title: Effects of D-amino acids on the EPS production and cell aggregation of Alteromonas macleodii strain JL2069.
abstract: Exopolysaccharide (EPS) is produced by many marine bacteria and is important for cell aggregation in the ocean. D-amino acids are important components in bacteria and are recently recognized as signal molecules for regulation of bacterial growth. In this study, the effects of D-amino acids on EPS production, cell aggregation, and metabolic activity were investigated using an EPS-producing bacterium Alteromonas macleodii strain JL2069. EPS produced by JL2069 was inhibited by 1 mM of D-Ala and D-Ser, but not by D-Glu. The formation of particulate organic matter (POM) was promoted by the three amino acids. A new technique of microcalorimetry analysis indicated that the metabolic activity of the JL2069 cells was inhibited by these D-amino acids. Our results suggested that D-amino acids may reduce the bacterial metabolism by changing bacterial lifestyle from planktonic to cell aggregation growth which occurs independent of the production of EPS.
authors: State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, 361102, People's Republic of China, zhangzilian@xmu.edu.cn.
authors: Zilian
authors: Z
authors: Zhang
authors: Zhipeng
authors: Z
authors: Li
authors: Nianzhi
authors: N
authors: Jiao
mesh_terms: D020591:Alteromonas / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D000596:Amino Acids / Q000378:metabolism*; D001422:Bacterial Adhesion; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D011135:Polysaccharides, Bacterial / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D000596:Amino Acids; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D011135:Polysaccharides, Bacterial; D012336:RNA, Ribosomal, 16S