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Three strains of Gram-negative, aerobic, neutrophilic and halophilic bacteria were isolated from samples of a salt lake on the Qinghai-Tibet Plateau and a subterranean saline well in the Si-Chuan Basin of China. These isolates, designated AJ275 T , AJ282 T and ZG16 T , were investigated using a polyphasic approach. Based on 16S rRNA gene sequence analysis, the isolates could be affiliated to the genus Halomonas. Genomic DNA G+C contents were 65.9 mol% for AJ275 T , 56.7 mol% for AJ282 T and 57.6 mol% for ZG16 T . The results of DNA-DNA hybridizations, fatty acid analysis and physiological and biochemical tests allowed the isolates to be differentiated genotypically and phenotypically from closely related species. It is proposed that strains AJ275 T (=CGMCC 1.6493 T =JCM 14606 T =LMG 23976 T ), AJ282 T (=CGMCC 1.6494 T =JCM 14607 T =LMG 23978 T ) and ZG16 T (=CGMCC 1.6495 T =JCM 14608 T =LMG 23977 T ) represent the type strains of three novel species in the genus Halomonas: Halomonas saccharevitans sp. nov., Halomonas arcis sp. nov. and Halomonas subterranea sp. nov., respectively.

Croceicoccus marinus gen. nov., sp. nov., a yellow-pigmented bacterium from deep-sea sediment, and emended description of the family Erythrobacteraceae A Gram-negative, aerobic, neutrophilic, coccoid bacterium, strain E4A9 T , was isolated from a deep-sea sediment sample collected from the East Pacific polymetallic nodule region. 16S rRNA gene sequence analysis showed that the isolate was related to the type strain of Altererythrobacter epoxidivorans (96.0 % sequence similarity). Lower 16S rRNA gene sequence similarities were observed with other members of the genera Altererythrobacter (94.7 %), Erythrobacter (94.0-95.4 %), Erythromicrobium (94.8 %) and Porphyrobacter (94.6-95.1 %) of the family Erythrobacteraceae. Phylogenetic analysis including all described species of the family Erythrobacteraceae and several members of the family Sphingomonadaceae revealed that the isolate formed a distinct phylogenetic lineage with the family Erythrobacteraceae. Chemotaxonomic analysis revealed ubiquinone-10 as the predominant respiratory quinone, anteiso-C 15 : 0 , iso-C 14 : 0 and iso-C 15 : 0 as major fatty acids, and phosphatidylglycerol as the major polar lipid. The DNA G+C content was 71.5 mol%. The isolate contained carotenoids, but no bacteriochlorophyll a. On the basis of phenotypic and genotypic data presented in this study, strain E4A9 T represents a novel species in a new genus in the family Erythrobacteraceae for which the name Croceicoccus marinus gen. nov., sp. nov. is proposed; the type strain is E4A9 T (5CGMCC 1.6776 T 5JCM 14846 T ).The family Erythrobacteraceae (order Sphingomonadales, class Alphaproteobacteria) was proposed by Lee et al. (2005) based on a comprehensive phylogenetic analysis and, at present, it comprises four recognized genera: Altererythrobacter (Kwon et al., 2007), Erythrobacter (Shiba & Simidu, 1982), Erythromicrobium (Yurkov et al., 1994) and Porphyrobacter (Fuerst et al., 1993).Members of the family Erythrobacteraceae are aerobic and produce pink, orange or yellow pigments. Ubiquinone-10 is the major respiratory quinone. Most species in the family have been isolated from various aquatic environments such as freshwater, seawater, marine mats or sediment, a hot spring, seaweed, a starfish and coral (Shiba & Simidu, 1982; Fuerst et al., 1993;Yurkov et al., 1994; Hanada et al., 1997; Denner et al., 2002; Hiraishi et al., 2002;Rainey et al., 2003;Yoon et al., 2003Yoon et al., , 2004a Yoon et al., , b, 2005a Yoon et al., , b, 2006Ivanova et al., 2005;Kwon et al., 2007). This study focuses on the description of strain E4A9 T , isolated from a deep-sea sediment sample. Based on the taxonomic data, it is proposed that this strain be included in a new genus within the family Erythrobacteraceae.The deep-sea sediment samples were collected by a multicorer from the East Pacific polymetallic nodule region (8 u 229 380 N 145 u 239 560 W) at a depth of Abbreviation: BChl a, bacteriochlorophyll a.The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain E4A9 T is EF62399...

BackgroundTapping panel dryness (TPD) is one of the most serious threats to natural rubber production. Although a great deal of effort has been made to study TPD in rubber tree, the molecular mechanisms underlying TPD remain poorly understood. Identification and systematical analyses of the genes associated with TPD are the prerequisites for elucidating the molecular mechanisms involved in TPD. The present study is undertaken to generate information about the genes related to TPD in rubber tree.ResultsTo identify the genes related to TPD in rubber tree, forward and reverse cDNA libraries from the latex of healthy and TPD trees were constructed using suppression subtractive hybridization (SSH) method. Among the 1106 clones obtained from the two cDNA libraries, 822 clones showed differential expression in two libraries by reverse Northern blot analyses. Sequence analyses indicated that the 822 clones represented 237 unique genes; and most of them have not been reported to be associated with TPD in rubber tree. The expression patterns of 20 differentially expressed genes were further investigated to validate the SSH data by reverse transcription PCR (RT-PCR) and real-time PCR analysis. According to the Gene Ontology convention, 237 unique genes were classified into 10 functional groups, such as stress/defense response, protein metabolism, transcription and post-transcription, rubber biosynthesis, etc. Among the genes with known function, the genes preferentially expressed were associated with stress/defense response in the reverse library, whereas metabolism and energy in the forward one.ConclusionsThe genes associated with TPD were identified by SSH method in this research. Systematic analyses of the genes related to TPD suggest that the production and scavenging of reactive oxygen species (ROS), ubiquitin proteasome pathway, programmed cell death and rubber biosynthesis might play important roles in TPD. Therefore, our results not only enrich information about the genes related to TPD, but also provide new insights into understanding the TPD process in rubber tree.