Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 29
Filter
Add more filters










Publication year range
1.
Mar Drugs ; 20(3)2022 Feb 23.
Article in English | MEDLINE | ID: mdl-35323458

ABSTRACT

Alginate oligosaccharides (AOS) have many biological activities and significant applications in prebiotics, nutritional supplements, and plant growth development. Alginate lyases have unique advantages in the preparation of AOS. However, only a limited number of alginate lyases have been so far reported to have potentials in the preparation of AOS with specific degrees of polymerization. Here, an alginate-degrading strain Pseudoalteromonasarctica M9 was isolated from Sargassum, and five alginate lyases were predicted in its genome. These putative alginate lyases were expressed and their degradation products towards sodium alginate were analyzed. Among them, AlyM2 mainly generated trisaccharides, which accounted for 79.9% in the products. AlyM2 is a PL6 lyase with low sequence identity (≤28.3%) to the characterized alginate lyases and may adopt a distinct catalytic mechanism from the other PL6 alginate lyases based on sequence alignment. AlyM2 is a bifunctional endotype lyase, exhibiting the highest activity at 30 °C, pH 8.0, and 0.5 M NaCl. AlyM2 predominantly produces trisaccharides from homopolymeric M block (PM), homopolymeric G block (PG), or sodium alginate, with a trisaccharide production of 588.4 mg/g from sodium alginate, indicating its promising potential in preparing trisaccharides from these polysaccharides.


Subject(s)
Alginates/chemistry , Bacterial Proteins , Polysaccharide-Lyases , Pseudoalteromonas/enzymology , Sargassum/microbiology , Trisaccharides/chemistry , Bacterial Proteins/chemistry , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Genome, Bacterial , Polysaccharide-Lyases/chemistry , Polysaccharide-Lyases/genetics , Polysaccharide-Lyases/metabolism , Pseudoalteromonas/genetics , Pseudoalteromonas/isolation & purification , RNA, Ribosomal, 16S
2.
Int J Syst Evol Microbiol ; 70(8): 4451-4457, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32687464

ABSTRACT

A novel Gram-stain-negative, straight or curved rod-shaped, non-spore-forming, strictly aerobic, motile bacterium with a single polar flagellum, designated D3211T, was isolated from marine alga collected at the seashore of Yantai, PR China. The organism grew optimally at 24 °C, pH 7.0 and in the presence of 2.0 % (w/v) NaCl. Strain D3211T contained ubiquinone 8 as the major respiratory quinone and C16 : 1 ω7c and/or C16 : 1 ω6c, C16 : 0, iso-C17 : 0 and anteiso-C17 : 1 B and/or iso-C17 : 1 I as the major fatty acids. The predominant polar lipids of strain D3211T were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The DNA G+C content of strain D3211T was 39.4 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that the novel strain was related most closely to Paraglaciecola arctica BSs20135T, Paraglaciecola aestuariivivens JDTF-33T, Paraglaciecola aquimarina KCTC 32108T, Paraglaciecola mesophila DSM 15026T, Paraglaciecola psychrophila JCM 13954T and Paraglaciecola polaris ARK 150T with 97.6, 97.6, 97.5, 97.4, 97.3 and 97.1 % sequence similarities, respectively. Calculated average nucleotide identity and DNA-DNAhybridization values between strain D3211T and its phylogenetically related Paraglaciecola species were in the range 70.2-73.4 % and 19.1-20.4 %, respectively. On the basis of polyphasic analyses, strain D3211T represents a novel species of the genus Paraglaciecola, for which the name Paraglaciecola marina sp. nov. is proposed. The type strain is D3211T (=KCTC 72122T=MCCC 1K03603T).


Subject(s)
Alteromonadaceae/classification , Phylogeny , Sargassum/microbiology , Alteromonadaceae/isolation & purification , Bacterial Typing Techniques , Base Composition , China , DNA, Bacterial/genetics , Fatty Acids/chemistry , Nucleic Acid Hybridization , Phospholipids/chemistry , RNA, Ribosomal, 16S/genetics , Seawater/microbiology , Sequence Analysis, DNA , Ubiquinone/chemistry
3.
Sci Rep ; 10(1): 10920, 2020 07 02.
Article in English | MEDLINE | ID: mdl-32616809

