Byung Kwon Jung

Host plant growth promotion and cadmium detoxification in Solanum nigrum, mediated by endophytic fungi

Current investigation conducted to evaluate the associated fungal endophyte interactions of a Cd hyper-accumulator Solanum nigrum Korean ecotype under varying concentrations of Cd. Two indole-3-acetic acid (IAA) producing fungal strains, RSF-4L and RSF-6L, isolated from the leaves of S. nigrum, were initially screened for Cd tolerance and accumulation potential. In terms of dry biomass production, the strain RSF-6L showed higher tolerance and accumulation capacity for Cd toxicity in comparison to RSF-4L. Therefore, RSF-6L was applied in vivo to S. nigrum and grown for six weeks under Cd concentrations of 0, 10, and 30mgKg-1 of dry sand. The effect of fungal inoculation assessed by plant physiological responses, endogenous biochemical regulations, and Cd profile in different tissues. Significant increase were observed in plant growth attributes such as shoot length, root length, dry biomass, leaf area, and chlorophyll contents in inoculated RSF-6L plants in comparison to non-inoculated plants with or without Cd contamination. RSF-6L inoculation decreased uptake of Cd in roots and above ground parts, as evidenced by a low bio-concentration factor (BCF) and improved tolerance index (TI). However, Cd concentration in the leaves remained the same for inoculated and non-inoculated plants under Cd spiking. Fungal inoculation protected the host plants, as evidenced by low peroxidase (POD) and polyphenol peroxidase (PPO) activities and high catalase (CAT) activity. Application of appropriate fungal inoculation that can improve tolerance mechanisms of hyper-accumulators and reduce Cd uptake can be recommended for phyto-stabilisation/immobilisation of heavy metals in crop fields.

Draft Genome Sequence of Entomopathogenic Bacterium Photorhabdus temperata Strain M1021, Isolated from Nematodes

ABSTRACT Photorhabdus temperata strain M1021 is an entomopathogenic bacterium belonging to the family Enterobacteriaceae and is symbiotically associated with nematodes. The draft genome sequence of P. temperata strain M1021 consists of 5,598,253 bp with a G+C content of 43.7%, and it has 6,120 protein-coding genes.

Complete genome sequence of Pseudomonas rhizosphaerae IH5T (=DSM 16299T), a phosphate-solubilizing rhizobacterium for bacterial biofertilizer.

Pseudomonas rhizosphaerae IH5(T) (=DSM 16299(T)), isolated from the rhizospheric soil of grass growing in Spain, has been reported as a novel species of the genus Pseudomonas harboring insoluble phosphorus solubilizing activity. To understanding the multifunctional biofertilizer better, we report the complete genome sequence of P. rhizosphaerae IH5(T).

Gibberellins synthesized by the entomopathogenic bacterium, Photorhabdus temperata M1021 as one of the factors of rice plant growth promotion

In the present study, different types of gibberellins (GAs) in the culture filtrate (CF) of Photorhabdus temperata M1021 were quantified. The analysis of CF helped in profiling various bioactive GAs: GA1, GA3, GA4, and GA7. Several physiologically inactive GAs: GA9, GA12, and GA20 were detected as well. Siderophore production was also investigated by growing P. temperata M1021 on chrome azurol-S blue agar plates. Furthermore, the strain was inoculated into ‘Waito-C’ (Oryza sativa L.) rice plants, which significantly (P < 0.05) increased plant growth attributes such as plant length, chlorophyll content, and fresh and dry biomass compared with those in controls. In a separate experiment, canola (Brassica napus L.) seeds treated with CF of M1021 were significantly (P < 0.05) accelerated germination rate as well as biomass production. Findings of the present study suggest that the strain M1021 contributes an important role in the plant growth by synthesizing a wide array of bioactive metabolites.

Draft Genome Sequence of Chryseobacterium sp. Strain P1-3, a Keratinolytic Bacterium Isolated from Poultry Waste

ABSTRACT Chryseobacterium sp. strain P1-3, harboring keratin degrading activity, has recently been isolated from poultry waste. Here, we report the 4.6-Mbp draft genome sequence of the keratinolytic bacterium with a G+C content of 37.0% and 4,087 protein-coding genes.

