Newly Isolated Priestia megaterium LAMA1607 for Enhanced Biological Phosphorus Removal: A Genomic and Functional Characterization
Authors: do Nascimento Maria Eduarda Castro , Montagna Letícia Coelho , Manfroi Laíza , Laaf Yan de Oliveira , Maiochi Luigi Ferrazza , da Silva Marcus Adonai Castro , Lima André Oliveira de Souza 
Published: December 2024

Background: Enhanced biological phosphorus removal (EBPR) systems utilize phosphorus-accumulating organisms (PAOs) to remove phosphorus from wastewater since excessive phosphorus in water bodies can lead to eutrophication. This study aimed to characterize a newly isolated PAO strain for its potential application in EBPR systems and to screen for additional biotechnological potential. Here, sequencing allowed for genomic analysis, identifying the genes and molecules involved, and exploring other potentials. Additionally, assessing the phosphorus removal performance of the PAO strain in common effluents is essential for its potential application in large-scale systems. Methods: A strain designated LAMA1607 was isolated from activated sludge and selected based on its ability to remove total phosphate from the culture medium. Genomic DNA was extracted and sequenced using the Illumina NovaSeq 6000 platform. Assembly and annotation were performed using CLC Genomics Workbench v.24.0 (QIAGEN®) and Rapid Annotation using Subsystem Technology (RAST)/Pathosystems Resource Integration Center (PATRIC) server tools. Functional prediction of uncharacterized proteins was completed using PHYRE2, and secondary metabolite identification was performed using antiSMASH. Further, additional enzymes with biotechnological applications were manually curated through the Association of Manufacturers and Formulators of Enzyme Products (AMFEP) list. The phosphorus removal capability was assessed in domestic and fishery effluents under enriched and unenriched conditions, where pH, microbial growth, and total phosphorus were monitored over 48 hours. Results: The genome sequence comprised 5,234,874 bp divided into 20 contigs, 5540 coding sequences, and a GC content of 38.0%; subsequently, LAMA1607 was identified through Basic Local Alignment Search Tool (BLAST) analysis as Priestia megaterium. Genome annotation revealed 27 genes potentially involved in phosphorus removal, including eight encoding transport proteins, three regulatory proteins, twelve enzymes, and others related to phosphorus incorporation and polyphosphate (polyP) granule formation. Moreover, other enzymes of interest were identified, such as hydrolases, lipases, proteases, and amylases, alongside secondary metabolite gene clusters, such as Non-ribosomal peptide synthetase-independent siderophore. P. megaterium LAMA1607 effectively removed up to 70% of the total phosphorus from the fishery effluent. Conclusions: Genomic analysis suggests that P. megaterium LAMA1607 possesses the mechanistic functions for phosphorus uptake, transport, and storage while also identifying additional biotechnologically relevant enzymes and capabilities. Meanwhile, tests on the effluent demonstrated significant phosphorus removal. These findings support the biotechnological potential and application of P. megaterium LAMA1607 in EBPR systems.