ABSTRACT

Alginate-degrading bacteria or alginate lyases can be used to oligomerize alginate. In this study, an alginate-degrading bacterium with high alginolytic activity was successfully screened by using Sargassum fusiforme sludge. When the strain was grown on a plate containing sodium alginate, the transparent ring diameter (D) was 2.2 cm and the ratio (D/d) of transparent ring diameter to colony diameter (d) was 8.8. After 36 h in culture at a temperature of 28 °C shaken at 150 r/min, the enzymatic activity of the fermentation supernatant reached 160 U/mL, and the enzymatic activity of the bacterial precipitate harvested was 2,645 U/mL. The strain was named Cobetia sp. cqz5-12. Its genome is circular in shape, 4,209,007 bp in size, with a 62.36% GC content. It contains 3,498 predicted coding genes, 72 tRNA genes, and 21 rRNA genes. The functional annotations for the coding genes demonstrated that there were 181 coding genes in the genome related to carbohydrate transport and metabolism and 699 coding genes with unknown functions. Three putative coding genes, alg2107, alg2108 and alg2112, related to alginate degradation were identified by analyzing the carbohydrate active enzyme (CAZy) database. Moreover, proteins Alg2107 and Alg2112 were successfully expressed and exhibited alginate lyase activity.


Subject(s)
Genome, Bacterial , Halomonadaceae/genetics , Alginates/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/isolation & purification , Chromosome Mapping , Chromosomes, Bacterial/genetics , DNA, Bacterial/genetics , DNA, Circular/genetics , Gene Ontology , Halomonadaceae/enzymology , Halomonadaceae/growth & development , Halomonadaceae/isolation & purification , Phylogeny , Polysaccharide-Lyases/genetics , Polysaccharide-Lyases/isolation & purification , Sargassum/microbiology , Whole Genome Sequencing
4.
Mar Drugs ; 18(6)2020 Jun 18.
Article in English | MEDLINE | ID: mdl-32570727

ABSTRACT

Halosmysin A, a new 14-membered macrodiolide with an unprecedented skeleton, was isolated from the fungus Halosphaeriaceae sp. OUPS-135D-4, which, in turn, was obtained from the marine algae Sargassum thunbergii. The chemical structure of the macrodiolide was elucidated using 1D and 2D NMR, as well as high resolution fast atom bombardment mass (HRFABMS) spectral analysis. The absolute stereochemistry was determined via chemical derivatization and comparison with a known compound, (6R,11R,12R,14R)-colletodiol. Additionally, halosmysin A was shown to be very potent against murine P388 leukemia, human HL-60 leukemia, and murine L1210 leukemia cell lines, with IC50 values ranging from 2.2 ± 3.1 to 11.7 ± 2.8 µM.


Subject(s)
Antineoplastic Agents/pharmacology , Ascomycota/chemistry , Macrolides/pharmacology , Sargassum/microbiology , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/isolation & purification , Cell Line, Tumor , Drug Screening Assays, Antitumor , Humans , Inhibitory Concentration 50 , Lactones/chemistry , Leukemia/drug therapy , Leukemia/pathology , Macrolides/chemistry , Macrolides/isolation & purification , Magnetic Resonance Spectroscopy , Mice , Molecular Structure , Stereoisomerism
5.
Int J Syst Evol Microbiol ; 69(12): 3857-3862, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31486761

ABSTRACT

A novel bacterial strain, C3212T, was isolated from a marine alga collected from the sea shore of Yantai, China. The strain was Gram-stain-negative, rod-shaped, aerobic, non-motile, and oxidase- and catalase-positive. Growth was observed at 8-37 °C (optimum, 28 °C), at pH 6.0-9.0 (optimum, pH 7.0) and in the presence of 1.0-7.0 % (w/v) NaCl (optimum, 4.0 %). The major respiratory quinone was ubiquinone-8 (Q-8). The polar lipids of strain C3212T consisted of diphosphatidylglycerol (cardiolipin), phosphatidylglycerol, phosphatidylethanolamine, an unidentified aminophospholipid, an unidentified phospholipid and an unidentified polar lipid. The major fatty acids were C16 : 1ω6c and/or C16 : 1ω7c, and C18 : 1ω6c and/or C18 : 1ω7c. The DNA G+C content of strain C3212T was 44.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that the novel strain was related most closely to Leucothrix pacifica XH122T, Leucothrix arctica IMCC 9719T and Leucothrix mucor DSM 2157T with similarities of 98.0, 97.5 and 94.3 %, respectively. Estimated DNA-DNA hybridization values were 14.2, 20.7 and 13.9 % between strain C3212T and L. pacifica XH122T, L. arctica IMCC 9719T and L. mucor DSM 2157T, respectively. Phenotypic, phylogenetic and genomic analyses revealed that strain C3212T represents a novel species of the genus Leucothrix, for which the name Leucothrix sargassi sp. nov. is proposed. The type strain is C3212T (=MCCC 1K03600T=KCTC 72121T).


