Tepidibacter aestuarii sp. nov., isolated from the Bach Dang Estuary, Haiphong, Vietnam.

A mesophilic, anaerobic, endospore-forming, fermentative bacterium designated strain 8C15bT was isolated from bank sediment of the Bach Dang Estuary, Haiphong, Vietnam. The Bach Dang Estuary, where Haiphong harbour is located, is subject to strong anthropogenic influence, resulting in high concentrations of black carbon and heavy metals. Strain 8C15bT grew optimally at 30 °C, pH 7.5 and with 2.5 % (w/v) NaCl. The main cellular fatty acids consisted of iso-C15 : 0 (51 %), iso-C15:1 ω7c (32 %) and iso-C13 : 0 (5 %). Genomic considerations of strain 8C15bT and comparisons with the phylogenetically closest strains of the genus Tepidibacter provide evidence that Tepidibacter thalassicus SC562T (=DSM 15285T), Tepidibacter formicigenes DV1184T (=DSM 15518T), Tepidibacter mesophilus B1T (=JCM 16806T) and strain 8C15bT could be differentiated at the species level. We propose the name Tepidibacter aestuarii sp. nov. for the type strain 8C15bT (=JCM 35983T=KCTC 25692T). Finally, the nickel-tolerance properties of strain 8C15bT are highlighted in this study.

Thermospira aquatica gen. nov., sp. nov., a novel thermophilic spirochete isolated from a Tunisian hot spring, and description of the novel family Thermospiraceae.

A novel thermophilic, anaerobic bacterium, strain F1F22T, was isolated from hot spring water collected in northern Tunisia. The cells were non-motile, Gram-negative and helical with hooked ends, 0.5×10-32 µm in size. Growth of the strain was observed at 45-70 °C (optimum, 55 °C), in 0.0-1.0 % (w/v) NaCl (optimum without NaCl) and at pH 6.5-8.5 (optimum, pH 7.5). Yeast extract was required for growth, and the strain grew on glucose, sucrose and maltose. The major fatty acids were C16:0 (40.2 %), iso-C16: 0 (30.2 %) and C16 :0 DMA (14.5 %). The genome consisted of a circular chromosome (2.5 Mb) containing 2672 predicted protein-encoding genes with a G+C content of 43.15 mol %. Based on a comparative 16S rRNA gene sequence analysis, strain F1F22T formed a deeply branching lineage within the phylum Spirochaetota, class Spirochaetia, order Brevinematales, and had only low sequence similarity to other species of the phylum (lower than 83 %). Genome-based analysis of average nucleotide identity and digital DNA-DNA hybridization of strain F1F22T with Treponema caldarium DSM 7334T, Brevinema andersonii ATCC 43811T and Spirochaeta thermophila DSM 6578T showed values between 63.26 and 63.52 %, and between 20 and 25 %. Hence, we propose strain F1F22T as a representative of a novel family (Thermospiraceae fam. nov.), genus and species of Brevinematales: Thermospira aquatica gen. nov., sp. nov. (type strain F1F22T=JCM 31314T=DSM 101182T).

Complete Genome Sequence of Tepidibacter sp. Strain 8C15b, Isolated from Bank Sediments of Haiphong Bay, Vietnam.

We report the complete genome sequence of Tepidibacter sp. strain 8C15b, isolated from bank sediments of Haiphong Bay, Vietnam. The genome includes a 3,628,320-bp circular chromosome and a plasmid of 38,213 bp.

Bacterial diversity obtained by culturable approaches in the gut of Glossina pallidipes population from a non sleeping sickness focus in Tanzania: preliminary results.

