• Microbiology and Biotechnology Letters
• /
• v.49 no.3
• /
• pp.432-439
• /
• 2021

Microbial community plays important roles in the culture environment of mud crab Scylla serrata. One of the environmental management efforts for the cultivation of S.serrata is by stabilizing microorganisms involved in nitrogen cycle process. The availability of dissolved inorganic nitrogen in its culture environment under a recirculating system closely relates to the nitrogen cycle, which involves both anaerobic and aerobic bacterial activities. Anaerobically, there are two major nitrogen compound degradation processes, i.e., denitrification and dissimilatory nitrate reduction to ammonium (DNRA). This study aimed to identify denitrifying and DNRA bacteria isolated from the recirculating cultivation of S. serrata. The water samples were collected from anaerobic filters called close filter system, which is anaerobically conditioned with the addition of varying physical filter materials in the recirculating mud crab cultures. The results showed that three denitrifying bacterial isolates and seven DNRA bacterial isolates were successfully identified. The phylogenetic analysis based on 16S rRNA gene of the denitrifying bacteria revealed that HIB_7a had the closest similarity to Stenotrophomonas daejeonensis strain MJ03. Meanwhile, DNRA bacterial isolate of HIB_92 showed a 100% similarity to Bacillus sonorensis strain N3, Bacillus vallismortis strain VITS-17, Bacillus tequlensis strain TY5, Geobacillus sp. strain DB24, Bacillus subtilis strain A1, and Bacillus mojavensis strain SSRAI21. This study provides basic information denitrifying and DNRA bacterial isolates identity which might have the potential to be applied as probiotics in aquaculture systems in order to maintain optimal environmental conditions.

• Journal of Microbiology and Biotechnology
• /
• v.31 no.12
• /
• pp.1624-1631
• /
• 2021

Prodigiosin as a high-valued compound, which is a microbial secondary metabolite, has the potential for antioxidant and anticancer effects. However, the large-scale production of functionally active Hahella chejuensis-derived prodigiosin by fermentation in a cost-effective manner has yet to be achieved. In the present study, we established carbon source-optimized medium conditions, as well as a procedure for producing prodigiosin by fermentation by culturing H. chejuensis using 10 L and 200 L bioreactors. Our results showed that prodigiosin productivity using 250 ml flasks was higher in the presence of glucose than other carbon sources, including mannose, sucrose, galactose, and fructose, and could be scaled up to 10 L and 200 L batches. Productivity in the glucose (2.5 g/l) culture while maintaining the medium at pH 6.89 during 10 days of cultivation in the 200 L bioreactor was measured and increased more than productivity in the basal culture medium in the absence of glucose. Prodigiosin production from 10 L and 200 L fermentation cultures of H. chejuensis was confirmed by high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) analyses for more accurate identification. Finally, the anticancer activity of crude extracted prodigiosin against human cancerous leukemia THP-1 cells was evaluated and confirmed at various concentrations. Conclusively, we demonstrate that culture conditions for H. chejuensis using a bioreactor with various parameters and ethanol-based extraction procedures were optimized to mass-produce the marine bacterium-derived high purity prodigiosin associated with anti-cancer activity.

