Methionine production by fermentation

Indian Institute of Technology Delhi, New Dilli, NCT, India
Biotechnology Advances (Impact Factor: 9.02). 02/2005; 23(1):41-61. DOI: 10.1016/j.biotechadv.2004.08.005
Source: PubMed


Fermentation processes have been developed for producing most of the essential amino acids. Methionine is one exception. Although microbial production of methionine has been attempted, no commercial bioproduction exists. Here, we discuss the prospects of producing methionine by fermentation. A detailed account is given of methionine biosynthesis and its regulation in some potential producer microorganisms. Problems associated with isolation of methionine overproducing strains are discussed. Approaches to selecting microorganism having relaxed and complex regulatory control mechanisms for methionine biosynthesis are examined. The importance of fermentation media composition and culture conditions for methionine production is assessed and methods for recovering methionine from fermentation broth are considered.

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Available from: James Gomes
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    • "Selection for feedback-resistant mutants has yielded strains that excrete up to 240 mg methionine l 21 (Usuda & Kurahashi, 2005). Similar studies have been carried out in numerous other species (Kumar & Gomes, 2005); however, no commercially viable fermentation process has been implemented to date. "
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    ABSTRACT: Methionine is essential in all organisms, as it is both a proteinogenic amino acid and a component of the cofactor, S-adenosyl methionine. The metabolic pathway for its biosynthesis has been extensively characterized in Escherichia coli; however, it is becoming apparent that most bacterial species do not use the E. coli pathway. Instead, studies on other organisms and genome sequencing data are uncovering significant diversity in the enzymes and metabolic intermediates that are used for methionine biosynthesis. In this review, we have summarized the different biochemical strategies that are employed in the three key steps for methionine biosynthesis from homoserine (i.e. acylation, sulfurylation and methylation). We have surveyed the presence and absence of the various biosynthetic enzymes in 1,593 representative bacterial species, shedding light on the non-canonical nature of the E. coli pathway. We have also highlighted ways in which knowledge of methionine biosynthesis can be utilized for biotechnological applications. Finally, we have noted gaps in the current understanding of bacterial methionine biosynthesis. For example, we discuss the presence of one gene (metC) in a large number of species that appear to lack the gene encoding the enzyme for the preceding step in the pathway (metB), as it is understood in E. coli. Therefore, this review aims to move the focus away from E. coli, in order to better reflect the true diversity of bacterial pathways for methionine biosynthesis.
    Full-text · Article · Jun 2014 · Microbiology
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    • "Chemical synthesis produces a mixture of D-and L-methionine [3] whereas hydrolysis of proteins leads to a complex mixture from which methionine must be separated. Biologically active L-methionine can be produced either by enzymatic synthesis (bioconversion of precursors), or by submerged fermentation using microorganisms [3]. Because fermentation processes have been able to inexpensively provide many other amino acids, there is a significant interest in developing a microbial process for commercial production of methionine [4] [5]. "

    Full-text · Article · Jan 2014 · Advances in Microbiology
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    • "a Unless otherwise indicated, the precursor protein is from bovine milk b The one-letter amino acid codes were used c Lb., Lactobacillus usually deficient in an exclusively vegetable diet (Kumar and Gomes, 2005). Lysine-producing strains of Lb. plantarum were used as starter cultures for the nutritional improvement of ogi (Adebawo et al., 2000). "
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    ABSTRACT: Functional microorganisms and health benefits represent a binomial with great potential for fermented functional foods. The health benefits of fermented functional foods are expressed either directly through the interactions of ingested live microorganisms with the host (probiotic effect) or indirectly as the result of the ingestion of microbial metabolites synthesized during fermentation (biogenic effect). Since the importance of high viability for probiotic effect, two major options are currently pursued for improving it--to enhance bacterial stress response and to use alternative products for incorporating probiotics (e.g., ice cream, cheeses, cereals, fruit juices, vegetables, and soy beans). Further, it seems that quorum sensing signal molecules released by probiotics may interact with human epithelial cells from intestine thus modulating several physiological functions. Under optimal processing conditions, functional microorganisms contribute to food functionality through their enzyme portfolio and the release of metabolites. Overproduction of free amino acids and vitamins are two classical examples. Besides, bioactive compounds (e.g., peptides, γ-amino butyric acid, and conjugated linoleic acid) may be released during food processing above the physiological threshold and they may exert various in vivo health benefits. Functional microorganisms are even more used in novel strategies for decreasing phenomenon of food intolerance (e.g., gluten intolerance) and allergy. By a critical approach, this review will aim at showing the potential of functional microorganisms for the quality of functional foods.
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