BACKGROUND: Glossina pallidipes is a haematophagous insect that serves as a cyclic transmitter of trypanosomes causing African Trypanosomiasis (AT). To fully assess the role of G. pallidipes in the epidemiology of AT, especially the human form of the disease (HAT), it is essential to know the microbial diversity inhabiting the gut of natural fly populations. This study aimed to examine the diversity of G. pallidipes fly gut bacteria by culture-dependent approaches. RESULTS: 113 bacterial isolates were obtained from aerobic and anaerobic microorganisms originating from the gut of G. pallidipes. 16S rDNA of each isolate was PCR amplified and sequenced. The overall majority of identified bacteria belonged in descending order to the Firmicutes (86.6%), Actinobacteria (7.6%), Proteobacteria (5.5%)and Bacteroidetes (0.3%). Diversity of Firmicutes was found higher when enrichments and isolation were performed under anaerobic conditions than aerobic ones. Experiments conducted in the absence of oxygen (anaerobiosis) led to the isolation of bacteria pertaining to four phyla (83% Firmicutes, 15% Actinobacteria, 1% Proteobacteria and 0.5% Bacteroidetes, whereas those conducted in the presence of oxygen (aerobiosis) led to the isolation of bacteria affiliated to two phyla only (90% Firmicutes and 10% Proteobacteria). Phylogenetic analyses placed these isolates into 11 genera namely Bacillus, Acinetobacter, Mesorhizobium, Paracoccus, Microbacterium, Micrococcus, Arthrobacter, Corynobacterium, Curtobacterium, Vagococcus and Dietzia spp.which are known to be either facultative anaerobes, aerobes, or even microaerobes. CONCLUSION: This study shows that G. pallidipes fly gut is an environmental reservoir for a vast number of bacterial species, which are likely to be important for ecological microbial well being of the fly and possibly on differing vectorial competence and refractoriness against AT epidemiology.

Abundance and diversity of prokaryotes in ephemeral hypersaline lake Chott El Jerid using Illumina Miseq sequencing, DGGE and qPCR assays.

Chott El Jerid is the largest hypersaline ephemeral lake in southern Tunisian Sahara desert and is one of the biggest depressions at the North of Africa. This study aimed to investigate the diversity and abundance of microbial communities inhabiting Chott El Jerid during wet season (when it was flooded), using molecular methods [Illumina Miseq sequencing, DGGE and qPCR (qPCR)]. 16S rRNA gene analyses revealed that bacterial community was dominated by Proteobacteria (especially Ralstonia species), followed by Firmicutes, Bacteroidetes, Cyanobacteria, Actinobacteria and Verrucomicrobia. The results obtained using prokaryotic universal primers showed low relative abundance of Archaea dominated by few OTUs related to Methanosarcinaceae and Methanomassiliicoccaceae families and the presence of sulfate-reducing Archaea affiliated with Archaeoglobus. However, the results obtained using Archaea-specific primers showed that archaeal community was mainly composed of aerobic Halobacteria (especially Halorubrum species) and anaerobic members of Methanomicrobia. These results also provided evidence for the presence of members of the genus Halohasta in this environment. qPCR results revealed that Archaea were more abundant in studied samples than Bacteria. The sulfate-reducing Bacteria were also found abundant (~ one-third of the bacterial community) and outnumbered methanogens, suggesting their potential important role in this sulfate-rich and hypersaline ecosystem.

Characterization of Desulfovibrio salinus sp. nov., a slightly halophilic sulfate-reducing bacterium isolated from a saline lake in Tunisia.

A novel slightly halophilic sulfate-reducing bacterium, designated strain P1BSRT, was isolated from water of a saline lake in Tunisia. Strain P1BSRT had motile (single polar flagellum), Gram-negative, rod-shaped, non-spore-forming cells, occurring singly or in pairs. Strain P1BSRT grew at temperatures between 15 and 45 °C (optimum 40 °C), and in a pH range between 6 and 8.5 (optimum pH 6.7). The strain required NaCl for growth (1 % w/v), and tolerated high NaCl concentration (up to 12 % w/v) with an optimum of 3 % (w/v). Sulfate, thiosulfate and sulfite served as terminal electron acceptors, but not elemental sulfur, fumarate, nitrate and nitrite. Strain P1BSRT utilized lactate, pyruvate, formate, d-fructose and glycerol as carbon and energy sources. The main cellular fatty acid was C16 : 0 (50.8 %). The genomic DNA G+C content was 47.7 mol%. Phylogenetic analysis of 16S rRNA gene sequence similarity indicated that strain P1BSRT was affiliated to the genus Desulfovibrio, with the type strains Desulfovibrio salexigens (96.51 %), Desulfovibrio zosterae (95.68 %), Desulfovibrio hydrothermalis (94.81 %) and Desulfovibrio ferrireducens (94.73 %) as its closest phylogenetic relatives. On the basis of genotypic, phenotypic and phylogenetic characteristics, it is proposed to assign strain P1BSRT to a novel species of the genus Desulfovibrio, Desulfovibrio salinus sp. nov. The type strain is P1BSRT (=DSM 101510T=JCM 31065T).

