Sandy Sediment Samples Research Articles

Structure and in vitro antiproliferative activity against breast cancer cells of the cell-wall polysaccharide from the marine bacterium Kangiella japonica KMM 3899T

Kangiella japonica KMM 3899T is a Gram-negative bacterium isolated from a sandy sediment sample collected from the Sea of Japan. Here the results of the structure and the biological activity against breast cancer cells of the cell-wall polysaccharide from K. japonica KMM 3899T have been described. The structure of the repeating unit of the polysaccharide was elucidated using chemical analysis and NMR spectroscopy:→4)-α-L-GalpNAc3AcA-(1 → 3)-α-D-GlcpNAc-(1 → 4)-β-D-GlcpNAc3NAcAN-(1→.The cell-wall polysaccharide had an antiproliferative effect against T-47D cells. Flow cytometric and Western blot analysis revealed that the polysaccharide induced S phase arrest and mitochondrial-dependent apoptosis.

Characterization and Genomic Analysis of Fererhizobium litorale gen. nov., sp. nov., Isolated from the Sandy Sediments of the Sea of Japan Seashore.

The taxonomic status of two gram-negative, whitish-pigmented motile bacteria KMM 9576T and KMM 9553 isolated from a sandy sediment sample from the Sea of Japan seashore was defined. Phylogenetic analysis revealed that strains KMM 9576T and KMM 9553 represent a distinct lineage within the family Rhizobiaceae, sharing 100% 16S rRNA sequence similarity and 99.5% average nucleotide identity (ANI) to each other. The strains showed the highest 16S rRNA sequence similarities of 97.4% to Sinorhizobium garamanticum LMG 24692T, 96.9% to Ensifer adhaerens NBRC 100388T, and 96.8% to Pararhizobium giardinii NBRC 107135T. The ANI values between strain KMM 9576T and Ensifer adhaerens NBRC 100388T, Sinorhizobium fredii USDA 205T, Pararhizobium giardinii NBRC 107135T, and Rhizobium leguminosarum NBRC 14778T were 79.9%, 79.6%, 79.4%, and 79.2%, respectively. The highest core-proteome average amino acid identity (cpAAI) values of 82.1% and 83.1% were estimated between strain KMM 9576T and Rhizobium leguminosarum NBRC 14778T and 'Rhizobium album' NS-104, respectively. The DNA GC contents were calculated from a genome sequence to be 61.5% (KMM 9576T) and 61.4% (KMM 9553). Both strains contained the major ubiquinone Q-10 and C18:1ω7c as the dominant fatty acid followed by 11-methyl C18:1ω7c and C19:0 cyclo, and polar lipids consisted of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminophospholipid, and two unidentified phospholipids. Based on phylogenetic and phylogenomic analyses, and phenotypic characterization, strains KMM 9576T and KMM 9553 are concluded to represent a novel genus and species, for which the name Fererhizobium litorale gen. nov., sp. nov. is proposed. The type strain of the type species is strain KMM 9576T (=NRIC 0957T).

A new species of Rhyncholagena Lang, 1944 (Copepoda, Harpacticoida, Miraciidae) from Palau.

A new species of Miraciidae Dana, 1846, Rhyncholagenacuspissp. nov., was described from Palau. Morphological descriptions and gene fragment sequence barcoding were performed on the 11th species of Rhyncholagena Lang, 1944 collected from sandy sediment samples in the subtidal zone of the Philippine Sea, Palau. Morphological characteristics were compared and an updated identification key was provided. A new species, Rhyncholagenacuspissp. nov., was found to be morphologically similar to Rhyncholagenalittoralis Por, 1967 and R.bermudensis Malt, 1990. This is the first record of the genus Rhyncholagena in Palau. The study provides basic data for future studies and highlights the need for continued exploration of marine biodiversity in Palau and other regions.

