• BMB Reports
• /
• v.33 no.4
• /
• pp.332-336
• /
• 2000

Phenazine 1-carboxylic acid (PCA) is an antifungal antibiotic isolated from a culture filtrate of Bacillus sp. B-6 producing an acyl CoA synthetase inhibitor. This antibiotic is reported as an inhibitor of an acyl CoA synthetase from Pseudomonas sp.. Bacillus sp. B-6 was resistant to PCA up to 350 ${\mu}g/ml$. We investigated the mechanism of the resistance of Bacillus sp. B-6 to PCA. The rate of growth in a medium containing up to 100 ${\mu}g/ml$ was as rapid as the PCA-free medium. At a PCA concentration of 300 ${\mu}g/ml$, the growth rate was more than half that of the control. In this work, we purified acyl CoA synthetase from Bacillus sp. B-6 and found that this acyl CoA synthetase was much less sensitive to PCA than the acyl CoA synthetase from other source. These findings suggested that the insensitivity of Bacillus sp. B-6 acyl CoA synthetase plays an important role in the PCA resistance of this bacterium.

• Korean Journal of Environmental Agriculture
• /
• v.19 no.1
• /
• pp.13-19
• /
• 2000

Seasonal variations of dominant algae species and the effects of these algae on coagulation and filteration of water treatment were investigated at Chilseo water treatment plant in downstream of Nakdong river from January in 1995 to Desember of 1998. The water quality of Nakdong river was found to be a hyper eutrophic state during the investigation periods. In the measurement, Chlorophyll-a contents ranged $20.7{\sim}180.9{\mu}g/l$ and total nitrogen contents(T-N) and total phosphorus contents(T-P) exceeded more than 3.4mg/l and 0.1mg/l, respectively. The changes in dominant algae species was in the order of Stepanodiscus sp., Asterionella sp., Melosira sp., Microcystis sp. and Synedra sp. from spring to winter. Microcystis sp. especially, was blooming during summer and Synedra sp. and Stepanodiscus sp. during winter. Although most diatomous algae appeared in the water treatment process caused filter clogging and reduced efficiency of coagulation and sedimentation, Synedra sp. and Stepanodiscus sp were revealed as the main trouble algae. Malfunction of water treatment process caused by Synedra sp. and Stepanodiscus sp. started at the algae concentrations of 800cells/ml and 1,820cells/ml, respectively. When chlorophyll-a content was $18.9{\mu}g/l$, the optimum amounts of coagulant were found to be 40mg/l of Alum and 16mg/l of PACS. Under condition of chlorophyll-a content of $154.1{\mu}g/l$, addition of Alum at the level of 75mg/l and PACS at the level of 35mg/l showed the lowest turibidity. The result indicates that increased amounts of the coagulants should be added for a better water treatment as chlorophyll-a contents increased. Addition of Alum at the amount of 60mg/l and 30mg/l of PACS removed Stepanodiscus sp. algae at the rate of 85% and 83%, respectively. In case of Synedra sp., 50mg/l of Alum and 25mg/l of PACS showed removal rates of 79% and 81%, respectively. Synedra sp. algae at the standing crops of 1,500cells/ml started filter clogging and a filtering process was completely inhibited after 8 hours. At this situation the filter clogging by Synedra sp. algae occurred at the depth of 5cm from the top anthracite layer. On the other, other algae did filter clogging at the depth of 10cm.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.14 no.1
• /
• pp.61-83
• /
• 2012

To identification of fungi that occurs round bale silages, 253 fungal contaminated samples were collected from 2009 to 2011. Total 253 silage samples from Italian ryegrass, sudan grass, rye, corn, barley and oat were analysed. Total 270 strains were purely isolated from contaminated round bale silages. The fungi were identified with morphological characteristics and rDNA sequence analysis. Nineteen species of fungi(Rhizopus sp., Fusarium spp., Coprinus sp., Blastomyces sp., Aureobasidium sp., Polypaecilum sp., Botryoderma sp., Mucor sp., Scytalidium sp., Sphaeropsis sp., Aspergillus spp., Trichocladium sp., Humicola sp., Staphylotrichum sp., Periconia sp., Verticillium sp., Diplococcium sp., Penicillium spp. and Trichoderma spp.) were identified by morphological characteristics. On the other hand, fungi isolated from silage were identified to Acremonium strictum, Aspergillus tubingensis, Bionectria ochroleuca, Dipodascaceae sp., Fusarium proliferatum, Fusarium oxysporum, Fusrium solani, Gelasinospora reticulata, Gibberella moniliformis, Gibberella zeae, Nectria mauritiicola, Penicillium paneum, Pseudallecheria boydii, Schizophyllum commune, Scopulariopsis brevicaulis and Simplicillium lamellicola by rDNA sequence analysis. Penicillium sp. and Trichoderma sp., were isolated 74 and 64 strains, respectively. Humicola sp., Aspergillus sp., Coprinus sp., and Fusarium spp. were identified 10 to 30 strains. Most fungi were isolated together with more than one species in a sample looked like one species with the naked eyes.