Desulfovibrio senegalensis sp. nov., a mesophilic sulfate reducer isolated from marine sediment.

Several strains of sulfate-reducing bacteria were isolated from marine sediments recovered from Hann Bay (Senegal). All were related to members of the genus Desulfovibrio. A strictly anaerobic, mesophilic and moderately halophilic strain designated BLaC1T was further characterized. Cells of strain BLaC1T stained Gram-negative and were 0.5 µm wide and 2-4 µm long, motile, rod-shaped and non-spore-forming. The four major fatty acids were anteiso-C15 : 0, iso-C15 : 0, iso-C17 : 0 and anteiso-C17 : 0. Growth was observed from 15 to 45 °C (optimum 40 °C) and at pH 5.5-8 (optimum pH 7.5). The salinity range for growth was 5-65 g NaCl l-1 (optimum 30 g l-1). Yeast extract was required for growth. Strain BLaC1T was able to grow on lactate and acetate in the presence of sulfate as an electron acceptor. Sulfate, thiosulfate and sulfite could serve as terminal electron acceptors, but not fumarate, nitrate or elemental sulfur. The DNA G+C content was 55.8 mol%. 16S rRNA gene sequence analysis assigned strain BLaC1T to the family Desulfovibrionaceae; its closest relative was Desulfovibrio oxyclinae DSM 19275T (93.7 % similarity). On the basis of 16S rRNA gene sequence comparisons and physiological characteristics, strain BLaC1T is proposed as representing a novel species of Desulfovibrio, with the name Desulfovibrio senegalensis sp. nov. The type strain is BLaC1T (=DSM 101509T=JCM 31063T).

Virgibacillus ainsalahensis sp. nov., a Moderately Halophilic Bacterium Isolated from Sediment of a Saline Lake in South of Algeria.

A Gram-positive, moderately halophilic, endospore-forming bacterium, designated MerVT, was isolated from a sediment sample of a saline lake located in Ain Salah, south of Algeria. The cells were rod shaped and motile. Isolate MerVT grew at salinity interval of 0.5-25% NaCl (optimum, 5-10%), pH 6.0-12.0 (optimum, 8.0), and temperature between 10 and 40 °C (optimum, 30 °C).The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, a glycolipid, a phospholipid, and two lipids, and MK-7 is the predominant menaquinone. The predominant cellular fatty acids were anteiso C15:0 and anteiso C17:0. The DNA G+C content was 45.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain MerVT was most closely related to Virgibacillus halodenitrificans (gene sequence similarity of 97.0%). On the basis of phenotypic, chemotaxonomic properties, and phylogenetic analyses, strain MerVT (=DSM = 28944T) should be placed in the genus Virgibacillus as a novel species, for which the name Virgibacillus ainsalahensis is proposed.

Paludifilum halophilum gen. nov., sp. nov., a thermoactinomycete isolated from superficial sediment of a solar saltern.

