• 유기물자원화
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• 제26권4호
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• pp.31-43
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• 2018

본 연구는 유기 농경지의 토양 및 양분관리 방법으로 가축분과 풋거름(헤어리베치)공급, 윤작 시스템. 그리고 경운 및 무경운 처리가 토양환경에 미치는 영향을 구명하고자 수행하였다. 신규 옥수수 재배 토양의 양분공급원으로 가축분 퇴비, 헤어리베치와 같은 유기물 공급이 화학비료 처리에 비해 토양 유기물 함량을 높이며 토양의 미생물 밀도와 미생물체량 C함량을 증가시키는 것을 알 수 있었다. 또한 토양 미생물 군집의 기능적 다양성이 증가하는 것을 확인하였다. 윤작재배 효과로 토양 화학성은 처리간의 차이가 뚜렷하게 나타나지 않았지만 옥수수-밀, 옥수수-헤어리베치 윤작 처리구가 옥수수 단작 처리구보다 토양의 미생물체량 C 함량과 종 다양성 지수가 높은 경향을 보였다. 경운 여부에 따른 토양 화학성은 처리간의 뚜렷한 차이를 나타내지 않았다. 토양 미생물 군집의 기질 이용에서 무경운이 경운처리 보다 다소 높게 나타났지만 통계적인 유의차는 없었다. 처리에 따른 토양의 화학성과 미생물상간의 요인간 상관관계 분석 결과, 토양 유기물 함량과 치환성 칼륨 함량은 기질 이용도, 기질 풍부도와 양의 상관관계를 보였다. 이러한 결과로부터 가축분 퇴비, 헤어리베치와 같은 유기물 시용으로 옥수수 재배 토양의 화학성 및 미생물상에 긍정적인 효과를 나타낸 것으로 판단되었다.

• Elastomers and Composites
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• 제32권5호
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• pp.325-329
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• 1997

Microbial treatment of the powdered waste tire was studied to recycle the waste tires. Chemoautotrophic acidophilic, iron-oxidizing bacterium was employed to unvulcanize the powdered tires. Biotreated rubber powder was compared to a untreated and a chemically treated powder. The results showed sulfur content of rubber powder(1.33%) were decreased to 1.22% by chemical treatment and 1.12% by microbial treatment for 20 days, 0.88%, for 30 days. One of the problems of the powdered utilization of the waste tires is that rubber powder leads to decrease mechanical properties when it is compounded with other virgin polymers. When tee biotreated powder was compounded with natural rubber, the mechanical properties were less decreased when untreated or chemically treated powder. Therefore, the microbial treatment can be one of useful methods to recycle the waste tire.

• 한국미생물·생명공학회지
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• 제48권3호
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• pp.358-365
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• 2020

An organic solvent- and bleach-stable protease-producing strain was isolated from a polluted river water sample and identified as Aeromonas veronii OB3 on the basis of biochemical properties (API 20E) and 16S rRNA sequence analysis. The strain was found to hyper-produce alkaline protease when cultivated on fish waste powder-based medium (HVSP, 4080 U/ml). The biochemical properties and compatibility of OB3 with several detergents and additives were studied. Maximum activity was observed at pH 9.0 and 60℃. The crude protease displayed outstanding stability to the investigated surfactants and oxidants, such as Tween 80, Triton X-100, and H₂O₂, and almost 36% residual activity when incubated with 1% SDS. Remarkably, the enzyme demonstrated considerable compatibility with commercial detergents, retaining more than 100% of its activity with Ariel and Tide (1 h, 40℃). Moreover, washing performance of Tide significantly improved by the supplementation of small amounts of OB3 crude protease. These properties suggest the potential use of this alkaline protease as a bio-additive in the detergent industry and other biotechnological processes such as peptide synthesis.

• 한국토양환경학회지
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• 제3권2호
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• pp.31-39
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• 1998

오염지역과 비오염지역으로부터 채집한 토양에서 토양의 습도, 유기물의 함량, 토양산도 등 물리적인 특징과 토양미생물의 분포와 같은 생물학적인 특징이 조사되었다. 지역에 따른 유기물의 함량과 토양산도는 큰 차이를 나타내었으나, 식물군락에 의한 토양수분과 유기물 함량의 차이점은 발견할 수 없었다. 토양의 산도는 미생물의 분포수와 상관관계를 나타내었다. 이러한 것은 식물이 자라는 토양에 변이를 주는 것으로 산성비와 관련이 있는 것으로 추정된다.

