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Becerril-Espinosa, A, Freel KC, Jensen PR, Soria-Mercado IE.  2013.  Marine Actinobacteria from the Gulf of California: diversity, abundance and secondary metabolite biosynthetic potential. Antonie Van Leeuwenhoek International Journal of General and Molecular Microbiology. 103:809-819.   10.1007/s10482-012-9863-3   AbstractWebsite

The Gulf of California is a coastal marine ecosystem characterized as having abundant biological resources and a high level of endemism. In this work we report the isolation and characterization of Actinobacteria from different sites in the western Gulf of California. We collected 126 sediment samples and isolated on average 3.1-38.3 Actinobacterial strains from each sample. Phylogenetic analysis of 136 strains identified them as members of the genera Actinomadura, Micromonospora, Nocardiopsis, Nonomuraea, Saccharomonospora, Salinispora, Streptomyces and Verrucosispora. These strains were grouped into 26-56 operational taxonomic units (OTUs) based on 16S rRNA gene sequence identities of 98-100 %. At 98 % sequence identity, three OTUs appear to represent new taxa while nine (35 %) have only been reported from marine environments. Sixty-three strains required seawater for growth. These fell into two OTUs at the 98 % identity level and include one that failed to produce aerial hyphae and was only distantly related (a parts per thousand currency sign95.5 % 16S identity) to any previously cultured Streptomyces sp. Phylogenetic analyses of ketosynthase domains associated with polyketide synthase genes revealed sequences that ranged from 55 to 99 % nucleotide identity to experimentally characterized biosynthetic pathways suggesting that some may be associated with the production of new secondary metabolites. These results indicate that marine sediments from the Gulf of California harbor diverse Actinobacterial taxa with the potential to produce new secondary metabolites.

Belofsky, GN, Jensen PR, Fenical W.  1999.  Sansalvamide: A new cytotoxic cyclic depsipeptide produced by a marine fungus of the genus Fusarium. Tetrahedron Letters. 40:2913-2916.   10.1016/s0040-4039(99)00393-7   AbstractWebsite

A new cyclic pentadepsipeptide, sansalvamide (1), has been isolated from organic extracts of the mycelium of a fungus of the genus Fusarium collected from the surface of the seagrass Halodule wrightii. The structure of 1 was determined through extensive analysis of 1D and 2D NMR data. Sansalvamide exhibited selective in vitro cytotoxicity toward COLO 205 colon and SK-MEL-2 melanoma cancer cell lines. (C) 1999 Elsevier Science Ltd. All rights reserved.

Belofsky, GN, Jensen PR, Renner MK, Fenical W.  1998.  New cytotoxic sesquiterpenoid nitrobenzoyl esters from a marine isolate of the fungus Aspergillus versicolor. Tetrahedron. 54:1715-1724.   10.1016/s0040-4020(97)10396-9   AbstractWebsite

Four new sesquiterpenoid nitrobenzoyl esters (1-4) have been isolated from organic extracts of the culture broth and mycelia of Aspergillus versicolor, a fungus isolated from the surface of the Caribbean green alga Penicillus capitatus. The structures of the four compounds were determined through extensive analysis of H-1 NMR, C-13 NMR, HMQC, and HMBC data. 9 alpha,14-Dihydroxy-6 beta-p-nitrobenzoylcinnamolide (1) displayed significant cytoxicity against HCT-116 human colon carcinoma cells in vitro and exhibited moderately selective cytotoxicity toward a panel of renal tumor cell lines. (C) 1998 Elsevier Science Ltd. Ali rights reserved.

Belofsky, GN, Anguera M, Jensen PR, Fenical W, Kock M.  2000.  Oxepinamides A-C and fumiquinazolines H-I: Bioactive metabolites from a marine isolate of a fungus of the genus Acremonium. Chemistry-a European Journal. 6:1355-1360.   10.1002/(sici)1521-3765(20000417)6:8<1355::aid-chem1355>;2-j   AbstractWebsite

Three new oxepin-containing natural products (1-3) and two new fumiquinazoline metabolites (4-5) have been isolated from organic extracts of the culture broth and mycelia of an Acremonium sp., a fungus obtained from the surface of the Caribbean tunicate Ectcinascidia turbinata. The structures of the five compounds were determined through extensive analysis of 1D- and 2D-NMR data, and mass spectrometry. Compound 1 exhibited good anti-inflammatory activity in a topical RTX-induced mouse ear edema assay. Compounds 4 and 5 exhibited weak antifungal activity toward Candida albicans in a broth microdilution assay.

Boehler, M, Jensen PR, Fenical W.  1997.  Bahamamide, an unusual cyclic bis-amide produced by an undescribed marine bacterium. Natural Product Letters. 10:75-78.   10.1080/10575639708043699   AbstractWebsite

An unusual 12-membered ring bis-amide, bahamamide (1), has been isolated from the culture broth of an undescribed gram-negative marine bacterial strain, CNE-852, isolated from a sediment sample collected in the Bahama Islands. The structure of bahamamide was assigned by interpretation of combined spectral data.

Boonlarppradab, C, Kauffman CA, Jensen PR, Fenical W.  2008.  Marineosins A and B, Cytotoxic Spiroaminals from a Marine-Derived Actinomycete. Organic Letters. 10:5505-5508.   10.1021/ol8020644   AbstractWebsite

Two novel spiroaminals, marineosins A and B (1, 2), containing two pyrrole functionalities, were isolated from cultures of a marine sediment-derived actinomycete related to the genus Streptomyces. The marineosins, which appear to be derived from unknown modifications of prodigiosin-like pigment pathways, showed significant inhibition of human colon carcinoma (HCT-116) in an in vitro assay (IC(50) = 0.5 mu M for marineosin A) and selective activities in diverse cancer cell types.