A New Species of the Genus Robertgurneya Apostolov & Marinov, 1988 (Copepoda: Harpacticoida: Miraciidae) from a Sublittoral Zone of Jeju Island, Korea

A new species, Robertgurneya jejuensis sp. nov., was described from sandy sediment samples collected at a depth of 25 m on Mun Island, Jeju, in June 2018. The new species is morphologically similar to Robertgurneya similis similis (Scott A., 1896) and Robertgurneya donghaensis Bang, 2021; this is the second record of the genus Robertgurneya in South Korea. The morphological characteristics of the similis group within the genus Robertgurneya, to which the new species is ascribed, are summarized here. Furthermore, an identification key is provided based on the summary. Molecular identification of the collected specimens, based on the nuclear 18S ribosomal RNA (18S rRNA) and the mitochondrial cytochrome oxidase subunit I fragment, was obtained. Finally, a phylogenetic tree was constructed to present the position of Robertgurneya within the Miraciidae family based on 18S rRNA sequences which is relatively conserved. As a result, the relationship with sister genera morphologically similar to Robertgurneya was also molecularly confirmed.

Removal of non-aqueous phase liquids (NAPLs) from TPH-saturated sandy aquifer sediments using in situ air sparging combined with soil vapor extraction

Contamination in coastal aquifer plains is of great concern in many countries given that non-aqueous phase liquids (NAPLs) have polluted numerous sites through accidental oil spills or improper disposal. We have developed a method to remove pollutants such as NAPLs from sandy sediment samples collected from the Mandol area of Gomso Bay in western South Korea. The sediments were collected from around the diffuser in a two-dimensional (2D) acrylic reaction apparatus, and these contained a total petroleum hydrocarbon (TPH) concentration of 89.3 ppm (mg/kg media). The maximum perchloroethylene (PCE) concentration was 398.51 ppm in the unsaturated zone and 0.77 ppm in the saturated zone. Volatile organic compounds (VOCs) were detected between 20 and 44 hour. However, non-volatile contaminants remained in the sediments after treatment. In situ air sparging (IAS) combined with soil vapor extraction (SVE), transformation from sorbed and nonaqueous phases to the vapor phase, is incomplete when treatment is performed using a pervasive air flow for sediments such as the sand of Mandol. During air transformation, the groundwater flow conditions increased the rate of contaminant removal. Although pilot-scale testing in the field site was fluctuated due to the heterogeneous of sediments condition, this 2D study found that the proposed method can alter the measurable geophysical properties of NAPLs. These findings demonstrate that IAS combined with SVE in the saturated zone is an effective technology for aquifer remediation high applicability of sandy coastal sediments contaminated by NAPLs.

Potential linkage between sediment oxygen demand and pore water chemistry in weir-impounded rivers

Due to recent weir construction on four major rivers in South Korea, sediment has accumulated in the river bottom near the weirs, which has in turn raised concerns over the quality of overlying water. In this study, the seasonal and spatial variations of sediment oxygen demand (SOD) and the influencing factors were explored using pore water chemistry for the weir-impounded rivers. Muddy and sandy sediment samples were taken from 24 different sites along the four major rivers in summer and autumn, 2016. The SOD was measured in a laboratory based on 10-hour incubation at in situ temperature. The measured pore water chemistry included the concentrations of dissolved organic carbon (DOC), total dissolved nitrogen (TDN), inorganic nitrogen (NH3-N, NO3-N, NO2-N), and phosphate phosphorous (PO4-P), and the optical properties from UV absorption spectra and fluorescence excitation-emission matrixes coupled with parallel factor analysis (EEM-PARAFAC). Significant differences in SOD values between muddy and sandy sediments were found only in summer (p=0.047). The higher SOD in summer versus autumn (p=0.015) was attributed to seasonal temperature differences. The higher NH3-N and the lower NO3-N of the pore water samples in summer versus autumn suggested that organic nitrogen decomposition via an ammonification and nitrification process could operate as an important factor for the SOD variations in summer and autumn, respectively. Principal component analysis revealed the mutual contributions of nitrogen-associated processes and the organic composition in pore water to increasing SOD levels. NH3-N in sediment pore water alone could be a good predictor for SOD. However, multiple regression analysis using NH3-N, fluorescence index and terrestrial humic-like components improved the estimation capability for SOD variations.