Subject(s)
Phylogeny , Sargassum/microbiology , Thiotrichaceae/classification , Bacterial Typing Techniques , Base Composition , China , DNA, Bacterial/genetics , Fatty Acids/chemistry , Nucleic Acid Hybridization , Phospholipids/chemistry , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Thiotrichaceae/isolation & purification , Ubiquinone/chemistry
6.
Biotechnol Lett ; 41(10): 1187-1200, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31418101

ABSTRACT

OBJECTIVES: Bifunctional alginate lyase can efficiently saccharify alginate biomass and prepare functional oligosaccharides of alginate. RESULTS: A new BP-2 strain that produces alginate lyase was screened and identified from rotted Sargassum. A new alginate lyase, Alg17B, belonging to the polysaccharide lyase family 17, was isolated and purified from BP-2 fermentation broth by freeze-drying, dialysis, and ion exchange chromatography. The enzymatic properties of the purified lyase were investigated. The molecular weight of Alg17B was approximately 77 kDa, its optimum reaction temperature was 40-45 °C, and its optimum reaction pH was 7.5-8.0. The enzyme was relatively stable at pH 7.0-8.0, with a temperature range of 25-35 °C, and the specific activity of the purified enzyme reached 4036 U/mg. A low Na+ concentration stimulated Alg17B enzyme activity, but Ca2+, Zn2+, and other metal ions inhibited it. Substrate specificity analysis, thin-layer chromatography, and mass spectrometry showed that Alg17B is an alginate lyase that catalyses the hydrolysis of sodium alginate, polymannuronic acid (polyM) and polyguluronic acid to produce monosaccharides and low molecular weight oligosaccharides. Alg17B is also bifunctional, exhibiting both endolytic and exolytic activities toward alginate, and has a wide substrate utilization range with a preference for polyM. CONCLUSIONS: Alg17B can be used to saccharify the main carbohydrate, alginate, in the ethanolic production of brown algae fuel as well as in preparing and researching oligosaccharides.


Subject(s)
Aquatic Organisms/enzymology , Gammaproteobacteria/enzymology , Polysaccharide-Lyases/isolation & purification , Polysaccharide-Lyases/metabolism , Sargassum/microbiology , Alginates/metabolism , Alginic Acid/metabolism , Aquatic Organisms/classification , Aquatic Organisms/genetics , Aquatic Organisms/isolation & purification , Enzyme Activators/analysis , Enzyme Inhibitors/analysis , Enzyme Stability , Gammaproteobacteria/classification , Gammaproteobacteria/genetics , Gammaproteobacteria/isolation & purification , Hydrogen-Ion Concentration , Hydrolysis , Molecular Weight , Monosaccharides/metabolism , Oligosaccharides/metabolism , Polysaccharide-Lyases/chemistry , Polysaccharide-Lyases/genetics , Polysaccharides, Bacterial/metabolism , Substrate Specificity , Temperature
7.
PLoS One ; 13(12): e0206734, 2018.
Article in English | MEDLINE | ID: mdl-30517113

ABSTRACT

Seaweed-associated microbiota experience spatial and temporal shifts in response to changing environmental conditions and seaweed physiology. These shifts may result in structural, functional and behavioral changes in the host with potential consequences for its fitness. They, thus, may help the host to adapt to changing environmental conditions. The current knowledge of seasonal variation of seaweed-associated microbiota is however still limited. In this study, we explored temporal and spatial variation of microbial communities associated with the invasive brown seaweed S. muticum. We sampled in northern and southern Portugal, in September, March and July-August (summer). In addition, as (pseudo-)perennial seaweeds display seasonal reproductive phenology, we sampled various parts of the individuals to disentangle the effect of temporal changes from those due to structural development variations. The diversity and structure of associated microbial communities were determined using next generation sequencing of the variable regions V5-7 of the 16S rDNA. We expected to find differentiation in associated microbial communities between regions and sampling months, but with differences depending on the seaweed structure examined. As expected, the study revealed substantial temporal shifts in S. muticum microbiome, for instance with large abundance of Rhodobacteraceae and Loktanella in September-March but prevalence of Pirellulales during the summer months. Variations between regions and tissues were also observed: in northern Portugal and on basal structures, bacterial diversity was higher as compared to the South and apical parts. All examined seaweed structures showed temporal differences in associated microbial community structure over time, except for holdfasts between September and March. Bacteria contributing to these changes varied spatially. Conversely to all other structures, the holdfast also did not show differences in associated community structure between southern and northern regions. Our study highlights the importance of structural microscale differentiations within seaweeds hosts with regard to their associated microbial communities and their importance across temporal and spatial dimensions.


