• 한국미생물·생명공학회지
• /
• 제50권3호
• /
• pp.395-403
• /
• 2022

본 연구에서는 한국형 프로바이오틱스와 홍삼을 발효하여 저분자 진세노사이드인 compound K (CK)로 생물전환되는지를 확인하였다. 프로바이오틱스 19종의 유전체 분석결과, 진세노사이드 Rb1에서 CK로 전환에 관련된 β-glucosidase는 19종 모든 균주에서 확인되었고, α-arabinofuranosidase 유전자는 3종의 균주, β-xylosidase는 6종 균주, α-rhamnosidase는 8종의 균주에서 확인되었다. 이 중 B. longum CBT BG7는 Rb1으로부터 CK까지 전환시켜, CK 함량을 증가시켰다. 또한, B. breve CBT BR3와 B. lactis CBT BL3은 Rb1을 Rd로 전환시켰다. 균체를 파쇄 또는 미파쇄하여 진세노사이드 전환 반응을 비교했을 때 미파쇄물이 F2와 CK로의 높은 전환량과 수율을 보였다. CBT BG7 + BL3와 BG7 + BR3 혼합균주는 CBT BG7 단독보다 진세노사이드 F2의 함량을 증가시켰다. CBT BG7과 α-amylase 효소를 함께 반응하였을 때에 F2 함량이 증가되었다. 본 연구는 한국형 프로바이오틱스인 CBT BG7, BR3, BL3와 홍삼을 함께 섭취할 경우, 건강에 도움을 주는 생리활성물질인 CK의 생산을 확인하였다. 추후 부탄올 등 다양한 추출용매를 활용하여 생물전환 효율 및 CK로의 전환율에 대한 추가 연구가 필요해 보인다.

• 한국수소및신에너지학회논문집
• /
• 제22권3호
• /
• pp.333-339
• /
• 2011

In the present work, it was attempted to produce $H_2$ from food waste by the two-stage fermentation system. Food waste was acidified to lactate by using indigenous lactic acid bacteria under mesophilic condition, and the lactate fermentation effluent (LFE) was subsequently converted to $H_2$ by photo-fermentation. $Rhodobacter$ $sphaeroides$ KD131 was used as the photo-fermenting bacteria. The optimal conditions for lactate fermentation were found to be pH of 5.5 and substrate concentration of 30 g Carbo. COD/L, under which yielded 1.6 mol lactate/mol glucose. By filtering the LFE and adding trace metal, $H_2$ production increased by more than three times compared to using raw LFE, and finally reached the $H_2$ yield of 3.6 mol $H_2$/mol lactate. Via the developed two-stage fermentation system $H_2$ yield of 5.8 mol $H_2$/mol glucose was achieved from food waste, whose value was the highest that ever recorded.

• Journal of Microbiology and Biotechnology
• /
• 제30권7호
• /
• pp.1005-1012
• /
• 2020

Acid mine drainage (AMD) has been a serious environmental issue that threatens soil and aquatic ecosystems. In this study, an acid-tolerant sulfate-reducing bacterium, strain S4, was isolated from the mud of an AMD storage pond in Vietnam via enrichment in anoxic mineral medium at pH 5. Comparative analyses of sequences of the 16S rRNA gene and dsrB gene involved in sulfate reduction revealed that the isolate belonged to the genus Desulfovibrio, and is most closely related to Desulfovibrio oxamicus (with 99% homology in 16S rDNA sequence and 98% homology in dsrB gene sequence). Denaturing gradient gel electrophoresis (DGGE) analyses of dsrB gene showed that strain S4 represented one of the two most abundant groups developed in the enrichment culture. Notably, strain S4 was capable of reducing sulfate in low pH environments (from 2 and above), and resistance to extremely high concentration of heavy metals (Fe 3,000 mg/l, Zn 100 mg/l, Cu 100 mg/l). In a batch incubation experiment in synthetic AMD with pH 3.5, strain S4 showed strong effects in facilitating growth of a neutrophilic, metal sensitive Desulfovibrio sp. strain SR4H, which was not capable of growing alone in such an environment. Thus, it is postulated that under extreme conditions such as an AMD environment, acid- and metal-tolerant sulfate-reducing bacteria (SRB)-like strain S4 would facilitate the growth of other widely distributed SRB by starting to reduce sulfate at low pH, thus increasing pH and lowering the metal concentration in the environment. Owing to such unique physiological characteristics, strain S4 shows great potential for application in sustainable remediation of AMD.