Evaluation of arsenic sorption and mobility in stream sediment and hot spring deposit in three drainages of the Tibetan Plateau

Enrichment of arsenic (As) in sediment (12–227 mg/kg) in the upstream tributaries of the Indus and Brahmaputra Rivers originating from the Tibetan Plateau where hot springs were abundant has been found. Sandy sediment samples from the Nu-Salween River, Lantsang-Mekong River and Jinsha-Yangtze River also originating from the Tibetan Plateau were collected in July, 2012 and were found to contain 6.8 mg/kg to 30.5 mg/kg As (average17.3 ± 6.5 mg/kg, n = 12). Deposits collected within 1 m of two hot springs in Changdu, Tibet displayed significantly higher As levels: 263.7 mg/kg in LD-2 with 65% quartz and 101.8 mg/kg in NuD-1 with 82% calcite. To evaluate the valence states of As and also the phases responsible for sorption, X-Ray Absorption Spectroscopy (XAS) was employed to analyze the two hot spring deposits and three river sediment samples: coarse sand NuD-6 (As 14.6 mg/kg), fine sand NuD-4 (As 17.8 mg/kg), and silty sand LD-1 (As 30.5 mg/kg). The X-ray absorption near edge spectrum (XANES) data indicate that 70% of As from 3 samples in the Nu-Salween River drainage (NuD-1, NuD-4 and NuD-6) is As(V) or arsenate, with the rest being As(0) or As–Fe sulfides. The proportion of As(V) is 90% for 2 samples in the Lantsang-Mekong River drainage (LD-1 and LD-2). Linear combination fit of the iron extended X-ray fine structure spectrum (EXAFS) show that 3 samples from the Nu-Salween River contain 20% ferrihydrite and 10% goethite without any hematite being detected but 2 samples from the Lantsang-Mekong River contain <10% ferrihydrite, 20% goethite and with 30–60% of hematite. Concentrations of reductively leached As and Fe are correlated (Pearson correlation coefficient 0.673), with an average value of extracted As being 1.7 ± 0.6 mg/kg (n = 8) and 4.3 ± 2.0 mg/kg (n = 3) for the Nu-Salween and Lantsang-Mekong river, respectively. Parameters from the Langmuir isotherm fit to sorption experiments of As(III) and As(V) onto three river sediment samples were used to estimate “sorbed” As concentrations in river sediment in equilibrium with the average river water As concentrations. The “sorbed” As concentrations were 0.8 mg/kg and 2.8 mg/kg for the Nu-Salween and Lantsang-Mekong drainage, respectively. Taken together, the data suggest that this pool of “sorbed” As in river sand, likely to have a geothermal As component, remains largely particle-bound in the oxic and circumneutral riverine environment during transport; it is subject to mobilization once buried in the floodplain areas down gradient.

Loss of soil phosphorus by tile drains during storm events

Phosphorus losses from agricultural soils are usually predominately caused by surface-runoff and only rarely by tile drain discharge. However, storm events can drastically increase P transfer to water bodies. In 2011 summer storm events caused 3.2 fold higher precipitation compared to the long-term average in Northern Germany. During these storm events excessive yellow-brown ochre flocs were observed in drain discharges and supposed to be potential P carrier. Therefore, water samples with ochre flocs were taken and analyzed by light and electron microscopy and for total elemental concentrations of P and its common binding partners (Al, Fe, Mn). Additionally, sandy sediment samples were taken in winter and analyzed for total and oxalate-extractable amounts of these elements. Water samples with ochre flocs revealed total P concentrations of approximately 27 to 141mgl−1. During the high discharge period a cumulative discharge of 124.6mm from a drain plot of 4.2ha was recorded, which resulted in a calculated minimum loss of 34kg Ptha−1. This was assumed to be promoted by the excessive occurrence of ochre flocs, which were mainly formed by fungal mycelia with precipitated Fe- and Mn-(hydr)oxides at the surface. The poor crystallinity of the Fe-oxides from the discharge of tile drains was confirmed by an amount of up to 94% of active Fe-oxides in the sandy sediment. The extremely high discharge from tile drains, the flocky nature of the ochre along with a poor crystallinity of Fe-oxides and high P concentrations possess the risk of increased input and bioavailability of P in water bodies. Therefore, discharge and P forms from tile drained areas should be monitored more intensively and retention of P on tile drain outlets should be considered to prevent water bodies from eutrophication.

