Yeast extract and terpenes
Metabolic Engineering of Yeast for the Production of Plant Secondary Metabolites
Metabolic engineering is the alteration of cellular activities by the manipulation of enzymatic, transport, and regulatory functions of the cell by using recombinant DNA technology. Difficulty to obtain sufficient amounts of desired plant, slow growth of plants, varying composition and concentration depending on the geographical position and climatic conditions, and low yield of isolated compounds are some of the limitations of commercial extraction of these compounds by using plant as a single resource. On the other hand, some of the bottlenecks of chemical synthesis may include higher energy requirements, pollution, low reaction load due to unwanted chemical reactions, cost and availability of starting materials, and cost of separating and purifying the end products. For the metabolic engineering of plant secondary metabolites, it is necessary to know the biosynthetic pathways of those compounds, rate-limiting steps, and enzymes involved
The acetate/mevalonate pathway for the formation of IPP, the basic five-carbon unit of terpenoid biosynthesis. Synthesis of each IPP unit requires three molecules of acetyl-CoA
The major subclasses of terpenoids are biosynthesized from the basic five-carbon unit, IPP, and from the initial prenyl (allylic) diphosphate, dimethylallyl diphosphate, which is formed by isomerization of IPP. In reactions catalyzed by prenyltransferases, ...
Production of Flavonoids in Yeast
Flavonoids are produced in yeast by expressing phenylpropanoid pathway. Many flavonoid compounds are successfully produced in yeast by cloning genes from different plant species and microorganisms. Flavanone has been successfully produced in yeast by expressing phenyl ammonia lyase (PAL), cinnamate-4-hydroxylase (C4H), 4-coumarate-CoA (4CL), and chalcone synthase (CHS) genes.[73] Flavones have also been produced in flavanone-producing recombinant yeast by expressing flavone synthase I (FSI) and flavone synthase II (FSII) genes.
Production of terpenoids in yeast
The biosynthesis of terpenes in higher plant cells shows two entirely separate enzymatic pathways: mevalonic acid pathway (MVA) and methylerythritol 4-phosphate pathway [Figure 5]. In yeast, only MVA pathway is involved in the biosynthesis of ergosterol as the major end product.
Production of monoterpenoids in yeast
Oswald et al.[74] engineered yeasts to produce monoterpenoids by expressing linalool synthase and geraniol synthase genes, and yeast strains successfully produced those monoterpenoid alcohols by using internal geranyl pyrophosphate.
Production of sesquiterpenes in yeast
Sesquiterpenes are the most diverse class of isoprenoids; some of them are interesting and extremely important compounds in human health because of their potent anticancer, antitumor, cytotoxic, antiviral, and antibiotic properties. Amorphadiene, a sesquiterpene of the antimalarial drug artemisin, is synthesized by the cyclization of farnesyl pyrophosphate (FPP). Ro et al.[75] used Saccharomyces cerevisiae to produce high amount of artemisinic acid using an engineered mevalonate pathway, amorphadiene synthase, and a novel cytochrome P450 monooxygenase from Artemisia annua.
Production of carotenoids in yeast
Schizosaccharomyces pombe, a noncarotenogenic yeast, is not able to produce any carotenoids but it synthesizes ergosterol from FPP through the sterol biosynthetic pathway. Gunel et al.[76] cloned a gene encoding geranyl geranyl pyrophosphate synthase from bell pepper (C. annum) in S. pombe and successfully redirected carbon flow from the terpenoid pathway leading to ergosterol formation toward the production of carotenoid through the heterologous expression of carotenoid biosynthetic gene in a noncarotenogenic yeast, S. pombe.
Production of plant-origin alkaloids in yeast
Geerlings et al.[77] expressed genes coding for strictosidine synthase and strictosidine glucosidase enzymes from medicinal plant C. roseus in S. cerevisiae and successfully produced cathenamine from tryptamine and secologanin by functionally expressing those two enzymes in yeast. Along with the increased knowledge on biosynthetic pathways of many plant secondary metabolites, utilities of different yeast species should be investigated in future for the efficient microbial production of such compounds. Overcoming rate-limiting steps, reducing flux through competitive pathways, reducing catabolism, and over expression of regulatory genes are some of the strategies that can be used for increased secondary metabolites production through metabolic engineering.
