• Asian-Australasian Journal of Animal Sciences
• /
• 제20권11호
• /
• pp.1694-1698
• /
• 2007

The objective of this study was to identify biohydrogenation pathways for linoleic, linolenic, oleic and stearic acids by Orpinomyces species of rumen fungus during in vitro culture. Biohydrogenation of linoleic acid produced conjugated linoleic acid (cis-9, trans-11 C18:2), which was then converted to vaccenic acid (trans-11 C18:1) as the end product of biohydrogenation. Biohydrogenation of linolenic acid produced cis-9, trans-11, cis-15 C18:3 and trans-11, cis-15 C18:2 as intermediates and vaccenic acid as the end product of biohydrogenation. Oleic acid and stearic acid were not converted to any other fatty acid. It is concluded that pathways for biohydrogenation of linoleic and linolenic acids by Orpinomyces are the same as those for group A rumen bacteria.

• Journal of Microbiology
• /
• 제45권3호
• /
• pp.199-204
• /
• 2007

The objective of this study was to evaluate the effect of soluble carbohydrates (glucose, cellobiose), pH (6.0, 6.5, 7.0), and rumen microbial growth factors (VFA, vitamins) on biohydrogenation of linoleic acid (LA) by mixed rumen fungi. Addition of glucose or cellobiose to culture media slowed the rate of biohydrogenation; only 35-40% of LA was converted to conjugated linoleic acid (CLA) or vaccenic acid (VA) within 24 h of incubation, whereas in the control treatment, 100% of LA was converted within 24 h. Addition of VFA or vitamins did not affect biohydrogenation activity or CLA production. Culturing rumen fungi at pH 6.0 slowed biohydrogenation compared with pH 6.5 or 7.0. CLA production was reduced by pH 6.0 compared with control (pH 6.5), but was higher with pH 7.0. Biohydrogenation of LA to VA was complete within 72 h at pH 6.0, 24 h at pH 6.5, and 48 h at pH 7.0. It is concluded that optimum conditions for biohydrogenation of LA and for CLA production by rumen fungi were provided without addition of soluble carbohydrates, VFA or vitamins to the culture medium; optimum pH was 6.5 for biohydrogenation and 7.0 for CLA production.

• 미생물학회지
• /
• 제43권2호
• /
• pp.100-105
• /
• 2007

홀스타인 건유우의 반추위에서 분리한 혼합 곰팡이에 첨가한 linoleic acid가 biohydrogenation 과정 중 생산되는 지방산의 농도와 종류를 측정하고, 최종 산물로 생산되는 지방산이 trans-11 vaccenic acid인지 stearic acid인지 조사하기 위하여 본 연구를 수행하였으며 결과는 다음과 같다. 반추위 혼합 박테리아 배양구에 linoleic acid 용액을 첨가한 결과, 배양 90분 이내에 100%의 linoleic acid가 stearic acid로 biohydrogenation되었다. 반면에 linoleic acid 용액을 반추위 혼합 곰팡이에 첨가한 결과 24시간 이내에 모든linoleic acid는 conjugated linoleic acid (cis-9, trans-11)와 trans-11 vaccenic acid로 biohydrogenation되었다. Linoleic acid가 함유된 혼합곰팡이 처리구는 배양시간이 증가할수록 stearic acid의 농도도 소량 증가하는 경향을 보였다. 또한 linoleic acid가 함유되지 않은 혼합곰팡이 대조구에서도 배양시간이 증가할수록 stearic acid 농도가 처리구와 비슷하게 증가하는 경향을 나타내었다. 그러나 혼합 박테리아의 linoleic acid 첨가구에서는 배양시간이 증가할수록 stearic acid의 농도가 급격하게 증가하는 것을 조사되어 반추위 혼합곰팡이의 stearic acid생산은 linoleic acid의 biohydrogenation과 무관하게 생산되는 것으로 조사되었다. 따라서 반추위 혼합 곰팡이에 의한 linoleic acid biohydrogenation의 최종 산물은 trans-11 vaccenic acid로 판단되며, 혼합 박테리아는 stearic acid로 나타났다.

• Journal of Animal Science and Technology
• /
• 제47권6호
• /
• pp.985-1000
• /
• 2005