Análisis de proveniencia de las arenas del complejo de dunas parabólicas El Socorro, Baja California, México, mediante una caracterización mineralógica y granulométrica

In this study, fourteen superficial sandy sediment samples and fifteen core samples, taken at 2 to 30 m in depth, were analyzed in order to determine the granulometry and mineralogical features of the dune system named duna costera El Socorro (DCES), San Quintin, Baja California, Mexico. In addition, we investigated the sediment provenance by analyzing twelve samples collected from three nearby arroyos and sand bars. The main components of the DCES are plagioclase and quartz (35 - 39 % and 36 - 58 % plagioclase, and 50 - 56 % and 38 - 60 % monocrystalline quartz for core samples and superficial samples, respectively). The remaining components include scarce lithic fragments and abundant heavy minerals, mostly hornblende and traces of pyroxene, but also small amounts of magnetite and ilmenite (> 1 % in volume). The samples from arroyo El Socorro (south of the DCES) and arroyo Santo Domingo (~45 km north of the DCES) contain 69 and 52 % monocrystalline quartz, respectively, while arroyo San Simon, located north of the DCES,

Poseidonocella pacifica gen. nov., sp. nov. and Poseidonocella sedimentorum sp. nov., novel alphaproteobacteria from the shallow sandy sediments of the Sea of Japan

The taxonomic study of two Gram-negative, aerobic, non-pigmented bacteria KMM 9010(T) and KMM 9023(T) isolated from a sandy sediment sample collected from the Sea of Japan seashore was performed. On the basis of the nearly complete 16S rRNA gene sequences, strains KMM 9010(T) and KMM 9023(T) clustered with the Roseobacter lineage (class Alphaproteobacteria) forming a distinct phylogenetic line adjacent to the genus Donghicola. Novel strains shared the highest sequence similarity of 96.4% to each other and lower than 96.1% similarities to other validly named genera of the class Alphaproteobacteria. In both strains, ubiquinone Q-10 was found to be the major respiratory quinone; phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidic acid, and an unknown aminolipid were the major polar lipids and C(18:1)ω7c and 11-methyl C(18:1)ω7c were predominant fatty acids. The DNA G+C content was 60.5mol% (KMM 9010(T)) and 65.4mol% (KMM 9023(T)). Based on phenotypic properties and phylogenetic evidence, strains KMM 9010(T) and KMM 9023(T) should be classified as two novel species in a new genus, Poseidonocella gen. nov., with Poseidonocella pacifica sp. nov., the type species with the type strain KMM 9010(T) (= NRIC 0794(T)=JCM 17310(T)), and Poseidonocella sedimentorum sp. nov. as the second species with the type strain KMM 9023(T) (= NRIC 0796(T)=JCM 17311(T)).

Non-pollen palynomorphs as environmental indicators in the surface samples from mangrove in Costa Rica

Different organic walled non-pollen palynomorphs were identified from thirteen surface silty and sandy sediment samples in the southern part of Costa Rica, where mangroves are widespread. Non-pollen palynomorphs are numerous and diverse in comparison with the scarce pollen and spores of vascular plants. They are represented by dinoflagellate cysts, algal palynomorphs of Chlorophyta, cyanobacteria, fungal spores and hyphae, microforaminifers, scolecodonts and phytoliths. The most frequently represented are Botryococcus and microforaminifers whose frequen- cies change depending on the salinity of environments related to marine influence. Chlamydospores of the fungus Glomus are related with erosive processes. Cyanobacteria of the Rivularia-type may be connected to an increase in eutrophication by organic phosphate within an estuary. Non-pollen palynomorphs data are important as a palynological complement in the coastal regions of Costa Rica. Non-pollen palynomorphs are associated with pollen of Rhizophora, Lagencularia, Avicennia, Poaceae, Cyperaceae, and spores of various mangrove vegetation ferns.