A novel filamentous, halophilic, thermotolerant bacterium, strain SMBg3T was isolated from superficial sediment of a solar saltern in Sfax, Tunisia. The isolate is Gram-staining-positive, aerobic, catalase- and oxidase-positive. Optimum growth occurred at 40-45 °C, with 10 % (w/v) NaCl and at pH 8.0-9.0. Long and well developed aerial and substrate mycelia, with long chains of fluorescent and circular spores, were observed on all tested media. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SMBg3T belongs to an independent phylogenetic lineage of the family Thermoactinomycetaceae and shows a gene sequence similarity of 94 % with Desmospora activa DSM 45169T 94.2 % with Kroppenstedtia eburnea DSM 45196T, 94.3 % with Kroppenstedtia guangzhouensis KCTC 29149T, 94.3 % with Melghirimyces algeriensisDSM 45474T and 94.5 % with Salinithrix halophila CECT 8506T. The predominant menaquinone is MK-7, but MK-8 and some minor unidentified components are also present in trace amounts. The major cellular fatty acids are anteiso-C15 : 0, iso-C15 : 0 and iso-C17 : 0. In addition to four major polar lipids identified as phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and phosphatidylmethylethanolamine, five minor unknown lipids were detected in cell membranes. The DNA G+C content of strain SMBg3T is 51.2 mol%. Strain SMBg3T is distinct from recognized genera of the family Thermoactinomycetaceae by morphological, biochemical and chemotaxonomic characteristics. On the basis of physiological and phylogenetic data, strain SMBg3T represents a novel species of a new genus in the family Thermoactinomycetaceae for which the name Paludifilum halophilum gen. nov., sp. nov. is proposed. The type strain of the type species is SMBg3T (=DSM 102817T=CCUG 68698T).

Bacterial ecology of abattoir wastewater treated by an anaerobic digestor

Abstract Wastewater from an anaerobic treatment plant at a slaughterhouse was analysed to determine the bacterial biodiversity present. Molecular analysis of the anaerobic sludge obtained from the treatment plant showed significant diversity, as 27 different phyla were identified. Firmicutes, Proteobacteria, Bacteroidetes, Thermotogae, Euryarchaeota (methanogens), and msbl6 (candidate division) were the dominant phyla of the anaerobic treatment plant and represented 21.7%, 18.5%, 11.5%, 9.4%, 8.9%, and 8.8% of the total bacteria identified, respectively. The dominant bacteria isolated were Clostridium, Bacteroides, Desulfobulbus, Desulfomicrobium, Desulfovibrio and Desulfotomaculum. Our results revealed the presence of new species, genera and families of microorganisms. The most interesting strains were characterised. Three new bacteria involved in anaerobic digestion of abattoir wastewater were published.

Bacterial ecology of abattoir wastewater treated by an anaerobic digestor.

Wastewater from an anaerobic treatment plant at a slaughterhouse was analysed to determine the bacterial biodiversity present. Molecular analysis of the anaerobic sludge obtained from the treatment plant showed significant diversity, as 27 different phyla were identified. Firmicutes, Proteobacteria, Bacteroidetes, Thermotogae, Euryarchaeota (methanogens), and msbl6 (candidate division) were the dominant phyla of the anaerobic treatment plant and represented 21.7%, 18.5%, 11.5%, 9.4%, 8.9%, and 8.8% of the total bacteria identified, respectively. The dominant bacteria isolated were Clostridium, Bacteroides, Desulfobulbus, Desulfomicrobium, Desulfovibrio and Desulfotomaculum. Our results revealed the presence of new species, genera and families of microorganisms. The most interesting strains were characterised. Three new bacteria involved in anaerobic digestion of abattoir wastewater were published.

Prokaryotic diversity in a Tunisian hypersaline lake, Chott El Jerid.

Prokaryotic diversity was investigated in a Tunisian salt lake, Chott El Jerid, by quantitative real-time PCR, denaturing gradient gel electrophoresis (DGGE) fingerprinting methods targeting the 16S rRNA gene and culture-dependent methods. Two different samples S1-10 and S2-10 were taken from under the salt crust of Chott El Jerid in the dry season. DGGE analysis revealed that bacterial sequences were related to Firmicutes, Proteobacteria, unclassified bacteria, and Deinococcus-Thermus phyla. Anaerobic fermentative and sulfate-reducing bacteria were also detected in this ecosystem. Within the domain archaea, all sequences were affiliated to Euryarchaeota phylum. Quantitative real-time PCR showed that 16S rRNA gene copy numbers of bacteria was 5 × 10(6) DNA copies g(-1) whereas archaea varied between 5 × 10(5) and 10(6) DNA copies g(-1) in these samples. Eight anaerobic halophilic fermentative bacterial strains were isolated and affiliated with the species Halanaerobium alcaliphilum, Halanaerobium saccharolyticum, and Sporohalobacter salinus. These data showed an abundant and diverse microbial community detected in the hypersaline thalassohaline environment of Chott El Jerid.

