• 한국환경농학회지
• /
• 제27권2호
• /
• pp.133-138
• /
• 2008

Fire can affect microbial community structure of soil through altered environmental conditions, nutrient availability, and biotic source for microbial re-colonization. We examined the influence of fire on chemical properties and soil enzyme activities of soil for 10 months. We also characterized the soil microbial community structure through ester-linked fatty acid analysis(EL-FAME). For this study, we established five burned plots(1*1 m) and 5 unburned plots outside the margin of fire. Soil was sampled three soil cores in a each plots and composited for analysis at 1, 3, 5, 8, and 10 month after fire. The fire caused an increase in soil pH, exchangeable Ca, and Mg, organic matter, available $P_2O_5$ compared to unburned sites. The content of $NH_4-N$ in burned site was significantly higher than that of unburned site and this effect continued for 8 months after fire. There was no difference of $NO_3-N$ content in soil between burned and unburned site. Fire caused no change in acid phosphatase and arylsulfatase activities but $\beta$-glucosidase and alkaline phosphatase activities in burned site were increased compared to unburned site. Microbial biomass as estimated by total concentration of EL-FAMEs in burned sites was significantly higher than that of unburned sites at one month after fire. Burned site decreased the EL-FAMEs indicative of gram-positive bacteria and tended to increase the fatty acid associated with gram-negative bacteria at one and three months after fire. The sum of EL-FAME compound $18:2{\omega}6,9c$ and $18:1{\omega}9c$ as served fungal biomarkers was decreased in burned site compared to unburned site.

• Applied Biological Chemistry
• /
• 제50권4호
• /
• pp.287-294
• /
• 2007

소금농도를 9%에서 6%로 줄이고 항균물질로 알코올과 겨자, 키토산을 혼합첨가 하여 제조한 저식염 고추장의 숙성중의 효소활성도와 미생물상 및 이화학적 특성을 비교하였다. 숙성 중 수분활성도의 저하는 식염 9%인 대조구에서 심하였고, 숙성 중에 효모수는 증가하였으나 알코올-겨자 혼합 첨가로 효모수를 조절할 수 있었다. 고추장 숙성 중 ${\beta}-amylase$ 활성은 항균물질 첨가시 증가하였으나 ${\alpha}-amylase$와 protease 활성은 조금 감소하였다. 고추장은 숙성이 진행되면서 L차 a-, b-값이 증가하였으며 알코올 첨가 고추장이 $({\Delta}E)$값의 변화가 적었다. 적정산도는 항균물질의 첨가로 숙성 후기에 저하되었으며, 산화환원전위의 저하는 대조구에서 심하였다. 고추장 숙성 중 총당의 감소는 알코올-겨자 혼합 첨가구(EM)에서 적어 환원당량이 많았으며, 숙성 후기의 알코올의 생성은 알코올에 키토산을 혼합 첨가한 고추장(EC)에서 높았다. 고추장 숙성 중기까지 아미노태 질소는 증가하였고, 숙성중 암모니아태 질소의 생성은 알코올-겨자-키토산 혼합 첨가구(EMC)에서 적었다. 12주 숙성된 고추장을 관능 평가한 결과 색과 향기에서 알코올(E) 또는 알코올-겨자 혼합 첨가구(EM)가 좋아 저식염 고추장 제조시 알코올 또는 알코올-겨자를 혼합 첨가하는 것이 전체적인 기호도에서 양호하였다.

• Weed & Turfgrass Science
• /
• 제6권4호
• /
• pp.322-332
• /
• 2017

골프장 잔디 관리에서 미생물제제는 잔디의 생육 및 품질을 개선하고, 병을 예방하기 위해 사용되어왔다. 본 연구는 유산균(Lactobacillus fermentum)을 함유하는 미생물제제의 처리에 따른 크리핑 벤트그래스의 생육과 품질에 미치는 영향을 조사하였다. 처리구는 무처리구(NF), 대조구(CF), 미생물제제 처리구(MFcL: microbial fertilizer containing L. fermentum; MFL: CF+MFcL $1.0g\;m^{-2}$; 2MFL: CF+ MFcL $2.0g\;m^{-2}$) 및 미생물제제 단독 처리구(OMF; MFcL $1.0g\;m^2$)로 설정하였다. 시험 종료 후 토양 화학성은 처리구별 차이를 나타내지 않아 MFcL의 처리가 토양 이화학성에 미치는 영향은 미미하였다. MFcL 처리 시 잔디의 시각적 품질, 잔디 예지물, 잔디 중 무기 성분 함량 및 흡수량은 대조구와 비슷하였다. 잔디 밀도는 MFcL처리구에서 대조구에 비해 약 20% 정도 증가하였다. 이들 결과는 유산균을 함유하는 미생물제제의 처리는 크리핑 벤트그래스의 밀도를 향상에 기여하는 것을 확인하였다.

