• Journal of Animal Science and Technology
• /
• 제61권6호
• /
• pp.313-323
• /
• 2019

The interactive effect of dietary fat supplementation and milk yield level on dairy cows performance under heat stress has not been thoroughly investigated. The purpose of this study was to evaluate the effect of production level, the source of fat supplements and their interaction on dairy cows performance under heat stress. In this study, 64 Holstein multiparous cows were divided into 2 groups and received one of two rations having either calcium salts of fatty acids (Ca-FA) or high-palmitic acid (PA) supplements (2.8% of DM; dry matter). After completing the experiment and based on maturity-equivalent milk, cows were divided into two groups of high-yielding (14,633 kg) and medium-yielding (11,616 kg). Average temperature humidity index (THI) was 71 during the trial period. Apparent digestibility of dry matter (p = 0.04), organic matter (p = 0.05), and neutral detergent fiber (NDF; p = 0.04) for cows fed Ca-FA were greater than cows fed PA. The milk fat content in high-producing cows was 0.3% greater than medium-producing cows (p = 0.03). The milk protein content in cows fed Ca-FA was greater than cows fed PA (p < 0.01). High-producing cows had greater serum cholesterol (p = 0.02) than medium-producing cows. The cows fed PA tended to have a greater BUN than cows fed Ca-FA (p = 0.06). Alanine aminotransferase and aspartate aminotransferase tended to be increased by PA, which indicates that cows in PA treatment may have experienced more adverse effect on the liver function than cows on Ca-FA. Therefore, under heat stress and in 90 d trial, milk production level does not affect the cows' response to PA or Ca-FA. Although cows fed Ca-FA received lower energy than those fed PA, they compensated for this shortage likely with increasing the digestibility and produced a similar amount of milk.

• Journal of Microbiology and Biotechnology
• /
• 제17권1호
• /
• pp.44-51
• /
• 2007

Marine bacterial strains were isolated trom coastal regions of Goa and screened for the strains that produce the highest amount of mucous expolysaccharide (EPS). Our screening resulted in the identification of the strain Vibrio furnissii VB0S3 (hereafter called VB0S3), as it produced the highest EPS in batch cultures during the late logarithmic growth phase. The isolate was identified as VB0S3 based on morphological and biochemical properties. Growth and EPS production were studied in mineral salts medium supplemented with NaCl (1.5%) and glucose (0.2%). The exopolymer was recovered from the culture supernatant by using three volumes of cold ethanol precipitation and dialysis procedure. Chemical analyses of EPS revealed that it is primarily composed of neutral sugars, uronic acids, and proteins. Fourier-transform infrared (FT-IR) spectroscopy revealed the presence of carboxyl, hydroxyl, and amide groups, which correspond to a typical heteropolymeric polysaccharide, and the EPS also possessed good emulsification activity. The gas chromatographic analysis of an alditol-acetate derivatized sample of EPS revealed that it was mainly composed of galactose and glucose. Minor components found were mannose, rhamnose, fucose, ribose, arabinose, and xylose. EPS was readily isolated from culture supernatants, which suggests that the EPS was a slime-like exopolysaccharide. This is the first report of exopolysaccharide characterization that describes the isolation and characterization of an EPS expressed by Vibrio surnissii strain VB0S3. The results of the study contribute significantly and go a long way towards an understanding of the correlation between growth and EPS production, chemical composition, and industrial applications of the exopolysaccharide in environmental biotechnology and bioremediation.

