Draft Genome Sequence of Streptomyces sp. Strain RKCA744, Isolated from the Arauca River, Colombia.

Streptomyces sp. strain RKCA744 was isolated from sediment collected from the Arauca River, Colombia.

Curvivirga aplysinae gen. nov., sp. nov., a marine bacterium isolated from the sea sponge Aplysina fistularis.

A Gram-stain-negative, strictly aerobic, motile bacterium, designated strain RKSG073T, was isolated from the sea sponge Aplysina fistularis, collected off the west coast of San Salvador, The Bahamas. Cells were curved-to-spiral rods with single, bipolar (amphitrichous) flagella, oxidase- and catalase-positive, non-nitrate-reducing and required salt for growth. RKSG073T grew optimally at 30-37 °C, pH 6-7, and with 2-3 % (w/v) NaCl. The predominant fatty acids of RKSG073T were summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c) and C16 : 0. Major isoprenoid quinones were identified as Q-10 and Q-9. Phylogenetic analyses of nearly complete 16S rRNA genes and genome sequences positioned strain RKSG073T in a clade with its closest relative Aestuariispira insulae AH-MY2T (92.1 % 16S rRNA gene sequence similarity), which subsequently clustered with Hwanghaeella grinnelliae Gri0909T, Marivibrio halodurans ZC80T and type species of the genera Kiloniella, Thalassospira and Terasakiella. The DNA G+C content calculated from the genome of RKSG073T was 42.2 mol%. On the basis of phylogenetic distinctiveness and polyphasic analysis, here we propose that RKSG073T (culture deposit numbers: ATCC collection = TSD-74T, BCCM collection = LMG 29869T) represents the type strain of a novel genus and species within the family Kiloniellaceae, order Rhodospirillales and class Alphaproteobacteria, for which the name Curvivirga aplysinae gen. nov., sp. nov. is proposed.

Fulvivirga aurantia sp. nov. and Xanthovirga aplysinae gen. nov., sp. nov., marine bacteria isolated from the sponge Aplysina fistularis, and emended description of the genus Fulvivirga.

Two Gram-stain-negative, strictly aerobic, marine bacteria, designated as strains RKSG066T and RKSG123T, were isolated from a sponge Aplysina fistularis collected at a depth of 15 m off the west coast of San Salvador, The Bahamas. Investigation of nearly full-length 16S rRNA gene and whole genome-based phylogenies revealed that both strains belong to the order Cytophagales within the class Cytophagia and phylum Bacteroidetes. Strain RKSG066T formed a monophyletic clade with described members of the genus Fulvivirga, while strain RKSG123T formed a well-supported paraphyletic branch apart from this and other related genera within the family Flammeovirgaceae. For both RKSG066T and RKSG123T, optimal growth parameters were 30-37 °C, pH 7-8 and 2-3 % (w/v) NaCl; cells were catalase- and oxidase-positive, and flexirubin-type pigments were absent. The predominant fatty acids were iso-C15 : 0, C16 : 0, C18 : 0, iso-C17 : 0 3-OH, C16 : 1 ω5c, iso-C15 : 0 3-OH, C18 : 1 ω9c and iso-C15 : 1 G for RKSG066T, and iso-C17 : 0 3-OH, C16 : 1 ω5c, iso-C15 : 0, C16 : 0 3-OH and summed feature 4 (iso-C17 : 1 I and/or anteiso-C17 : 1 B) for RKSG123T. Menaquinone-7 was the major respiratory quinone for both strains. The DNA G+C contents of RKSG066T and RKSG123T were 39.5 and 36.7 mol%, respectively. On the basis of phylogenetic distinctiveness and polyphasic analysis, the type strain RKSG066T (=TSD-73T=LMG 29870T) is proposed to represent a novel species of the genus Fulvivirga, for which the name Fulvivirga aurantia sp. nov. is proposed. The type strain RKSG123T (=TSD-75T=LMG 30075T) is proposed to represent the type species of a novel genus and species with the proposed name Xanthovirga aplysinae gen. nov., sp. nov. Additionally, the genus Fulvivirga is emended to include strains of orange-pigmented colonies that contain the predominant cellular fatty acids C16 : 0, C18 : 0, C16  :  1 ω5c and C18  :  1 ω9c.

