Quantitative determination of aromatic amino acids and related compounds in rumen fluid by high-performance liquid chromatography

Khan, Rokibul Islam; Amin, Mohammad Ruhul; Mohammed, Nazimuddin; Onodera, Ryoji

doi:10.1016/s0378-4347(98)00103-0

Cited by 25 publications

(11 citation statements)

References 30 publications

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“…All the supernatant fluids of the incubations and hydrolysates of the pellets were analyzed by HPLC (Khan et al, 1998). The net increases of Phe and Tyr in the microbial pellets in 6h and 12h of incubations were assumed as incorporation and production of these compounds at respective hours.…”

Section: Methodsmentioning

confidence: 99%

“…Recently we established a HPLC method for the quantitative determination of the aromatic amino acids and their related eleven compounds with which Tyr can clearly be separated from HPA (Khan et al, 1998). The present research was conducted to verify whether Tyr is produced from Phe by mixed rumen bacteria and protozoa, and simultaneously to make a quantitative investigation of other metabolites produced during the in vitro metabolism of Phe.…”

Section: Introductionmentioning

confidence: 99%

“…A quantitative study was also carried out to investigate and compare the production of these compounds in the actual rumen microbial ecosystem, important for the nutrition and physiology of the host animal (Hungate, 1950). All the quantitative analyses were done using the HPLC method (Khan et al, 1998).…”

Section: Introductionmentioning

confidence: 99%

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Production of tyrosine and other aromatic compounds from phenylalanine by rumen microorganisms

et al. 1999

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Rumen contents from three fistulated Japanese native goats fed Lucerne hay cubes (Medicago sativa) and concentrate mixture were collected to prepare the suspensions of mixed rumen bacteria (B), mixed protozoa (P) and a combination of the two (BP). Microbial suspensions were anaerobically incubated at 39 degrees C for 12 h with or without 1 mM of L-phenylalanine (Phe). Phe, tyrosine (Tyr) and other related compounds in both supernatant and microbial hydrolysates of the incubations were analyzed by HPLC. Tyr can be produced from Phe not only by rumen bacteria but also by rumen protozoa. The production of Tyr during 12 h incubation in B (183.6 mumol/g MN) was 4.3 times higher than that in P. One of the intermediate products between Phe and Tyr seems to be p-hydroxyphenylacetic acid. The rate of the net degradation of Phe incubation in B (76.0 mumol/g MN/h) was 2.4 times higher than in P. In the case of all rumen microorganisms, degraded Phe was mainly (> 53%) converted into phenylacetic acid. The production of benzoic acid was higher in P than in B suspensions. Small amount of phenylpyruvic acid was produced from Phe by both rumen bacteria and protozoa, but phenylpropionic acid and phenyllactic acid were produced only by rumen bacteria.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Production of tyrosine and other aromatic compounds from phenylalanine by rumen microorganisms

et al. 1999

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“…It was found that LAB produced PhLA as a reaction product of amino acid metabolism [22,23]. Its detection by reverse-phase HPLC is simple and widely adopted method for quantitative measurement of PhLA present in fermentation broth [24], honey [19] and rumen fluid [25]. GC/MS and capillary electrophoresis were also used for quantitative measurement of PLA.…”

Section: Phla Occurrence and Its Detectionmentioning

confidence: 99%

Phenyllactic Acid: A Potential Antimicrobial Compound in Lactic acid Bacteria

Ss¹

2016

JBMOA

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Abstract3-Phenyllactic acid (PhLA) is a broad spectrum antimicrobial compound active against bacteria and fungi. PhLA exists in two chiral isomers, L-PhLA and D-PhLA which show antimicrobial activity. D-PhLA shows more antimicrobial activity than L-PhLA and hence it is receiving great attention as food and feed additive in place antibiotics which control the microbial contamination and thereby increase the shelf life of food and food ingredients. This review summarizes the recent developments on the resources, detection and analysis and antimicrobial activity of PhLA. In addition, the article presents the recent studies of the key enzymes such as lactate dehydrogenases and pyruvate reductases involved in PhLA synthesis. The metabolic pathway and regulation of PLA synthesis in lactic acid bacteria (LAB) along with its high level production are also discussed.

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“…Khan et al 35) established a new method with which Tyr and HPA can be separated and quantitatively analyzed. Using the new method it was strongly suggested that Tyr was produced from Phe36) not only by rumen bacteria but also by rumen protozoa.…”

Section: Protozoa Also Produce Phenylalanine and Tyrosinementioning

confidence: 99%