• Bulletin of the Korean Chemical Society
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• 제24권4호
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• pp.437-440
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• 2003

In a mediator-aided microbial fuel cell, the choice of a proper mediator is one of the most important factors for the development of a better fuel cell system as it transfers electrons from bacteria to the electrode. The electrochemical behaviors within the lipid layer of two representative mediators, thionin and safranine O both of which exhibit reversible electron transfer reactions, were compared with the fuel cell efficiency. Thionin was found to be much more effective than safranine O though it has lower negative formal potential. Cyclic voltammetric and fluorescence spectroscopic analyses indicated that both mediators easily penetrated the lipid layer to pick up the electrons produced inside bacteria. While thionin could pass through the lipid layer, the gradual accumulation of safranine O was observed within the layer. This restricted dynamic behavior of safranine O led to the poor fuel cell operation despite its good negative formal potential.

• 한국축산식품학회지
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• 제33권1호
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• pp.58-66
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• 2013

In this study, the effect of packaging methods [aerobic packaging (AP), vacuum packaging (VP) and modified atmosphere packaging (MAP: 75% $N_2$, 25% $CO_2$)] on colour, lipid quality and microbial growth of beef patties enhanced with flaxseed flour was investigated during storage at $2{\pm}1^{\circ}C$ for 10 d. L and a values of beef patties packaged in MAP and VP were higher (p<0.05) than that of the samples packaged in AP. Packaging in MAP and VP retarded the lipid oxidation (TBA value) and inhibited the bacterial growth of beef patties enhanced with flaxseed flour. Furthermore, TBA values in beef patties were correlated with a values (r = -0.340; p<0.05). Packaging in MAP was more effective than packaging in VP for inhibiting microbial growth. The samples packaged in VP lost their shape due to the compression by external atmosphere. Packaging treatment had no significant effect on saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) levels in beef patties. The a and b, TBA and MUFA values changed during storage time. TBA values for beef patties increased during storage time, but did not reach to the limit value (1 mg/kg) until the end of the storage time. The results suggest that the shelf life of beef patties enhanced with flaxseed flour can be extended by packaging in MAP.

• 한국축산식품학회지
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• 제44권2호
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• pp.372-389
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• 2024

This study investigated the efficacy of ultraviolet-C (UV-C) irradiation in enhancing the quality of raw bovine milk by targeting microbial populations and lipid peroxidation, both of which are key factors in milk spoilage. We categorized the raw milk samples into three groups based on initial bacterial load: low (<3 Log 10 CFU/mL), medium (3-4 Log 10 CFU/mL), and high (>4 Log 10 CFU/mL). Using a 144 W thin-film UV-C reactor, we treated the milk with a flow rate of 3 L/min. We measured the bacterial count including standard plate count, coliform count, coagulase-negative staphylococci count, and lactic acid bacteria count and lipid peroxidation (via thiobarbituric acid reactive substances assay) pre- and post-treatment. Our results show that UV-C treatment significantly reduced bacterial counts, with the most notable reductions observed in high and medium initial load samples (>4 and 3-4 Log 10 CFU/mL, respectively). The treatment was particularly effective against coliforms, showing higher reduction efficiency compared to coagulase-negative staphylococci and lactic acid bacteria. Notably, lipid peroxidation in UV-C treated milk was significantly lower than in pasteurized or untreated milk, even after 72 hours. These findings demonstrate the potential of UV-C irradiation as a pre-treatment method for raw milk, offering substantial reduction in microbial content and prevention of lipid peroxidation, thereby enhancing milk quality.

• Asian-Australasian Journal of Animal Sciences
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• 제13권2호
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• pp.176-181
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• 2000

In order to clarify the inhibitory effects of orchardgrass (Dactylis glomerata L.) lipids on ruminal fermentation and digestion, two experiments were carried out in vitro. Experiment 1 was carried out using residues of grass hay from which the lipid fraction was removed by ether extraction. To ground grass samples were added 0, 1.5, 3.0, 4.5 and 6.0% lipids and incubated anaerobically at $39^{\circ}C$ for 24 h, with the mixtures of artificial saliva and rumen fluid. Increasing grass lipid levels remarkably reduced DM and NDF disappearances. Volatile fatty acid concentration was significantly reduced at 3.0, 4.5 and 6.0% lipid levels. Microbial nitrogen proportion to total nitrogen tended to decrease by the addition of the lipids. These results indicated that grass lipids have a marked inhibitory effect on ruminal fermentation and digestion, especially when to the substrate was added 3% or more grass lipids as ether extracts. Experiment 2 was conducted to study the relationship between changes in the free fatty acids and changes in the fermentation traits. Samples were incubated for 3, 6, 9, 12, 15, 18, 21 and 24 h as a sole substrate. The polyunsaturated fatty acids steadily decreased during incubation, whereas the saturated fatty acid ($C_{18:0}$) increased. It was suggested that the hydrogenation was extended during the initial stage of incubation. The unsaturated fatty acids ($C_{18:2}$, $C_{18:3}$) produced at the initial stage of incubation were negatively correlated with the amount of microbial N and DM disappearance, indicating that polyunsaturated fatty acids had the possibility to show an inhibiting effect on ruminal fermentation and digestion.