Description of Sansalvadorimonas verongulae gen. nov., sp. nov., a gammaproteobacterium isolated from the marine sponge Verongula gigantea.

A Gram-stain-negative, strictly aerobic, motile, rod-shaped bacterium, designated strain RKSG058T, was isolated from the marine sponge Verongula gigantea, collected off the west coast of San Salvador, The Bahamas. Phylogenetic analyses based on 16S rRNA gene sequences revealed that RKSG058T formed a distinct lineage within the family Hahellaceae (order Oceanospirillales, class Gammaproteobacteria), and was most closely related to the genus Endozoicomonas, with sequence similarities to members of this genus ranging from 92.0 to 93.7 %. Optimal growth occurred at 30 °C, at pH 7 and in the presence of 2-3 % (w/v) NaCl. The predominant cellular fatty acids were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C16 : 0. The major and minor respiratory quinones were Q-9 and Q-8, respectively. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, three unidentified aminolipids, an unidentified phospholipid and five unidentified lipids. The DNA G+C content was 42.3 mol%. Biochemical, chemotaxonomic and phylogenetic analyses indicated that strain RKSG058T represents the first cultured isolate of a novel bacterial genus and species within the family Hahellaceae, for which the name Sansalvadorimonas verongulae gen. nov., sp. nov. is proposed. The type strain of Sansalvadorimonas verongulae is RKSG058T (=TSD-72T=LMG 29871T). An emended description of the genus Kistimonas is provided.

Post Polyketide Synthase Carbon-Carbon Bond Formation in Type-II PKS-Derived Natural Products from Streptomyces venezuelae.

Polyketide synthase (PKS) derived natural products are biosynthesized by head-to-tail addition of acetate and malonate extender units resulting in linear extended-polyketide chains. Despite the well-documented structural diversity associated with PKS-derived natural products, C-C chain branching deviating from the usual linear pattern is relatively rare. Herein, type-II PKS angucyclic natural products containing a hemiaminal functionality were identified and proposed as the parent of a series of C-C-branched analogues. These C-C linked acetate or pyruvate branching units were located at the α-positions on the extended polyketide chains of jadomycins incorporating 3- and 4-aminomethylbenzoic acids. Labeling studies utilizing [1-13C]-d-glucose provided mechanistic evidence that the C-C bond formation occurred as a result of a previously unidentified post-PKS processing, additional to the enzymes encoded within the biosynthetic gene cluster. Selected compounds were evaluated in cytotoxic or antimicrobial assays.

Furan and Lactam Jadomycin Biosynthetic Congeners Isolated from Streptomyces venezuelae ISP5230 Cultured with Nε-Trifluoroacetyl-l-lysine.

Angucycline antibiotics are composed of a classical four-ring angularly linked polyaromatic backbone. Differential cyclization chemistry of the A- and B-rings in jadomycin biosynthesis led to the discovery of two new furan analogues, while oxidation led to a ring-opened form of the jadomycin Nε-trifluoroacetyl-l-lysine (TFAL) congener. The compounds were isolated from Streptomyces venezuelae ISP5230 cultures grown with TFAL. Biosynthetic incorporation using d-[1-13C]-glucose in cultures enabled the unambiguous assignment of the aldehyde, alcohol, and amide functionalities present in these new congeners through NMR spectroscopy. Tandem mass spectrometry analysis of cultures grown with 15Nα- or 15Nε-lysine demonstrated the incorporation of Nα exclusively into the angucycline backbone, contrasting results with ornithine [J. Am. Chem. Soc. 2015, 137, 3271]. Compounds were evaluated against antimicrobial and cancer cell panels and found to possess good activity against Gram-positive bacteria.

Bioprospecting from cultivable bacterial communities of marine sediment and invertebrates from the underexplored Ubatuba region of Brazil.