Reclassification of Anaerobaculum mobile, Anaerobaculum thermoterrenum, Anaerobaculum hydrogeniformans as Acetomicrobium mobile comb. nov., Acetomicrobium thermoterrenum comb. nov. and Acetomicrobium hydrogeniformans comb. nov., respectively, and emendation of the genus Acetomicrobium.

Taking into account their 16S rRNA gene sequences, it appears that Acetomicrobium flavidum and the three species of the genus Anaerobaculum described so far belong to the same phylogenetic clade with high levels (>95 %) of similarity. In this respect, these three Anaerobaculum species should be reclassified within the genus Acetomicrobium, which has priority over the genus Anaerobaculum, which was validated since the genus Acetomicrobium. The DNA G+C content of Acetomicrobium flavidum is 47.1 mol%, which is of the same order as that of the three Anaerobaculum species. All these bacteria have in common iso-C15 : 0 as their main fatty acid. Based on further phylogenetic, genetic and chemotaxonomic studies, we propose that Anaerobaculum mobile ( = DSM 13181T = JCM 12221T), Anaerobaculum thermoterrenum ( = DSM 13490T = ACM 5076T) and Anaerobaculum hydrogeniformans ( = DSM 22491T = ATCC BAA-1850T) be reclassified as Acetomicrobium mobile comb. nov., Acetomicrobium thermoterrenum comb. nov. and Acetomicrobium hydrogeniformans comb. nov., respectively. The four bacterial species belong to the phylum Synergistetes.

Analysis of a population of magnetotactic bacteria of the Gulf of Gabès, Tunisia.

The occurrence of magnetotactic bacteria (MTB) on a Tunisian marine coast exposed to heavy metals pollution (Sfax, Gulf of Gabès, Mediterranean Sea) was investigated. The MTB population of this Southern Mediterranean coast was compared to the MTB populations previously investigated on the French Northern Mediterranean coast. A dominant MTB coccus morphotype was observed by microscopy analysis. By pyrosequencing technology, the analysis of the 16S ribosomal RNA (rDNA) revealed as much as 33 operational taxonomic sequence units (OTUs) close to sequences of MTB accessible in the databases. The majority were close to MTB sequences of the "Med group" of α-Proteobacteria. Among them, a dominant OTU_001 (99 % of the MTB sequences) affiliated within the Magnetococcales order was highlighted. Investigating the capacities of this novel bacterium to be used in bioremediation and/or depollution processes could be envisaged.

Crassaminicella profunda gen. nov., sp. nov., an anaerobic marine bacterium isolated from deep-sea sediments.

A novel, anaerobic, chemo-organotrophic bacterium, designated strain Ra1766H(T), was isolated from sediments of the Guaymas basin (Gulf of California, Mexico) taken from a depth of 2002  m. Cells were thin, motile, Gram-stain-positive, flexible rods forming terminal endospores. Strain Ra1766H(T) grew at temperatures of 25-45 °C (optimum 30 °C), pH 6.7-8.1 (optimum 7.5) and in a salinity of 5-60 g l(-1) NaCl (optimum 30 g l(-1)). It was an obligate heterotrophic bacterium fermenting carbohydrates (glucose and mannose) and organic acids (pyruvate and succinate). Casamino acids and amino acids (glutamate, aspartate and glycine) were also fermented. The main end products from glucose fermentation were acetate, butyrate, ethanol, H2 and CO2. Sulfate, sulfite, thiosulfate, elemental sulfur, fumarate, nitrate, nitrite and Fe(III) were not used as terminal electron acceptors. The predominant cellular fatty acids were C14  : 0, C16 : 1ω7, C16 : 1ω7 DMA and C16 : 0. The main polar lipids consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and phospholipids. The G+C content of the genomic DNA was 33.7 mol%. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain Ra1766H(T) was affiliated to cluster XI of the order Clostridiales, phylum Firmicutes. The closest phylogenetic relative of Ra1766H(T) was Geosporobacter subterraneus (94.2% 16S rRNA gene sequence similarity). On the basis of phylogenetic inference and phenotypic properties, strain Ra1766H(T) ( = DSM 27501(T) = JCM 19377(T)) is proposed to be the type strain of a novel species of a novel genus, named Crassaminicella profunda.