• 한국의류학회지
• /
• 제17권3호
• /
• pp.380-390
• /
• 1993

Effect of interfacial electrical conditions on adhesion of ${\alpha}-Fe_2O_3$ particles to PET fabric and the removal of ${\alpha}-Fe_2O_3$ particles from PET fabric, were investigated as functions of pH, electrolyte and ionic strength. The ${\zeta}$ potential of PET fiber and ${\alpha}-Fe_2O_3$ particles in the electrolyte solution were measured by streaming potential and microelectrophoresis methods respectively. The potential energy of interaction between ${\alpha}-Fe_2O_3$ particles and PET fabric were calculated by using the heterocoagulation theory for a sphere-plate model. The negative ${\zeta}$ potential of ${\alpha}-Fe_2O_3$ particle and PET fiber increased with pH, and then decreased certain pH and isoelectric points of ${\alpha}-Fe_2O_3$ particles and PET fiber were pH 6.5 and pH 3.5, respectively. The negative ${\zeta}$ potential of ${\alpha}-Fe_2O_3$ particle and PET fiber affected by electrolytes, were relatively high with polyanion electrolytes in solutions and were low with neutral salts. However, at surfactant solution, ${\zeta}$ potential was levelled off. The influence of the ionic strength on the ${\zeta}$ potential of ${\alpha}-Fe_2O_3$ particle was small but the negative ${\zeta}$ potential of PET fiber increased with the ionic strength. In the presence of anionic surfactant, the ${\zeta}$ potential of ${\alpha}-Fe_2O_3$ particle and PET fiber increased regardless of solution conditions. The interaction energy between ${\alpha}-Fe_2O_3$ particle and PET fabric increased with pH. The interaction energy was relatively high with polyanion electrolytes in solution, and the influence of ionic strength on the interaction energy was small, and the effective thickness of electrical double layer increased with decreasing the ionic strength.

• 한국동물학회지
• /
• 제4권1호
• /
• pp.7-12
• /
• 1961

1) Respiratory metabolism patterns and its enzyme systems in the gill tissue of the fresh water mussels, Cristaria plicata were investigated through the examination on the effects of respiratory enzyme inhibitors, (KCN, NAF) and succinoxidase assay, while studying the effects of neutral salts (NaCL, KCL, CaCl2) and pH on oxygen consumption of the gill tissue. 2) In the limited concentration of KCL (0.3mM) and NaCl (0.4mM) solutions, oxygen consumption of the intact gill tissue was accelerated, but in CaCl2(0.5mM) solution, it showed no significant effect. The oxygen consumption was gradually decreased at the above concentrations of these limitations. The optimum pH for the respiration of the gill was 7.3. 3)Cyanide in 10-8M solution inhibited 88.8% of the respiration of the intact gill tissue. Methylene blue accelerated the respiration of the noral gill tissue, and slightly but significantly reversed the cyaniide poisoned respiration. 4)Oxygen consumption of the gill homogenate was apparently increased by the mixed addition of succinate, cytochrome c and activators (AlCl3 and CaCl2). This results suggested that succinoxidase system acts on the respiratory pattern of the gil tissue. 5) It was able to recognize that the enolase, which acts on the anaerobic glycolytic system, participated in the tissue respiration of the gill for NaF in 5$\times$10-2 M solution inhibited 55.5% of the respiration of the same intact tissue.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제13권2호
• /
• pp.44-53
• /
• 2008

폐탄처리과정에서 오염된 중금속 오염토양의 정화에 있어 무기산(HCl), 중성염($CaCl_2$), 킬레이트제(citric acid, $Na_2$-EDTA)들을 이용한 토양세척 가능성을 평가하였다. 실험에 사용된 추출액(HCl, $CaCl_2$, citric acid, $Na_2$-EDTA)들의 추출효율은 HCl > citric acid > $Na_2$-EDTA > $CaCl_2$의 순으로 나타났는데 HCl(1.0 M)에 의해서 Cd, Cu, Pb와 Zn이 초기농도 대비 각각 82%, 86%, 80%, 46% 정도 추출된 것으로 나타났다. 추출효율과 반응액의 pH 간에는 고도의 음의 상관관계가 존재하였다. 폐탄약처리장 부지 토양 중 중금속은 탄산염결합태, Fe, Mn-산화물 결합태 형태로 존재하고 있었는데 HCl, citric acid 세척에 의해서 이들 분획의 현저한 감소가 이루어졌지만 이동성이 상대적으로 큰 치환태가 증가되는 것으로 나타났다. 이동성이 큰 분획의 증가는 지하수 오염 등의 문제를 야기시킬 수 있음으로 이에 대한 적절한 관리가 필요할 것으로 판단된다.