• Journal of Microbiology and Biotechnology
• /
• 제26권7호
• /
• pp.1320-1332
• /
• 2016

Light hydrocarbons accumulated in subsurface soil by long-term microseepage could favor the anomalous growth of indigenous hydrocarbon-oxidizing microorganisms, which could be crucial indicators of underlying petroleum reservoirs. Here, Illumina MiSeq sequencing of the 16S rRNA gene was conducted to determine the bacterial community structures in soil samples collected from three typical oil and gas fields at different locations in China. Incubation with n-butane at the laboratory scale was performed to confirm the presence of "universal microbes" in light-hydrocarbon microseepage ecosystems. The results indicated significantly higher bacterial diversity in next-to-well samples compared with background samples at two of the three sites, which were notably different to oil-contaminated environments. Variation partitioning analysis showed that the bacterial community structures above the oil and gas fields at the scale of the present study were shaped mainly by environmental parameters, and geographic location was able to explain only 7.05% of the variation independently. The linear discriminant analysis effect size method revealed that the oil and gas fields significantly favored the growth of Mycobacterium, Flavobacterium, and Pseudomonas, as well as other related bacteria. The relative abundance of Mycobacterium and Pseudomonas increased notably after n-butane cultivation, which highlighted their potential as biomarkers of underlying oil deposits. This work contributes to a broader perspective on the bacterial community structures shaped by long-term light-hydrocarbon microseepage and proposes relatively universal indicators, providing an additional resource for the improvement of microbial prospecting of oil and gas.

• Asian-Australasian Journal of Animal Sciences
• /
• 제33권10호
• /
• pp.1610-1616
• /
• 2020

Objective: This study was to evaluate the effect of husbandry systems and strains on cecum microbial diversity of Jingyang chickens under the same dietary conditions. Methods: A total of 320 laying hens (body weight, 1.70±0.15 kg; 47 weeks old) were randomly allocated to one of the four treatments: i) Silver-feathered hens in enrichment cages (SEC) with an individual cage (70×60×75 cm), ii) Silver-feathered hens in free range (SFR) with the stocking density of 1.5 chickens per ten square meters, iii) Gold-feathered hens in enrichment cages (GEC), iv) Gold-feathered hens in free range (GFR). The experiment lasted 8 weeks and the cecum fecal samples were collected for 16S rDNA high throughput sequencing at the end of experiment. Results: i) The core microbiota was composed of Bacteroidetes (49% to 60%), Firmicutes (21% to 32%) and Proteobacteria (2% to 4%) at the phylum level. ii) The core bacteria were Bacteroides (26% to 31%), Rikenellaceae (9% to 16%), Parabacteroides (2% to 5%) and Lachnoclostridium (2% to 6%) at the genus level. iii) The indexes of operational taxonomic unit, Shannon, Simpson and observed species were all higher in SFR group than in SEC group while in GEC group than in GFR group, with SFR group showing the greatest diversity of cecum microorganisms among the four groups. iv) The clustering result was consistent with the strain classification, with a similar composition of cecum bacteria in the two strains of laying hens. Conclusion: The core microbiota were not altered by husbandry systems or strains. The free-range system increased the diversity of cecal microbes only for silver feathered hens. However, the cecum microbial composition was similar in two strain treatments under the same dietary conditions.

• 식물병연구
• /
• 제15권2호
• /
• pp.101-105
• /
• 2009

Serratia plymuthica A21-4는 양파(Allitum fistulosum L.) 근권에서 분리된 고추 역병 생물적 방제 미생물이다. 토양 환경이 S. plymuthica A2l-4 근권정착에 미치는 영향을 알아본 결과 사질이 많이 포함되어 공극이 많은토양에 3% 중량(w/w)의 부숙된 옥수수 줄기를 첨가하고 토양 수분함양이 40% 정도, 토양온도가 $20^{\circ}C$, 토양 pH가 중성이거나 약산성 토양이 S. plymuthica A2l-4의 근권정착에 유리하였다. 그리고 토착미생물이 있는 것이 살균한 토양에서 보다 S. plymuthica A21-4의 근권정착에 유리하였다.

• 한국환경농학회지
• /
• 제31권1호
• /
• pp.68-74
• /
• 2012

BACKGROUND: Some microorganisms extant in nature have ability to suppress various plant pathogens, and also can promote plant growth. Thus microorganisms are such great source of antimicrobial agents to develop antagonistic microorganism production and eco-friendly crop management. We isolated the microorganisms in various eco-friendly formulations. The suppressive abilities against plant pathogens have been characterized in vitro level. METHODS AND RESULTS: The indigenous microorganisms have been isolated from Cooked rice, Black sugar, Rice Bran, and Red clay using dilution plating method. Population of bacteria and fungi were above 107 in the all formulations. We isolated and pure cultured the microorganisms based on morphological characteristics. Three major plant pathogens (Fusarium oxysporum, Rhizoctonia solani, Phytophthora capsici) have been used to select antagonistic microorganisms. Total 20 bacteria and 9 fungi showed the pathogen growth suppression ability in vitro condition. The selected microorganisms were identified by ITS sequence similarity. CONCLUSION: All tested eco-friendly formulations contained high-density of the microorganisms. Among the isolated microorganisms, Bacillus spp. and Streptomyces spp. showed the most effective antifungal activity against the plant pathogens such as F. oxysporum, R. solani, and P. capsici. Among the selected fungi Trichoderma sp. demonstrated antifungal activity. Our results suggest that the currently adapted eco-friendly formulations might useful for sustain agricultural system.

