Tryptophan biosynthesis and production of other related compounds from indolepyruvic acid by mixed ruminal bacteria, protozoa, and their mixture in vitro.

Mohammed, Nazimuddin; Onodera, Ryoji; Khan, Rokibul Islam

doi:10.2323/jgam.45.143

Cited by 10 publications

(10 citation statements)

References 23 publications

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“…Trp produced from IND plus Ser was simultaneously incorporated into bacterial protein, and the amounts were 55.5 and 98.3 µM after 6-and 12-h incubations, respectively. A similar trend was also found in Trp biosynthesis from IPA [14]. Thus, 5.9 and 9.8% of IND that disappeared were converted to Trp during 6-and 12-h incubations, respectively.…”

Section: Resultssupporting

confidence: 77%

“…It is known that protozoa always engulf bacteria in the rumen ecosystem. In this connection, Mohammed et al [14] and Amin et al [3] also reported the same effect in the BP suspension during production of Trp from indolepyruvic acid, and Phe from phenylpyruvate and phenylacetate, respectively.…”

Section: Resultsmentioning

confidence: 76%

“…In the B suspension, a minor quantity of Trp (3.5 µM) was found only in the supernatant after 6-h incubation, and almost all of it was found in the hydrolyzate of bacterial cells both after 6-and 12-h incubations. The opposite results were obtained during production of Trp from IPA [14]. Trp produced from IND plus Ser was simultaneously incorporated into bacterial protein, and the amounts were 55.5 and 98.3 µM after 6-and 12-h incubations, respectively.…”

Section: Resultsmentioning

confidence: 76%

“…In relation to Trp biosynthesis in the rumen, it has been postulated that indoleacetic acid (IAA) was reductively carboxylated to form indolepyruvic acid (IPA) and then transaminated to form Trp by mixed rumen microorganisms in strained rumen fluid or whole ingesta [1, 2], mixed ruminal bacteria [2,9], and pure culture of Ruminococcus albus [1,2]. In this connection, quantitative data concerning the production of Trp from indolepyruvic acid (IPA) by mixed ruminal bacteria (B), protozoa (P), and their mixture (BP) in vitro have been separately indicated in our previous paper [14].On the other hand, tryptophanase (4. 1.…”

mentioning

confidence: 98%

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Tryptophan Biosynthesis and Production of Other Related Compounds from Indole and L-Serine by Mixed Ruminal Bacteria, Protozoa, and Their Mixture In Vitro

Mohammed

Onodera

Khan

1999

Current Microbiology

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Tryptophan (Trp) biosynthesis and production of other related compounds from 1 mM each of indole (IND), L-serine (Ser), and IND plus Ser by mixed ruminal bacteria (B), protozoa (P), and their mixture (BP) in an in vitro system were quantitatively investigated. Ruminal microorganisms were anaerobically incubated at 39 degrees C for 12 h. Trp and other related compounds produced in both the supernatants and microbial hydrolyzates of the incubation were analyzed by HPLC. B, P, and BP suspensions were not able to produce Trp when incubated with only IND or Ser. Appreciable amounts of Trp (9.8, 3.1, and 6.6% of substrate) were produced from IND plus Ser after 12 h by B, P, and BP suspensions, respectively. Trp produced from IND + Ser in B was found only in the hydrolyzate, whereas it was found in the medium as a free form in P after a 12-h incubation period. Rumen bacteria and protozoa were separately demonstrated for the first time to produce Trp from IND plus Ser, and the ability of P to produce Trp from IND plus Ser was about one-third that of B in 12 h. Trp produced from IND plus Ser by B, P, and BP suspensions was simultaneously degraded into its related compounds, and, among them, indoleacetic acid (IAA) was a major product found in B. Production of IAA was 4.3, 0.3, and 3.2% of IND in 12 h by B, P, and BP suspensions, respectively. A small amount of skatole (SKT) (1.1 and 2.5% in B and BP, respectively) and p-cresol (CRL) (2.4 and 3.4% in B and BP, respectively) were also produced from IND plus Ser during 12-h incubation. P suspension produced no SKT or CRL from IND plus Ser in 12-h incubation. These results suggested for the first time that both rumen bacteria and protozoa have an ability to produce Trp from IND plus Ser, and the ability was higher in B than in P. The ratios of Trp produced from IND plus Ser to that from indolepyruvic acid by B, P, and BP were 1:3.4, 1:14.2, and 1:6.6 during 12-h incubation period. From these results, the degree of importance of producing Trp from IND plus Ser in the rumen was indicated.

