balance. To date, how to restrict the growth of Cladophora without affecting E. nuttallii remains explorable. In this study, we conducted a comparative study on the metabolomics of E. nuttallii and Cladophora. A total of 756 metabolites were identified, 377 of which were classified as annotated differential metabolites between E. nuttallii and Cladophora. 2-Methyl-5-(8-pentadecenyl)-1,3-benzenediol and 1-(2-hydroxyethyl)-2,2,6-trimethyl-1,4-cyclohexanediol were the most abundant metabolites in E. nuttallii and Cladophora, respectively. Some of metabolites with medicinal functions, such as 2-deacetoxytaxinine B, 3,19-dihydroxyurs-12-ene-23,28-dioic acid, crocin 3, (10E,15Z)-9,12,13-trihydroxyoctadeca-10,15-dienoic acid, and 9,12,15-octadecatrien-1-ol were detected in high concentrations in E. nuttallii and Cladophora. Compared with E. nuttallii, six specific KEGG functional pathway metabolites (KFPMs) were detected in Cladophora. Based on these six specific KFPMs, 24 potential target enzymes and coenzymes were identified for selectively inhibiting the growth of Cladophora. The results of this study provide fundamental information for the development and utilization of E. nuttallii and Cladophora, in addition to pave the way for selectively inhibiting the growth of Cladophora.