Subject(s)
Bacteria , Introduced Species , Microbial Consortia/physiology , Sargassum/microbiology , Seasons , Bacteria/classification , Bacteria/genetics , Bacteria/growth & development , RNA, Bacterial/genetics , RNA, Ribosomal, 16S/genetics
8.
Org Lett ; 20(19): 6306-6309, 2018 10 05.
Article in English | MEDLINE | ID: mdl-30256119

ABSTRACT

Tricholumin A (1) with an unprecedented carbon skeleton was isolated from the fungus Trichoderma asperellum cf44-2, an endophyte from the marine brown alga Sargassum sp. Its structure and relative configuration were identified by extensive 1D/2D NMR and mass spectrometric data, and the absolute configuration was assigned by X-ray diffraction and ECD calculations. Compound 1 represents a highly transformed ergosterol derivative, and it exhibited inhibition of some pathogenic microbes and marine phytoplankton species.


Subject(s)
Anti-Infective Agents/chemistry , Ergosterol/chemistry , Sargassum/microbiology , Trichoderma/chemistry , Anti-Infective Agents/isolation & purification , Endophytes/chemistry , Endophytes/isolation & purification , Ergosterol/isolation & purification , Molecular Structure , Phytoplankton/drug effects , Structure-Activity Relationship , Trichoderma/isolation & purification
9.
Int J Syst Evol Microbiol ; 67(9): 3540-3546, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28866993

ABSTRACT

An aerobic, gliding and yellow-pigmented bacterium, designated strain SFD31T, was isolated from brown alga collected from the South Sea, Republic of Korea. Cells were Gram-stain-negative, and catalase- and oxidase-positive. The neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain SFD31T forms an independent lineage within the genus Winogradskyella. Strain SFD31T was related distantly to Winogradskyella echinorum KMM 6211T (97.9 %, 16S rRNA gene sequence similarity), Winogradskyellalitoriviva KMM 6491T (97.4 %), Winogradskyellapulchriflava EM106T (97.2 %) and Winogradskyellaeckloniae EC29T (96.9 %). The major fatty acids of strain SFD31T were iso-C15 : 0, iso-C15 : 1 G, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and unknown 13.565. The only isoprenoid quinone of the isolate was menaquinone 6. The major polar lipids were phosphatidylethanolamine, four unidentified aminolipids and two unidentified lipids. The DNA G+C content of strain SFD31T was 36.0 mol%. Phenotypic characteristics distinguished strain SFD31T from the related species of the genus Winogradskyella. On the basis of the evidence presented in this study, a novel species, Winogradskyella flava sp. nov., is proposed for strain SFD31T (=KCTC 52348T=JCM 31798T).


Subject(s)
Flavobacteriaceae/classification , Phylogeny , Sargassum/microbiology , Bacterial Typing Techniques , Base Composition , DNA, Bacterial/genetics , Fatty Acids/chemistry , Flavobacteriaceae/genetics , Flavobacteriaceae/isolation & purification , Phosphatidylethanolamines/chemistry , Pigmentation , RNA, Ribosomal, 16S/genetics , Republic of Korea , Sequence Analysis, DNA , Vitamin K 2/analogs & derivatives , Vitamin K 2/chemistry
10.
Int J Syst Evol Microbiol ; 67(11): 4482-4486, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28933321

ABSTRACT

A non-motile, yellow-coloured and rod-shaped bacterium, designated strain SFD34T, was isolated from seaweed collected from the South Sea, Republic of Korea. Cells were Gram-stain-negative, aerobic, catalase-positive and oxidase-negative. The major fatty acids were iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1 G. Strain SFD34T contained MK-6 and phosphatidylethanolamine as the only isoprenoid quinone and major polar lipid, respectively. The DNA G+C content was 35 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain SFD34T formed evolutionary lineage within the radiation enclosing the members of the genus Dokdonia with Dokdoniapacifica SW230T (96.86 % sequence similarity) as its nearest neighbour. A number of phenotypic characteristics distinguished strain SFD34T from related members of the genus Dokdonia. On the basis of the evidence presented in this study, a novel species, Dokdonia lutea sp. nov., is proposed for strain SFD34T (=KCTC 52269T=JCM 31795T).


