• Mycobiology
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• v.31 no.4
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• pp.251-254
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• 2003

To select active bacterial strains to control plant diseases, 57 bacterial strains were isolated from the rhizosphere of the plants growing in various areas such as coast, middle and top of Halla Mountain in Jeju Island. Anti-fungal effect of isolated bactrial strains was tested in vitro by incubating in potato dextrose agar with isolates of four fungal plant pathogens Rhizoctonia solani, Fusarium oxysporum, Colletotrichum gloeosporioides and C. orbiculare, respectively. Thirty-four bacterial strains inhibited the hyphal growth of the plant pathogens, from which 17 strains inhibited one of the tested fungi, 10 strains two fungi, six strains three and a strain TRL2-3 inhibited all of the tested fungi. Some bacterial strains could inhibit weakly the hyphal growth of the plant pathogens, whereas some did very strongly with apparent inhibition zone between the plant pathogens and bacterial strains indicating the unfavorable condition for hyphal growth. Although there was no apparent inhibition zone, some bacterial strains showed a strong suppression of hyphal growth of plant pathogens. Especially, the inhibition by TRL2-3 was remarkably strong in all cases of the tested plant pathogens in this study that could be a possible candidate for biological control of various plant diseases.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.4
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• pp.565-574
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• 2011

The development of satisfactory alternatives for supplying the nutrients needed by crops could decrease the problems associated with conventional NPK chemical fertilizers. In this study, the effects of bacterial and fungal effective microorganisms (EM) on the growth of Chinese cabbage (Brassica rapa) were evaluated. This investigation was carried out parrallel with conventional NPK chemical fertilizer and a commercial sold microbial fertilizer to compare between each of their effect. Sterile water and molasses were served as controls. Azotobacter chroococcum effect also was studied either alone or in combination with the effective microorganisms on the growth parameters. In contrast to the bacterial EM, the fungal EM alone without A. chroococcum had a more stimulating effect than fungal EM combined with A. chroococcum. Results showed that seedling inoculation significantly enhanced B. rapa growth. Shoot dry and fresh weight, and leaf length and width significantly were increased by both bacterial and fungal inoculation. The results indicated that the NPK chemical fertilizer deteriorates the microflora inhabiting the soil, while the effective microorganisms either fungal or bacterial ones increased the microbial density significantly. This study implies that both of fungal and bacterial EM are effective for the improvement of the Chinese cabbage growth and enhance the microorganisms in soil. The results showed antagonism occurred between A. chroococcum and each of Penicillium sp and Trichoderma sp in both agar and plant assays. The data were statistically analyzed by ANOVA and Dunnett test.

• Journal of Microbiology and Biotechnology
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• v.29 no.5
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• pp.809-812
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• 2019

Bacterial strains that improve mycelial morphology and growth of white-rot fungi in liquid medium could enhance the impact of white-rot fungi towards lesser recovery of neonicotinoids when cocultured. This was demonstrated by the recovery of clothianidin and acetamiprid from cocultures of the white-rot fungus Phlebia brevispora strains with two mycelial-growth-promoting bacteria, Enterobacter sp. TN3W-14 and Pseudomonas sp. TN3W-8. Clothianidin recovery from cocultures of white-rot fungi and bacteria was over 40% lower than that from axenic microbial cultures and mixed-bacterial cultures. About 20% less acetamiprid was equally recovered from both TMIC33929+TN3W-14 cocultures and mixed-bacterial cultures than from axenic fungal and bacterial cultures.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.11
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• pp.847-854
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• 2011

To deal with issues from global climate changes, renewable bioenergy has become important. Algae have been regarded as a good resource for biorefinery and bioenergy, and also have potential capability to remove nutrient and non-decompositional pollutants for wastewater advanced treatment. Although algal-bacterial ecological interaction would be a crucially important factor in using algae for wastewater advanced treatment and resource recovery from wastewater, very little is known about ecological interaction between algae and bacteria in a real wastewater environment. In this study, under a real municipal wastewater condition, we characterized wastewater pollutant treatability and bacterial communities in response to growth of Ankistrodesmus gracilis SAG278-2, which can grow in wastewater and has a high lipid contents. The growth of algal population using the wastewater was inhibited by increase in wastewater bacteria while bacterial survival and cellular decay rate were not influenced by the algal growth. Removals of recalcitrant organic matters and total nitrogen were improved in the presence of algal growth. According to T-RFLP and statistical analysis, algal growth affected time-course changes in bacterial community structures. The following 16S rRNA gene amplicon, cloning results showed that the algal growth changes in bacterial community structure, and that bacterial populations belonging to Sediminibacterium, Sphingobacterium, Mucilaginibacter genera were identified as cooperative with the algal growth in the wastewater.

• Journal of the Korean Society of Tobacco Science
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• v.30 no.1
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• pp.1-7
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• 2008

Bacterial wilt caused by Ralstonia solanacearum has become a severe problem on tobacco in Korea. No effective single control measure is available at present time. One of the most potential way for controlling the bacterial wilt on tobacco is growing tobacco cultivars resistant to the bacterial wilt. In this study, optimal conditions for screening tobacco cultivars resistant to the bacterial wilt were examined to provide reproducible and efficient methods in growth chamber testing and field experiments for evaluating plant disease resistance. For this, already-known inoculation methods, inoculum densities, and incubation temperature, and plant growth stages at the time of inoculation were compared using tobacco cultivars resistant (Nicotiana tabacum cv, NC95), moderately resistant (N. tabacum cv. SPG70), and susceptible (N. tabacum BY4) to the bacterial disease. It was determined that root-dipping of tobacco seedlings at six true leaf stage into the bacterial suspension with inoculum level of $10^8$ colony-forming units (CFU)/ml for 20 min before transplanting was simple and most efficient in testing for resistance to the bacterial wilt of tobacco caused by R. solanacearum, for which disease incidences and severities were examined at 2 weeks of plant growth after inoculation at $20{\sim}25^{\circ}C$ in a growth chamber. These experimental conditions could discriminate one tobacco cultivar from the others by disease severity better than any other experimental conditions. In field testing, the optimum time for examining the disease occurrence was late June through early July. These results can be applied to establishing a technical manual for the screening of resistant tobacco cultivars against the bacterial wilt caused by R. solanacearum.