Reclassification of Acetomicrobium faecale as Caldicoprobacter faecalis comb. nov.

Taking into account its phenotypical and genetic characteristics, Acetomicrobium faecale was first recognized as a member of the genus Acetomicrobium, family Bacteroidaceae, order Bacteroidales, phylum Bacteroidetes, with Acetomicrobium flavidum the type species of the genus. However, it was found that A. faecale had 95.8 %, 97.6 % and 98.4 % similarity, respectively, with Caldicoprobacter guelmensis, Caldicoprobacter algeriensis and Caldicoprobacter oshimai and only 82 % similarity with A. flavidum. The DNA G+C content of A. faecale is 45 mol , which is of the same order as the DNA G+C content of the three strains of species of the genus Caldicoprobacter and its main fatty acid is C16 : 0, with its second most prominent fatty acid, iso-C17 : 0, also common to strains of species of the genus Caldicoprobacter. On the basis of further phylogenetic, genetic and chemotaxonomic studies, we propose that A. faecale (type strain DSM 20678T = JCM 30420T) be reclassified as Caldicoprobacter faecalis comb. nov.

Melghiribacillus thermohalophilus gen. nov., sp. nov., a novel filamentous, endospore-forming, thermophilic and halophilic bacterium.

A novel filamentous, endospore-forming, thermophilic and moderately halophilic bacterium designated strain Nari2A(T) was isolated from soil collected from an Algerian salt lake, Chott Melghir. The novel isolate was Gram-staining-positive, aerobic, catalase-negative and oxidase-positive. Optimum growth occurred at 50-55 °C, 7-10% (w/v) NaCl and pH 7-8. The strain exhibited 95.4, 95.4 and 95.2% 16S rRNA gene sequence similarity to Thalassobacillus devorans G19.1(T), Sediminibacillus halophilus EN8d(T) and Virgibacillus kekensis YIM-kkny16(T), respectively. The major menaquinone was MK-7. The polar lipid profile consisted of phosphatidylglycerol, diphosphatidylglycerol, three unknown phosphoglycolipids and two unknown phospholipids. The predominant cellular fatty acids were iso-C(15 : 0) and iso-C(17 : 0). The DNA G+C content was 41.9 mol%. Based on the phenotypic, chemotaxonomic and phylogenetic data, strain Nari2A(T) is considered to represent a novel species of a new genus in the family Bacillaceae , order Bacillales , for which the name Melghiribacillus thermohalophilus gen. nov., sp. nov. is proposed. The type strain of Melghiribacillus thermohalophilus is Nari2A(T) ( = DSM 25894(T) = CCUG 62543(T)).

Fusibacter bizertensis sp. nov., isolated from a corroded kerosene storage tank.