Subject(s)
Flavobacteriaceae/classification , Phylogeny , Sargassum/microbiology , Bacterial Typing Techniques , Base Composition , DNA, Bacterial/genetics , Fatty Acids/chemistry , Flavobacteriaceae/genetics , Flavobacteriaceae/isolation & purification , Phosphatidylethanolamines/chemistry , RNA, Ribosomal, 16S/genetics , Republic of Korea , Seaweed/microbiology , Sequence Analysis, DNA , Vitamin K 2/analogs & derivatives , Vitamin K 2/chemistry
11.
Microb Ecol ; 74(4): 868-876, 2017 11.
Article in English | MEDLINE | ID: mdl-28624904

ABSTRACT

Holobionts are characterized by the relationship between host and their associated organisms such as the biofilm associated with macroalgae. Considering that light is essential to macroalgae survival, the aim of this study was to verify the effect of light on the heterotrophic activity in biofilms of the brown macroalgae Sargassum furcatum during its growth cycle. Measurements of heterotrophic activity were done under natural light levels at different times during a daily cycle and under an artificial extinction of natural light during the afternoon. We also measured Sargassum primary production under these light levels in the afternoon. Both measurements were done with and without photosynthesis inhibitor and antibiotics. Biofilm composition was mainly represented by bacteria but diatoms, cyanobacteria, and other organisms were also common. When a peak of diatom genera was recorded, the heterotrophic activity of the biofilm was higher. Heterotrophic activity was usually highest during the afternoon and the presence of a photosynthesis inhibitor caused an average reduction of 17% but there was no relationship with Sargassum primary production. These results indicate that autotrophic production in the biofilm was reduced by the inhibitor with consequences on bacterial activity. Heterotrophic activity was mainly bacterial and the antibiotics chloramphenicol and penicillin were more effective than streptomycin. We suggest primary producers in the biofilm are more important to increase bacterial activity than the macroalgae itself because of coherence of the peaks of heterotrophic and autotrophic activity in biofilm during the afternoon and the effects of autotrophic inhibitors on heterotrophic activity.


Subject(s)
Anti-Bacterial Agents/pharmacology , Autotrophic Processes , Bacterial Physiological Phenomena , Biofilms , Light , Bacterial Physiological Phenomena/drug effects , Biofilms/drug effects , Biofilms/growth & development , Biofilms/radiation effects , Brazil , Circadian Rhythm , Sargassum/microbiology , Seasons
12.
Mar Drugs ; 15(2)2017 Jan 25.
Article in English | MEDLINE | ID: mdl-28125012

ABSTRACT

Four new indolediketopiperazine derivatives (1-4), along with nine known congeners (5-13), were isolated and identified from the culture extract of Eurotium cristatum EN-220, an endophytic fungus obtained from the marine alga Sargassum thunbergii. The structures of thesecompounds were elucidated on the basis of extensive spectroscopic analysis and the absolute configurations of compounds 1-4 were established by NOESY experiments and by chiral HPLC analyses of their acid hydrolysates. The absolute configuration of C-8 (a quaternary carbon substituted with a hydroxyl group) in 5 of preechinulin class was firstly determined by electronic circular dichroism (ECD) calculations. All these compounds were evaluatedfor brine shrimp (Artemia salina) lethality and nematicidal activity as well as antioxidativeand antimicrobial potency.


Subject(s)
Alkaloids/pharmacology , Eurotium/chemistry , Fungi/chemistry , Sargassum/chemistry , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Antioxidants/chemistry , Antioxidants/pharmacology , Aquatic Organisms/chemistry , Aquatic Organisms/microbiology , Artemia/drug effects , Circular Dichroism/methods , Microbial Sensitivity Tests/methods , Sargassum/microbiology
13.
Appl Microbiol Biotechnol ; 101(2): 569-583, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27624095