• 생명과학회지
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• 제31권3호
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• pp.346-355
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• 2021

이 연구의 목적은 Bacillus polyfermentricus KJS-2 (BP2)와 Bacillus mojavensis KJS-3 (Moja3) 및 이들 균주 복합물의 투여가 혈청 지질 수준을 조절할 수 있는지에 대한 가능성을 밝히기 위한 것이다. 고지질혈증 유발 설치류를 대상으로 균주를 2주 동안 경구 투여한 후 혈액 내 세포수준의 변화, 대사기능 평가, 혈중 지질 수준의 변화를 관찰하였다. 백혈구내 주요세포변화를 측정한 결과 균주 투여에 따른 혈중 백혈구(WBC) 수준에는 크게 영향을 미치지는 않았다. 단위 혈액 내 혈소판(PLT) 수치는 Triton WR-1339처리시 18.4% 감소하였고 약물투여그룹 및 균주 투여그룹에서 다시 정상 그룹 수준으로 회복되었다(p<0.05). Triton WR-1339로 유도된 고지혈증에 의해 적혈구의 기능적인 변화는 초래하지 않았다. 혈중 AST, ALT, BUN, Creatinine 수치는 혼합 균주투여 그룹에서 모두 회복하여 간기능, 신장기능에 영향을 미치지 않았다. 혈중 지질수준 변화는 미생물 균주 투여그룹에서 트리글리세라이드(TG)와 총콜레스테롤(TC) 혈청 수치가 감소했고, 혈청 HDL 콜레스테롤 수치는 증가했다. BP2가 생산하는 SMA의 HMG-CoA reductase 저해율은 atorvastatin에 비해 1,000배 낮은 농도에서 비슷한 활성을 보였다. 또한, 고지혈증 유발 설치류에 미생물 균주의 복합투여는 식이에 영향을 미치지 않으면서 체중증가율은 감소시켰다. 따라서 BP2와 Moja3 균주 복합투여시 혈청 지질 수치를 조절함으로써 혈액 순환을 개선시킬 수 있을 것이다.

• 한방비만학회지
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• 제18권2호
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• pp.64-73
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• 2018

Objectives: This study investigated the effect on microbial ecology, fermentation characteristics and anti-obesity of Platycodon grandiflorum (PG) fermentation with salt. Methods: PG was fermented for four weeks with 2.5% salt and the characteristics of fermented PG were performed by measuring pH, total sugar content, viable bacteria number and microbial profiling. Also, we measured total polyphenol, flavonoid and the percent of inhibition of lipase activity and lipid accumulation. Results: Salt added to PG for fermentation had an effect on pH, total sugar, total and the number of lactic acid bacteria. Total sugar and pH were reduced and number of total and lactic acid bacteria were increased after fermentation. The majority of bacteria for fermentation were Lactobacillus plantarum, Leuconostoc psedomesenteroides and Lactococcus lactis subspecies lactis regardless of salt addition. However, microbial compositions were altered by added salt and additional bacteria including Weissella koreensis, W. viridescens, Lactobacillus sakei and Lactobacillus cuvatus were found in fermented PG with salt. Total flavonoid was increased in fermented PG and lipid accumulation on HepG2 cells treated with fermented PG was reduced regardless of salt addition. Moreover, fermented PG without salt suppressed lipase activity. Conclusions: Addition of salt for PG fermentation had influence on fermentation characteristics including pH and sugar content as well as number of bacteria and microbial composition. In addition, fermented PG showed anti-obesity effect by increasing flavonoid content and inhibition of lipase activity and lipid accumulation.