Bruns, H, Crusemann M, Letzel AC, Alanjary M, McInerney JO, Jensen PR, Schulz S, Moore BS, Ziemert N.  2018.  Function-related replacement of bacterial siderophore pathways. Isme Journal. 12:320-329.   10.1038/ismej.2017.137   AbstractWebsite

Bacterial genomes are rife with orphan biosynthetic gene clusters (BGCs) associated with secondary metabolism of unrealized natural product molecules. Often up to a tenth of the genome is predicted to code for the biosynthesis of diverse metabolites with mostly unknown structures and functions. This phenomenal diversity of BGCs coupled with their high rates of horizontal transfer raise questions about whether they are really active and beneficial, whether they are neutral and confer no advantage, or whether they are carried in genomes because they are parasitic or addictive. We previously reported that Salinispora bacteria broadly use the desferrioxamine family of siderophores for iron acquisition. Herein we describe a new and unrelated group of peptidic siderophores called salinichelins from a restricted number of Salinispora strains in which the desferrioxamine biosynthesis genes have been lost. We have reconstructed the evolutionary history of these two different siderophore families and show that the acquisition and retention of the new salinichelin siderophores co- occurs with the loss of the more ancient desferrioxamine pathway. This identical event occurred at least three times independently during the evolution of the genus. We surmise that certain BGCs may be extraneous because of their functional redundancy and demonstrate that the relative evolutionary pace of natural pathway replacement shows high selective pressure against retention of functionally superfluous gene clusters.

Bucarey, SA, Penn K, Paul L, Fenical W, Jensen PR.  2012.  Genetic Complementation of the Obligate Marine Actinobacterium Salinispora tropica with the Large Mechanosensitive Channel Gene mscL Rescues Cells from Osmotic Downshock. Applied and Environmental Microbiology. 78:4175-4182.   10.1128/aem.00577-12   AbstractWebsite

Marine actinomycetes in the genus Salinispora fail to grow when seawater is replaced with deionized (DI) water in complex growth media. While bioinformatic analyses have led to the identification of a number of candidate marine adaptation genes, there is currently no experimental evidence to support the genetic basis for the osmotic requirements associated with this taxon. One hypothesis is that the lineage-specific loss of mscL is responsible for the failure of strains to grow in media prepared with DI water. The mscL gene encodes a conserved transmembrane protein that reduces turgor pressure under conditions of acute osmotic downshock. In the present study, the mscL gene from a Micromonospora strain capable of growth on media prepared with DI water was transformed into S. tropica strain CNB-440. The single-copy, chromosomal genetic complementation yielded a recombinant Salinispora mscL(+) strain that demonstrated an increased capacity to survive osmotic downshock. The enhanced survival of the S. tropica transformant provides experimental evidence that the loss of mscL is associated with the failure of Salinispora spp. to grow in low-osmotic-strength media.

Buchanan, GO, Williams PG, Feling RH, Kauffman CA, Jensen PR, Fenical W.  2005.  Sporolides A and B: Structurally unprecedented halogenated macrolides from the marine actinomycete Salinispora tropica. Organic Letters. 7:2731-2734.   10.1021/ol050901i   AbstractWebsite

Analysis of the fermentation broth of a strain of the marine actinomycete Salinispora tropica has led to the isolation of two unprecedented macrolides, sporolides A (1) and B (2). The structures and absolute stereochemistries of both metabolites were elucidated using a combination of NMR spectroscopy and X-ray crystallography.

Bugni, TS, Woolery M, Kauffman CA, Jensen PR, Fenical W.  2006.  Bohemamines from a marine-derived Streptomyces sp. Journal of Natural Products. 69:1626-1628.   10.1021/np0602721   AbstractWebsite

Investigation of the culture extracts of a marine-derived Streptomyces sp. led to the isolation of three new bohemamine-type pyrrolizidine alkaloids, bohemamine B (1), bohemamine C (2), and 5-chlorobohemamine C (3). The structures were elucidated using NMR methods, and the relative stereochemistry was determined using double-pulsed-field-gradient spin echo (DPFGSE) NOE studies.

Busch, J, Agarwal V, Schorn M, Machado H, Moore BS, Rouse GW, Gram L, Jensen PR.  2019.  Diversity and distribution of the bmp gene cluster and its Polybrominated products in the genus Pseudoalteromonas. Environmental Microbiology. 21:1575-1585.   10.1111/1462-2920.14532   AbstractWebsite

The production of pentabromopseudilin and related brominated compounds by Pseudoalteromonas spp. has recently been linked to the bmp biosynthetic gene cluster. This study explored the distribution and evolutionary history of this gene cluster in the genus Pseudoalteromonas. A phylogeny of the genus revealed numerous clades that do not contain type strains, suggesting considerable species level diversity has yet to be described. Comparative genomics revealed four distinct versions of the gene cluster distributed among 19 of the 101 Pseudoalteromonas genomes examined. These were largely localized to the least inclusive clades containing the Pseudoalteromonas luteoviolacea and Pseudoalteromonas phenolica type strains and show clear evidence of gene and gene cluster loss in certain lineages. Bmp gene phylogeny is largely congruent with the Pseudoalteromonas species phylogeny, suggesting vertical inheritance within the genus. However, the gene cluster is found in three different genomic environments suggesting either chromosomal rearrangement or multiple acquisition events. Bmp conservation within certain lineages suggests the encoded products are highly relevant to the ecology of these bacteria.