• Food Science of Animal Resources
• /
• v.42 no.6
• /
• pp.928-941
• /
• 2022

This study aimed to analyze the microbiological composition and sensory characterization of fermented sausage using strains isolated from Kimchi (GK1, Pediococcus pentosaceus SMFM2016-GK1; NK3, P. pentosaceus SMFM2016-NK3), Doenjang (D1, Debaryomyces hansenii SMFM2021-D1), and spontaneously fermented sausage (S8, D. hansenii SMFM2021-S8; S6, Penicillium nalgiovense SMFM2021-S6). The control was commercial starter culture. Nine treatments were applied [GD (GK1+D1), GS (GK1+S8), GDS (GK1+D1+S8), ND (NK3+D1), NS (NK3+S8), NDS (NK3+D1+S8), GND (GK1+NK3+D1), GNS (GK1+NK3+S8), and GNDS (GK1+NK3+D1+S8)] by mixing lactic acid bacteria and yeast, and S6 was sprayed. The microbial composition of fermented sausage was analyzed [aerobic bacteria (AC), Lactobacillus spp. (LABC), Staphylococcus spp. (STPC), and yeast and mold (YMC)], and pH and electronic nose and tongue measurements were taken. The AC, LABC, STPC, and YMC values of the control and treatment groups tended to increase during fermentation (p>0.05). The STPC values of the GD, GS, ND, and GDS groups were similar to that of the control on day 3. The pH of the control on day 3 was significantly lower than that of the GD, ND, and GND groups (p<0.05). Higher levels of 4-methylpentanol, 2-furanmethanol, and propyl nonanoate, which provide a "fermented" flavor, were detected in the GD group compared to in the control and other treatment groups. GD and ND groups showed higher umami values than the control and other treatment groups. Therefore, it is expected that GD can be valuable as a starter culture unique to Korea when manufacturing fermented sausage.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.95.1-95
• /
• 2003

Plant growth promoting rhizobacteria (PGPR) have been shown to suppress phytopthora blight. This suppression has been related to both microbial antagonism and induced resistance. The PGPR isolates were screened by dual culture plate method and most of the isolates were showed varying levels of antagonism. Among the PGPR isolates pyoverdin, pyochelin and salicylic acid producing strains showed the maximum inhibition of mycelial growth of Phytopkhora capsici and increased plant growth promotion in red pepper. PGPR isolates further analysed for its ability to induce production of defence related enzymes and chemicals. The activities such as Phenyle alanin ammonia Iyase (PAL), Peroxidase (PO), Polyphenol oxidase (PPO) and accumulation of phenolics were observed in PGPR pretreated red pepper plants challenged with Phytopkhora capsici. The present study shows that an addition of direct antagonism and plant growth promotion, induction of defense related enzymes involved to enhance resistance against invasion of P. capsici in red pepper.

• Journal of Environmental Health Sciences
• /
• v.22 no.1
• /
• pp.99-106
• /
• 1996

The purpose of this study is to observe a specific removal efficiency of synthethetic wastewater which is managed by upflow submerged type at porous media which was sinteringed on a comparative low temperature 600$\circ$C, was annexed slag and humus soil with main material kaolinite. Observing removal efficiency quality of each media, a mixed media of kaolinite and humus soil by gravity percent 60, 40% respectively showed the most excellent removal utility, and applied predictive models for suspended culture kinetics without consideration diffusion limitation, and when analyzed kinetic which had been processed by this study the removal efficiency accompanied by carbon, nitrogen, phosphorous volumetric loading rate variation standed for a comparative large change rate 61~71%, it means the selection of the most proper load factor had a great effect on the highly removal efficiency, yield coefficient(Y) and specific microbial attach equation showed 1.53 mgVSS/mgCOD, $m_p=10039.4\times ((S_0)/(6.75+S_0))$ repectively.

• Microbiology and Biotechnology Letters
• /
• v.21 no.4
• /
• pp.322-328
• /
• 1993

During the screening of antifungal compounds from microbial secondary metabolites to control phytophthora blight of red pepper caused by Phytophthora capsici, a soil isolate, strain 38D10 was selected. Based on taxonomic studies, this strain was identified as Streptomyces neyagawaensis. The antifungal compound was purified from culture broth by HP-20 column chromatography, ethyl acetate extraction, silica gel column chromatography, HPLC and identified as concanamycin B by UV. $^1H$-NMR, $^{13}C$-NMR, SIMS analysis. Concanamycin B has strong antifungal activity against some phytopathogenic fungi but not antivacterial activity and preventive value were 50% and 100% at 125ppm and 250ppm in pot assay.

