Expression of organophosphorus-degradation gene (opd) in aggregating and non-aggregating filamentous nitrogen-fixing cyanobacteria |
| |
Authors: | Qiong Li Qing Tang Xudong Xu Hong Gao |
| |
Institution: | (1) MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824-1312, USA;(2) Department of Plant Biology, Michigan State University, East Lansing, MI 48824-1312, USA;(3) Present address: Feinberg School of Medicine, Northwestern University, 303 East Chicago Avenue, Chicago, IL 60611-3008, USA;(4) Present address: College of Life Sciences, Anhui Normal University, Wuhu, Anhui, 241000, People’s Republic of China;(5) Present address: Department of Physiology, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA;(6) Present address: Department of Chemistry, Michigan State University, East Lansing, MI 48824-1312, USA;(7) Present address: Chemical Sciences Division, Oak Ridge National Laboratory, MS-6194, Oak Ridge, TN 37830, USA |
| |
Abstract: | Genetic engineering in filamentous N2-fixing cyanobacteria usually involves Anabaena sp. PCC 7120 and several other non-aggregating species. Mass culture and harvest of such species are more energy consuming
relative to aggregating species. To establish a gene transfer system for aggregating species, we tested many species of Anabaena and Nostoc, and identified Nostoc muscorum FACHB244 as a species that can be genetically manipulated using the conjugative gene transfer system. To promote biodegradation
of organophosphorus pollutants in aquatic environments, we introduced a plasmid containing the organophosphorus-degradation
gene (opd) into Anabaena sp. PCC 7120 and Nostoc muscorum FACHB244 by conjugation. The opd gene was driven by a strong promoter, P
psbA
. From both species, we obtained transgenic strains having organophosphorus-degradation activities. At 25°C, the whole-cell
activities of the transgenic Anabaena and Nostoc strains were 0.163±0.001 and 0.289±0.042 unit/μg Chl a, respectively. However, most colonies resulting from the gene transfer showed no activity. PCR and DNA sequencing revealed
deletions or rearrangements in the plasmid in some of the colonies. Expression of the green fluorescent protein gene from
the same promoter in Anabaena sp. PCC 7120 showed similar results. These results suggest that there is the potential to promote the degradation of organophosphorus
pollutants with transgenic cyanobacteria and that selection of high-expression transgenic colonies is important for genetic
engineering of Anabaena and Nostoc species. For the first time, we established a gene transfer and expression system in an aggregating filamentous N2-fixing cyanobacterium. The genetic manipulation system of Nostoc muscorum FACHB244 could be utilized in the elimination of pollutants and large-scale production of valuable proteins or metabolites. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|