Dietary nutrient status modulates nutrient regeneration in the marine ciliate Euplotes vannus  

作　　者：Xuejia He Zhang Lu Weijie Chen Zhen Shi Linjian Ou Ren Hu 

机构地区：[1]College of Life Science and Technology and Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes,Jinan University,Guangzhou 510000,China [2]South China Sea Institute of Oceanology,Chinese Academy of Science,Guangzhou 510000,China [3]Institute of Hydrobiology,Jinan University,Guangzhou 510000,China

出　　处：《Acta Oceanologica Sinica》2023年第11期81-89,共9页海洋学报（英文版）

基　　金：The Natural Science Foundation of Guangdong under contract No.2021A1515011384。

摘　　要：Marine ciliates play important roles not only in linking the microbial loop to the classic pelagic and benthic food chains but also in regenerating nutrients,yet how dietary nutrient imbalance impacts their nutrient regeneration has not been thoroughly addressed.The growth and physiological responses of Euplotes vannus to low dietary nitrogen(LN)and low dietary phosphorus(LP)conditions were studied,with the bacterium Pseudomonas putida as prey.Feeding on LN prey reduced the growth rate of E.vannus.Dietary nutrient limitation changed the types and quantities of nutrient recycling.Feeding on LP prey enhanced dissolved organic carbon excretion but reduced orthophosphate excretion,whereas feeding on LN prey generally resulted in decreases in the excretion rate in all N forms(ammonium,urea,and nitrate).In addition,the proportion of ammonium in regenerated N increased significantly under the LN condition.These findings indicate that a nutrient-imbalanced diet triggers E.vannus to retain limited macronutrients and promotes the recycling of excessive macronutrients,which may potentially form positive and negative feedback to ambient N and P limitations,respectively.

关 键 词：PROTIST EXCRETION BACTERIA microbial loop nutrient regeneration 

分 类 号：Q958.8[生物学—动物学]