• KSBB Journal
• /
• 제26권2호
• /
• pp.100-106
• /
• 2011

Strain BCNU 5011 was isolated from forest soil samples collected in the Taebaek mountain in the Gangwon province, Korea. The biochemical, physiological and 16S rRNA sequence analysis strongly indicated that this isolate was most closely related to Paenibacillus polymyxa. A maximum production level of antimicrobial substances of Paenibacillus sp. BCNU 5011 was achieved under aerobic incubation at $30^{\circ}C$ for 3 days in SST broth.Paenibacillus sp. BCNU 5011 showed a broad spectrum of activity against Gram positive and Gram negative bacteria, including methicllinresistant Staphylococcus aureus (MRSA). Paenibacillus sp. BCNU 5011 was also shown to inhibit the growth of different potential human pathogenic bacteria and fungi in vitro. Peptide extract showed better antimicrobial activity than solvent extracts. But active antimicrobial compounds might be included in both peptide extract and solvent extracts. Further separation, purification and identification of active principles leads project to develop antimicrobial agents and anti-MRSA agents.

• 한국환경과학회지
• /
• 제31권3호
• /
• pp.265-274
• /
• 2022

Lipoxygenase is an enzyme, mainly produced by plants, capable of converting unsaturated fatty acids to fatty acids. It has vast application potential in the food, pharmaceutical and agricultural industries. The aim of this study was to isolate novel lipoxygenase-producing bacteria from the environment and to investigate the lipoxygenase enzymatic properties for industrial production. The strain, NC1, isolated from cultivation soils, was identified as Bacillus subtilis based on the phenotypic characteristics and 16S rRNA gene sequencing. This strain formed a pink color around the colony when cultured on indamine dye formation plates. The production of lipoxygenase by B. subtilis NC1 was influenced by the composition of the medium and linoleic acid concentrations. The optimum temperature and pH for lipoxygenase activity was determined to be 40 ℃ and pH 6, respectively. The enzyme showed relatively high stability at temperatures ranging from 20-50 ℃ and acid-neutral regions. In addition, the lipoxygenase produced by B. subtilis NC1 was able to degrade commercially available oils including sunflower seed oil and Perilla oil. In this study, a useful indigenous bacterium was isolated, and the fundamental physicochemical data of bacterial lipoxygenase giving it industrial potential are presented.

• 미생물학회지
• /
• 제50권1호
• /
• pp.40-45
• /
• 2014

전 세계적으로 친환경 농업을 위해 식물생장촉진 근권세균을 이용한 미생물 비료에 대한 관심이 증가하고 있는데 투여하는 세균을 식물 근권에 보다 장기간 잔류시키기 위해 식물생장 촉진능이 있는 균주를 alginate bead에 고정화하여 식물생장을 조사하였다. 발아된 토마토 유묘에 Arthrobacter woluwensis ED를 $1{\times}10^6$ cells/g 로 처리하고 30일 재배 후 자라난 토마토의 shoot와 뿌리 길이 및 습윤과 건조중량을 측정한 결과 비접종 대조군과 비교하여 균주 현탁액 접종군은 각각 36.2, 59.0, 51.1과 37.5%씩 유의성 있게 증가하였으며 고정화 균주 접종군은 각각 42.0, 67.4, 62.5와 60.4%씩 유의성 있게 증가하였다. 고정화 균주 접종군은 균주 현탁액 접종군에 비하여 각각 6, 8, 11과 23% 증가하였다. 접종 균주가 식물 근권에서 유지되는 양상을 관찰하기 위해 denaturing gradient gel electrophoresis를 이용하여 토양세균 군집을 분석하였는데 균주 현탁액 접종군에서 ED 균주의 DNA band intensity는 접종일로부터 1주일까지 가장 높게 나타났으나 그 이후로 감소하여 접종 2주 후 비접종 대조군과 비슷한 band intensity를 나타내었다. 반면, 고정화 균주 접종군의 ED 균주 band intensity는 접종일로부터 초기에는 비접종 대조군과 비슷하였으나 이후 급격하게 증가하여 계속 높게 유지되어 3주까지 band intensity가 현탁액 접종군 보다 높았다. 따라서 alginate에 A. woluwensis ED를 고정하여 적용하는 방법이 현탁액 적용보다 식물 근권에 균주의 공급을 효과적으로 유지하면서 식물생장을 더욱 촉진하는 것으로 나타났다.