Genetic Diversity and Distribution of Korean Isolates of Burkholderia glumae

Burkholderia glumae causes panicle blight of rice (grain rot in Japan and Korea) and the severity of damage is increasing worldwide. During 2017‒2018, 137 isolates of B. glumae were isolated from symptomatic grain rot of rice cultivated in paddy fields throughout South Korea, and genetic diversity of the isolates was determined using transposase-based polymerase chain reaction (Tnp-PCR) genomic fingerprinting. All 138 isolates, including the B. glumae BGR1 strain, produced toxoflavin in various amounts, and 17 isolates produced an unidentified purple or orange pigment on Luria-Bertani (LB) and casamino acid-peptone-glucose (CPG) media, respectively, at 28°C. Tnp-PCR genomic fingerprinting was performed using a novel primer designed based on transposase (tnp) gene sequences located at the ends of the toxoflavin efflux transporter operon, and this method provided reliable and reproducible results. Through Tnp-PCR genomic fingerprinting, the genetic groups of Korean B. glumae isolates were divided into 11 clusters and three divisions. The Korean B. glumae isolates were mainly grouped in division I (73%). Interestingly, most of the pigment-producing isolates were grouped in divisions II and III, of which 10 were grouped in cluster VIII, which comprised 67% of this cluster. Phylogenetic analysis based on tofI and hrpB gene sequences was consistent with classification by Tnp-PCR genomic fingerprinting. The BGR1 strain did not belong to any of the clusters, indicating that this strain does not exhibit the typical genetic representation of B. glumae. Burkholderia glumae isolates showed diversity in the use of carbon and nitrogen sources, but no correlation with genetic classification by PCR fingerprinting was found. This is the first study to analyze the geographical distribution and genetic diversity of Korean B. glumae isolates.

Using ISSR Genomic Fingerprinting to Study the Genetic Differentiation of Artemia Leach, 1819 (Crustacea: Anostraca) from Iran and Neighbor Regions with the Focus on the Invasive American Artemia franciscana

Due to the rapid developments in the aquaculture industry, Artemia franciscana, originally an American species, has been introduced to Eurasia, Africa and Australia. In the present study, we used a partial sequence of the mitochondrial DNA Cytochrome Oxidase subunit I (mt-DNA COI) gene and genomic fingerprinting by Inter-Simple Sequence Repeats (ISSRs) to determine the genetic variability and population structure of Artemia populations (indigenous and introduced) from 14 different geographical locations in Western Asia. Based on the haplotype spanning network, Artemia urmiana has exhibited higher genetic variation than native parthenogenetic populations. Although A. urmiana represented a completely private haplotype distribution, no apparent genetic structure was recognized among the native parthenogenetic and invasive A. franciscana populations. Our ISSR findings have documented that despite that invasive populations have lower variation than the source population in Great Salt Lake (Utah, USA), they have significantly revealed higher genetic variability compared to the native populations in Western Asia. According to the ISSR results, the native populations were not fully differentiated by the PCoA analysis, but the exotic A. franciscana populations were geographically divided into four genetic groups. We believe that during the colonization, invasive populations have experienced substantial genetic divergences, under new ecological conditions in the non-indigenous regions.

Using ISSR Genomic Fingerprinting to Study the Genetic Differentiation of Artemia Leach, 1819 (Crustacea: Anostraca) from Iran and Neighbor Regions with the Focus on the Invasive American Artemia franciscana

Due to the rapid developments in aquaculture industry, Artemia franciscana, originally an American species, has been intentionally introduced to the Eurasia, Africa and Australia. In the present study, we used a partial sequence of the mitochondrial DNA Cytochrome Oxidase subunit I (mt-DNA COI) gene and genomic fingerprinting by Inter-Simple Sequence Repeats (ISSRs) to determine the genetic variability and population structure of Artemia populations (indigenous and introduced) from 14 different geographical locations in Western Asia. Based on the haplotype spanning network, Artemia urmiana has exhibited higher genetic variation than native parthenogenetic populations. Although A. urmiana represented a completely private haplotype distribution, no apparent genetic structure was recognized among the native parthenogenetic and invasive A. franciscana populations. Our ISSR findings have documented that despite invasive populations have lower variation than source population in Great Salt Lake (Utah, USA), they have significantly revealed higher genetic variability compare to the native populations in Western Asia. According to the ISSR results, the native populations were not fully differentiated by the PCoA analysis, but the exotic A. franciscana populations were geographically divided in four genetic groups. We believe that during the colonization, invasive populations have experienced substantial genetic divergences, under new ecological conditions in the non-indigenous regions.

Piacentinu Ennese PDO Cheese as Reservoir of Promising Probiotic Bacteria

Piacentinu Ennese is a protected designation of origin (PDO) cheese produced in the surrounding area of Enna (Sicily, Italy), using raw ewe’s milk without the addition of any starter cultures. In the present study, the Lactobacillus population of Piacentinu Ennese PDO cheese was in vitro screened in order to select promising probiotic strains to be further used in humans. One hundred and sixty-nine lactic acid bacteria (LAB) were isolated from 90 days ripened cheeses and identified by Rep-PCR genomic fingerprinting, using the (GTG)5-primer, and by MALDI-TOF MS. One hundred and thirteen (113) isolates belonging to QPS-list species were characterized for both safety and functional properties. All tested isolates were considered safe because none showed either gelatinase, DNase, mucinase, or hemolytic activity. Tolerance to lysozyme, bile salts, and acidic conditions, along with ability to survive under simulated gastrointestinal digestion, were observed. In addition, based on antimicrobial activity against pathogens, cell surface characteristics, Caco-2 adhesion abilities, and anti-inflammatory potential, it was possible to confirm the strain-dependent functional aptitude, suggesting that Piacentinu Ennese PDO cheese may be considered a precious source of probiotic candidates.