Conclusion
In future, metabolic engineering and biotechnological approaches can be used as an alternative production system to overcome the limited availability of biologically active, commercially valuable, and medicinally important plant secondary metabolite compounds. Advances in biotechniques, particularly methods for culturing plant cell cultures, should provide new means for the commercial processing of even rare plants and the chemicals they provide. The advantage of this method is that it can ultimately provide a continuous, reliable source of natural products. The major advantage of the cell cultures includes synthesis of bioactive secondary metabolites, running in controlled environment, independently from climate and soil conditions. The use of in vitro plant cell culture for the production of chemicals and pharmaceuticals has made great strides building on advances in plant science. The increased use of genetic tools and an emerging picture of the structure and regulation of pathways for secondary metabolism will provide the basis for the production of commercially acceptable levels of product. Knowledge of biosynthetic pathways of desired phytochemicals in plants and in cultures is often still in its infancy, and consequently strategies needed to develop an information based on a cellular and molecular level. These results show that in vitro plant cell cultures have potential for commercial production of secondary metabolites. The introduction of newer techniques of molecular biology, so as to produce transgenic cultures and to effect the expression and regulation of biosynthetic pathways, is also likely to be a significant step toward making cell cultures more generally applicable to the commercial production of secondary metabolites. The commercial values of plant secondary metabolites have been the main impetus for the enormous research effort put into understanding and manipulating their biosynthesis using various chemical, physiological, and biotechnological pathways. In vitro propagation of medicinal plants with enriched bioactive principles and cell culture methodologies for selective metabolite production is found to be highly useful for commercial production of medicinally important compounds. The increased use of plant cell culture systems in recent years is perhaps due to an improved understanding of the secondary metabolite pathway in economically important plants. Advances in plant cell cultures could provide new means for the cost-effective, commercial production of even rare or exotic plants, their cells, and the chemicals that they will produce. Knowledge of the biosynthetic pathways of desired compounds in plants as well as of cultures is often still rudimentary, and strategies are consequently needed to develop information based on a cellular and molecular level. A key to the evaluation of strategies to improve productivity is the realization that all the problems must be seen in a holistic context. At any rate, substantial progress in improving secondary metabolite production from plant cell cultures has been made within last few years. These new technologies will serve to extend and enhance the continued usefulness of higher plants as renewable sources of chemicals, especially medicinal compounds. We hope that a continuation and intensification efforts in this field will lead to controllable and successful biotechnological production of specific, valuable, and as yet unknown plant chemicals.
Chemical analysis of yeast extract
Vitamins
mg ⁄100g dry weight
Carbohydrates
mg ⁄100g dry weight
Amino acid
mg ⁄100g dry weight
Arginine 1.99
Carbohydrates 23.2
Vit.B1 2.23
Vit.B2 1.33
Vit.B6 1.25
Vit B12 0.15
Histidine 2.63
Glucose 13.33
Isoleucine 2.31
leucine 3.09
Lysine 2.95
Thimain 2.71
Methionine 0.72
Riboflavin 4.96
2.01 Insitol 0.26
Phenylalanine
Threonine 2.09
Biotin 0.09
Tryptophan 0.45
Nicotinic acid 39.88
Valine 2.19
Panthothenic acid 19.56
Glutamic acid 2.00
Pamino benzoic acid 9.23
Serine 1.59
Folic acid 4.36
Aspartic acid 1.33
Pyridoxine 2.90
Cystine 0.23
Proline 1.53
Tyrosine 1.49
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3283951/
I see yeast extract on a lot of big name supplements, does the actual extract help or is it the carbs and vitamines ect. that are the real key.
In other words is it best to supplement with the extract.
Is it of any value other than what is listed above?
Or just make sure you get the carbs and vitamins,amino's,sugars ect.