ABSTRACT

The brown seaweed, Sargassum myriocystum associated with heterotrophic bacterium, Bacillus subtilis MTCC 10407 (JF834075) exhibited broad-spectra of potent antibacterial activities against pathogenic bacteria Aeromonas hydrophila, Vibrio vulnificus, and Vibrio parahaemolyticus. B. subtilis MTCC 10407 was found to be positive for polyketide synthetase (pks) gene, and therefore, was considered to characterize secondary metabolites bearing polyketide backbone. Using bioassay-guided fractionation, two new antibacterial O-heterocyclic compounds belonging to pyranyl benzoate analogs of polyketide origin, with activity against pathogenic bacteria, have been isolated from the ethyl acetate extract of B. subtilis MTCC 10407. In the present study, the secondary metabolites of B. subtilis MTCC 10407 with potent antibacterial action against bacterial pathogens was recognized to represent the platform of pks-1 gene-encoded products. Two homologous compounds 3 (3-(methoxycarbonyl)-4-(5-(2-ethylbutyl)-5,6-dihydro-3-methyl-2H-pyran-2-yl)-butyl benzoate) and 4 [2-(8-butyl-3-ethyl-3,4,4a,5,6,8a-hexahydro-2H-chromen-6-yl)-ethyl benzoate] also have been isolated from the ethyl acetate extract of host seaweed S. myriocystum. The two compounds isolated from ethyl acetate extract of S. myriocystum with lesser antibacterial properties shared similar structures with the compounds purified from B. subtilis that suggested the ecological and metabolic relationship between these compounds in seaweed-bacterial relationship. Tetrahydropyran-2-one moiety of the tetrahydropyrano-[3,2b]-pyran-2(3H)-one system of 1 might be cleaved by the metabolic pool of seaweeds to afford methyl 3-(dihydro-3-methyl-2H-pyranyl)-propanoate moiety of 3, which was found to have no significant antibacterial activity. It is therefore imperative that the presence of dihydro-methyl-2H-pyran-2-yl propanoate system is essentially required to impart the greater activity. The direct involvement of polarisability (Pl) with the target bioactivity in 2 implied that inductive (field/polar) rather than the steric effect (parachor) appears to be the key factor influencing the induction of antibacterial activity. The present work may have a footprint on the use of novel O-heterocyclic polyketide products from seaweed-associated bacterium for biotechnological, food, and pharmaceutical applications mainly as novel antimicrobial secondary metabolites.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bacillus subtilis/chemistry , Bacillus subtilis/isolation & purification , Biological Products/pharmacology , Heterocyclic Compounds/pharmacology , Sargassum/chemistry , Aeromonas/drug effects , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Aquatic Organisms/chemistry , Aquatic Organisms/microbiology , Biological Products/chemistry , Biological Products/isolation & purification , Heterocyclic Compounds/chemistry , Heterocyclic Compounds/isolation & purification , Microbial Sensitivity Tests , Sargassum/microbiology , Vibrio/drug effects
14.
Microb Ecol ; 73(1): 91-100, 2017 01.
Article in English | MEDLINE | ID: mdl-27815589

ABSTRACT

The environmental impact of major oil spills on marine microorganisms has yet to be thoroughly investigated using molecular biology techniques. The Deepwater Horizon (DWH) drilling rig explosion of 2010 affected an approximately 176,000 km2 surface area of the Gulf of Mexico (GOM) when an estimated 210 million gallons of oil from the Macondo Prospect spilled into the environment. Pelagic Sargassum, a complex of two surface drifting species (Sargassum natans and Sargassum fluitans) of marine brown macroalgae and a critically important habitat in the GOM ecosystem, was suffused by Macondo Prospect 252 oil released during the DWH event. Using 16S rRNA PCR and Roche 454 pyrosequencing, the effect of the oil on the bacterial population associated with pelagic Sargassum and contiguous waters was examined by comparing sequence data generated from samples collected from oiled and non-oiled locations in the northern GOM. Sequence data showed similar microbial composition in Sargassum regardless of exposure to oil primarily dominated by five phyla; Proteobacteria, Bacteroidetes, Actinobacteria, Verrucomicrobia, and unclassified bacteria. The microbial composition in water samples was significantly less diverse than for Sargassum and consisted primarily of Proteobacteria, Firmicutes, and Bacteroidetes. Due to the evenly distributed abundance of microbial species on oiled and non-oiled pelagic Sargassum, study findings indicate that DWH spilled oil had minimal effect on the composition and diversity of the microbial community associated with Sargassum and contiguous waters. However, higher abundances of Sulfitobacter and one species of Psychrobacter were found in oiled water samples when compared to non-oiled water samples indicating some effect of DHW oil in the microbial composition of seawater. Though there are a number of marine studies using molecular biology approaches, this is the first molecular examination of the impact of the DWH oil spill on bacterial communities associated with pelagic Sargassum and contiguous waters from the GOM.


