• Journal of Microbiology and Biotechnology
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• 제26권7호
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• pp.1190-1197
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• 2016

The acid response of Bifidobacterium longum subsp. longum BBMN68 has been studied in our previous study. The fab gene, which is supposed to be involved in membrane fatty acid biosynthesis, was demonstrated to be induced in acid response. In order to investigate the relationship between acid response and cell membrane fatty acid composition, the acid adaptation of BBMN68 was assessed and the membrane fatty acid composition at different adaptation conditions was identified. Indeed, the fatty acid composition was influenced by acid adaptation. Our results showed that the effective acid adaptations were accompanied with decrease in the unsaturated to saturated fatty acids ratio (UFA/SFA) and increase in cyclopropane fatty acid (CFA) content, which corresponded to previous studies. Moreover, both effective and non-effective acid adaptation conditions resulted in decrease in the C_18:1 cis-9/C_18:1 trans-9 ratio, indicating that the C_18:1 cis-9/C_18:1 trans-9 ratio is associated with acid tolerance response but not with acid adaptation response. Taken together, this study indicated that the UFA/SFA and CFA content of BBMN68 were involved in acid adaptation and the C_18:1 cis-9/C_18:1 trans-9 ratio was involved in acid tolerance response.

• Restorative Dentistry and Endodontics
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• 제5권1호
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• pp.19-23
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• 1979

This experimental study was made to investigate the tensile strength of composite resins to etched enamel surface with a 50% phosphoric acid. Recently extraced 40 maxillary incisors were chosen. These were divied into 4 groups: Group I: Restodent adaptation to the etched enamel surface with 50% phosphoric acid. Group II: Restodent adaptation to only the ground enamel surface. Group III: Hi-pol adaptation to the etched enamel surface with 50% phosphoric acid. Group IV: Hi-pol adaptation to only the ground enamel surface. The results were as follows: 1. The tensile strength of Hi-pol showed much better results than that of Restodent. 2. Hi-pol and Restodent on the ground enamel surfaces showed little difference. 3. Adhesion to enamel increased on the average over 200% after a 50% phosphoric acid etch.

• Restorative Dentistry and Endodontics
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• 제8권1호
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• pp.107-113
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• 1982

The purpose of this study was to observe the tensile strength of composite resins to etched dentin surface with the various methods of placing bonding agent before composite resin or placing composite resin alone. Recently extracted 60 maxillary incisors were chosen. These were divided into 6 groups: Group I : Immediate Silar adaptation to the etched dentin surface with 37% phosphoric acid for 60 seconds without bonding agent. Group II : Immediate Silar adaptation to the etched dentin surface with 37% phosphoric acid for 60 seconds with bonding agent. Group III : Silar adaptation to the etched dentin surface with 37% phosphoric acid for 60 seconds after 5 minutes of bonding agent. Group IV : Immediate Enamelite adaptation to the etched dentin surfaces with 50% phosphoric acid for 120 seconds without bonding agent. Group V : Immediate Enamelite adaptation to the etched dentin surface with 50% phosphoric acid for 120 second s with bonding again. Group VI : Enamelite adaptation to the etched dentin surface with 50% phosphoric acid for 120 seconds after 5 minutes of bonding agent. All specimens were immersed in water at $37^{\circ}C$ for 24 hours before testing. The results were as follows: 1. The tensile strength of powder/liquid composite resin system was higher than that of pastel paste composite resin system. 2. The tensile strength of the composite resin group II, III, V, & VI with bonding agent was higher than that of the composite resin group I & IV without bonding agent. 3. The tensile strength of the composite resin group III & VI after 5 minutes added to bonding agent was higher than that of the composite resin group II & V immediately added to bonding agent.

