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S Kaijalainen

Publications and source records attributed to S Kaijalainen.

8 recordsLinked to original sources
PubMed2001

AFLP fingerprinting as a tool to study the genetic diversity of Rhizobium galegae isolated from Galega orientalis and Galega officinalis.

AFLP fingerprints of Rhizobium galegae strains that infect Galega orientalis and Galega officinalis obtained from different geographical sources, and of taxonomically diverse rhizobia representing the recognized species, were generated. Comparisons of the fingerprints from fluorescent labeled AFLP products using capillary electrophoresis on ABI prism 310, slab gel electrophoresis on ABI prism 377 genetic analyzers and silver staining were in good agreement. All methods delineated the G. orientalis strains from G. officinalis strains, the G. orientalis strains formed a tight cluster whereas the G. officinalis strains seem to show a greater level of genetic diversity. Comparison of fluorescent AFLP with other detection methods revealed that fluorescent labeling is more sensitive and practical, in addition, the deleterious effect of radioactivity associated with 32P-labeling, the delicate process of blotting polyacrylamide gels or the tedious procedure of silver staining can be avoided. The automated system facilitated a large number of runs at a time and the subsequent analysis of the data by generating exportable raw data. The congruency of the experiments was analyzed using the Bionumerics software.

DNA Fingerprinting↗
PubMed1999

Phylogeny and diversity of Bradyrhizobium strains isolated from the root nodules of peanut (Arachis hypogaea) in Sichuan, China.

Twenty-two rhizobial strains isolated from the root nodules of two Chinese peanut cultivars (Arachis hypogaea L. Tianfu no. 3 and a local cultivar) growing at four different sites in the Sichuan province, Southwest China, were characterized by growth rate, rep-PCR, PCR-RFLP of 16S rDNA, partial sequencing of ribosomal genes, and fatty acid-methyl ester analysis (FAME), and compared with strains representing Bradyrhizobium japanicum, B. elkanii and other unclassified Bradyrhizobium sp. All peanut isolates from Sichuan were bradyrhizobia. Dendrograms constructed using the rep-PCR fingerprints grouped the strains mainly according to their geographic and cultivar origin. Based on PCR-RFLP and partial sequence analysis of 16S rDNA it appears that peanut bradyrhizobial strains from Sichuan are similar to peanut strains from Africa and Israel, and closely related to B. japonicum. In contrast, analysis of FAME data using two-dimensional principal component analysis indicated that Bradyrhizobium sp. (Arachis) were similar to, but slightly different from other bradyrhizobia. The presence and level of fatty acid 16:1 w5c was the distinguishing feature. The results of PCR-RFLP of the 16S rRNA gene, the partial sequence analysis of 16S rDNA, and FAME were in good agreement.

Arachis↗
PubMed1997

MPN-PCR-quantification method for staphylococcal enterotoxin c1 gene from fresh cheese.

PCR detection methods have been extensively used in diagnostic microbiology. However, a lack of a simple and reliable method for quantification of the PCR products has partly hindered the use of PCR in routine food laboratories. The quantification of PCR products can be done by combining the principles of MPN statistics and PCR technique. We have developed a simple and sensitive MPN-PCR assay for detection and enumeration of enterotoxin C producing Staphylococcus aureus NCTC 10655 from fresh cheese. By amplifying single copy chromosomal enterotoxin C gene fragment, we could detect as little as 20 cfu/g. By Moran's test, most of the DNA dilution series appeared to fulfill the basic mathematical assumptions of ordinary MPN methods. The analysis with MPN-PCR took one day to perform compared with three days analysis time with plate counting. This MPN-PCR method can be readily applied with different primer systems without extensive development work.

Cheese↗
PubMed1996

Assessment of competitiveness of rhizobia infecting Galega orientalis on the basis of plant yield, nodulation, and strain identification by antibiotic resistance and PCR.