• Microbiology and Biotechnology Letters
• /
• v.28 no.3
• /
• pp.139-146
• /
• 2000

산업적으로 유용한 미생물 유래 셀룰로오스를 생산 이용하기 위해 전국 각지 양조식초의 덧으로부터 세룰로오스의 생산성이 높고 조질의 균일성을 나타내는 균주를 분리하였다 분리균 GS11은 gram 음성이고 간균(0.6$\times$2.2~3.2 $\mu\textrm{m}$)의형태를 하고 있으며 편모를 가지고 있어 운동성을 보였다. 또한 세포내 지방산 조성은 다량의 불포화 지방산 {{{{ {C}_{18:1} }}}}과 포화지반산 {{{{ {C}_{16:0 } }}}}, {{{{ {C}_{14:0 } }}}} 이 대부분을 차지하였고 DNA 염기조성 (G+C) 함량은 58.4% 이였으며 ubiqunone 은 {{{{ { Q}_{10 } }}}}을 갖는 것으로 나타났다 이러한 형태학적 생리.생화학적 특성의 결과에 따라 본 균주는 Acetobacter xylinum GS11으로 동정되었다 A. xylinum, GS11 의배양기간 동안 셀룰로오스 생산성을 검토하고자 250mL 삼각플라스크에 균주를 접종하여 $30^{\circ}C$에서 12일간 정치배양하였다 그결과 기질인 glucose의 소비는 접종 후 급소하게 감소하여 셀룰로오스 생산에 이용되었으며 셀룰오스의 생산은 배양 9일 경에 2.8g/l로 최대의 생산량을 나타냈다.

• Microbiology and Biotechnology Letters
• /
• v.23 no.1
• /
• pp.98-103
• /
• 1995

During the screening of antifungal antibiotics from microbial metabolites, we selected Pseudomonas aeruginosa KGM-100 showing powerful antagonistic activity against various phytopathogenic fungi. Antibiotics KGM-100A and KGM-100B were purified from the culture broth of Pseudomonas aeruginosa KGM-100 by diaion HP-20 column chromatography, ethyl acetate extraction, silica gel column chromatography, preparative TLC and recrystallization. KGM-100A which was recrystallized in MeOH showed antimicrobial activities against a broad spectrum of fungi and bacteria. Physico-chemical properties of KGM-100A were determined and identified to be phenazine-l-carboxylic acid by UV, IR, $^{1}$H-NMR, $^{13}$C-NMR, mass spectrum, and elemental analyses.

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 1979.04a
• /
• pp.116-116
• /
• 1979

In the experiment of cholesterols and steroidal compounds. gas chromatography has been widely used to determine the compounds. Without the facility, we could determine the amount of 17-ketosteroids in the use of t. 1. c technique. In the muicrobial conversion of cholesterol to 17-ketsoteroids, $\alpha,$ $\alpha'-dipyridyl$ which might be a inhibitor of $9\alpha-hydroxylase$ of steroid skeleton was added to microbial culture broth. The inhibitor contaminated due to its solubility in organic solvents and hindered the determination of 17-ketost eroids on t.1. c in all the process of the experiment. we successfully determined the 17-ketosteroids by the use of Ag$^{+}$ band on t. 1. c. plate.e.

• Microbiology and Biotechnology Letters
• /
• v.25 no.5
• /
• pp.490-494
• /
• 1997

A variety of microbial strains isolated from soil were tested for their ability to produce D-tagatose from D-galactose. An organism that can convert D-galactose into D-tagatose was selected and was identified as Enterobacter agglomerans. The cells grown on the induction medium containing 20 g/l arabinose were found to the best conversion potential among different carbohydrates and the conversion yield was about 15% when 20 gll galactose was used. The isolated crystals were obtained from the culture broth after the purification process such as treatment of ion resins, crystallization, and drying. The recovery yield was 70% after the purification. The crystals were identified as D-tagatose by the infrared spectroscopy, HPLC, specific optical rotation, and melting point.