• 한국토양비료학회지
• /
• 제44권6호
• /
• pp.1164-1168
• /
• 2011

경남지역 논 토양 미숙답 6개소, 보통답 9개소, 사질답 5개소를 대상으로 2011년에 미생물 세포벽 지방산 함량을 분석하여 미생물 군집과 토양 화학성을 주성분분석으로 해석하였다. 토양 미생물체량은 보통답이 $1,235mg\;kg^{-1}$으로 사질답 $441mg\;kg^{-1}$ 보다 유의적으로 많았으며 (p<0.05) 미숙답은 $854mg\;kg^{-1}$으로 유의적인 차이가 없었다. 토양 유기물 함량은 미숙답과 보통답이 $33g\;kg^{-1}$으로 사질답의 $18g\;kg^{-1}$ 보다 유의적으로 많았다 (p<0.05). 미생물 군집은 보통답이 총 세균 33.0%, 그람음성 세균 18.1%로서 사질답의 총 세균 29.4%, 그람음성 세균 14.8% 그리고 미숙답의 그람음성 세균 15.4%에 비해 유의적으로 많았다 (p<0.05). 주성분 분석결과 토양 유기물 함량과 총 세균 군집 비율이 경남지역 논 토양의 보통답과 사질답의 특성을 구분할 수 있었다.

• Journal of Microbiology and Biotechnology
• /
• 제32권6호
• /
• pp.761-767
• /
• 2022

EHT1 and EEB1 are the key Saccharomyces cerevisiae genes involved in the synthesis of ethyl esters during wine fermentation. We constructed single (Δeht1, Δeeb1) and double (Δeht1Δeeb1) heterogenous mutant strains of the industrial diploid wine yeast EC1118 by disrupting one allele of EHT1 and/or EEB1. In addition, the aromatic profile of wine produced during fermentation of simulated grape juice by these mutant strains was also analyzed. The expression levels of EHT1 and/or EEB1 in the relevant mutants were less than 50% of the wild-type strain when grown in YPD medium and simulated grape juice medium. Compared to the wild-type strain, all mutants produced lower amounts of ethyl esters in the fermented grape juice and also resulted in distinct ethyl ester profiles. ATF2, a gene involved in acetate ester synthesis, was expressed at higher levels in the EEB1 downregulation mutants compared to the wild-type and Δeht1 strains during fermentation, which was consistent with the content of acetate esters. In addition, the production of higher alcohols was also markedly affected by the decrease in EEB1 levels. Compared to EHT1, EEB1 downregulation had a greater impact on the production of acetate esters and higher alcohols, suggesting that controlling EEB1 expression could be an effective means to regulate the content of these aromatic metabolites in wine. Taken together, the synthesis of ethyl esters can be decreased by deleting one allele of EHT1 and EEB1 in the diploid EC1118 strain, which may modify the ester profile of wine more subtly compared to the complete deletion of target genes.

• 한국초지조사료학회지
• /
• 제44권2호
• /
• pp.113-117
• /
• 2024

본 연구는 옥수수 사일리지에서 첨가제 처리와 저장기간을 달리 하였을 때 사일리지의 품질 변화 및 미생물 군집 변화를 검토함으로써 품질 향상 방안을 찾기 위해 수행되었다. 각 미생물 미접종 시험구(CON)와 미생물 접종 시험구(ADD) 내에서 저장기간에 따른 옥수수 사일리지의 영양소 함량의 변화는 없었다(p>0.05). 그러나 각 시험구 내에서 저장기간에 따른 건물(DM)의 감소(CON, 35.9~33.2%; ADD, 34.5~32.7%; p<0.05)와 젖산 함량의 증가(CON, 6.03~6.71%; ADD, 6.02~9.00%; p<0.05) 및 Lactobacillales의 상대적 비율의 증가(CON, 34.3~79.5%; ADD, 84.8~93.3%)는 발효 120일까지 지속적인 발효가 진행되었음을 나타낸다. 옥수수 사일리지의 발효 전에는 Enterobacterales (33.0%), Flavobacteriales (14.4%), Sphingobacteriales (12.7%), Burkholderiales (9.28%), Pseudomonadales (6.18%)등이 우점하였으나, 발효 후 Lactobacillales (69.4%), Bacillales (11.5%), Eubacteriales (7.59%)의 우점으로 인해 미생물의 다양성이 급격히 감소하였다. 결과적으로 옥수수 사일리지는 모든 저장기간에서 첨가제 유무에 관계 없이 양호한 발효 품질을 유지하였으나, 장기간 저장에도 발효가 지속되는 점과 호기적 안정성을 고려한다면 미생물 첨가제를 이용하는 것이 유리할 것으로 사료된다.