Subject(s)
Actinobacteria/classification , Bacteroidetes/classification , Environmental Monitoring/methods , Firmicutes/classification , Petroleum Pollution , Proteobacteria/classification , Sargassum/microbiology , Verrucomicrobia/classification , Actinobacteria/genetics , Actinobacteria/isolation & purification , Bacteroidetes/genetics , Bacteroidetes/isolation & purification , DNA, Bacterial/genetics , Environment , Firmicutes/genetics , Firmicutes/isolation & purification , Gulf of Mexico , Microbiota/genetics , Oil and Gas Industry , Petroleum/toxicity , Proteobacteria/genetics , Proteobacteria/isolation & purification , RNA, Ribosomal, 16S/genetics , Sargassum/growth & development , Seawater/chemistry , Seawater/microbiology , Verrucomicrobia/genetics , Verrucomicrobia/isolation & purification
15.
J Nat Prod ; 79(12): 3031-3038, 2016 Dec 23.
Article in English | MEDLINE | ID: mdl-28006908

ABSTRACT

Eleven new polyketides, pallidopenillines 1-11, were isolated from the alga-derived fungus Penicillium thomii. The structures of these compounds were established based on spectroscopic methods. The absolute configuration of pallidopenilline A (1) as 4R, 5S, 8S, 9R, 10R, 13R was established using a combination of the modified Mosher's method, X-ray analysis, and NOESY data. The absolute configurations of 2-5 were determined by time-dependent density functional theory calculations of the ECD spectra and ECD and NOESY data. It was shown that 1-acetylpallidopenilline A (2) and pallidopenilline G (10) inhibit the growth of colonies of 22Rv1 cells by 40% at 2 and 1 µM, respectively.


Subject(s)
Antineoplastic Agents/isolation & purification , Penicillium/chemistry , Polyketides/isolation & purification , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Drug Screening Assays, Antitumor , HCT116 Cells , Humans , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Polyketides/chemistry , Polyketides/pharmacology , Sargassum/microbiology
16.
Microbiologyopen ; 5(6): 1038-1049, 2016 12.
Article in English | MEDLINE | ID: mdl-27440453

ABSTRACT

Algae have long been used to augment plant productivity through their beneficial effects. Alginate oligosaccharide is believed to be one of the important components to enhance growth and crop yield. In this study, we isolated and characterized a Bacillus litoralis strain, named Bacillus M3, from decayed kelps. We further demonstrated that the M3 strain could secrete alginate lyase to degrade alginate. The crude enzyme exhibited the highest activity (33.74 U/mg) at pH 7.0 and 50°C. The M3 strain was also able to ferment the brown alga Sargassum horneri. Fermentation results revealed that a fermentation period of 8-12 hr was the best harvest time with the highest level of alginate oligosaccharides. Plant growth assay showed that the seaweed fermentation extract had an obvious promotion effect on root and seedling growth of Lycopersicon eseulentum L. Our results suggest that fermentation extract of Sargassum horneri by the novel strain of Bacillus litoralis M3 has significant development potential for biofertilizer production and agriculture application.


Subject(s)
Bacillus/metabolism , Fertilizers/analysis , Sargassum/metabolism , Seaweed/metabolism , Solanaceae/growth & development , Alginates/metabolism , Bacillus/classification , Bacillus/isolation & purification , Bioreactors/microbiology , Fermentation , Fertilizers/microbiology , Glucuronic Acid/metabolism , Hexuronic Acids/metabolism , Plant Extracts/metabolism , Sargassum/microbiology , Seaweed/microbiology
17.
Bioorg Med Chem Lett ; 25(16): 3125-8, 2015 Aug 15.
Article in English | MEDLINE | ID: mdl-26099531

ABSTRACT

Nine diketopiperazines were characterized from the culture of marine fungal isolate MR2012 which based on DNA amplification and sequencing of the fungal internal transcribed spacer (ITS) region was identified as Aspergillus fumigatus. The isolated fungal metabolites 4-12 were unambiguously identified as a series of simple and re-arranged diketopiperazines by analysis of spectroscopic data. t-Butoxycarbonyl group (BOC) derivatization was used to separate the intractable mixture of 4 and 5. When all compounds were evaluated for antimicrobial activity against gram positive bacteria, the isolated metabolites showed moderate to weak effects, while the semisynthetic derivatives 4a and 5a displayed strong activity comparable to the positive control, tetracycline against gram positive bacteria.


