Kandeliimicrobium roseum gen. nov., sp. nov., a new member of the family Rhodobacteraceae isolated from mangrove rhizosphere soil.

A Gram-stain-negative, non-flagellated, short rod-shaped bacterium, designated XY-R6T, was isolated from the rhizosphere soil of a mangrove plant, Kandelia candel (L.) Druce, in Mai Po Nature Reserve, Hong Kong. Growth of strain XY-R6T was observed at pH 5.0-9.5 (optimum 6.5-8.0), between 8 and 42 °C (optimum 28-34 °C), and in the presence of 0-9.5 % (w/v) NaCl (optimum 1-4 %). The predominant isoprenoid quinone was ubiquinone-10. The major fatty acids were summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c) (55.61 %), C19 : 0cycloω8c (21.59 %) and C16 : 0 (11.24 %). The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, aminolipid, phosphatidylcholine and diphosphatidylglycerol. The genomic DNA G+C content of strain XY-R6T was 69.3 mol%. Phylogenetic analyses, based on 16S rRNA gene sequences, revealed that strain XY-R6T belonged to the family Rhodobacteraceae of the class Alphaproteobacteria and formed a distinct lineage, showing the highest gene sequence similarities to the members of genus Wenxinia(94.5-94.3 %), followed by the genera Profundibacterium (94.3 %), Defluviimonas(93.8-92.5 %), Oceanicola (93.8 %) and Cereibacter (93.7 %). Similarities to other genera within the family Rhodobacteraceae were below 94.0 %. Based on comprehensive phenotypic, phylogenetic and chemotaxonomic characterization, it is indicated that strain XY-R6T represents a novel species of a new genus in the family Rhodobacteraceae, for which the name Kandeliimicrobium roseum gen. nov., sp. nov. is proposed, with XY-R6T (=MCCC 1K01498T=KCTC 52266T=DSM 104294T) as the type strain.

A novel assessment of the traction forces upon settlement of two typical marine fouling invertebrates using PDMS micropost arrays.

Marine biofouling poses a severe threat to maritime and aquaculture industries. To prevent the attachment of marine biofouling organisms on man-made structures, countless cost and effort was spent annually. In particular, most attention has been paid on the development of efficient and environmentally friendly fouling-resistant coatings, as well as larval settlement mechanism of several major biofouling invertebrates. In this study, polydimethylsiloxane (PDMS) micropost arrays were utilized as the settlement substrata and opposite tractions were identified during early settlement of the barnacle Amphibalanus amphitrite and the bryozoan Bugula neritina The settling A. amphitrite pushed the periphery microposts with an average traction force of 376.2 nN, while settling B. neritina pulled the periphery microposts with an average traction force of 205.9 nN. These micropost displacements are consistent with the body expansion of A. amphitrite during early post-settlement metamorphosis stage and elevation of wall epithelium of B. neritina during early pre-ancestrula stage, respectively. As such, the usage of micropost array may supplement the traditional histological approach to indicate the early settlement stages or even the initiation of larval settlement of marine fouling organisms, and could finally aid in the development of automatic monitoring platform for the real-time analysis on this complex biological process.