Tetracycline hydrochloride-stressed changes in phosphorus fractions during swine manure composting: Emphasize on phosphorus functional genes

Available information on the phosphorus (P) transformation under tetracycline hydrochloride (TCH)-stressed conditions: Emphasize on phosphorus functional genes, during the composting process has received less attention. Thus, this research explored the variation in P-fractions and P functional genes, as well as ascertained the potential microbial phylum carrying P functional genes during the TCH-amended composting. P-fractions was as the following order: Org-P (66.74–69.28%)﹥Ex-P (14.18–24.96%)﹥Ca-P (7.29–18.05%)﹥Al-P ≈ Fe-P ≈ O-P. During the composting process, Ex-P was converted into Ca-P, resulting in a 7.73–10.48% decrease in P-bioavailability. Low-concentration TCH (50 mg/kg) increased the abundance in gcd, pqqc, appA and phoA genes at the temperature- cooling and maturation phases. While TCH reduced the abundance in phosphorus functional genes affiliate to bacteria, but not to fungi. These conclusions can provide basic data for the directional research on the P-dissolving microbial inoculants.