Subject(s)
Anti-Bacterial Agents/chemistry , Diketopiperazines/chemistry , Fungi/chemistry , Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/pharmacology , Aspergillus fumigatus/chemistry , Aspergillus fumigatus/metabolism , Diketopiperazines/isolation & purification , Diketopiperazines/pharmacology , Fungi/classification , Fungi/metabolism , Gram-Positive Bacteria/drug effects , Microbial Sensitivity Tests , Phylogeny , Sargassum/microbiology , Structure-Activity Relationship
18.
J Nat Prod ; 77(6): 1390-5, 2014 Jun 27.
Article in English | MEDLINE | ID: mdl-24852445

ABSTRACT

Ten new austalide meroterpenoids (1-10) were isolated from the alga-derived fungi Penicillium thomii KMM 4645 and Penicillium lividum KMM 4663. Their structures were elucidated by extensive spectroscopic analysis and by comparison with related known compounds. The absolute configurations of some of the metabolites were assigned by the modified Mosher's method and CD data. Compounds 1, 2, 8, and 9 were able to inhibit AP-1-dependent transcriptional activity in JB6 Cl41 cell lines at noncytotoxic concentrations. Austalides 1-5, 8, and 9 exhibited significant inhibitory activity against endo-1,3-ß-D-glucanase from a crystalline stalk of the marine mollusk Pseudocardium sachalinensis.


Subject(s)
Penicillium/chemistry , Terpenes/isolation & purification , Animals , Aspergillus/chemistry , Drug Screening Assays, Antitumor , Japan , Mice , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Oceans and Seas , Sargassum/microbiology , Terpenes/chemistry , Terpenes/pharmacology , Transcription Factor AP-1/drug effects
19.
J Nat Prod ; 77(2): 429-32, 2014 Feb 28.
Article in English | MEDLINE | ID: mdl-24499164

ABSTRACT

Through addition of suberoylanilide hydroxamic acid, two new aromatic norditerpenes, aspewentins A (1) and B (2), along with an oxygenated derivative, aspewentin C (3), were obtained from the culture of an Aspergillus wentii strain (na-3) isolated from the tissue of the brown alga Sargassum fusiforme. The structures and absolute configurations were unambiguously elucidated by spectroscopic analyses and quantum chemical calculations. Aspewentins A-C were produced before sporulation and exhibited potent bioactivities against some marine-derived organisms.


Subject(s)
Aspergillus/chemistry , Diterpenes/isolation & purification , Diterpenes/chemistry , Electron Spin Resonance Spectroscopy , Hydroxamic Acids/pharmacology , Marine Biology , Molecular Structure , Sargassum/microbiology , Vorinostat
20.
Bioresour Technol ; 132: 313-9, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23416618

ABSTRACT

An extracellular cellulase produced by marine bacterium Pseudoalteromonas sp. was studied for its activity and stability in six different ionic liquids (ILs) over a wide range of concentrations (1-20% v/v) and compared with aqueous medium as control. Enzyme showed its optimal activity at 45°C and at pH 5 in control. Although the activity varied with the type of IL and its concentration used, the activity measured at 5% (v/v) was maximum with [EMIM]Br followed by [EMIM]Ac, [BMIM]Cl, [C2MIM][CH3SO3], [BMIM][OTF] and [BMPL][OTF] with 115%, 104.7%, 102.2%, 98.33%, 93.84% and 92.67%, respectively, and >80% activity at 15% (v/v) in all ILs. The enzyme stability at 5% (v/v) IL concentration for 36h was superior to commercial cellulase. The cellulase activity enhanced by 1.35- to 1.72-fold over control when 5% (v/v) IL based reaction medium with algal biomass was used and thus showed potentials for saccharification of biomass in a single step process.


Subject(s)
Cellulase/biosynthesis , Cellulase/isolation & purification , Pseudoalteromonas/enzymology , Sargassum/microbiology , Biomass , Catalysis , Cellulase/metabolism , DNA, Ribosomal/genetics , Hydrogen-Ion Concentration , Ionic Liquids/metabolism , Pseudoalteromonas/genetics , Sequence Analysis, DNA , Temperature
SELECTION OF CITATIONS
SEARCH DETAIL
...