리놀렌산(C18:3)과 리놀산(C18:2)의 biohydrogenation 과 반추위 내에서의 이들 지방산의 bypass를 검토하기 위하여 3 구로 나누어 티모시 조사료를 반추위액과 함께 in vitro상에서 39℃, 0, 3, 6, 9, 24, 36 시간 동안 혐기 배양 시험을 하였다. 첫번째 시험의 목적은 C18:2과 C18:3의 in vitro biohydrogenation에 대한 조사료의 성장 단계(stem elongation, early heading, late heading, early flowering)와 질소 시비(0 and 120kg N ha－1)의 영향을 시험하는 것이었다. 수소첨가가능분획(hydrogenable fraction), C18:2과 C18:3의 효과적인 소실과 bypass는 stem elongation 시 수확된 티모시에서 높았고, 성숙함에 따라 일정하게 감소하였다. 질소시비구는 C18:3의 수소첨가가능분획, C18:2과 C18:3의 효과적인 소실과 bypass가 증가하였다. 그러나 C18:2과 C18:3의 소실율은 성숙과 질소시비(P≻0.1)에 의해 영향을 받지 않았다. 2번째 시험에서는 in vitro C18:2과 C18:3 biohydrogenation에 대한 티모시 보존 방법의 영향을 보았다. 사일리지는 C18:2과 C18:3를 가장 효과적으로 소실시켰으며, 건초는 가장 효과가 낮았다. C18:2과 C18:3의 biohydrogenation 된 양은 건초에서 보다 헤일리지와 사일리지에서 더 높았다. 티모시 헤일리지와 비교하였을 때 C18:3의 bypass는 신선 목초, 시든풀, 건초에서 더 높았다. C18:2의 bypass는 건초와 헤일리지에 비해 신선목초와 사일리지가 더 높았다. 3번째 시험에서는 C18:2과 C18:3의 소거와 bypass에 대한 티모시 헤일리지와 사일리지에 대한 개미산 첨가와 Lactobacillus plantarum 접종의 효과를 검토하였다. 개미산의 첨가는 헤일리지와 사일리지에 있어서 C18:3의 biohydrogenation 비율을 증가시켰으나 사일리지에 있어서 C18:2의 수소첨가 가능분획을 감소시켰다. 이러한 3가지 배양구의 결과는 티모시에 있어 C18:2과 C18:3의 수소첨가 가능분획과 bypass가 성숙도에 따라 감소하였고 질소시비에 따라 증가하였음을 보여 준다. 헤일리지와 사일리지에서 건초에서 보다 C18:2과 C18:3의 더 많은 양이 biohydrogenation 되었으며 C18:3의 반추위 소실은 헤일리지에서 보다 신선목초, 시든풀, 건초에서 더 높았다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제14권7호
• /
• pp.960-965
• /
• 2001

The effects of different feeding ratios of concentrate (C) and roughage (R) on balance of long chain fatty acids and microbial fatty acids in the rumen of sheep were investigated. The diets were divided into 8:2 (concentrate feeding), 4:6 (middle mixture) and 0:10 (roughage feeding) ratios (C:R). Duodenal digesta was collected through 24 hours after feeding. Biohydrogenation rate, total duodenal flow of fatty acids and microbial fatty acids were measured. Total duodenal flow of fatty acids was significantly (p<0.05) increased with increasing concentrate. Total duodenal flow of fatty acid was greater than intake of fatty acid in all diets. In comparison with intake of each fatty acid, duodenal flow of stearic acid ($C_{18:0}$) remarkably increased in all diets. Biohydrogenation rate for total C18 unsaturated fatty acids in the rumen tended to increase (p<0.10) when sheep were fed the middle mixture. In particular, biohydrogenation rate of linoleic acid ($C_{18:2}$) and linolenic acid ($C_{18:3}$) with the middle mixture were highest (p<0.05) compared with other diets. Duodenal flow of protozoal fatty acids was significantly (p<0.05) increased with the increased supply of concentrate. That of bacterial fatty acids was significantly (p<0.05) increased with both concentrate diets compared with the roughage feeding diet. $C_{18:0}$ occupied the greater part of both protozoal and bacterial fatty acids in all treatments. Results indicated that biohydrogenation of free unsaturated fatty acids was actively carried out when the middle mixture diet was supplied, and that microbial uptake and synthesis of fatty acids were accelerated by adding the supply of concentrate.

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

• Journal of Animal Science and Technology
• /
• 제45권4호
• /
• pp.617-626
• /
• 2003

본 연구는 사료 내 농후사료의 비율을 높임으로서 불포화 지방산의 반추위 내 by-pass율의 향상 가능성을 조사하고, 아마종실과 전지대두 급여 시 CLA 생산을 상호 비교하기 위하여 연속배양장치를 이용하여 수행하였다. 지방 급원에 따른 발효 성상의 차이는 보이지 않았다. 한편 사료 내 농후사료 비율이 높은 (80%) 처리구는 농후사료 비율이 낮은 (40%) 처리구와 비교하여 pH는 감소하였으나, 암모니아, 총 휘발성 지방산, acetate, butyrate 및 valerate 농도가 증가되었다. 지방급원 (전지대두 vs 아마종실)과 사료 내 농후사료 비율은 organic matter (OM), total nitrogen, neutral detergent fiber (NDF) 및 acid detergent fiber (ADF)의 소화율에 영향을 끼치지 않았다. 반면에 전지대두는 아마종실과 비교하여 trans C18:1, C18:2 n-6 및 C18:3 n-3 유출율은 증가시켰다. 지방 급원에 의한 CLA flow는 영향을 받지 않았으나 사료 내 농후사료 비율이 높을 때와 전지대두와 아마종실의 함량이 높았을 때는 증가되었다. 수소 첨가현상은 C18:1 n-9 와 C18:2 n-6에서 지방 급원에 의하여 영향을 받지 않았으나, 아마종실 처리구에서는 C18:3 n-3 과 총 C18 불포화지방산의 수소 첨가현상이 전지대두 처리구와 비교하여 높은 비율로 발생했다. 한편 사료 내 농후사료 비율이 높을 때 처리구에서 C18:2 n-6, C18:3 n-3 및 총 C18 불포화 지방산의 수소 첨가현상은 농후사료 저 처리구와 비교하여 감소되었다.