Vadicella arenosi gen. nov., sp. nov., a Novel Member of the Class Alphaproteobacteria Isolated from Sandy Sediments from the Sea of Japan Seashore

A taxonomic study of three aerobic, Gram-negative, non-pigmented, non-motile rod-shaped bacterial strains, designated KMM 9008, KMM 9017, and KMM 9024(T), which were isolated from a sandy sediment sample collected from the Sea of Japan seashore, was undertaken. The DNA-DNA hybridization values of 88-96% obtained between novel strains confirm their assignment to the same species. An analysis of the nearly complete 16S rRNA gene sequences showed that the novel isolates were closely related to each other (99.6-100% sequence similarity) and shared highest sequence similarities to the described genera Celeribacter (96.2-95.9%), Pseudoruegeria (95.6-94.3%), and Thalassobacter (95.2-93.1%) within the class Alphaproteobacteria. The major isoprenoid quinone was Q-10, polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidic acid, an unknown aminolipid and an unknown lipid as prevalent, and phosphatidylethanolamine was a minor component, and major fatty acids were C(18:1) ω7c , followed by 11-Methyl C(18:1) ω7c, C(12:1) and C(10:0) 3-OH in all strains. The DNA G+C content of strains KMM 9008, KMM 9017, and KMM 9024(T) was in the range of 56.7-60 mol%. Based on distinctive phenotypic characteristics and phylogenetic distance, strain KMM 9024(T) (=NRIC 0787(T) = JCM 17190(T)) represents the type strain of a novel species in a novel genus, for which the name Vadicella arenosi gen. nov., sp. nov. is proposed.

Pacificibacter maritimus gen. nov., sp. nov., isolated from shallow marine sediment

An aerobic, Gram-stain-negative, non-pigmented, non-motile bacterium, strain KMM 9031(T), was isolated from a sandy sediment sample collected from the shore of the Sea of Japan and subjected to phenotypic and phylogenetic analysis. Based on comparative 16S rRNA gene sequence analysis, strain KMM 9031(T) constituted a separate phylogenetic line within the Roseobacter clade of the class Alphaproteobacteria, sharing highest sequence similarities with members of the genera Roseovarius (92.7-95.3 %), Pseudoruegeria (94.5 %), Sulfitobacter (92.7-94.4 %) and Thalassobacter (94.2-94.3 %). The predominant fatty acid of strain KMM 9031(T) was C(18 : 1)ω7c, with C(16 : 0), C(10 : 0) 3-OH and C(12 : 1) 3-OH present in lesser amounts. The DNA G+C content of the isolate was 52.6 mol%. The major isoprenoid quinone was Q-10 and polar lipids comprised phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol and two unknown lipids. On the basis of phylogenetic analysis and physiological and biochemical characterization, strain KMM 9031(T) represents a novel species in a new genus, for which the name Pacificibacter maritimus gen. nov., sp. nov. is proposed; the type strain is KMM 9031(T) ( = NRIC 0785(T) = JCM 17096(T)).

Roseovarius nanhaiticus sp. nov., a member of the Roseobacter clade isolated from marine sediment

An aerobic, Gram-staining-negative, rod or ovoid-shaped bacterial isolate, strain NH52J(T), was isolated from a sandy sediment sample from the South China Sea. Strain NH52J(T) exhibited tumbling motility, formed beige or faint pink colonies, gave a positive reaction in tests for catalase and oxidase and required NaCl for growth. Optimal growth was observed at pH 7.8-9.3, at 30 degrees C and in the presence of 2.0-4.0 % (w/v) NaCl. The novel strain did not synthesize bacteriochlorophyll a, and the DNA G+C content was 62 %. The major fatty acids were C(18 : 1)omega7c, C(16 : 0) and C(18 : 1)omega7c 11-methyl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NH52J(T) was affiliated to the genus Roseovarius of the class Alphaproteobacteria. Roseovarius pacificus and Roseovarius aestuarii were the most closely related recognized species to strain NH52J(T) with 16S rRNA gene sequence similarity values of 95.0 and 95.7 %, respectively. Sequence similarity values between strain NH52J(T) and other phylogenetically related species were all below 95.0 %. Based on the phenotypic, chemotaxonomic and phylogenetic data presented, strain NH52J(T) is considered to represent a novel species of the genus Roseovarius, for which the name Roseovarius nanhaiticus sp. nov. is proposed. The type strain is NH52J(T) (=LMG 24840(T)=CCTCC AB 208317(T)=MCCC 1A03543(T)).