• 한국축산식품학회지
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• 제30권6호
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• pp.886-895
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• 2010

The level of fat and salt can affect the product quality and storage stability of processed meats. Additionally, consumers' demands require dietary guidelines for developing low-fat/salt functional foods. Microbial transglutaminase (MTGase), which enhances textural properties by catalyzing protein-protein cross-linkages, was introduced to develop healthier lowfat/salt meat products. The potential possibilities of low-fat/salt processed meats were reviewed under optimal conditions for functional ingredients from several previous studies. The addition of non-meat protein (e.g. sodium caseinate and soy protein isolates), hydrocolloids (e. g. konjac flour, carrageenan, and alginates), and MTGase alone or in combination with other functional ingredients improved textural and sensory properties similar to those of regularly processed meats. When MTGase was combined with hydrocolloids (konjac flour or sodium alginate) or other functional ingredients, gelling properties of meat protein were improved even at a low salt level. Based on these reviews, functional ingredients combined with new processing technologies could be incorporated into processed meats to improve the functionality of various low-fat/salt meat products.

• 한국토양비료학회지
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• 제47권6호
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• pp.496-499
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• 2014

The present study investigated variations in soil microbial communities and the chemical properties of forest soils by differing amounts of penetrating sunlight. The soil temperature was significantly higher in higher light-penetrated soils. Higher light-penetrated soils (LP70) showed significantly more fungal communities than the lower light-penetrated soils (LP40 and LP50) (p < 0.05). The $NH_4$-N concentration in LP70 was significantly lower than those of LP40 and LP50, whereas the other chemical properties showed no significant difference among the soils. The cy19:0 to $18:1{\omega}7c$ ratio was significantly lower in LP70 than in LP 40 and LP50 showing the negative correlation of light level with microbial stresses (p < 0.05). The soil microbial communities and the chemical properties that showed positive eigenvector coefficients for PC1 were the fungi to bacteria, fungi, arbuscular mycorrhizal fungi, and Gram-positive bacteria, whereas negative eigenvector coefficients were found for $NH_4$-N, actinomycetes, Gram-negative bacteria, and bacteria. Consequently, the amount of penetrating light was responsible for microbial compositions in the forest soils in correlation with the concentration of $NH_4$-N and soil temperature.

• Journal of Microbiology and Biotechnology
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• 제30권9호
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• pp.1310-1320
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• 2020

Low-quality soil for land reuse is a crucial problem in vegetation quality and especially to waste disposal sites in mining areas. It is necessary to find suitable materials to improve the soil quality and especially to increase soil microbial diversity and activity. In this study, pot experiments were conducted to investigate the effect of a mixed material of humic acid, super absorbent polymer and biochar on low-quality soil indexes and the microbial community response. The indexes included soil physicochemical properties and the corresponding plant growth. The results showed that the mixed material could improve chemical properties and physical structure of soil by increasing the bulk density, porosity, macro aggregate, and promote the mineralization of nutrient elements in soil. The best performance was achieved by adding 3 g·kg^-1 super absorbent polymer, 3 g·kg^-1 humic acid, and 10 g·kg^-1 biochar to soil with plant total nitrogen, dry weight and height increased by 85.18%, 266.41% and 74.06%, respectively. Physicochemical properties caused changes in soil microbial diversity. Acidobacteria, Bacteroidetes, Chloroflexi, Cyanobacteria, Firmicutes, Nitrospirae, Planctomycetes, and Proteobacteria were significantly positively correlated with most of the physical, chemical and plant indicators. Actinobacteria and Armatimonadetes were significantly negatively correlated with most measurement factors. Therefore, this study can contribute to improving the understanding of low-quality soil and how it affects soil microbial functions and sustainability.