• 생명과학회지
• /
• 제21권5호
• /
• pp.761-765
• /
• 2011

효소의 염에 대한 안정성은 식품산업 응용에 있어서 중요한 인자이다. 이전에, leucine aminopeptidase (LAP)은 Bacillus sp. N2에서 정제되었다. 본 연구에서는, LAP효소의 염 효과에 관한 연구를 수행했다. LAP은 고농도의 NaCl (4 M)에서 L-leucine-${\rho}$-nitroanilide의 가수분해활성을 가지고 있지만, 다른 중성 염들(LiBr, LiCl, NaBr, KBr, KCl)에서는 활성이 없었다. 그 효소는 0-4 M NaCl 농도에서 C-말단 Xaa쪽에 소수성 아미노산과 친수성 아미노산을 가진 여러 di-peptide 합성 기질들을 가수분해하였는데, 이러한 결과는 LAP의 가수분해성은 기질의 Scissile bond에 있는 아미노산 사이드 체인의 소수성과는 관련이 없다라는 것을 의미한다. 또한, LAP의 가수분해활성은 4.5 M NaCl 농도에서 다른 LAP와 Aminopeptidase의 활성 보다 1-3배가 높다라는 것을 보여주었다. 이러한 결과들은 NaCl에 내성을 지닌 LAP을 치즈와 멸치 젓갈과 같은 식품 산업에 응용될 수 있다는 것을 보여준다.

• 한국토양비료학회지
• /
• 제45권6호
• /
• pp.1222-1229
• /
• 2012

간척지토양은 일반적으로 매우 높은 염농도를 가지고 있으며 염고농도의 염 특히, 높은 $Na^+$ 농도는 점토의 분산을 일으키고 토양의 공극을 감소시켜 토양의 공기와 수분의 유통을 악화시키고 고농도의 염은 생리적가뭄(physiological drought)의 한 가지 형태인 낮은 수분퍼텐셜을 발생시켜서 수분과 양분의 흡수를 어렵게 한다. 따라서 간척지를 효율적으로 활용하기 위해서는 간척지 토양에 대한 제염이 선행되어야 한다. 이러한 제염 효과를 증진시키기 위해서는 상기에서 살펴본 바와 같이 물리성 개선을 통하여 토양의 화학성을 개선시켜야 한다. 본 조사를 기준으로한 간척지토양 개선은 물리성 중 물질의 이동을 용이하게 하는 심층토 내 토양압밀층 개선이 우선되어야 할 것으로 판단한다. 그리고 높은 지하수위에 의한 모세관상승에 동반한 재염화를 방지하기 위한 토양관리방안이 필요하다. 따라서 최종적으로 간척지의 효과적 재염 (Resalization)방지와 제염(Desalinazation) 방안에 대한 토질역학적 측면에서 연구가 추진되어야 한다.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
• /
• 제4권3호
• /
• pp.173-183
• /
• 2000

