Salinicola peritrichatus sp. nov., isolated from deep-sea sediment.

A Gram stain-negative, aerobic and rod-shaped bacterium, strain DY22(T), was isolated from a deep-sea sediment collected from the east Pacific Ocean. The isolate was found to grow in the presence of 0-20.0 % (w/v) NaCl and at pH 4.5-8.5; optimum growth was observed with 0.5-2.0 % (w/v) NaCl and at pH 5.0-7.0. Chemotaxonomic analysis showed the presence of ubiquinone-9 as predominant respiratory quinone and C16:0, C19:0 ω8c cyclo and C12:0 3-OH as major cellular fatty acids. The genomic DNA G+C content was determined to be 59.6 mol%. Comparative 16S rRNA gene sequence analysis revealed that the novel isolate belongs to the genus Salinicola. Strain DY22(T) exhibited the closest phylogenetic affinity to the type strain of Salinicola salarius with 97.2 % sequence similarity and less than 97 % sequence similarity with respect to other Salinicola species with validly published names. The DNA-DNA reassociation values between strain DY22(T) and S. salarius DSM 18044(T) was 52 ± 4 %. On the basis of phenotypic, chemotaxonomic and genotypic data, strain DY22(T) represents a novel species of the genus Salinicola, for which the name Salinicola peritrichatus sp. nov. (type strain DY22(T) = CGMCC 1.12381(T) = JCM 18795(T)) is proposed.

Microfluidic accumulation assay to quantify the attachment of the marine bacterium Cobetia marina on fouling-release coatings.

Testing the adhesion of marine biofilm formers on bioresistant coatings is important to determine their fouling-release and antifouling properties. A dynamic attachment assay for the marine bacterium Cobetia marina (C. marina) was developed to test the adhesion on coatings and bioresistant surfaces. With well-defined culture conditions, the reproducibility of the microfluidic accumulation experiments with C. marina was verified using self-assembling monolayers as model surfaces. The assay discriminated the attachment of C. marina on four different surfaces with different wettability and protein resistances. In addition to these benchmark experiments on self-assembled monolayers, the adhesion of C. marina on polyglycerol coatings with different thicknesses was investigated.

No exception to the rule: Candidatus Portiera aleyrodidarum cell wall revisited.

Many insect endosymbionts described so far are gram-negative bacteria. Primary endosymbionts are obligatory bacteria usually harboured by insects inside vacuoles in specialized cells called bacteriocytes. This combination produces a typical three-membrane system with one membrane derived from the insect vacuole and the other two from the bacterial gram-negative cell envelope, composed by the cell wall (the outer membrane plus the periplasmic space) and the plasma membrane (the inner membrane). For the last 21 years, the primary endosymbiont of whiteflies 'Candidatus Portiera aleyrodidarum' was considered an exception to this rule. Previous works stated that only two membranes were present, the vacuolar membrane and one of the two bacterial membranes. The absence of the cell wall was related to the special vertical transmission of the endosymbionts in whiteflies. In this work, we present electron microscopic studies showing a complete cell envelope in 'Ca. Portiera aleyrodidarum' from the whitefly Bemisia tabaci. Additionally, comparison of the inferred metabolism from the gene content did not show any difference in cell envelope biogenesis compared with the closely related three-membrane endosymbionts 'Candidatus Carsonella ruddii' and 'Candidatus Evansia muelleri' Xc1. Our results rule out the proposal that 'Ca. Portiera aleyrodidarum' is an exception to the three-membrane system.