Isolation and characterization of a recombinant class C acid phosphatase from Sphingobium sp. RSMS strain

Biotechnol Rep (Amst). 2022 Feb 8:33:e00709. doi: 10.1016/j.btre.2022.e00709. eCollection 2022 Mar.

Abstract

Tributyl phosphate (TBP) is extensively used in nuclear industry and is a major environmental pollutant. The mechanism for TBP degradation is not identified in any TBP-degrading bacteria. Here, we report identification of an acid phosphatase from Sphingobium sp. RSMS (Aps) that exhibits high specific activity towards monobutyl phosphate (MBP) and could be a terminal component of the TBP degradation process. A genomic DNA library of the bacteria was screened using a histochemical method which yielded 35 phosphatase clones. Among these, the clone that showed the highest MBP degradation was studied further. DNA sequence analysis showed that the genomic insert encodes a protein (Aps) which belongs to class C acid phosphatase. The recombinant Aps was found to be a dimer and hydrolysed MBP with a Kcat 68.1 ± 5.46 s- 1 and Km 2.5 mM ± 0.50. The protein was found to be nonspecific for phosphatase activity and hydrolyzed disparate organophosphates.

Keywords: Class C acid phosphatase; Monobutyl phosphate; Sphingobium sp. RSMS strain.