This study measured the zeta potential of both latex colloidal particles with carboxylate surface groups and glass beads (collectors) with silanol surface group employing various solution with different chemical characteristics. The results have been compared with the surface chemistry theory. The zeta potential of the particle and collector increased with increasing pH up to 5.0 regardless of the solution chemistry. For a monovalent electrolyte solution(sodium chloride solution) the zeta potential steadily increased until the pH reached 9.5. In contrast, little change in zeta potential was made between 5.0 and 9.5 for a divalent electrolyte solution (sodium chloride solution) the zeta potential steadily increased until the pH reached 9.5. In contrast, little change in zeta potential was made between 5.0 and 9.5 for a divalent electrolyte solution (calcium chloride solution). In other words, the more the pH decreases, the larger the effect of neutral salts, such as NaCl and CaCl$_2$, have on the ζ-potential values. In this study, the PZPC(point of zero proton condition) of the particle and collector occurred below a pH of 3.1, H(sup)+ and OH(sup)- acted as a PDI (potential determining ion), and Na(sup)+ acted as an IDI(indifferent ion). The magnitude of the negative ζ-potential values of the particle and collector monotonically increased as the concentrations of Na(sup)+ or Ca(sup)2+([Na(sup)+] or [Ca(sup)2+]) decreased (the values of pNa or pCa increased). In the case of latex particles, the ζ-potential should aproach zero (isoelectric point; IEP) asymptotically as the pNa approaches zero, while in the case of calcium chloride electrolyte, ζ-potential reversal may be expected to occur around 3.16$\times$10(sup)-2MCaCl$_2$(pCa=1.5). pH, valance and ionic strength can be used in various ways to improve the water treatment efficiency by modifying the charge characteristics of the particle and collector. Predictive capability is far less certain when EDL(electrical double layer) repulsive forces exist between the particle and collector.

• 한국식품영양과학회지
• /
• 제16권3호
• /
• pp.27-34
• /
• 1987

우리나라 전통효소식품(傳統酵素食品)인 고추장의 품질(品質)을 개선(改善)하기 위한 자료(資料)를 얻고자 일반가정(一般家庭)에서 재래식(在來式)으로 담근 80시료(試料)의 고추장을 수집(蒐集)하여 일반성분(一般成分)을 분석(分析)하고 5개월간(個月間) 효소숙성(酵素熟成)킨 고추장의 향기성분(香氣成分)을 동정(同定)한 결과(結果)를 요약(要約)하면 다음과 같다. 일반가정(一般家庭)에서 수집(蒐集)된 고추장의 일반성분(一般成分)은 수분(水分) 40.51%, 염분(鹽盆) 6.0%, 조지질(粗脂質) 3.25%, 조탄분(粗炭分) 10.30%, 환원당(還元糖) 19.60%, 아미노질소(室素) 179.5mg/100g 및 총질소(總窒素) 4.43%였고, pH는 4.79, 적정산도(滴定酸度)(0.1N NaOH)는 9.28ml였으며 관능검사점수(官能檢査点數)는 평균치(平均値)가 125.01점(点)이였고 표준편차(標準偏差)는 15.42였다. 또한 담금고추장의 휘발성성분(擇發性成分)은 중성회분(中性劃分)에서 methoxy acetophenone 외(外) 29성분(成分), phenol성획분(性劃分)에서 thymol 외(外) 7성분(成分) 및 산성획분(酸性劃分)에서 methyl octanoic acid 외(外) 7성분(成分)으로 모두 46성분(成分)이 동정(同定)되었으며 염기성획분(盛基性劃分)에서는 검출(檢出)되지 않았다.

• 한국버섯학회지
• /
• 제20권4호
• /
• pp.263-269
• /
• 2022

본 실험은 국내 자생하는 한입버섯 균에 대한 특성과 적정 배양 조건을 구명하고 인공재배의 기초적인 자료 활용을 위해 균사체의 특성과 적정 배양 조건에 관한 연구를 수행하였다. 한입버섯 KACC52303 균주의 형태 특성은 불규칙형과 굴곡형, 솜털 또는 면과 유사한 질감의 형태를 보였고 미세구조는 후막포자 형성 전 단계로 보였으며 클램프는 보이지 않았다. 적정 배양온도는 중·고온인 25~30℃로 조사되었으며, pH는 약산성 4부터 중성 7까지 범위가 넓게 확인되었다. 적정 영양원에서 탄소원 dextrine 2.5%, 유기질소원 yeast extract 0.1%의 혼합배지에서 균사생장이 양호하였다. 아미노산은 leucine, 유기산은 acetic acid, gluconic acid, 무기염류는 KCl, KH₂PO₄에서 가장 빠른 균사생장을 보였다. 칼럼 시험은 소나무 80%, 미강 10%, 콘코브 10% 톱밥의 혼합 배지에서 가장 양호한 균사생장을 보였다.