Permanent Draft Genome sequence for Frankia sp. strain CcI49, a Nitrogen-Fixing Bacterium Isolated from Casuarina cunninghamiana that Infects Elaeagnaceae

Frankia sp. strain CcI49 was isolated from Casuarina cunninghamiana nodules. However the strain was unable to re-infect Casuarina, but was able to infect other actinorhizal plants including Elaeagnaceae. Here, we report the 9.8-Mbp draft genome sequence of Frankia sp. strain CcI49 with a G+C content of 70.5 % and 7,441 candidate protein-encoding genes. Analysis of the genome revealed the presence of a bph operon involved in the degradation of biphenyls and polychlorinated biphenyls

Draft Genome Sequences for the Frankia sp. strains CgS1, CcI156 and CgMI4, Nitrogen-Fixing Bacteria Isolated from Casuarina sp. in Egypt

Frankia sp. strains CgS1, CcI156 and CgMI4 were isolated from Casuarina glauca and C. cunninghamiana nodules. Here, we report the 5.26-, 5.33- and 5.20-Mbp draft genome sequences of Frankia sp. strains CgS1, CcI156 and CgMI4, respectively. Analysis of the genome revealed the presence of high numbers of secondary metabolic biosynthetic gene clusters

Permanent Draft Genome Sequences for Mesorhizobium sp. Strains LCM 4576, LCM 4577, and ORS3428, Salt-Tolerant, Nitrogen-Fixing Bacteria Isolated from Senegalese Soils

The genus Mesorhizobium contains many species that are able to form nitrogen-fixing nodules on plants of the legume family. Here, we report the draft genome sequences for three Mesorhizobium strains. The genome sizes of strains LCM 4576, LCM 4577, and ORS3428 were 7.24, 7.02, and 6.55 Mbp, respectively

Permanent Draft Genome Sequence of Rhizobium sp. Strain LCM 4573, a Salt-Tolerant, Nitrogen-Fixing Bacterium Isolated from Senegalese Soils

The genus Rhizobium contains many species that are able to form nitrogen-fixing nodules on plants of the legume family. Here, we report the 5.5-Mb draft genome sequence of the salt-tolerant Rhizobium sp. strain LCM 4573, which has a G+C content of 61.2% and 5,356 candidate protein-encoding genes

Permanent draft genome sequence of Ensifer sp. strain LCM 4579, a salt-tolerant, nitrogen-fixing bacterium isolated from Senegalese soil

The genus Ensifer (formerly Sinorhizobium) contains many species able to form nitrogen-fixing nodules on plants of the legume family. Here, we report the 6.1-Mb draft genome sequence of Ensifer sp. strain LCM 4579, with a G+C content of 62.4% and 5,613 candidate protein-encoding genes

Draft Genome Sequences of 10 Bacterial Strains Isolated from Root Nodules of Alnus Trees in New Hampshire

Here, we report the draft genome sequences obtained for 10 bacterial strains isolated from root nodules of Alnus trees. These members of the nodule microbiome were sequenced to determine their potential functional roles in plant health. The selected strains belong to the genera Rhodococcus, Kocuria, Rothia, Herbaspirillum, Streptomyces, and Thiopseudomonas

Simple colony PCR procedure for the filamentous actinobacteria Frankia

Molecular analysis of the filamentous actinobacteria Frankia is laborious because of the slow growth rate and required biomass needed for these techniques. An efficient and simple colony PCR protocol for Frankia was developed that saved time for analysis of any Frankia strains growing on a plate. Previously, it took 5–6 weeks to get the correct size Frankia colonies on plates and then a minimum of 5 weeks of growth in liquid culture for DNA extraction. With this technique, these colonies could be screened after 5–6 weeks of growth by colony PCR. The procedure used a combination of mechanical and heat treatments and required no added buffers or chemicals. Our results demonstrate rapid and efficient PCR

Stable Transformation of the Actinobacteria Frankia spp

A stable and efficient plasmid transfer system was developed for nitrogen-fixing symbiotic actinobacteria of the genus Frankia, a key first step in developing a genetic system. Four derivatives of the broad-host-range cloning vector pBBR1MCS were successfully introduced into different Frankia strains by a filter mating with Escherichia coli strain BW29427. Initially, plasmid pHKT1 that expresses green fluorescent protein (GFP) was introduced into Frankia casuarinae strain CcI3 at a frequency of 4.0 × 10−3, resulting in transformants that were tetracycline resistant and exhibited GFP fluorescence. The presence of the plasmid was confirmed by molecular approaches, including visualization on agarose gel and PCR. Several other pBBR1MCS plasmids were also introduced into F. casuarinae strain CcI3 and other Frankia strains at frequencies ranging from 10−2 to 10−4, and the presence of the plasmids was confirmed by PCR. The plasmids were stably maintained for over 2 years and through passage in a plant host. As a proof of concept, a salt tolerance candidate gene from the highly salt-tolerant Frankia sp. strain CcI6 was cloned into pBBR1MCS-3. The resulting construct was introduced into the salt-sensitive F. casuarinae strain CcI3. Endpoint reverse transcriptase PCR (RT-PCR) showed that the gene was expressed in F. casuarinae strain CcI3. The expression provided an increased level of salt tolerance for the transformant. These results represent stable plasmid transfer and exogenous gene expression in Frankia spp., overcoming a major hurdle in the field. This step in the development of genetic tools in Frankia spp. will open up new avenues for research on actinorhizal symbiosis

Advances in Frankia genome studies and molecular aspects of tolerance to environmental stresses

Actinobacteria from the genus Frankia are Gram+, aerobic, heterotrophic and filamentous bacteria found living independently in soil or as facultative symbionts that form N2-fixing root nodules on diverse and globally distributed angiosperms called actinorhizal species. This symbiotic association has important ecological and economic roles such as soil stabilization, land reclamation, crop protection and timber and fuel wood production. Some Frankia strains are resistant to abiotic stresses including salinity, heavy metal, pH, and temperature and have developed complexed mechanisms to adapt to these conditions. Under environmentally stressed conditions, actinorhizal plants that had associations with adapted Frankia strains show improved plant performance. Recent “Omics” studies including genomic, transcriptomic and proteomic developed on Frankia have provided different clues for a better understanding of these adaptation mechanisms. In this chapter, we review recent advances in Frankia genome studies and in molecular aspects of Frankia tolerance to environmental stresses

Kabul Times. (Kabul, Afghanistan), 1966-07-30

Kabul Times. (Kabul, Afghanistan), 1966-07-30; Volume 5; Number 10