Halomonas elongata strain Mar (=CCUG 52759) isolated from table-olive fermentation is the first halophilic bacterium to be shown to transform ferulic acid to vanillic acid under hypersaline conditions. During growth on ferulic acid, this strain was capable of promoting the formation of a significant amount of vanillic acid and trace quantities of vanillin. The products were confirmed by high-performance liquid chromatography and gas chromatography-mass spectrometry analyses. Based on the different metabolites identified, an oxidative side chain degradation pathway of ferulic acid bioconversion to vanillic acid was suggested. Phylogenetic analysis of 16S rRNA gene revealed that this isolated strain Mar was identified as H. elongata. To increase the formation of vanillic acid, a resting cell method using H. elongata strain Mar was performed. The optimal yield of vanillic acid (86%) was obtained after a 6 h reaction using 5 mM of ferulic acid and 4 g of dry weight of cells L(-1) pregrown on ferulic acid and harvested at the end of the exponential phase.

An aerobic, moderately halophilic, Gram-negative, motile, non-sporulating bacterium, strain LIT2T, was isolated from an oilfield-water injection after enrichment on crude oil. Strain LIT2T grew between 15 and 45 °C and optimally at 37 °C. It grew in the presence of 1–25 % (w/v) NaCl, with an optimum at 10 % (w/v) NaCl. Predominant fatty acids were C16 : 0 (26.9 %), C18 : 1 ω7c (22.6 %), C16 : 1 ω7c (20.4 %) C19 : 0 cyclo ω8c (10.9 %) and C17 : 0 (8 %). Interestingly, the relative percentages of these last two fatty acids were intermediate compared with most species among the family Halomonadaceae for which fatty acid composition has been determined. The DNA G+C content was 53.7 mol%, which is very low among the family Halomonadaceae. Strain LIT2T exhibited 16S rRNA gene sequence similarity values of 94.06–95.15 % to members of the genus Chromohalobacter, 94.21–94.65 % to members of the genus Halomonas and 93.57 % with the single species representative of the genus Cobetia. Based on the phylogenetic and phenotypic evidence presented in this paper, we propose the name Modicisalibacter tunisiensis gen. nov., sp. nov. to accommodate strain LIT2T. The type strain of Modicisalibacter tunisiensis is LIT2T (=CCUG 52917T =CIP 109206T). A reassignment of the descriptive 16S rRNA signature characteristics of the family Halomonadaceae permitted placement of the new genus Modicisalibacter into the family.

During growth on ferulic acid, Halomonas elongata DSM 2581 T was capable of promoting the formation of a significant amount of vanillic acid. The products were confirmed by high-performance liquid chromatography and gas chromatography mass-spectrometry analyses. To enhance the formation of vanillic acid and prevent its degradation, a resting-cell method using Halomonas elongata was developed. The growth state of the culture utilized for biomass production, the concentration of the biomass, the amount of ferulic acid that was treated and the reutilization of the biomass were optimized. The optimal yield of vanillic acid (82%) was obtained after a 10-h reaction using 10 mM ferulic acid and 5 g/l of cell pregrown on ferulic acid and harvested at the end of the exponential phase.

A strictly anaerobic, halotolerant and thermotolerant strain, designated C5BELT, was isolated in north Tunisia from storage tanks holding waste generated by the recycling of discarded motor oils. Cells of strain C5BELT were Gram-stain-positive, motile by laterally inserted flagella, straight, and spore-forming. Their two major fatty acids were iso-C15 : 0 and iso-C15 : 0 dimethyl acetal. Growth was observed at temperatures of 25–55 °C (optimum, 40 °C) and at pH 6–9 (optimum, pH 7.5). The salinity range for growth was 0–100 g l−1 NaCl (optimum, 5 g l−1). Yeast extract was required for growth. Strain C5BELT was heterotrophic, able to use glucose, pyruvate, succinate, yeast extract, bio-trypticase and peptone, but unable to grow on Casamino acids. Sulfate, thiosulfate, sulfite, elemental sulfur, fumarate, nitrate and nitrite were not reduced. The DNA G+C content of strain C5BELT was 31.1 mol%. 16S rRNA gene sequence analysis indicated that strain C5BELT was a member of the family Clostridiaceae , class Clostridia , phylum Firmicutes and was most closely related to Sporanaerobacter acetigenes Lup33T ( = DSM 13106T) (92.4 % similarity). On the basis of 16S rRNA gene sequence comparisons and physiological characteristics, strain C5BELT can be classified as a novel species in a new genus, for which the name Anaerosalibacter bizertensis gen. nov., sp. nov. is proposed. The type strain of the type species is C5BELT ( = DSM 23801T = JCM 17239T).

A novel strictly anaerobic, moderately halophilic and mesophilic bacterium, designated strain SOL3f37 T , was isolated from a hydrocarbon-polluted soil surrounding a deep petroleum environment located in south Tunisia. Cells of strain SOL3f37T stained Gram-positive and were motile, straight and spore-forming. Strain SOL3f37 T had a typical Gram-positive-type cell-wall structure, unlike the thick, multilayered cell wall of its closest relative Clostridiisalibacter paucivorans. The major fatty acids were iso-C 15 : 0 (41 %), iso-C 14 : 0 3-OH and/or iso-C 15 : 0 dimethyl acetal (21.6 %), iso-C 13 : 0 (4.4 %), anteiso-C 15 : 0 (3.9 %) and iso-C 15 : 1 (2.8 %). Strain SOL3f37 T grew between 20 and 48 6C (optimum 40 6C) and at pH 6.2-8

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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).

A novel slightly halophilic sulfate-reducing bacterium, designated strain P1BSR, was isolated from water of a saline lake in Tunisia. Strain P1BSR had motile (single polar flagellum), Gram-negative, rod-shaped, non-spore-forming cells, occurring singly or in pairs. Strain P1BSR 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 P1BSR 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 P1BSR 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 P1BSR to a novel species of the genus Desulfovibrio, Desulfovibrio salinus sp. nov. The type strain is P1BSR (=DSM 101510=JCM 31065).