Salinispora arenicola

About: Salinispora arenicola is a research topic. Over the lifetime, 66 publications have been published within this topic receiving 4122 citations.

Phylogenetic diversity of Gram -positive bacteria and their secondary metabolite genes

Abstract: To assess the bacterial diversity of marine sediments, a culture-dependent approach was employed to assess the diversity of Gram-positive bacteria in marine sediments collected around the islands of Palau. The survey of the total, aerobic Gram-positive bacterial diversity present in tropical marine sediments resulted in the isolation of a diverse assemblage of Gram-positive isolates. Of the 78 operational taxonomic units cultured (OTUs based on ≥ 98% 16S rRNA gene sequence identity), 52 were determined to be members of the order Actinomycetales and 26 were determined to be members of the order Bacillales. Bacterial genome sequencing has provided opportunities to assess the secondary metabolite biosynthetic potential of individual strains. By elucidating entire biosynthetic pathways in the context of all other genes and pathways present, it is also possible to address questions related to the evolution of gene clusters or individual genes within a cluster. The complete genome sequence of Salinispora arenicola strain CNS-205, an actinomycete isolated during the research expedition to Palau, provided an opportunity to investigate the evolution of type I modular polyketide synthase (PKS) gene clusters. While a tremendous amount can be learned from analyzing the entire genetic blueprint of a microorganism, additional natural product discovery approaches are necessary to gain insight into the biosynthetic potential of unsequenced organisms prior to fermentation, extraction and chemical analyses. A PCR based approach has been used successfully to suggest which representative isolates from the 52 Actinomycetales OTUs harbor type I PKS, enediyne PKS and nonribosomal peptide synthetase (NRPS) pathways. Over half of the cultured Actinomycetales OTUs were found to possess genes associated with at least one PKS or NRPS biosynthetic pathway and although some of these actinomycetes represent families well known to produce secondary metabolites, the results suggest that novel secondary metabolites can be isolated from both filamentous and unicellular actinomycete families. In addition to determining if these pathways are present, a phylogenetic approach was used successfully to suggest the number and novelty of type I PKS pathways present. By using the phylogenetic approach, the diversity, novelty and identity of type I PKS metabolites can be predicted.

The First Total Synthesis of Emericellamide A.

Abstract: A highly convergent asymmetric total synthesis of emericellamide A, a 19-membered antibacterial depsipeptide isolated from the co-culture of an Emericella sp. (strain CNL-878) and a Salinispora arenicola (strain CNH-665) is described.

Salinisporamycin, a Novel Metabolite from Salinispora arenicora.

Abstract: A new rifamycin antibiotic, salinisporamycin (1), has been isolated from a culture of a marine actinomycete. The producing organism was identified as Salinispora arenicola [corrected] on the basis of the 16S rRNA sequence. High-resolution FAB-MS established the molecular formula of 1 as C(33)H(43)NO(9). The planar structure of 1 was elucidated by NMR spectral analysis including COSY, heteronuclear single quantum coherence and heteronuclear multiple bond correlation. The relative stereochemistry of 1 was determined on the basis of rotating frame nuclear Overhauser effect spectroscopy. In addition, the solvatochromic behavior of 1 was investigated by measuring the UV spectra. This compound inhibited the growth of A549 cells, the human lung adenocarcinoma cell line, with an IC(50) value of 3 microg ml(-1), and also showed antimicrobial activity.

A novel amidase signature family amidase from the marine actinomycete Salinispora arenicola CNS-205

Abstract: We cloned a new gene from the amidase signature (AS) family, designated am, from the marine actinomycete Salinispora arenicola CNS-205. As indicated by bioinformatics analysis and site-directed mutagenesis, the AM protein belonged to the AS family. AM was expressed, purified, and characterised in Escherichia coli BL21 (DE3), and the AM molecular mass was determined to be 51 kDa. The optimal temperature and pH were 40 °C and pH 8.0, respectively. AM exhibited a wide substrate spectrum and showed amidase, aryl acylamidase, and acyl transferase activities. AM had high activity towards aromatic and aliphatic amides. The AM substrate specificity for anilides was very narrow; only propanil could be used as an effective substrate. The extensive substrate range of AM indicates it may have broad potential applications in biosynthetic processes and biodegradation.

Substrate specificity and biochemical characterization of an adenylation domain from an obligate marine actinomycete

Abstract: Salinispora arenicola CNS-205 was a first-isolated obligate marine actinomycete. A gene (sare0357), annotated as ‘‘amino acid adenylation domain’’ located on the genome of Salinispora arenicola CNS-205, was cloned and characterized. The recombinant target protein Sare0357 was expressed in E. coli. Sare0357 specifically recognized and activated tryptophan (Trp) and phenylalanine (Phe). The basic kinetic parameters of Sare0357 for Trp were Km = 0.04 mM, Vmax = 2.1 μM/min, kcat = 14.2 min−1, and for Phe were Km = 0.03 mM, Vmax = 1.6 μM/min, kcat = 10.4 min−1. Our data elucidated Sare0357 biological role and biochemical properties as a Trp and Phe-activating adenylation domain.