• 한국토양비료학회지
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• 제47권4호
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• pp.254-261
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• 2014

The scientific information between microbial activities and chemical properties of reclaimed tidal soil is not enough to apply for reclamation projects. This study was conducted to investigate the relation between chemical properties and microbial activities of reclaimed tidal lands located at western coastal area (25 samples from Nampo, Ewon, Sukmoon and Shihwa sites). Most of the reclaimed soils showed chemical characteristics as salinity soil except Nampo site. The major component influenced the salinity of reclaimed soil was identified as a sodium from the relationship between EC and exchangeable cation. With an increase in EC of soil, the population of mesophilic bacteria decreases whereas halotolerant and halophilic bacteria increases. The population of mesophilic bacteria increased with an increase in both organic matter and dehydrogenase activity. However, the population of halotolerant and halophilic bacteria decreased with an increase in organic matter. Based on the relation between chemical property and microbial activity of reclaimed tidal soil, electrical conductivity and organic matter as chemical properties of soil, population of mesophilic bacteria, halotolerant and halophilic bacteria and dehydrogenase activity as microbial activities could be the major parameters for reclamation process.

• Animal Bioscience
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• 제36권10호
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• pp.1596-1603
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• 2023

Objective: Sous-vide cooking offers several advantages for poultry meat, including enhanced tenderness, reduced cooking loss, and improved product yield. However, in duck meat, there are challenges associated with using the sous-vide method. The prolonged cooking time at low temperatures can lead to unstable microbial and oxidative stabilities. Thus, we aimed to assess how varying sous-vide cooking temperatures and durations affect the physicochemical and microbial characteristics of duck breast meat, with the goal of identifying an optimal cooking condition. Methods: Duck breast meat (Anas platyrhynchos) aged 42 days and with an average weight of 1,400±50 g, underwent cooking under various conditions (ranging from 50℃ to 80℃) for either 60 or 180 min. Then, physicochemical, microbial, and microstructural properties of the cooked duck breast meat were assessed. Results: Different cooking conditions affected the quality attributes of the meat. The cooking loss, lightness, yellowness, Hue angle, whiteness, and thiobarbituric acid reactive substance (TBARS) values of the duck breast meat increased with the increase in cooking temperature and time. In contrast, the redness and chroma values decreased with the increase in cooking temperature and time. Cooking of samples higher than 60℃ increased the volatile basic nitrogen contents and TBARS. Microbial analysis revealed the presence of Escherichia coli and Coliform only in the samples cooked at 50℃ and raw meat. Cooking at lower temperature and shorter time increased the tenderness of the meat. Microstructure analysis showed that the contraction of myofibrils and meat density increased upon increasing the cooking temperature and time. Conclusion: Our data indicate that the optimal sous-vide method for duck breast meat was cooking at 60℃ for 60 min. This temperature and time conditions showed good texture properties and microbial stability, and low level of TBARS of the duck breast meat.

• 한국축산식품학회지
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• 제33권2호
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• pp.221-228
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• 2013

This study was performed to evaluate the effects of various levels of mungbean flour (MF) (0-2.4%) on the quality characteristics of pork model sausages (PMS) in experiment 1 and also select the optimum level of MF to enhance the water retention and gelling properties of low-salt PMS (LSPMS) with or without microbial transglutaminase (MTGase) in experiment 2. In experiment 1, the addition of MF did not affect pH, chemical compositions (fat and moisture contents), color values, and functional properties (expressible moisture, EM (%) and cooking yield, CY (%)) of PMS. However, the addition of MF increased the chewiness of PMS and hardness if the mungbean flour at the level of more than 1.2% was incorporated. Since the interaction between the microbial transglutaminase (MTGase) treatment and MF level was not significant (p>0.05), data were pooled by different factors (MTGase treatment and MF level) in experiment 2. MF improved the water binding ability and textural springiness of LSPMS. On the other hand, MTGase treatment decreased the pH and cooking yield (%) of LSPMS, but increased most textural properties. In conclusion, the addition of MF could enhance the water retention and textural properties of PMS and LSPMS, regardless of MTGase, when it was added to over 1.2%. Based on these results, mungbean protein may interact with MTGase on the low-salt comminuted meat systems. Therefore, further study might be needed to understand the mechanisms of interaction between MTGase and functional components induced from MF.