• The Journal of Korean Physical Therapy
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• v.6 no.1
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• pp.109-119
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• 1994

The study was carried out to investigate the change of bacterial growth in vitro according to polarity, current intensity and time, to prepare the basic data for electrotherapy and clinical research. The Gram positive Staphylococcus aureus and Gram negative Escherichia coli 1mm infect wound were cultured in Trypticase Soy Brath and Trypticase Soy Agar. The results were as followings. 1. The current stimulated group was changed in bacterial growth according to polarity, current intensity and time respectively. 2. The bacteriolytic effect revealed in the anode but the inhibitory effect of bacterial growth revealed in the cathode. 3. The lumber of E. coli reduced after 6-hours but the numbers of S. aureus reduced after 2 hours in Trypticase Soy Brath. 4. The anode showed acid reaction and cathode showed alkaline reaction in Trypticase Soy Agar.

• The Plant Pathology Journal
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• v.24 no.1
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• pp.52-57
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• 2008

Twenty isolates of Bacillus spp. obtained from livestock manure composts and cotton-waste composts were tested for in vitro antagonistic effects against soilborne plant pathogenic fungi, Fusarium oxysporum, Phytophthora capsici, Rhizoctonia solani AG-4, and Sclerotinia sclerotiorum. Seven isolates of Bacillus spp. had antagonistic effects on mycelial growth of all the isolates of F. oxysporum tested. The bacterial isolate RM43 was the most effective to inhibit the mycelial growth of the fungal isolates. Twelve isolates of Bacillus spp. had antagonistic effects on mycelial growth of all the isolates of P. capsici tested. The bacterial isolates M34 and M47 were very effective to inhibit the mycelial growth of the fungal isolates. Thirteen isolates of Bacillus spp. had antagonistic effects on mycelial growth of all the isolates of R. solani AG-4 tested. The bacterial isolates M27 and M75 were very effective to inhibit the mycelial growth of the fungal isolates. Fourteen isolates of Bacillus sp. had antagonistic effects on mycelial growth of all the isolates of S. sclerotiorum tested. The bacterial isolates M49 and M75 were very effective to inhibit the mycelial growth of the fungal isolates. The antagonistic effects of most Bacillus spp. isolates against the isolates of the four fungi differed depending on the fungal species and the isolates of each fungus. The bacterial isolates M27 and M75 were the most effective to inhibit the mycelial growth of all four fungi.

• Journal of Microbiology and Biotechnology
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• v.23 no.10
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• pp.1472-1477
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• 2013

Microalgae have been regarded as a natural resource for sustainable materials and fuels, as well as for removal of nutrients and micropollutants from wastewater, and their interaction with bacteria in wastewater is a critical factor to consider because of the microbial diversity and complexity in a variety of wastewater conditions. Despite their importance, very little is known about the ecological interactions between algae and bacteria in a wastewater environment. In this study, we characterized the wastewater bacterial community in response to the growth of a Selenastrum gracile UTEX 325 population in a real municipal wastewater environment. The Roche 454 GS-FLX Titanium pyrosequencing technique was used for indepth analysis of amplicons of 16S rRNA genes from different conditions in each reactor, with and without the algal population. The algal growth reduced the bacterial diversity and affected the bacterial community structure in the wastewater. The following in-depth analysis of the deep-sequenced amplicons showed that the algal growth selectively stimulated Sphingobacteria class members, especially the Sediminibacterium genus population, in the municipal wastewater environment.

• Journal of Environmental Science International
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• v.12 no.9
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• pp.935-941
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• 2003

To investigate the interaction of bacteria and Microcystis isolated from a hypertrophic reservoir(Seo-Nakdong River), the response of five bacteria in relation to the different treatment of Microcystis and microcystin production by addition of dominant bacteria Staphylococcus sciuri were examined. Five bacteria (S. sciuri, S. capitis, S. epidermis, Pseudomonas aeruginosa and Aeromonas aimonicida) were identified from the reservoir. In the experiment of bacterial response, two types of bacterial growth pattern were observed. All bacteria showed active growth in heated Microcystis-added media. Especially, three species of bacteria (S. sciuri, S. capitis and P. aeruginosa) among them showed active growth in live Microcystis-added media. In Microcystis response, increase of microcystin production showed when dominant bacteria, S. sciuri was added.

• Journal of Marine Life Science
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• v.4 no.1
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• pp.22-28
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• 2019

The bacterial diversity of an Antarctic hard coral, Errina fissurata, was examined by isolating bacterial colonies from crushed coral tissue and by sequencing their 16S rRNA gene. From the analyzed results, the bacteria were classified as Actinobacteria (56%), Firmicutes (35%) and Proteobacteria (9%). The thirty-four isolates were cultured in liquid media at different temperatures and their growth was assessed over time. The majority of the isolates displayed their highest growth rate at 25℃ during the first three days of cultivation, even though the coral was from a cold environment. Nevertheless, strains showing their highest growth rate at low temperatures (15℃ and 4℃) were also found. This study reports the composition of an Antarctic hard coral-associated culturable bacterial community and their growth behavior at different temperatures.