Biosynthetic potential of phylogenetically unique endophytic actinomycetes from tropical plants.
The culturable diversity of endophytic actinomycetes associated with tropical, native plants is essentially unexplored. In this study, 123 endophytic actinomycetes were isolated from tropical plants collected from several locations in Papua New Guinea and Mborokua Island, Solomon Islands. Isolates were found to be prevalent in roots but uncommon in leaves. Initially, isolates were dereplicated to the strain level by ribotyping. Subsequent characterization of 105 unique strains by 16S rRNA gene sequence analysis revealed that 17 different genera were represented, and rare genera, such as Sphaerisporangium and Planotetraspora, which have never been previously reported to be endophytic, were quite prevalent. Phylogenetic analyses grouped many of the strains into clades distinct from known genera within Thermomonosporaceae and Micromonosporaceae, indicating that they may be unique genera. Bioactivity testing and liquid chromatography-mass spectrometry (LC-MS) profiling of crude fermentation extracts were performed on 91 strains. About 60% of the extracts exhibited bioactivity or displayed LC-MS profiles with spectra indicative of secondary metabolites. The biosynthetic potential of 29 nonproductive strains was further investigated by the detection of putative polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) genes. Despite their lack of detectable secondary metabolite production in fermentation, most were positive for type I (66%) and type II (79%) PKS genes, and all were positive for NRPS genes. These results suggest that tropical plants from New Guinea and the adjacent archipelago are hosts to unique endophytic actinomycetes that possess significant biosynthetic potential.
Janso
Jeffrey E
JE
Pfizer, 445 Eastern Point Road, Groton, CT 06340, USA. Jeffrey.Janso@Pfizer.com
Carter
Guy T
GT
D039903:Actinobacteria / Q000145:classification / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification; D001709:Biotechnology; D020459:Genes, rRNA; D008542:Melanesia; D008848:Micromonosporaceae / Q000145:classification / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification; D008969:Molecular Sequence Data; D010219:Papua New Guinea; D010453:Peptide Synthases / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D010944:Plants / Q000382:microbiology*; D048630:Polyketide Synthases / Q000235:genetics / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D021521:Ribotyping; D017422:Sequence Analysis, DNA; D014329:Tropical Climate
D012336:RNA, Ribosomal, 16S; D048630:Polyketide Synthases; D010453:Peptide Synthases; C104385:non-ribosomal peptide synthase
Appl Environ Microbiol. 2003 Sep;69(9):5603-8
12957950
J Microbiol Biotechnol. 2008 Nov;18(11):1741-6
19047815
Environ Microbiol. 2008 Oct;10(10):2684-91
18631363
Antonie Van Leeuwenhoek. 2000 Aug;78(2):171-85
11204769
J Ind Microbiol Biotechnol. 2003 Aug;30(8):472-9
12687492
Microbiol Mol Biol Rev. 2002 Jun;66(2):223-49
12040125
Int J Syst Bacteriol. 1994 Apr;44(2):193-203
8186084
Appl Environ Microbiol. 1994 Jun;60(6):2113-9
7518219
Int J Syst Evol Microbiol. 2008 Jul;58(Pt 7):1644-52
18599710
Molecules. 2008 Jun 20;13(6):1406-26
18596666
Microb Ecol. 2005 Jan;49(1):10-24
15614464
Appl Environ Microbiol. 1992 Aug;58(8):2691-3
16348757
Gene. 2006 Aug 1;377:109-18
16806745
Curr Microbiol. 2009 Jan;58(1):87-94
18953605
J Ind Microbiol Biotechnol. 2006 Jul;33(7):507-13
16418869
Antimicrob Agents Chemother. 2006 Jun;50(6):2167-77
16723579
Int J Syst Evol Microbiol. 2007 Aug;57(Pt 8):1735-1739
17684247
Microb Ecol. 2009 May;57(4):749-56
18853084
Int J Syst Evol Microbiol. 2001 Mar;51(Pt 2):373-383
11321082
Comput Appl Biosci. 1994 Sep;10(5):569-70
7828077
Proc Natl Acad Sci U S A. 2007 Jun 19;104(25):10376-81
17563368
Microb Ecol. 2007 Jan;53(1):12-9
16944339
Appl Environ Microbiol. 2005 Jan;71(1):460-6
15640222
Cancer Res. 1983 Jun;43(6):2819-30
6221794
Int J Syst Evol Microbiol. 2009 Aug;59(Pt 8):1867-74
19567582
J Gen Appl Microbiol. 2003 Jun;49(3):141-54
12949697
FEMS Microbiol Lett. 2005 Jun 15;247(2):147-52
15935565
FEMS Microbiol Lett. 1999 Nov 1;180(1):1-6
10547437
Nucleic Acids Res. 1997 Dec 15;25(24):4876-82
9396791
J Mol Biol. 1990 Oct 5;215(3):403-10
2231712