Shrimp fisheries along the Brazilian coast have significant environmental impact due to high by-catch rates (21 kg per kilogram of shrimp). Typically discarded, by-catch contains many invertebrates that may host a great variety of bacterial genera, some of which may produce bioactive natural products with biotechnological applications. Therefore, to utilize by-catch that is usually discarded we explored the biotechnological potential of culturable bacteria of two abundant by-catch invertebrate species, the snail Olivancillaria urceus and the sea star Luidia senegalensis. Sediment from the collection area was also investigated. Utilizing multiple isolation approaches, 134 isolates were obtained from the invertebrates and sediment. Small-subunit rRNA (16S) gene sequencing revealed that the isolates belonged to Proteobacteria, Firmicutes and Actinobacteria phyla and were distributed among 28 genera. Several genera known for their capacity to produce bioactive natural products (Micromonospora, Streptomyces, Serinicoccus and Verrucosispora) were retrieved from the invertebrate samples. To query the bacterial isolates for their ability to produce bioactive metabolites, all strains were fermented and fermentation extracts profiled by UP LC-HRMS and tested for antimicrobial activity. Four strains exhibited antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus warneri.

Description of Pseudobacteriovorax antillogorgiicola gen. nov., sp. nov., a bacterium isolated from the gorgonian octocoral Antillogorgia elisabethae, belonging to the family Pseudobacteriovoracaceae fam. nov., within the order Bdellovibrionales.

A bacterial strain designated RKEM611(T) was isolated from the octocoral Antillogorgia elisabethae, collected off the coast of San Salvador, The Bahamas. The strain is Gram-stain-negative, an obligate aerobe, and pleomorphic. It requires NaCl for growth and exhibits optimal growth at 1-2 % (w/v) NaCl, 30-37 °C and pH 6.0-8.0. The predominant cellular fatty acids are C16 : 1ω5c and C16 : 0; the major respiratory quinone is menaquinone MK-6, and the DNA G+C content is 46.3 mol%. Based on phylogenetic analysis of the 16S rRNA gene, in addition to phenotypic characteristics, RKEM611(T) represents a novel species and genus of a novel family within the order Bdellovibrionales. The names Pseudobacteriovoracaceae fam. nov. and Pseudobacteriovorax antillogorgiicola gen., nov., sp., nov. are proposed. Isolate RKEM611(T) ( = NCCB 100521(T) = LMG 28452(T)) is the type strain.

Description of Endozoicomonas euniceicola sp. nov. and Endozoicomonas gorgoniicola sp. nov., bacteria isolated from the octocorals Eunicea fusca and Plexaura sp., and an emended description of the genus Endozoicomonas.

Two Gram-negative, facultatively anaerobic, rod-shaped bacteria, strains EF212(T) and PS125(T), were isolated from the octocorals Eunicea fusca and Plexaura sp., respectively. EF212(T) was isolated from a specimen of E. fusca collected off the coast of Florida, USA, and PS125(T) was isolated from a specimen of Plexaura sp. collected off the coast of Bimini, Bahamas. Analysis of the nearly full-length 16S rRNA gene sequences showed that these novel strains were most closely related to Endozoicomonas montiporae CL-33(T), E. elysicola MKT110(T) and E. numazuensis HC50(T) (EF212(T), 95.6-97.2 % identity; PS125(T), 95.1-96.4 % identity). DNA-DNA hybridization values among EF212(T), PS125(T), E. montiporae LMG 24815(T) and E. elysicola KCTC 12372(T) were far below the 70 % cut-off, with all values for duplicate measurements being less than 35 %. Both EF212(T) and PS125(T) required NaCl for growth and showed optimal growth at 2-3 % NaCl, 22-30 °C and pH 8.0. The predominant cellular fatty acids were summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c), summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c), C16 : 0 and C14 : 0. The DNA G+C content of EF212(T) was 48.6 mol% and that of PS125(T) was 47.5 mol%. In addition to the genotypic differences observed between the two novel strains and related type strains, phenotypic and chemotaxonomic experiments also revealed differences between strains. Thus, strains EF212(T) and PS125(T) represent novel species of the genus Endozoicomonas, for which the names Endozoicomonas euniceicola sp. nov. and Endozoicomonas gorgoniicola sp. nov., respectively, are proposed. The type strains are EF212(T) ( = NCCB 100458(T) = DSM 26535(T)) for Endozoicomonas euniceicola sp. nov. and PS125(T) ( = NCCB 100438(T) = CECT 8353(T)) for Endozoicomonas gorgoniicola sp. nov. An emended description of the genus Endozoicomonas is also provided to encompass differences observed in the results of genotypic, chemotaxonomic and phenotypic tests compared from the original and amended genus descriptions.