• The Korean Journal of Ecology
• /
• 제21권5_3호
• /
• pp.695-702
• /
• 1998

This study was carried out to investigate to determine seasonal variation of dehydrogenase activity, phosphatase activity, adenosine tri-phosphate content and some physicochemical properties, such as soil pH, moisture content, organic matter and several heavy metal concentrations from Apr. 1997 to jan. 1998 in Pinus densiflora and Quercus mongolica forest in Mt. Nam, to explain a relationship between enzyme activity and the soil factors. There were ranges of 4.03-4.65 in soil pH, 18.65-51.09% in moisture content and 6.69-95.95% in orgainc matter. The organic matter content decreased with soil horizon, showing the higher values in Q. mongolica forest. In comparison to the results of Kawngneung site as control area, there were slightly differences due to a development level of forest ecosystem and microbial degradation of organic matter. The heavy metal concentrations showed 32.50-75.55 ${\mu}g/g$ in Cu, 69.33-134.84 ${\mu}g/g$ in Zn, 57.02-150.32 ${\mu}g/g$ in Pb, and 0.36-1.00 ${\mu}g/g$ in Mt. Nam. These values are higher than in Kwangneung site because of long-term exposure to air pollutants from central city. On the other hand, ATP contents in Mt. Nam were lower than in Kawngneung site in relation to soil organic matter, moisture content and relatively high heavy metal concentrations. ATP contents per soil weight was largest in F+H layer and in spring time of other seasons. Dehydrogenase activity as an index of soil microbial activity had a ranges of 170.67-1,221.66 ${\mu}g$ TPF/g that showed lower values than in Kawngneung site. However, phophatase activity had a contray tendency due to P fertilization for a continuous management. Those values increased through spring to a maximum in the summer and fall in autumn. This is basically caused by metabolic state of soil on the biological activity and several and several factors, such as aeration, soil temperature, vegetation and microflora.

• 한국축산식품학회지
• /
• 제43권6호
• /
• pp.1150-1169
• /
• 2023

Edible insects are gaining popularity as a potential future food source because of their high protein content and efficient use of space. Black soldier fly larvae (BSFL) are noteworthy because they can be used as feed for various animals including reptiles, dogs, fish, chickens, and pigs. However, if the edible insect industry is to advance, we should use automation to reduce labor and increase production. Consequently, there is a growing demand for sensing technologies that can automate the evaluation of insect quality. This study used short-wave infrared (SWIR) hyperspectral imaging to predict the proximate composition of dried BSFL, including moisture, crude protein, crude fat, crude fiber, and crude ash content. The larvae were dried at various temperatures and times, and images were captured using an SWIR camera. A partial least-squares regression (PLSR) model was developed to predict the proximate content. The SWIR-based hyperspectral camera accurately predicted the proximate composition of BSFL from the best preprocessing model; moisture, crude protein, crude fat, crude fiber, and crude ash content were predicted with high accuracy, with R² values of 0.89 or more, and root mean square error of prediction values were within 2%. Among preprocessing methods, mean normalization and max normalization methods were effective in proximate prediction models. Therefore, SWIR-based hyperspectral cameras can be used to create automated quality management systems for BSFL.

• Journal of Microbiology and Biotechnology
• /
• 제13권6호
• /
• pp.1013-1017
• /
• 2003

A thermophilic nonspore-forming rod isolated from hay compost in Korea was subjected to a taxonomic study. The microorganism, designated as $SC-1^T$, was identified as a nitrate-reducing and nonmotile bacterium. Although the strain was negatively Gram-stained, a KOH test showed that the strain $SC-1^T$ belonged to a Gram-positive species. Growth was observed between 45 and $70^{\circ}C$. The optimal growth temperature and pH were $60^{\circ}C$ and pH 7.5, respectively. The G+C content of the genomic DNA was 65 mol% and the major quinone types were MK-6 and MK-7. A phylogenetic analysis based on 16S rDNA sequences revealed that the strain $SC-1^T$ was most closely related to Symbiobacterium thermophilum. However, the level of DNA-DNA relatedness between strain $SC-1^T$ and the type strain for Symbiobacterium thermophilum was approximately 30%. Accordingly, on the basis of the phenotypic traits and molecular systematic data, the strain $SC-1^T$ would appear to represent a new species within the genus Symbiobacterium. The type strain for the new species is named $SC-1^T$ ($=KCTC\;0307BP^T;\;DSM15906^T$).

• 한국식품영양학회지
• /
• 제9권3호
• /
• pp.289-293
• /
• 1996

Population changes of aerobic bacteria and lactic acid bacteria and changes of pH, acidity, and total sugar content were creased from initial period of fermentation. Lactic acid bacteria Increased during the first one nay rapidly and thereafter they creased slowly thereafter. Acidity increased on the third day of fermentation. Acidity was very low In Kimchi containing both Total sugar content decreased gradually from initial period to late period of fermentation.