Journal of Microbiology

Research Support, Non-U.S. Gov't

Green Fluorescent Protein as a Marker for Monitoring a Pentachlorophenol Degrader Sphingomonas chlorophenolica ATCC39723: Eun-Taex Oh , Jae-Seong So , Byung-Hyuk Kim , Jong-Sul Kim , Sung-Cheol Koh; J. Microbiol. 2004;42(3):243-247.; DOI: https://doi.org/2081 [pii]

Abstract: Sphingomonas chlorophenolica ATCC39723 was successfully labeled with the gfp (green fluorescent protein) gene inserted into the pcpB gene by homologous recombination. As the gfp recombinant was easily distinguished from other indigenous organisms, the population of gfp recombinant was monitored after being released into the soil microcosms. Their population density dropped from 108 to 106 (cfu/ml) in the non-sterilized soil microcosms during the first 6 days. Moreover, the gfp recombinant was not detected even at lower dilution rates after a certain time period. The recombinant, however, survived for at least 28 days in the sterilized soil microcosms. Although the gfp recombinant did not degrade pentachlorophenol (PCP), this experiment showed the possibility of using gfp as a monitoring reporter system for S. chlorophenolica ATCC39723 and potentially other species of Sphingomonas.

Reversible function of RapA with the C-terminus of RapC in Dictyostelium: Dongju Kim , Wonbum Kim , Taeck Joong Jeon; J. Microbiol. 2021;59(9):853-848.; DOI: https://doi.org/10.1007/s12275-021-1400-5

Abstract: Rap small GTPases are involved in diverse signaling pathways associated with cell growth, proliferation, and cell migration. There are three Rap proteins in Dictyostelium, RapA, RapB, and RapC. RapA is a key regulator in the control of cell adhesion and migration. Recently RapA and RapC have been reported to have opposite functions in the regulation of cellular processes. In this study, we demonstrate that the C-terminus of RapC, which is not found in RapA, is essential for the opposite functions of RapC and is able to reverse the functions of RapA when fused to the tail of RapA. Cells lacking RapC displayed several defective phenotypes, including spread morphology, strong adhesion, and decreased cell migration compared to wild-type cells. These phenotypes were rescued by full-length RapC, but not by RapC missing the C-terminus. Furthermore, recombinant RapA fused with the C-terminus of RapC completely recovered the phenotypes of rapC null cells, indicating that the functions of RapA were modified to become similar to those of RapC by the C-terminus of RapC with respect to cell morphology, cell adhesion and migration, cytokinesis, and development. These results suggest that the C-terminal residues of RapC are able to suppress and change the functions of other Ras proteins in Ras oncogenic signaling pathways.

Bacterial Color Response to Hexavalent Chromium, Cr^6+: Ka Hong Cheung , Ji-Dong Gu; J. Microbiol. 2002;40(3):234-236.

Abstract: A blue pigment-producing bacterium, Vogesella indigofera, was isolated and quantified for the relationship between its synthesis of a blue pigment and exposure concentrations of Cr^6+ . The concentration of Cr^6+ and the percentage of blue colonies on agar plates was negatively correlated (r^2 = -0.8683). Critical concentrations inhibiting bacterial pigment production were found to be between 100-150 ug Cr^6+ /ml on agar plates and 200-300 ug Cr^6+ /ml in liquid culture. As the blue color is characteristic and easily observable, the bacterium Vogesella indigofera may have potential applications in the detection and monitoring of environmental pollution.

Search