Potential for phosphonoacetate utilization by marine bacteria in temperate coastal waters.
Phosphonates are organic compounds that contain a C-P bond and are a poorly characterized component of the marine phosphorus cycle. They may represent a potential source of bioavailable phosphorus, particularly in oligotrophic conditions. This study has investigated the distribution of the phnA gene which encodes phosphonoacetate hydrolase, the enzyme that mineralizes phosphonoacetate. Using newly designed degenerate primers targeting the phnA gene we analysed the potential for phosphonoacetate utilization in DNA and cDNA libraries constructed from a phytoplankton bloom in the Western English Channel during July 2006. Total RNA was isolated and reverse transcribed and phosphonoacetate hydrolase (phnA) transcripts were PCR amplified from the cDNA with the degenerate primers, cloned and sequenced. Phylogenetic analysis demonstrated considerable diversity with 14 sequence types yielding five unique phnA protein groups. We also identified 28 phnA homologues in a 454-pyrosequencing metagenomic and metatranscriptomic study from a coastal marine mesocosm, indicating that > 3% of marine bacteria in this study contained phnA. phnA homologues were also present in a metagenomic fosmid library from this experiment. Finally, cultures of four isolates of potential coral pathogens belonging to the Vibrionaceae contained the phnA gene. In the laboratory, these isolates were able to grow with phosphonoacetate as sole P and C source. The fact that the capacity to utilize phosphonoacetate was evident in each of the three coastal environments suggests the potential for widespread utilization of this bioavailable P source.
Gilbert
Jack A
JA
Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL1 3DH, UK. jagi@pml.ac.uk
Thomas
Simon
S
Cooley
Natalie A
NA
Kulakova
Anna
A
Field
Dawn
D
Booth
Tim
T
McGrath
John W
JW
Quinn
John P
JP
Joint
Ian
I
D000469:Alkaline Phosphatase; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D010746:Phosphonoacetic Acid / Q000378:metabolism*; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics; D010802:Phylogeny; D012623:Seawater / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D000469:Alkaline Phosphatase; D010744:Phosphoric Monoester Hydrolases; C097254:phosphonoacetate hydrolase; D010746:Phosphonoacetic Acid