• Journal of Microbiology and Biotechnology
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• 제32권12호
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• pp.1599-1604
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• 2022

Storage stability of freeze-dried lactic acid bacteria is a critical factor for their cost-effectiveness. Long-term storage of lactic acid bacteria enables microbial industry to reduce distribution costs. Herein, we investigated the effect of cold adaptation under supercooling conditions at -5℃ on the viability of Leuconostoc mesenteroides WiKim32 during the freeze-drying process and subsequent storage. Cold adaptation increased the thickness of exopolysaccharides (EPS) and improved the viability of freeze-dried Leu. mesenteroides WiKim32. Compared to non-adapted cells, cold-adapted cells showed a 35.4% increase in EPS thickness under supercooling conditions. The viability of EPS-hydrolyzed cells was lower than that of untreated cells, implying that EPS plays a role in protection during the freeze-drying process. Cold adaptation increased the storage stability of freeze-dried Leu. mesenteroides WiKim32. Fifty-six days after storage, the highest viability (71.3%) was achieved with cold adaptation at -5℃. When EPS-containing broth was added prior to the freeze-drying process, the viability further increased to 82.7%. These results imply that cold adaptation by supercooling pretreatment would be a good strategy for the long-term storage of Leu. mesenteroides WiKim32.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권4호
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• pp.357-361
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• 2005

The bioconversion of linoleic acid (LA) to conjugated linoleic acid (CLA) was investigated to examine LA-adaptation of Bifidobacterium breve KCTC 3461 to additions of 1 to 5 mg/mL of LA overtime. To induce LA-adaptation, B. breve KCTC 3461 was treated with LA, according to three schemes. For LA-adapted B. breve the maximum concentration of CLA, $300\~350{\mu}g/mL$, was obtained in cys-MRS medium containing 1 mg/mL of LA. The CLA production significantly increased with increasing LA concentration, from 1 to 4 mg/mL, but the conversion of LA to CLA gradually decreased. The CLA production capability of B. breve, and its tolerance, improved significantly with LA-adaptation. The addition of LA (1 mg/mL) into the culture broth after 24 h of cultivation in a 100-mL media bottle was most effective at promoting CLA production. In a 2.5-L stirred-tank bioreactor, the observed conversion and productivity of $56.6\%\;and\;35.4{\mu}gmL^{-1}h^{-1}$, respectively, by LA-adapted B. breve were approximately 6.6 and 9.8 times higher than those of LA-unadapted B. breve.

• Journal of Plant Biology
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• 제34권4호
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• pp.317-323
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• 1991

Partial recovery in auxin transport capacity from inhibition by N-naphthylphthalamic acid (NPA) was observed when corn coleoptile segments were subjected to a prolonged NPA treatment. Kinetic data indicated that the recovery time is a function of the concentration of NPA applied. Desensitization to NPA was also seen in tissue slices where NPA increased net uptake of auxin, indicating that the apparant adaptation in the auxin transport system did not results possibly from auxin accumulated during transport inhibition. Studies on in vitro binding of NPA to membrane vesicles isolated from the coleoptile indicated that preincubation of the tissue with NPA resulted in the reduced binding activity. Scatchard analysis of the data indicated that this was due to decreases in the number of NPA binding sites. The possibility of causal relationship of modified NPA receptors to the sensory adaptation in auxin transport observed in coleoptile segments will be discussed.

• Animal Bioscience
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• 제37권3호
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• pp.492-499
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• 2024

Objective: The objective was to determine the influence of amino acid (AA) supplementation during the adaptation period on the ileal digestibility of crude protein and AA in corn and soybean meal (SBM) fed to pigs. Methods: Six barrows with an initial body weight of 30.9±2.6 kg fitted with a T-cannula at the distal ileum were assigned to a 6×6 Latin square design with 6 dietary treatments and 6 periods. Two experimental diets contained corn or SBM as the sole AA source and an N-free diet was additionally prepared. For AA supplementation groups, an AA mixture consisted of Gly, Lys, Met, Thr, Trp, Ile, Val, His, and Phe was added to the corn diet and the N-free diet at the expense of cornstarch, and an AA mixture of Lys, Met, and Thr was added to the SBM diet. All diets contained 0.5% of chromic oxide. The 6 experimental diets were fed to the pigs for four and half days, and the 3 diets containing an AA mixture were switched to the respective diets without AA mixture during the following two and half days. Ileal digesta were collected on days 6 and 7. Results: The addition of an AA mixture during the adaptation period increased apparent ileal digestibility of Arg and Trp in corn (p<0.05) but did not affect that in SBM. The addition of an AA mixture during the adaptation period increased apparent ileal digestibility of Pro and Gly regardless of feed ingredient (p<0.05) but did not affect that of other AA. All AA except Pro in corn and SBM were unaffected by the addition of the AA mixture during the adaptation period. Conclusion: The addition of amino acids to a low-protein diet during the adaptation period does not affect the standardized ileal digestibility of indispensable amino acids in pigs.

