ABSTRACT
Rossellomorea sp. DA94, isolated from mangrove sediment in the South China Sea (Beihai, Guangxi province), is an agarolytic and orange-pigmented bacterium. Here, we present the complete genome sequence of strain DA94, which comprises 4.63 Mb sequences with 43.5% GC content. In total, 4589 CDSs, 33 rRNA genes and 110 tRNA genes were obtained. Genomic analysis of strain DA94 revealed that 108 CAZymes were organized in 4578 PULs involved in polysaccharides degradation, transport, and regulation. Further, we performed the diversity of CAZymes and PULs comparison among Rossellomorea strains. Less CAZymes were organized more PULs, indicating highly efficiently polysaccharides utilization in Rossellomorea. Meanwhile, PUL0459, PUL0460 and PUL0316 related to agar degradation, and exolytic beta-agarase GH50, endo-type beta-agarase GH86 and arylsulfatase were identified in the genome of strain DA94. We verified that strain DA94 can degrade agar to form a bright clear zone around the bacterial colonies in the laboratory. Moreover, the carotenoid biosynthetic pathways were proposed, which may be responsible for orange-pigment of Rossellomorea sp. DA94. This study represents a thorough genomic characterization of CAZymes repertoire and carotenoid biosynthetic pathways of Rossellomorea, provides insight into diversity of related enzymes and their potential biotechnological applications.
Subject(s)
Bacteria , Genomics , Agar , China , CarotenoidsABSTRACT
The scyphozoan genus Aurelia is one of the main contributors causing jellyfish blooms in global coastal waters. The population and reproduction of polyps are important factors to the outbreak of jellyfish. In this study, the effects of different salinity on the survival and asexual reproduction of Aurelia coerulea polyps were explored, which were cultured at the high (21 â) and low temperature (12 â), respectively. The results showed that more than 90% polyps could survive in the salinity range of 15-40 at the high temperature, with a range of salinity for budding being 20-32 and an optimum value of 28. The polyps were able to produce podocysts to tolerate low (≤15) and high (≥36) salinity conditions. At the low temperature, the survival rates of polyps were more than 90% in the salinity range of 20-40. The polyps could produce more buds in the salinity range of 20-32, with an optimum of 28. The salinity range of 20-40 was suitable for strobilation, with an optimum range of 28-32. It is concluded that the polyps of Aurelia coerulea can tolerate wide salinity variations, and that the salinity in a certain range has no significant influence on the asexual reproduction of polyps.
Subject(s)
Salinity , Scyphozoa/physiology , Temperature , Animals , Reproduction , Reproduction, AsexualABSTRACT
Meretrix meretrix were collected for 3 times from 2011 to 2012, at 5 stations along west coast of Guangxi and wild and used as a biological indicator for assessing the marine environmental stress. Six biomarkers at individual, cellular and molecular levels were selected, including time required to drill the sand, phagocytic ability, stability of lysosomal membrane, ferric reducing ability of plasma (FRAP), acetylcholinesterase activity (AChE), and comet rate. Utilizing the Integrated Biological Response Index (IBR) model, the above biomarkers were integratedly analyzed and the data were displayed by intuitionistic star plots to evaluate the environmental situation of the 5 stations. The results indicated that the biological response indices (IBR/n) of the 5 stations varied between 2.30 and 8.68. Maowei Sea had the highest environmental stress, whereas Beilun Estuary had the lowest. Although different biomarkers were different in response to pollution stress, IBR model could effectively distinguish environmental stress of a specific area. The results of biomarker monitoring were basically in agreement with those of chemical monitoring.