A microbial community analysis of the octocoral Eunicea fusca

While there is a significant and growing body of knowledge describing the microbial communities of marine invertebrates such as sponges, there are very few such studies focused on octocorals. The octocoral Eunicea fusca is common on reefs in various regions of the Caribbean and has been the subject of natural product investigations. As part of an effort to describe the microbial community associated with octocorals, a culture-independent analysis of the bacterial community of E. fusca was conducted. Specifically, a 16S rDNA clone library analysis was performed to provide baseline data. A total of 40 bacteria members from 11 groups were found. In general, Proteobacteria were the dominant group with a total of 24 species and α-Proteobacteria represented the highest percentage of bacteria associated with E. fusca (27.5 percent). Other prominent groups observed were Acidobacteria, Actinobacteria, Cyanobacteria, Planctomycetes, delta-Proteobacteria, Lentisphaerae and Nitrospirae. This is the first analysis of bacterial populations associated with the gorgonian E. fusca.

Sesquiterpene variability in the gorgonian genus Plexaurella.

Gorgonian corals have proven to be a prolific source of a variety of biologically active terpenes. Corals of the genus Plexaurella are known to be the source of a diverse array of sesquiterpenes, and past reports have indicated variability in terpene content. This study involved an examination of the terpene chemistry of 109 individuals of five of the six known species of this genus in an attempt to identify links between sesquiterpene chemistry and species, location and depth. The data indicated a high level of variability of sesquiterpene content and essentially no correlation between species and sesquiterpene chemistry. There was also no correlation between location or depth and sesquiterpene content. We therefore conclude that Plexaurella spp. are chemically indistinguishable species with respect to terpene chemistry.

Comparison of two total RNA extraction protocols using the marine gorgonian coral Pseudopterogorgia elisabethae and its symbiont Symbiodinium sp

Marine invertebrates such as soft corals are important sources of secondary metabolites with promising biomedical applications and commercial value. RNA isolation in conjunction with reverse-transcriptase polymerase chain reaction (RT-PCR) are valuable tools utilized to study the molecular elements involved in secondary metabolite production and functional genomics. Two total RNA extraction protocols were compared using fresh tissue and flash frozen preparations from the coral Pseudopterogorgia elisabethae and from its symbiont Symbiodinium sp. isolated using RNeasy minicolumns (Qiagen®) and Trizol reagent (Invitrogen®). In general, higher yields were obtained by using Trizol reagent when compared to RNeasy. No significant differences were observed in RNA yield when live or flash frozen tissue was used. However, flash frozen holobiont tissue isolated by Trizol resulted in the highest RNA yield of all preparations analyzed. To conclude, both protocols are suitable for RNA isolation. Trizol is recommended if higher yields are the primary concern, but RNeasy is recommended if time is an issue.

Cyclobutenbriarein A, the first diterpene with a tricyclo[8.4.0.0(3,6)]tetradec-4-ene ring system isolated from the Gorgonian Briareum asbestinum.

Cyclobutenbriarein A (2), a novel class of C20-rearranged diterpene briarane possessing an unprecedented tricyclo[8.4.0.0(3,6)]tetradec-4-ene ring system was isolated, along with five new briarane diterpenoids (1 and 3-6), from the organic extracts of the Bahamian gorgonian Briareum asbestinum. The structures of these secondary metabolites were established on the basis of extensive NMR studies and accurate mass measurements (HRFABMS).