Leisingera nanhaiensis sp. nov., isolated from marine sediment

An aerobic, Gram-staining-negative, motile, rod-shaped bacterium, strain NH52F(T), was isolated from a sandy sediment sample taken from the South China Sea. On M2 agar medium (a complex medium), colonies were beige in colour. The isolate showed highest 16S rRNA gene sequence similarities to members of the genera Leisingera (96.7 % similarity), Phaeobacter (95.4-96.0 %) and Marinovum (94.1 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NH52F(T) formed a distinct cluster with Leisingera methylohalidivorans MB2(T) and Leisingera aquimarina LMG 24366(T). Optimal growth was observed at pH 7.0-8.5 and 25 degrees C and the new isolate required the presence of 1-4 % (w/v) NaCl. The major fatty acids were C(18 : 1)omega7c, C(16 : 0) 2-OH, C(10 : 0) 3-OH, C(12 : 0) 3-OH, C(16 : 0) and 11-methyl C(18 : 1)omega7c. The DNA G+C content was 60.5 mol%. The phylogenetic and chemotaxonomic characteristics of strain NH52F(T) were similar to those of the genus Leisingera. However, the differences in phenotypic properties and the 16S rRNA gene similarity values demonstrated that the new isolate differed from recognized species of the genus Leisingera. On the basis of phenotypic, chemotaxonomic and phylogenetic data, this organism should be classified as a representative of a novel species in the genus Leisingera, for which the name Leisingera nanhaiensis sp. nov. is proposed. The type strain is NH52F(T) (=LMG 24841(T)=CCTCC AB 208316(T)=MCCC 1A04178(T)).

Aestuariibacter litoralis sp. nov., isolated from a sandy sediment of the Sea of Japan

The phenotypic and phylogenetic characteristics of an aerobic, Gram-negative, motile, non-pigmented Alteromonas-like bacterium (designated strain KMM 3894(T)), isolated from a sandy sediment sample collected offshore of the Sea of Japan, were investigated. Comparative 16S rRNA gene sequence analysis revealed that strain KMM 3894(T) belonged to the genus Aestuariibacter and was most closely related to Aestuariibacter halophilus JC2043(T) (95.5 % sequence similarity). Fatty acid analysis showed C(16 : 1)omega7c, C(18 : 1)omega7c, and C(16 : 0) as the dominant components. Strain KMM 3894(T) could be differentiated from recognized species of the genus Aestuariibacter by its ability to grow at 4 degrees C and at 30 degrees C, the optimum temperature for growth, and its inability to utilize most carbohydrates. On the basis of the phenotypic, chemotaxonomic and phylogenetic data, strain KMM 3894(T) is considered to represent a novel species of the genus Aestuariibacter, for which the name Aestuariibacter litoralis sp. nov. is proposed. The type strain is KMM 3894(T) (=NRIC 0754(T)=JCM 15896(T)).

Arenibacter nanhaiticus sp. nov., isolated from marine sediment of the South China Sea

An aerobic, Gram-stain-negative, rod-shaped bacterial isolate, strain NH36A(T), was isolated from a sandy sediment sample from the South China Sea. Colonies of the isolate were dark orange on M2 agar. Optimal growth was observed at pH 7.0-8.5, 30 degrees C and in the presence of 0.5-4.0 % (w/v) NaCl. The major fatty acids were C(15 : 0), iso-C(15 : 0), anteiso-C(15 : 0), iso-C(15 : 1), iso-C(15 : 0) 3-OH, iso-C(17 : 0) 3-OH and summed feature 3 (comprising iso-C(15 : 0) 2-OH and/or C(16 : 1)omega7c). The DNA G+C content was 38.9 mol%. 16S rRNA gene sequence analysis revealed that strain NH36A(T) was most closely related to members of the genus Arenibacter, exhibiting 94.3-96.2 % sequence similarity to the type strains of Arenibacter species. On the basis of phenotypic, chemotaxonomic and phylogenetic data, this organism should be classified as a representative of a novel species in the genus Arenibacter. The name Arenibacter nanhaiticus sp. nov. is proposed and the type strain is NH36A(T) (=LMG 24842(T)=CCTCC AB 208315(T)=MCCC 1A04137(T)).