Strain LTF Kr01(T), a novel mesophilic, anaerobic, halotolerant, rod-shaped bacterium, was isolated from a drain at the bottom of a corroded kerosene storage tank of the Société Tunisienne des Industries de Raffinage (STIR), Bizerte, northern Tunisia. Cells were Gram-positive-staining rods, occurred singly or in pairs, and were motile by one lateral flagellum. Strain LTF Kr01(T) grew at temperatures between 15 and 40 °C (optimum 30 °C), between pH 5.5 and 8.2 (optimum pH 7.2) and at NaCl concentrations between 0 and 50 g l(-1) (optimum 5 g l(-1)). It reduced thiosulfate and elemental sulfur into sulfide, but did not reduce sulfate or sulfite. It utilized a wide range of carbohydrates (cellobiose, d-glucose, d-fructose, d-mannitol, d-ribose, sucrose, d-xylose, maltose, d-galactose, starch and trehalose) and produced acetate, CO2 and H2 as end products from glucose fermentation. The DNA G+C content was 37.4 mol%. The predominant cellular fatty acids were C14:0 and C16:0. Phylogenetic analysis of the 16S rRNA gene sequence suggested that Fusibacter tunisiensis was the closest relative of strain LTF Kr01(T) (gene sequence similarity of 94.6%). Based on phenotypic, phylogenetic and genotypic taxonomic characteristics, strain LTF Kr01(T) is proposed to represent a novel species of the genus Fusibacter, order Clostridiales, for which the name Fusibacter bizertensis sp. nov. is proposed. The type strain is LTF Kr01(T) ( = DSM 28034(T) = JCM 19376(T)).

Characterization of Sporohalobacter salinus sp. nov., an anaerobic, halophilic, fermentative bacterium isolated from a hypersaline lake.

Halophilic, obligately anaerobic, Gram-stain-negative bacterial strains were isolated from a sediment sample taken from under the salt crust of El-Jerid hypersaline lake in southern Tunisia by using tryptone or glucose as the substrate. One strain, CEJFT1B(T), was characterized phenotypically and phylogenetically. Cells were non-motile, non-spore-forming, short rods. Strain CEJFT1B(T) was able to grow in the presence of 5-30 % (w/v) NaCl (optimum 20 %) and at 30-60 °C (optimum 45 °C). It grew at pH 5.5-7.8 and the optimum pH for growth was 6.8. The isolate required yeast extract for growth. Substrates utilized by strain CEJFT1B(T) as the sole carbon source included glucose, fructose, sucrose, pyruvate, Casamino acids and starch. Individual amino acids such as glutamate, lysine, methionine, serine, tyrosine, and amino acid mixtures formed by the Stickland reaction such as alanine-glycine, valine-proline, leucine-proline, isoleucine-proline were also utilized. Products of glucose fermentation were acetate (major product), butyrate, H2 and CO2. The genomic DNA G+C content of strain CEJFT1B(T) was 32.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CEJFT1B(T) should be assigned to the genus Sporohalobacter. The sequence similarity between strain CEJFT1B(T) and Sporohalobacter lortetii was 98.5 %, but DNA-DNA hybridization between the two strains revealed a relatedness value of 56.4 %, indicating that they are not related at the species level. The combination of phylogenetic analysis, DNA-DNA hybridization data, and differences in substrate utilization support the view that strain CEJFT1B(T) represents a novel species of the genus Sporohalobacter, for which the name Sporohalobacter salinus sp. nov. is proposed. The type strain is CEJFT1B(T) ( = DSM 26781(T) = JCM 19279(T)).

Marinobacter piscensis sp. nov., a moderately halophilic bacterium isolated from salty food in Tunisia.

An aerobic, Gram-negative, moderately halophilic bacterium, oxidase, and catalase positive-designated Abdou3(T), was isolated from salted traditional foods (Anchovies) in Tunisia. Cells were rod-shaped, non-spore-forming and motile. Growth occurred at 15-45 °C (optimum, 37 °C), pH 5.5-8.75 (optimum, 7.3), and in the presence of 1-15 % NaCl (optimum, 10 %). Strain Abdou3(T) used glucose, D-arabinose, and sucrose. Strain Abdou3(T) had Q9 as the major respiratory quinone and C18:1 ω9c and C16:0 as predominant fatty acids. The DNA G+C content was 55.2 mol%. Phylogenetic analysis of the small-subunit ribosomal RNA (rRNA) gene sequence indicated that strain Abdou3(T) had as its closest relative Marinobacter maritimus (identity of 96 %). Based on phenotypic, phylogenetic, and taxonomic characteristics, strain Abdou3(T) is proposed as a novel species of the genus Marinobacter within the order Alteromonadales, for which the name M. piscensis sp. nov. is proposed. The type strain is Abdou3(T) (=DSM 26804(T)).