• Microbiology and Biotechnology Letters
• /
• v.32 no.2
• /
• pp.172-178
• /
• 2004

This research is performed for a biological control of Chinese cabbage clubroot, we isolated an antagonistic bacterium AC-3 against Plasmodiophora sp., causal pathogens of cabbage clubroot. The isolated strain was identified as Streptomyces sp. by culture morphology, biochemical reactions, and homology research based on l6S rDNA sequences. Streptomyces sp. AC-3 produced chitinase (9.3 units/$m\ell$) in culture broth. So Plasmodiophora sp. mycelia changed abnonnal swelling, curling and branching mycelia by Streptomyces sp. AC-3 culture. In a field infected by Plasmodiophora sp., the treatment of a organic fertilizer added 2% Streptomyces sp. AC-3 microbial inoculant, it resulted in about 50% reducing the severity of cabbage clubroot significantly on cabbage plants compared with treated organic fertilizer plants. Additional disease such as sclerotinia rot, fusarium wilt and pythium rot were also significantly reduced by the treatment of the organic fertilizer added Streptomyces sp. AC-3 microbial inoculant.

• Korean Journal of Environmental Biology
• /
• v.36 no.3
• /
• pp.336-344
• /
• 2018

Four new species of the genus Alloclubionoides collected from mountain litter and hillock litter around the agricultural ecosystem of Korea are described in the present work with appropriate body measurements and morphological illustrations; A. hwaseongensis sp. nov., A. imi sp. nov., A. namhansanensis sp. nov. and A. nasuta sp. nov. Females of A. hwaseongensis sp. nov., A. namhansanensis sp. nov. and A. nasuta sp. nov. can be distinguished based on the epigyne shape and structure of internal genitalia from previously described species. Males of A. imi sp. nov. can also be distinguished based on the shapes of retrolateral tibial apophysis, embolus tip and conductor from previously described species. Also, a key to the Korean Alloclubionoides spiders is provided. Alloclubionoides gajiensis Seo, 2014 is newly synonymized with Alloclubionoides cochlea (Kim et al. 2007).

• Korean Journal of Microbiology
• /
• v.46 no.4
• /
• pp.401-404
• /
• 2010

Tho1 is a RNA-binding protein that assembles co-transcriptionally onto the nascent mRNA and is thought to be involved in mRNP biogenesis and mature mRNA export to cytoplasm in budding yeast. In fission yeast Schizosaccharomyces pombe, a homologue of THO1 (spTho1) was identified based on sequence alignment. A deletion mutant in a diploid strain was constructed by replacing one of spTho1-coding region with an ura4+ gene using one-step gene disruption method. Tetrad analysis showed that the spTho1 was not essential for growth. The spTho1 mutant did not show any defects of bulk mRNA export. However, over-expression of spTho1 from strong nmt1 promoter caused the growth defects and accumulation of poly(A)$^+$ RNA in the nucleus. These results suggest that spTho1 is involved in mRNA export from the nucleus to cytoplasm though it is not essential.

• Molecules and Cells
• /
• v.22 no.1
• /
• pp.89-96
• /
• 2006

"Determinate" and "indeterminate" inflorescences in plants are controlled by a single recessive gene, for example, SELF-PRUNING (SP) in Solanum lycopersicum, TERMINAL FLOWER1 in Arabidopsis, CENTRORADIALIS in Antirrhinum, and CENTRORADIALIS-like gene in tobacco. Pepper (Capsicum annuum L.) is an indeterminate species in which shoots grow indefinitely. In this study, we cloned and characterized the pepper SP-like gene (CaSP). RT-PCR revealed that the CaSP transcript accumulates to higher levels in floral buds than in other organs. Comparison of genomic DNA and cDNA sequences from indeterminate and determinate pepper plants revealed the insertion of a single base in the first exon of CaSP in the determinate pepper plants. CaSP is annotated in linkage group 8 (chromosome 6) of the SNU2 pepper genetic map and showed similar synteny to SP in tomato. Transgenic tobacco plants overexpressing CaSP displayed late-flowering phenotypes similar to the phenotypes caused by overexpression of CaSP orthologs in other plants. Collectively, these results suggest that pepper CaSP is an ortholog of SP in tomato.