Competition between effective and ineffective Rhizobium galegae strains nodulating Galega orientalis was examined on the basis of plant growth, nodulation, antibiotic resistance, and PCR results. In a preliminary experiment in Leonard's jars, ineffective R. galegae strains HAMBI 1207 and HAMBI 1209 competed in similar manners with the effective strain R. galegae HAMBI 1174. In a pot experiment, soil was inoculated with 0 to 10(5) HAMBI 1207 cells per g before G. orientalis was sown. Seeds of G. orientalis were surface inoculated with 2 x 10(4) and 2 x 10(5) cells of HAMBI 1174 per seed (which represent half and fivefold the commercially recommended amount of inoculant, respectively). Plant yield and nodulation by the effective strain were significantly reduced, with as few as 10(2) ineffective rhizobia per g of soil, and the inoculation response was not improved by the 10-fold greater dose of the inoculant. Bacteria occupying the nodules were identified by antibiotic resistance and PCR with primers specific for R. galegae HAMBI 1174, R. galegae, and genes coding for bacterial 16S rRNA (bacterial 16S rDNA). Sixty-two large nodules examined were occupied by the effective strain HAMBI 1174, as proven by antibiotic resistance and amplification of the strain-specific fragment. From 20 small nodules, only the species-specific fragment could be amplified, and isolated bacteria had the same antibiotic resistance and 16S PCR restriction pattern as strain HAMBI 1207. PCR with our strain-specific and species-specific primers provides a powerful tool for strain identification of R. galegae directly from nodules without genetic modification of the bacteria.

Base Sequence↗
PubMed1994

Isolation of a Rhizobium galegae strain-specific DNA probe.

We have isolated a strain-specific DNA probe from the strain Rhizobium galegae HAMBI 1174 by a subtraction hybridization procedure followed by PCR amplification and DNA cloning. The specificity of the 342-bp DNA probe (P3) was tested in dot blot or Southern blot hybridizations against total genomic DNA of 41 bacterial strains (21 of them belong to R. galegae, 15 to other Rhizobium species and five to other bacterial species). Only the samples from four R. galegae strains, which are different isolates but identical to the strain HAMBI 1174, hybridized with the probe. The P3 probe was sequenced and PCR primers were designed based on its sequence. PCR amplification from purified total genomic DNA of 52 strains and subsequent hybridization with the P3 probe proved that the primers are strain specific.

Base Sequence↗
PubMed1990

Stability of Markers Used for Identification of Two Rhizobium galegae Inoculant Strains after Five Years in the Field.

The stability of identification markers was examined for two Rhizobium galegae inoculant strains after 5 years in the field. The two strains are genetically closely related, but differ in their lipopolysaccharides. Strain HAMBI 540 has lipopolysaccharide of the rough type, whereas that of strain HAMBI 1461 is of the smooth type. The properties that were examined for 10 field isolates of each inoculant type were symbiotic phenotype, phage type, intrinsic antibiotic resistance, maximum growth temperature, lipopolysaccharide and total soluble protein patterns, immunological properties, DNA restriction profiles, and DNA hybridization patterns, which were determined by using nifHDK and recA sequences as probes. Of these properties, all remained stable in soil, with the exception of some variation in intrinsic antibiotic resistance and the acquisition of an extra EcoRI restriction fragment by one of the isolates. Thus, both the rough and the smooth lipopolysaccharide phenotypes persisted equally well in soil.

Journal Article↗
PubMed1989

Restriction fragment length polymorphism analysis of Rhizobium galegae strains.

Total DNA of various Rhizobium galegae strains representing different geographical origins, and taxonomic divergence was digested with three restriction enzymes separately, Southern blotted, and hybridized with six heterologous probes. The sequence divergences for different pairwise comparisons were calculated from proportions of conserved hybridizing fragments. The unweighted pair group method was used to group the strains. The symbiotic common nod and nifHDK probes used were highly conserved and grouped the strains according to the host plant, Galega orientalis or G. officinalis. The grouping derived from combined data of the constitutive hemA, glnA, ntrC, and recA probes was similar to that obtained in total DNA-DNA hybridization experiments. The constitutive probes grouped the strains in a different order than did the symbiotic probes, a result that may reflect interstrain transfer of symbiotic sequences in the course of evolution.

Blotting, Southern↗