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Section: Resultssupporting

confidence: 77%

Section: Resultsmentioning

confidence: 76%

Section: Resultsmentioning

confidence: 76%

mentioning

confidence: 98%

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Tryptophan Biosynthesis and Production of Other Related Compounds from Indole and L-Serine by Mixed Ruminal Bacteria, Protozoa, and Their Mixture In Vitro

Mohammed

Onodera

Khan

1999

Current Microbiology

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“…Injection volume, flow rate and λ absorbance were 50 µL, 1.2 ml/min and 220 nm, respectively (21, 22). For sample analysis, L-Trp was dissolved to a concentration of 1 mg/mL with purified water as stock solution.…”

Section: Methodsmentioning

confidence: 99%

Optimization of L-Tryptophan Biosynthesis From L-Serine of Processed Iranian Beet and Cane Molasses and Indole by Induced Escherichia coli ATCC 11303 Cells

Sadeghiyan-Rizi

Fooladi

Heravi

et al. 2014

Jundishapur J Microbiol

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Background:L-tryptophan is an important ingredient in medicines, especially in neuromedicines such as antidepressants. Many commercial processes employ various microorganisms with high tryptophan synthase activity to produce L-tryptophan from indole and L-serine, but these processes are very costly due to the costs of precursors, especially L-serine.Objectives:For this reason, we studied the ability to use processed Iranian cane and beet molasses as L-serine sources for L-tryptophan production, which enables us to reach a cost-effective process.Materials and Methods:Whole cells of Escherichia coli ATCC 11303 were induced for L-tryptophan synthase by addition of indole to the growth medium and bacterial cells harvested from the growth medium were used as biocatalysts in the production medium. Conditions of the production medium were optimized and Iranian cane and beet molasses were processed by solvent extraction with ethanol and n-butanol and used as L-serine sources of the production medium. Amount of L-tryptophan and theoretical yield of L-tryptophan production were determined by High Performance Liquid Chromatography and by a colorimetrical method on the basis of the remaining indole assay, respectively.Results:L-tryptophan production increased by 15 folds, when indole was used as an inducer. L-tryptophan was produced from processed Iranian beet molasses in satisfactory amounts (0.53 mM) and no exogenous pyridoxal phosphate was required as a cofactor under our experimental conditions.Conclusions:The obtained results proved that Iranian beet molasses include significant amounts of L-serine that makes them a suitable substitution for L-serine. Findings of the present study give impetus to use of Iranian beet molasses for cost-effective L-Trp production in the amino acid industry.

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Functional genomics via metabolic footprinting: monitoring metabolite secretion by Escherichia coli tryptophan metabolism mutants using FT–IR and direct injection electrospray mass spectrometry

et al. 2003

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We sought to test the hypothesis that mutant bacterial strains could be discriminated from each other on the basis of the metabolites they secrete into the medium (their ‘metabolic footprint’), using two methods of ‘global’ metabolite analysis (FT–IR and direct injection electrospray mass spectrometry). The biological system used was based on a published study of Escherichia coli tryptophan mutants that had been analysed and discriminated by Yanofsky and colleagues using transcriptome analysis. Wild-type strains supplemented with tryptophan or analogues could be discriminated from controls using FT–IR of 24 h broths, as could each of the mutant strains in both minimal and supplemented media. Direct injection electrospray mass spectrometry with unit mass resolution could also be used to discriminate the strains from each other, and had the advantage that the discrimination required the use of just two or three masses in each case. These were determined via a genetic algorithm. Both methods are rapid, reagentless, reproducible and cheap, and might beneficially be extended to the analysis of gene knockout libraries.

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Tryptophan biosynthesis and production of other related compounds from indolepyruvic acid by mixed ruminal bacteria, protozoa, and their mixture in vitro.

Cited by 10 publications

References 23 publications

Tryptophan Biosynthesis and Production of Other Related Compounds from Indole and L-Serine by Mixed Ruminal Bacteria, Protozoa, and Their Mixture In Vitro

Tryptophan Biosynthesis and Production of Other Related Compounds from Indole and L-Serine by Mixed Ruminal Bacteria, Protozoa, and Their Mixture In Vitro

Optimization of L-Tryptophan Biosynthesis From L-Serine of Processed Iranian Beet and Cane Molasses and Indole by Induced Escherichia coli ATCC 11303 Cells

Functional genomics via metabolic footprinting: monitoring metabolite secretion by Escherichia coli tryptophan metabolism mutants using FT–IR and direct injection electrospray mass spectrometry

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