Response of amino acid metabolism to decreased temperatures in anammox consortia: Strong, efficient and flexible

Although amino acid (AA) metabolism is basis of bacterial activities, unique characteristics of its response to decreased temperatures are not fully understood. Achieving nitrogen removal rate of 130-150 mg N/ (L center dot d), metabolic differences of anammox consortia between 35 ?C and four decreased temperatures (15-30 ?C) were revealed respectively. 0-11.4-fold abundance variation of marker metabolites evidenced change of key metabolism (metabolism of AA, lipid and energy production) at decreased temperatures. However, AA metabolism varied more obviously than others, implying stronger response and higher functional potential. Efficiently, network topology confirmed more cellular processes represented by growth metabolism and biofilm formation were influenced by AA metabolism. Flexibly, down-regulated biosynthesis of unfavorable AAs for psychrophilic enzyme differed from enhanced biosynthesis of costly AAs, which only matched partial decreased temperatures to save energy. This work elucidates advantages of AA metabolism over others, exogenous amino acids could significantly promote activity of anammox bacteria at decreased temperatures.

Automated summary

This study reveals that amino acid metabolism in anammox consortia shows a stronger response and higher functional potential to decreased temperatures compared to other metabolisms. Exogenous amino acids significantly promote the activity of anammox bacteria at decreased temperatures.