• 한국축산식품학회지
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• 제31권4호
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• pp.551-556
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• 2011

본 연구는 표준균주 C. sakazakii(CAFM2)와 4개의 야생균주(EB 1, EB 5, EB 7, EB 41)를 사용하여 pH를 조정한 산성 환경에서의 저항성을 살펴보았다. C. sakazakii는 pH 4.5 TSB에서 5시간, 10시간 동안 적응한 경우, pH 4.5 TSB에서 적응하지 않은 경우와 비교하여 EB 7을 제외한 모든 균주가 pH 2.5 TSB에서의 D값이 유의적으로 높게 나타났다(p<0.05). 따라서 약산성 환경에서 적응한 균주는 강산성 환경에서의 저항성이 증가하였다. C. sakazakii는 pH 4.5 TSB에서 배양한 경우, pH 7.2 TSB에서 배양한 경우와 비교하여 모든 균주가 pH 2.5 TSB에서의 D값이 유의적으로 높게 나타났다(p<0.05). 따라서 약산성 환경에서 배양한 균주는 강산성 환경에서의 저항성이 증가하였다. 본 연구를 통해 C. sakazakii는 약산성 환경에 적응한 경우 강산성 환경에서의 저항성이 증가하는 것으로 나타났다. 이러한 acid adaptation response는 C. sakazakii와 관련된 식품 가공 산업에서의 hurdle technology를 적용하는데 있어서 안전성 확보와 관련된 시사점을 제공할 수 있을 것으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권9호
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• pp.1414-1422
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• 2019

Objective: Two experiments were conducted to determine the effects of adaptation time and inclusion level of sugar beet pulp (SBP) on nutrient digestibility and to evaluate the ileal amino acid digestibility of SBP fed to pigs. Methods: In Exp. 1, thirty-six crossbred barrows ($85.0{\pm}2.1kg$) were allotted to 6 diets in a completely randomized design with six replicates per diet. Diets included a corn-soybean meal diet and 5 test diets containing 14.6%, 24.4%, 34.2%, 43.9%, or 53.7% SBP, respectively. The adaptation time consisted 7, 14, 21, or 28 d consecutively for each pig followed by 5 d for fecal collection. Feces were collected from d 8 to 13, d 15 to 20, d 22 to 27, and d 29 to 34, respectively. In Exp. 2, six pigs ($35.1{\pm}1.7kg$) with T-cannulas at the terminal ileum were fed to 3 diets in a replicated $3{\times}3$ Latin square design with 3 periods and 2 replicate pigs per diet. Each period consisted 5 d for diet adaptation followed by 2 d for digesta collection. Results: The digestible energy (DE) value and the apparent total tract digestibility (ATTD) of gross energy (GE), dry matter (DM), ash, and organic matter in diets linearly decreased (p<0.05) as the adaptation time increased or as the dietary SBP increased, while the ATTD of neutral detergent fibre and acid detergent fibre in diets linearly increased (p<0.01) as the dietary SBP increased. The DE value and the ATTD of GE and crude protein (CP) in SBP linearly increased (p<0.05) as the adaptation time increased, while the ATTD of CP in SBP linearly decreased (p<0.01) as the inclusion level increased. The standardized ileal digestibility of Lys, Met, Thr, and Trp in SBP was 37.03%, 51.62%, 40.68%, and 46.22%, respectively. Conclusion: The results of this study indicated that the ATTD of energy and nutrients were decreased as inclusion rate of SBP increased.

• KSBB Journal
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• 제16권6호
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• pp.626-631
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• 2001

본 연구에서 L. crispatus KLB46을 저온 전처리함으로서 제제화 과정에 받게 되는 얼림과 녹임, 건조 스트레스뿐만 아니라, 여러 다른 환경 스트레스에 대한 내성이 증진된다는 것을 확인하였다. 그리고 내성 증진에 신규 단백질 합성이 필요함을 확인하였으며 나아가, 저온 충격 유전자 (csp)를 확인하였다. 따라서 이 균주를 제제화 하기 위한 방법으로 저온 전처리를 이용할 경우 생균력 유지에 큰 효과를 얻을 수 있다고 사료된다.