• Korean Journal of Breeding Science
• /
• v.42 no.4
• /
• pp.344-350
• /
• 2010

Sweet pepper inbred lines (KNU1003, KNU1006, KNU1007, KNU1009, KNU1015, KNU1017 and KNU2006) developed at Kangwon National University (KNU) through conventional means, inbred lines (5AVS1, 5AVS2, 5AVS3, 5AVS5, 5AVS7 and 5AVS8) collected at Rural Development Administration (RDA) and inbred lines (SP12, SP27 and SP14) derived from anther culture were used as female parents and anther culture derived homozygous lines (SP9, SP10, SP14, SP24, SP25, SP27, SP30, SP32, SP34, SP38, SP43, SP45 and SP51) were used as male parents to produce $F_1$ hybrids. A total of 37 $F_1$ hybrids were evaluated for fruit yield and quality characters in summer season, 2007. Variation in fruit number, fruit weight, fruit yield per plant and fruit volume was observed among the $F_1$ hybrids. Superiority on yield over standard/commercial varieties were differed among $F_1$ hybrids. Hybrid $5AVS8{\times}SP45$ exhibited highest heterosis over Special (16.5%) and Fiesta (24.7%). Fruit quality characters (fruit length, fruit width, pericarp thickness, total soluble solid, fruit shape and fruit color) were varied among the $F_1$ hybrids. Fruit number, fruit weight and fruit volume per plant were correlated with fruit yield. Based on the standard heterosis expressed by the hybrids and quality characters evaluation, $KNU1017{\times}SP27$, $5AVS1{\times}SP43$, $5AVS5{\times}SP27$, $5AVS8{\times}SP45$, $SP12{\times}SP38$ and $SP27{\times}SP25$ hybrids were found to be superior over commercial cultivars and are selected. Inbred lines of these hybrid combinations can be used to produce $F_1$ hybrid seed for commercial production.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.2
• /
• pp.233-240
• /
• 2016

FK506, a widely used immunosuppressant, is a 23-membered polyketide macrolide that is produced by several Streptomyces species. FK506 high-yielding strain Streptomyces sp. RM7011 was developed from the discovered Streptomyces sp. KCCM 11116P by random mutagenesis in our previous study. The results of transcript expression analysis showed that the transcription levels of tcsA, B, C, and D were increased in Streptomyces sp. RM7011 by 2.1-, 3.1-, 3.3-, and 4.1-fold, respectively, compared with Streptomyces sp. KCCM 11116P. The overexpression of tcsABCD g enes in Streptomyces sp. RM7011 gave rise to approximately 2.5-fold (238.1 μg/ml) increase in the level of FK506 production compared with that of Streptomyces sp. RM7011. When vinyl pentanoate was added into the culture broth of Streptomyces sp. RM7011, the level of FK506 production was approximately 2.2-fold (207.7 μg/ml) higher than that of the unsupplemented fermentation. Furthermore, supplementing the culture broth of Streptomyces sp. RM7011 expressing tcsABCD genes with vinyl pentanoate resulted in an additional 1.7-fold improvement in the FK506 titer (498.1 μg/ml) compared with that observed under non-supplemented condition. Overall, the level of FK506 production was increased approximately 5.2-fold by engineering the supply of allylmalonyl-CoA in the high-yielding strain Streptomyces sp. RM7011, using a combination of overexpressing tcsABCD genes and adding vinyl pentanoate, as compared with Streptomyces sp. RM7011 (95.3 μg/ml). Moreover, among the three precursors analyzed, pentanoate was the most effective precursor, supporting the highest titer of FK506 in the FK506 high-yielding strain Streptomyces sp. RM7011.

• BMB Reports
• /
• v.44 no.6
• /
• pp.387-392
• /
• 2011

To investigate the molecular scavenging capabilities of the larvae of Hermetia illucens, two serine proteases (SPs) were cloned and characterized. Multiple sequence alignments and phylogenetic tree analysis of the deduced amino acid sequences of Hi-SP1 and Hi-SP2 were suggested that Hi-SP1 may be a chymotrypsin- and Hi-SP2 may be a trypsin-like protease. Hi-SP1 and Hi-SP2 3-D homology models revealed that a catalytic triad, three disulfide bonds, and a substrate-binding pocket were highly conserved, as would be expected of a SP. E. coli expressed Hi-SP1 and Hi-SP2 showed chymotrypsin or trypsin activities, respectively. Hi-SP2 mRNAs were consistently expressed during larval development. In contrast, the expression of Hi-SP1 mRNA fluctuated between feeding and molting stages and disappeared at the pupal stages. These expression pattern differences suggest that Hi-SP1 may be a larval specific chymotrypsin-like protease involved with food digestion, while Hi-SP2 may be a trypsin-like protease with diverse functions at different stages.