• 한국축산식품학회지
• /
• 제24권3호
• /
• pp.303-309
• /
• 2004

Conjugated linoleic acid (CLA) is currently under intensive investigation due to its health benefits. A great deal of interest has been paid to the possible health-promoting roles of CLA, but there are not many studies available on the mechanism of CLA production by ruminal microorganisms. CLA is produced as an intermediate of the characteristic biohydrogenation process of linoleic acid(LA) in the rumen and its production has direct relationship to numerous environmental factors including particle association, substrate concentration, forage-to-grain ratio, pH, ionopore, bacterial cell density, etc. Some of these factors were known to affect hydrogenating activities of Butyrivibrio fibrisolvens A38 which is an active rumen bacterium in CLA production. Dairy cow is a main source of CLA, and its level could be increased by dietary manipulation changing the physiological environment of rumen bacteria such as B. fibrisolvens A38. Therefore, the effects of various factors on. ruminal biohydrogenation should be carefully considered to optimize not only CLA production, but also other fatty acid metabolism, both of which are directly affecting nutritional quality and functionality of dairy products. In this review, the relationship between various environmental factors and ruminal CLA production is discussed focusing on the CLA production of B. fibrisolvens A38.

• Asian-Australasian Journal of Animal Sciences
• /
• 제25권7호
• /
• pp.962-970
• /
• 2012

This study aimed to investigate the effects of ruminal infusion of garlic oil (GO) on fermentation dynamics, fatty acid (FA) profile, and abundance of bacteria involved in biohydrogenation in the rumen. Six wethers fitted with ruminal fistula were assigned to two groups for cross-over design with a 14-d interval. Each 30-d experimental period consisted of a 27-d adaptation and a 3-d sample collection. Goats were fed a basal diet without (control) or with GO ruminal infusion (0.8 g/d). Ruminal contents collected before (0 h) and at 2, 4, 6, 8, and 10 h after morning feeding were used for fermentation analysis, and 0 h samples were further used for FA determination and DNA extraction. Garlic oil had no influence on dry matter intakes of concentrate and hay. During ruminal fermentation, GO had no effects on total VFA concentration and individual VFA molar proportions, whereas GO increased the concentrations of ammonia nitrogen and microbial crude protein (p<0.05). Compared with control, GO group took a longer time for total VFA concentration and propionate molar proportion to reach their respective maxima after morning feeding. The ratio of acetate to propionate in control reduced sharply after morning feeding, whereas it remained relatively stable in GO group. Fatty acid analysis showed that GO reduced saturated FA proportion (p<0.05), while increasing the proportions of C18, t11-18:1 (TVA), c9,t11-conjugated linoleic acid (c9,t11-CLA), t10,c12-CLA, and polyunsaturated FA (p<0.05). The values of TVA/(c9,t11-CLA+TVA) and C18:0/(TVA+C18:0) were reduced by GO (p<0.05). Real-time PCR showed that GO tended to reduce Butyrivibrio proteoclasticus abundance (p = 0.058), whereas GO had no effect on total abundance of the Butyrivibrio group bacteria. A low correlation was found between B. proteoclasticus abundance and C18:0/(TVA+C18:0) (p = 0.910). The changes of fermentation over time suggested a role of GO in delaying the fermentation process and maintaining a relatively modest change of ruminal environment. The inhibitory effects of GO on the final step of biohydrogenation may be related to its antibacterial activity against B. proteoclasticus and other unknown bacteria involved.

• Asian-Australasian Journal of Animal Sciences
• /
• 제30권5호
• /
• pp.622-637
• /
• 2017

Fatty acids such as n-3 and n-6 polyunsaturated fatty acids (PUFA) are critical nutrients, used to improve male reproductive performance through modification of fatty acid profile and maintenance of sperm membrane integrity, especially under cold shock or cryopreservation condition. Also, PUFA provide the precursors for prostaglandin synthesis and can modulate the expression patterns of many key enzymes involved in both prostaglandin and steroid metabolism. Many studies carried out on diets supplemented with PUFA have demonstrated their capability to sustain sperm motility, viability and fertility during chilling and freezing as well as improving testis development and spermatogenesis in a variety of livestock species. In addition to the type and quantity of dietary fatty acids, ways of addition of PUFA to diet or semen extender is very crucial as it has different effects on semen quality in male ruminants. Limitation of PUFA added to ruminant ration is due to biohydrogenation by rumen microorganisms, which causes conversion of unsaturated fatty acids to saturated fatty acids, leading to loss of PUFA quantity. Thus, many strategies for protecting PUFA from biohydrogenation in rumen have been developed over the years. This paper reviews four aspects of PUFA in light of previous research including rumen metabolism, biological roles, influence on reproduction, and strategies to use in male ruminants.