title: Optimizations of particle size and pulp density for solubilization of rock phosphate by a microbial consortium from activated sludge.
abstract: Microbial solubilization of rock phosphate is getting more and more attention recently. However, the microorganisms used in previous studies were mostly single or known species, and seldom studies focused on the mixed microorganisms or microbial consortia from natural environments. In this study, a microbial consortium taken from activated sludge was used to solubilize two different mid-low-grade rock phosphates. The results showed that the microbial consortium could effectively solubilize the rock phosphates in National Botanical Research Institute's phosphate growth medium and released soluble phosphorus in the broth. The biomass increased gradually, whereas the pH decreased sharply during the solubilizing process. The maximum phosphorus solubilization was recorded at particle size of 150 µm. Higher or lower than this optimal particle size, the phosphorus solubilization decreased. The phosphorus solubilization gradually decreased with a larger pulp density from 1 to 5%, and the optimal pulp density was 1%. The solubilization level of microbial consortium varied with different rock phosphates. The results revealed that the soluble phosphorus released from high-silicon ore was higher than which from high-magnesium ore. A strong positive correlation between biomass and phosphorus solubilization in the broth was observed from regression analysis results, and the phosphorus solubilization also had a significant negative correlation with pH in the broth.
authors.affiliation: a Key Laboratory for Green Chemical Process of Ministry of Education , Wuhan Institute of Technology , Wuhan , China.|b Hubei Novel Reactor and Green Chemical Technology Key Laboratory , Wuhan Institute of Technology , Wuhan , China.
authors.forename: Chunqiao
authors.initials: C
authors.lastname: Xiao
authors.affiliation: a Key Laboratory for Green Chemical Process of Ministry of Education , Wuhan Institute of Technology , Wuhan , China.|b Hubei Novel Reactor and Green Chemical Technology Key Laboratory , Wuhan Institute of Technology , Wuhan , China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Wu
authors.affiliation: a Key Laboratory for Green Chemical Process of Ministry of Education , Wuhan Institute of Technology , Wuhan , China.|b Hubei Novel Reactor and Green Chemical Technology Key Laboratory , Wuhan Institute of Technology , Wuhan , China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Liu
authors.affiliation: a Key Laboratory for Green Chemical Process of Ministry of Education , Wuhan Institute of Technology , Wuhan , China.|b Hubei Novel Reactor and Green Chemical Technology Key Laboratory , Wuhan Institute of Technology , Wuhan , China.
authors.forename: Guang
authors.initials: G
authors.lastname: Xu
authors.affiliation: a Key Laboratory for Green Chemical Process of Ministry of Education , Wuhan Institute of Technology , Wuhan , China.|b Hubei Novel Reactor and Green Chemical Technology Key Laboratory , Wuhan Institute of Technology , Wuhan , China.
authors.forename: Ruan
authors.initials: R
authors.lastname: Chi
mesh_terms: D019015:Geologic Sediments / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D059013:Microbial Consortia; D010316:Particle Size; D010710:Phosphates / Q000737:chemistry*; D012722:Sewage / Q000032:analysis* / Q000382:microbiology*; D012995:Solubility
chemical_list: D010710:Phosphates; D012722:Sewage
keywords: Activated sludge; microbial consortium; particle size; pulp density; rock phosphate; solubilization