• Journal of Microbiology and Biotechnology
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• 제19권8호
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• pp.810-817
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• 2009

The effect of cryoprotectants (maltodextrin+glycerol) and cryoprotectants+antioxidant [ascorbic acid and/or butylated hydroxytoluene (BHT)] mixtures on the survival, electrolyte leakage, and lipid degradation of freeze-dried Weissella paramesenteroides LC11 during storage was investigated and compared with that of the control (cells without additives) over a 90-day storage period at 4 or $20^{\circ}C$ in glass tubes with water activity ($a_w$) of 0.23. The survival, electrolyte leakage, and lipid degradation were evaluated through colony counts, electrical conductivity, and thiobarbituric acid reactive substances (TBARS) content, respectively. The fatty acids composition was determined by gas chromatography, in both the total lipid extract and the polar lipid fraction, and compared with that of the control after the 90-day storage period. As the storage proceeded, increases in leakage value and TBARS content, as well as a decrease in viability, were observed. After 90 days of storage, the major fatty acids found in both the total lipid extract and the polar lipid fraction were palmitic (16:0), palmitoleic (16:1), stearic (18:0), oleic (18:1), linoleic (18:2), and linolenic (18:3) acids. The survival, leakage value, TBARS content and 18:2/16:0 or 18:3/16:0 ratio were the greatest for the protected strain held at $4^{\circ}C$. Cells with the cryoprotectants+BHT mixture showed the highest percentage of survival and 18:2/16:0 or 18:3/16:0 ratio in both lipid extracts, as well as the lowest leakage value and TBARS content after the 90-day storage period. Drying cells with the cryoprotectants+BHT mixture considerably slowed down polar lipid degradation and loss of membrane integrity, resulting in improved viability during storage.

• 한국수소및신에너지학회논문집
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• 제28권5호
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• pp.440-446
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• 2017

This study was aimed at evaluating the effects of carbohydrate, protein and lipid content of substrate on hydrogen yields and microbial communities. The hydrogen yields were linearly correlated to carbohydrate content of substrates while others (content of proteins and lipids) did not make a significant contribution. The chemical composition of substrates produced effects on the final products of anaerobic hydrogen fermentation. Acetate and butyrate were the main fermentation products, with their concentration proving to correlate with carbohydrate and protein content of substrates. The result of microbial community analysis revealed that the relative abundances of Clostridium butyricum increased and Clostridium perfringens decreased as the carbohydrate content increased.

• Preventive Nutrition and Food Science
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• 제9권1호
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• pp.1-6
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• 2004

Fresh ground beef was mixed with ascorbic acid, basil essential oil, majoram essential oil, or each essential oil combined with ascorbic acid and stored at 1 $\pm$ 1$^{\circ}C$ for 7 days. Color, lipid oxidation (TBARS formation), aerobic bacterial counts and pH were determined. Basil and majoram essential oils were effective in inhibiting color deterioration, lipid oxidation and bacterial growth. The combined addition of basil and ascorbic acid showed the highest protection against color fading, followed by majoram + ascorbic acid, and ascorbic acid alone. Basil and majoram essential oils were most effective in delaying TBARS formation (p < ().01). Ascorbic acid did not exert an antioxidative effect and even exhibited a pro-oxidant effect. The pH values of all samples increased slightly, but no significant differences were observed, either among treatments or throughout the storage time (p > 0.05).

• Asian-Australasian Journal of Animal Sciences
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• 제22권9호
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• pp.1341-1350
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• 2009

Dietary lipids are rapidly hydrolysed and biohydrogenated in the rumen resulting in meat and milk characterised by a high content of saturated fatty acids and low polyunsaturated fatty acids (PUFA), which contributes to increases in the risk of diseases including cardiovascular disease and cancer. There has been considerable interest in altering the fatty acid composition of ruminant products with the overall aim of improving the long-term health of consumers. Metabolism of dietary lipids in the rumen (lipolysis and biohydrogenation) is a major critical control point in determining the fatty acid composition of ruminant lipids. Our understanding of the pathways involved and metabolically important intermediates has advanced considerably in recent years. Advances in molecular microbial technology based on 16S rRNA genes have helped to further advance our knowledge of the key organisms responsible for ruminal lipid transformation. Attention has focused on ruminal biohydrogenation of lipids in forages, plant oils and oilseeds, fish oil, marine algae and fat supplements as important dietary strategies which impact on fatty acid composition of ruminant lipids. Forages, such as grass and legumes, are rich in omega-3 PUFA and are a useful natural strategy in improving nutritional value of ruminant products. Specifically this review targets two key areas in relation to forages: i) what is the fate of the lipid-rich plant chloroplast in the rumen and ii) the role of the enzyme polyphenol oxidase in red clover as a natural plant-based protection mechanism of dietary lipids in the rumen. The review also addresses major pathways and micro-organisms involved in lipolysis and biohydrogenation.