Search

Phycosphere environment is a typical marine niche, harbor diverse populations of microorganisms, which are thought to play a critical role in algae host and influence mutualistic and competitive interactions. Understanding quorum sensing-based acyl-homoserine lactone (AHL) language may shed light on the interaction between algal-associated microbial communities in the native environment. In this work, we isolated an epidermal bacterium (was tentatively named Enterobactersp. ST3, and deposited in SOA China, the number is MCCC1K02277-ST3) from the marine dinoflagellate Scrippsiella trochoidea, and found it has the ability to produce short-chain AHL signal. In order to better understand its communication information at molecular level, the genomic map was investigated. The genome size was determined to be 4.81Mb with a G+C content of 55.59%, comprising 6 scaffolds of 75 contigs containing 4647 protein-coding genes. The functional proteins were predicted, and 3534 proteins were assigned to COG functional categories. An AHL-relating gene, LuxR, was found in upstream position at contig 1. This genome data may provide clues to increase understanding of the chemical characterization and ecological behavior of strain ST3 in the phycosphere microenvironment.

To study the globoidal indexing cams parametric design, this paper introduced three kinds of its parametric modeling method.That was offset surfaces method , direct modeling method and "point - curve - surface" method. Then modeled the globoidal indexing cams which had the same parameters and specifications by three parametric methods and Pro/Engineer.Meanwhile, used curvature comb command in Pro/Engineer to conduct the curvature analysis of indexing segment of cam profile. At last, conducted the indexing mechanisms kinematic simulation by ADAMS. From the characteristics of these three parametric methods and the result of cam profiles curvature analysis, this paper explains the reason of jitter acceleration in the simulation results.