Modeling of <i>Anabaena flos-aquae</i> growth kinetics of light intensity and temperature within different levels of phosphorus concentrations

Abstract

Anabaena flos-aquae is one of the common harmful cyanobacteria species. However,its growth kinetics co-impacted by phosphate concentration,light intensity and temperature have rarely been reported. In this paper,eight PO3-4-P concentration gradients( 0,0. 1,0. 2,0. 5,0. 75,1. 0,2. 5 and 5. 0 μmol / L),four water temperatures( 15,20,25 and 30℃) and four light intensities( 1000,2000,3000 and 5000 lx) were selected to carry out single factor batch experiments. A maximum specific growth rate( μmax) was used to indicate algae specific growth rate under optimal growth condition. Half-saturation constant( KS)could be applied to describe affinity of algae to nutrients. Regression results from Monod model showed that Anabaena flos-aquae reached μmaxat 20℃ and 3000 lx. The μmaxand KSwere 0. 447 d-1and 0. 081 μmol P / L,respectively. Regression results based on Lehman and Steele Model that examines the relationship between specific growth rate and continuous changing of temperature as well as light intensity,demonstrated that the optimum light intensity( Ik) and temperature( Topt) were 2650. 93 ± 88. 19 lx and21. 22 ± 0. 98℃,respectively. Besides,the kinetic parameters μmax,KS,and Toptfrom Lehman Model were 0. 421 ± 0. 011 d-1,0. 055 ± 0. 009 μmol P / L and 21. 22 ± 0. 98℃,respectively. In the Steele model,μmax,KSand Ikwere 0. 461 ± 0. 010 d-1,0. 051 ± 0. 009 μmol P / L and 2650. 93 ± 88. 19 lx,respectively.