Two Gram-positive, endospore-forming bacterial strains, CR-502^T and CR-14b, which produce surfactant molecules are described. Phenotypic tests and phylogenetic analyses showed these strains to be members of the genus Bacillus and related to the species Bacillus atrophaeus, Bacillus mojavensis, Bacillus subtilis, Bacillus vallismortis and Bacillus amyloliquefaciens, although they differ from these species in a number of phenotypic characteristics. DNA–DNA hybridization confirmed that they show less than 20 % hybridization with the above-mentioned species and therefore represent a novel species of Bacillus. The DNA G+C content is 46·4 mol% in strain CR-502^T and 46·1 mol% in strain CR-14b. The main fatty acids in strain CR-502^T are 15 : 0 anteiso (32·70 %), 15 : 0 iso (29·86 %) and 16 : 0 (13·41 %). The main quinone in strain CR-502^T is MK-7 (96·6 %). In the light of the polyphasic evidence gathered in this study, it is proposed that these strains be classified as a novel species of the genus Bacillus, with the name Bacillus velezensis sp. nov. The type strain (CR-502^T=CECT 5686^T=LMG 22478^T) was isolated from a brackish water sample taken from the river Vélez at Torredelmar in Málaga, southern Spain.

Salipiger mucescens gen. nov., sp. nov. is a moderately halophilic, exopolysaccharide-producing, Gram-negative rod isolated from a hypersaline habitat in Murcia in south-eastern Spain. The bacterium is chemoheterotrophic and strictly aerobic (i.e. unable to grow under anaerobic conditions either by fermentation or by nitrate or fumarate respiration). It does not synthesize bacteriochlorophyll a. Catalase and phosphatase are positive. It does not produce acids from carbohydrates. It cannot grow with carbohydrates or amino acids as sole sources of carbon and energy. It grows best at 9–10 % w/v NaCl and requires the presence of Na⁺ but not Mg²⁺ or K⁺, although they do stimulate its growth somewhat when present. Its major fatty-acid component is 18 : 1ω7c (78·0 %). The predominant respiratory lipoquinone found in strain A3^T is ubiquinone with ten isoprene units. The G+C content is 64·5 mol%. Phylogenetic analyses strongly indicate that this strain forms a distinct line within a clade containing the genus Roseivivax in the subclass α-Proteobacteria. The similarity value with Roseivivax halodurans and Roseivivax halotolerans is 94 %. In the light of the polyphasic evidence gathered in this study it is proposed that the isolate be classified as representing a new genus and species, Salipiger mucescens gen. nov., sp. nov. The proposed type strain is strain A3^T (=CECT 5855^T=LMG 22090^T=DSM 16094^T).

The effects of monovalent and divalent cations on the rheological behavior of Halomonas eurihalina exopolysaccharide (EPS) were studied. Sodium, potassium, magnesium and calcium were added and the relative abilities to increase viscosity were as follows: KCl > NaCl > MgCl₂ > CaCl₂. The highest viscosity value was measured in acidic 10⁻⁴ M KCl, in which a gel formed. A loss of sulfate content seemed to correlate with the increase of viscosity. H. eurihalina produced EPS in all growth media. Addition of hydrophobic substrates to culture media produced changes in chemical composition and emulsifying activity of the EPS. Xylene was the most effectively emulsified substance and the EPS produced on tetradecane and on corn oil the most active emulsifier.

ThreeHalomonasstrains, FP34, FP35^Tand FP36, which were isolated from soil samples taken from Fuente de Piedra, a saline wetland in the province of Málaga in southern Spain, are described. Phylogenetic analyses based on 16S rRNA gene sequences show that the three isolates belong to the genusHalomonasin theγ-Proteobacteriaand form an independent genetic line. Phenotypically, they share the characteristics ofHalomonasand differ from the most closely related species,Halomonas campisalis, in the following features: they are strictly aerobic and, because of their production of exopolysaccharides, form cream-coloured, mucoid colonies; they produce phosphatase and grow within narrow pH and temperature ranges; and they are susceptible to kanamycin and streptomycin. Their G+C content varies between 60·0 and 61·4 mol%. The nameHalomonas anticariensissp. nov. is proposed for these isolates. Strain FP35^T(=LMG 22089^T=CECT 5854^T) is the type strain. The bacterium grows best in 7·5 % (w/v) NaCl and does not require magnesium or potassium salts for growth, although they do stimulate growth somewhat when present. Its major fatty acids are 18 : 1ω7c, 16 : 0, 16 : 1ω7c, 15 : 0 iso 2-OH, 12 : 0 3-OH, 12 : 0, 10 : 0 and 19 : 0 cycloω8c. Its predominant respiratory lipoquinone is ubiquinone with nine isoprene units (Q-9).