Complete genome sequence of a keratin-degrading bacterium Chryseobacterium gallinarum strain DSM 27622T isolated from chicken

Chryseobacterium gallinarum strain DSM 27622(T) is a keratin-degrading bacterium belonging to the class Flavobacteriia, which was isolated from chicken. Here, we report the 4633,632bp complete genome sequence of the strain DSM 27622(T) with 4161 genes.

Draft genome sequence of a caprolactam degrader bacterium: Pseudomonas taiwanensis strain SJ9.

Pseudomonas taiwanensis strain SJ9 is a caprolactam degrader, isolated from industrial wastewater in South Korea and considered to have the potential for caprolactam bioremediation. The genome of this strain is approximately 6.2 Mb (G + C content, 61.75%) with 6,010 protein-coding sequences (CDS), of which 46% are assigned to recognized functional genes. This draft genome of strain SJ9 will provide insights into the genetic basis of its caprolactam-degradation ability.

Complete mitochondrial genome of Cygnus cygnus (Aves, Anseriformes, Anatidae).

Abstract In this study, the complete mitochondrial genome of Cygnus cygnus (Aves, Anseriformes, Anatidae) was sequenced. The genome, consisting of 16 724 base pairs (bp), encoded 13 protein coding genes (PCGs), two ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs), and a control region (CR). Two rRNA genes for 12S rRNA (991 bases) and 16S rRNA (1608 bases) are located between tRNA-Phe and tRNA-Leu (UUR) and divided by the tRNA-Val. The CR, of 1156 bp in length, is located between tRNA-Glu and tRNA-Phe. The overall base composition of C. cygnus is G + C: 47.2%, A + T: 52.8%, apparently with a slight AT bias. Phylogenetic analysis showed that the C. cygnus was closed to Cygnus columbianus.

The complete mitochondrial genome sequence of the greater wax moth Galleria mellonella (Insecta, Lepidoptera, Pyralidae): sequence and phylogenetic analysis comparison based on whole mitogenome

Abstract The larva of Galleria mellonella is widely used as a model organism for in vivo toxicology and pathogenicity testing. Here, we report complete sequence of the mitochondrial genome (mitogenome) from G. mellonella, which is comprised of 15,320 base pairs encoding 13 protein-coding genes, two ribosomal RNAs, 22 transfer RNAs, and an A + T rich region. The overall base composition was G + C: 19.6%, A + T: 80.4%, with an apparent AT bias. Phylogenetic analysis using whole mitogenome revealed that G. mellonella was closely related to Corcyra cephalonica, which is in the same Pyralidae family.

Genomic and phenotypic analyses of Serratia fonticola strain GS2: a rhizobacterium isolated from sesame rhizosphere that promotes plant growth and produces N-acyl homoserine lactone

The genus Serratia incorporates many agriculturally important species. Serratia fonticola strain GS2, isolated from a sesame rhizosphere, can produce N-acyl homoserine lactone quorum sensing signal molecules and indole-3-acetic acid (IAA). Here we report the complete genome sequence and phenotypic characteristics based on genomic information of this bacterium. The complete genome sequence of S. fonticola strain GS2 consists of a chromosome of 6.1 Mbp and two plasmids of 132 kbp and 94 kbp. The genome clusters for IAA and N-acyl homoserine lactone biosynthesis were identified in the genome. Subsequently, the Salkowski test and gas chromatography-mass spectrometry (GC-MS) analysis also revealed that the strain GS2 produces indolic compounds (27.1μgmL-1) and IAA (6.7μgmL-1) in its culture broth. HPLC analysis confirmed that the strain GS2 produced the quorum sensing signal molecules N-hexanoyl-L-homoserine lactone and N-octanoyl-L-homoserine lactone. This new information on the genome sequence and phenotype features will inform future ecological studies related to plant-microbe interactions.