• 생명과학회지
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• 제31권8호
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• pp.778-785
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• 2021

오이 씨앗의 발아는 세포의 지방체내 저장지방의 분해 결과인 acyl-CoA의 글라이옥시좀으로 이동 후 베타 산화의 결과물인 acetyl-CoA의 글라이옥실산 회로로의 유입과 지방의 유동으로 촉발된다. Acetyl-CoA는 글라이옥실산 회로의 가동을 위한 탄소원을 제공하며 시트르산과 말산을 생성하며 글라이옥실산 회로의 작동을 유도한다. 지방 저장 종자의 발아에 있어서 글라이옥실산 회로는 필수적 요소이며, 그 결과물인 말산 및 숙신산의 미토콘드리아로의 이동은 TCA 회로의 가동과 옥살초산의 생성 및 세포질로의 유동으로 PEPCK에 의한 당신생을 가능하게 한다. 즉, 저장 지방을 원료로 여러 대사물질의 생산 및 이동과 다중의 대사경로를 통하여 발아 시 사용 가능한 에너지원인 포도당의 형태로 전환이 이루어진다. 이에 동반하여 많은 유전자의 발현 조절이 이루어지고, 세포내 소기관 특히 미소체로 대표되는 글라이옥시좀은 말산 합성효소(malate synthase)와 이소 시트르산 분해효소(isocitrate lyase)로 특화된다. 또 다른 acetyl-CoA의 유동은 carnitine을 매개로 하는 BOU (A BOUT DE SOUFFLE)의 작동이다. 이것은 카니틴의 대사와 관련하여 고등식물의 발달과 대사과정에서의 중요성이 확인된 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제26권2호
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• pp.233-240
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• 2013

The objective of this study was to investigate the effects of L-carnitine on growth performance, organ weight, biochemical parameters of blood, heart and liver, and ascites susceptibility of broilers at different ages reared under a low-temperature environment. A total of 420 1-d-old male Ross 308 broilers were randomly assigned to two dietary treatments with fifteen replicates of fourteen broilers each. Treatment diets consisted of L-carnitine supplementation at levels of 0 and 100 mg/kg. At 11-d of age, low temperature stress was used to increase ascites susceptibility. Blood, heart and liver samples were collected at different ages for analysis of boichemical parameters. The results showed that, there was no significant difference in growth performance with L-carnitine supplementation, but the mortality due to ascites was significantly decreased. Dietary L-carnitine supplementation significantly reduced heart index (HI) and ascites heart index (AHI) on d 21, lung index (LUI) on d 35 and liver index (LI) on d 42. The broilers fed diets containing L-carnitine had significantly lower red blood cell counts (RBC), hemoglobin (HGB) concentration and hematocrit (HCT) on d 42. Dietary L-carnitine supplementation significantly reduced malondialdehyde (MDA) content of heart tissue on d 21 and 35, and significantly increased total superoxide dismutase (T-SOD) and Glutathione peroxidase (GSH-Px) activity of the heart on d 21 and 42. L-carnitine supplementation significantly reduced serum triglyceride (TG) content on d 28 and 35 and serum glucose (GLU) on d 35 and 42, and significantly increased serum total protein (TP) and globulin (GLO) content on d 42. L-carnitine supplementation significantly enhanced liver succinodehydrogenase (SDH), malic dehydrogenase (MDH) and $Na^+$-$K^+$-ATPase activity on d 28, and tended to reduce the lactic acid (LD) level of liver on d 35 (p = 0.06). L-carnitine supplementation significantly reduced serum uric acid (UA) content on d 28, 35 and 42. Based on the current results, it can be concluded that dietary L-carnitine supplementation reduced organ index, red blood cell counts and hematocrit, enhanced antioxidative capacity of the heart, enhanced liver enzymes activity involved in tricarboxylic acid cycle, and reduced serum glucose and triglyceride. Therefore, it is suggested that L-carnitine can potentially reduce susceptibility and mortality due to ascites.

• Journal of Microbiology and Biotechnology
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• 제31권2호
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• pp.259-271
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• 2021

Many bacteria metabolize aromatic compounds via catechol as a catabolic intermediate, and possess multiple genes or clusters encoding catechol-cleavage enzymes. The presence of multiple isozyme-encoding genes is a widespread phenomenon that seems to give the carrying strains a selective advantage in the natural environment over those with only a single copy. In the naphthalene-degrading strain Pseudomonas putida ND6, catechol can be converted into intermediates of the tricarboxylic acid cycle via either the ortho- or meta-cleavage pathways. In this study, we demonstrated that the catechol ortho-cleavage pathway genes (catBICIAI and catBIICIIAII) on the chromosome play an important role. The catI and catII operons are co-transcribed, whereas catAI and catAII are under independent transcriptional regulation. We examined the binding of regulatory proteins to promoters. In the presence of cis-cis-muconate, a well-studied inducer of the cat gene cluster, CatRI and CatRII occupy an additional downstream site, designated as the activation binding site. Notably, CatRI binds to both the catI and catII promoters with high affinity, while CatRII binds weakly. This is likely caused by a T to G mutation in the G/T-N11-A motif. Specifically, we found that CatRI and CatRII regulate catBICIAI and catBIICIIAII in a cooperative manner, which provides new insights into naphthalene degradation.