Distribution and Statistical Analysis of Leachable and Total Heavy Metals in the Sediments of the Suez Gulf

The concentrations of nine heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pd and Zn) in the labile and total fractions of muddy and sandy sediment samples collected from twelve sites in Suez Gulf during April 1999 were studied to evaluate the pollution status of the Suez Gulf. The enrichment factors (EF) for each element were calculated. There are extremely high concentrations of Cd, Ni, Pb and slightly concentration of Cr and Cu in both muddy and sandy sediments. The concentration of Zn was moderately high and can be considered as seriously contaminate Metal pollution index (MPI) shows high values ranged between 46 to 156 and 40 to 232 for both sandy and muddy sediments, respectively. Concentrations of heavy metals were normalized against iron for total fraction in both of sandy and muddy sediments. Principal component analysis (PCA) was studied on the data matrix obtained and represented three-factor model explaining 92.22% for labile and 88.82% for total fractions of muddy sediment. The main source of contamination is the offshore oil fields and industrial wastes. This is largely a result of ineffective and inefficient operation equipment, illegal discharge of dirty ballast water from tankers and lack of supervision and prosecution of offenders.

Remediation of α-methylnaphthalene-contaminated sediments using peroxy acid

Laboratory experiments have been conducted to elucidate the degradation of α-methylnaphthalene in lake sediments using an advanced oxidation process (AOP) employing peroxy-acids as oxidizing agents. Abiotic degradation of α-methylnaphthalene was observed in sediment samples exposed to a 1:1:1 v/v/v mixture of water/organic acid/hydrogen peroxide solution. Sediment samples were collected from Lake Macatawa (Holland, MI) and ranged in total organic carbon content from 2.1% (sandy sediment sample III) to 12.8% (silty-clay sediment sample I) and surface area, which ranged from 3.2 m 2/g (sandy sediment sample III) to 22.0 m 2/g (silty-clay sediment sample I). Analytical measurements performed by gas chromatography revealed varied rates of degradation, depending on the type of acid and the characteristics of the sediment sample. Within 24 h, α-methylnaphthalene was reduced to 70% and 100% of its original concentration when propionic acid and acetic acid were used as the organic acids, respectively. The formation of products was explored using a gas chromatograph equipped with a mass spectrometer and indicated mainly the formation of lower molecular weight compounds, such as alkyl chains. This AOP method of PAH degradation in sediment/liquid slurry was fast acting and products were most likely biodegradable.

Arenibacter gen. nov., new genus of the family flavobacteriaceae and description of a new species, Arenibacter latericius sp. nov.

Five dark-orange-pigmented, Gram-negative, rod-shaped, non-motile, aerobic bacterial strains were isolated from sandy sediment samples collected in the South China Sea in the Indian Ocean, from a holothurian, Apostichopus japonicus, in the Sea of Japan and from a brown alga, Chorda filum, from the Sea of Okhotsk in the Pacific Ocean. Phenotypic data were collected, demonstrating that the bacteria are chemo-organotrophic and require seawater-based media for growth. Polar lipids were analysed and 27% of the total extract comprised phosphatidylethanolamine as the major component. The predominant cellular fatty acids were branched-chain saturated and unsaturated [i-C15:0, i-C15:1, a-C15:0, C15:0, C16:1(n-7)]. The DNA base composition was 37.5-38.2 mol % G+C. The level of DNA homology of the five isolates was 83-94%, indicating that these isolates belong to the same species. A 16S rDNA sequence of the type strain KMM 426T was determined and phylogenetic analysis, based on neighbour-joining and Fitch-Margoliash methods, revealed that the type strain formed a distinct phyletic line in a clade corresponding to the family Flavobacteriaceae and represented a new genus. From the results of this polyphasic taxonomic analysis, it is proposed that the bacterial strains be classified in a new genus, Arenibacter gen. nov., and species, Arenibacter latericius sp. nov. The type strain is KMM 426T (VKM B 2137DT = LMG 19694T = CIP 106861T).