Metabolic Engineering of Yeast for the Production of Plant Secondary Metabolites
Metabolic engineering is the alteration of cellular activities by the manipulation of enzymatic, transport, and regulatory functions of the cell by using recombinant DNA technology. Difficulty to obtain sufficient amounts of desired plant, slow growth of plants, varying composition and concentration depending on the geographical position and climatic conditions, and low yield of isolated compounds are some of the limitations of commercial extraction of these compounds by using plant as a single resource. On the other hand, some of the bottlenecks of chemical synthesis may include higher energy requirements, pollution, low reaction load due to unwanted chemical reactions, cost and availability of starting materials, and cost of separating and purifying the end products. For the metabolic engineering of plant secondary metabolites, it is necessary to know the biosynthetic pathways of those compounds, rate-limiting steps, and enzymes involved
The acetate/mevalonate pathway for the formation of IPP, the basic five-carbon unit of terpenoid biosynthesis. Synthesis of each IPP unit requires three molecules of acetyl-CoA
The major subclasses of terpenoids are biosynthesized from the basic five-carbon unit, IPP, and from the initial prenyl (allylic) diphosphate, dimethylallyl diphosphate, which is formed by isomerization of IPP. In reactions catalyzed by prenyltransferases, ...
Production of Flavonoids in Yeast
Flavonoids are produced in yeast by expressing phenylpropanoid pathway. Many flavonoid compounds are successfully produced in yeast by cloning genes from different plant species and microorganisms. Flavanone has been successfully produced in yeast by expressing phenyl ammonia lyase (PAL), cinnamate-4-hydroxylase (C4H), 4-coumarate-CoA (4CL), and chalcone synthase (CHS) genes.[73] Flavones have also been produced in flavanone-producing recombinant yeast by expressing flavone synthase I (FSI) and flavone synthase II (FSII) genes.
Production of terpenoids in yeast
The biosynthesis of terpenes in higher plant cells shows two entirely separate enzymatic pathways: mevalonic acid pathway (MVA) and methylerythritol 4-phosphate pathway [Figure 5]. In yeast, only MVA pathway is involved in the biosynthesis of ergosterol as the major end product.
Production of monoterpenoids in yeast
Oswald et al.[74] engineered yeasts to produce monoterpenoids by expressing linalool synthase and geraniol synthase genes, and yeast strains successfully produced those monoterpenoid alcohols by using internal geranyl pyrophosphate.
Production of sesquiterpenes in yeast
Sesquiterpenes are the most diverse class of isoprenoids; some of them are interesting and extremely important compounds in human health because of their potent anticancer, antitumor, cytotoxic, antiviral, and antibiotic properties. Amorphadiene, a sesquiterpene of the antimalarial drug artemisin, is synthesized by the cyclization of farnesyl pyrophosphate (FPP). Ro et al.[75] used Saccharomyces cerevisiae to produce high amount of artemisinic acid using an engineered mevalonate pathway, amorphadiene synthase, and a novel cytochrome P450 monooxygenase from Artemisia annua.
Production of carotenoids in yeast
Schizosaccharomyces pombe, a noncarotenogenic yeast, is not able to produce any carotenoids but it synthesizes ergosterol from FPP through the sterol biosynthetic pathway. Gunel et al.[76] cloned a gene encoding geranyl geranyl pyrophosphate synthase from bell pepper (C. annum) in S. pombe and successfully redirected carbon flow from the terpenoid pathway leading to ergosterol formation toward the production of carotenoid through the heterologous expression of carotenoid biosynthetic gene in a noncarotenogenic yeast, S. pombe.
Production of plant-origin alkaloids in yeast
Geerlings et al.[77] expressed genes coding for strictosidine synthase and strictosidine glucosidase enzymes from medicinal plant C. roseus in S. cerevisiae and successfully produced cathenamine from tryptamine and secologanin by functionally expressing those two enzymes in yeast. Along with the increased knowledge on biosynthetic pathways of many plant secondary metabolites, utilities of different yeast species should be investigated in future for the efficient microbial production of such compounds. Overcoming rate-limiting steps, reducing flux through competitive pathways, reducing catabolism, and over expression of regulatory genes are some of the strategies that can be used for increased secondary metabolites production through metabolic engineering.
Conclusion
In future, metabolic engineering and biotechnological approaches can be used as an alternative production system to overcome the limited availability of biologically active, commercially valuable, and medicinally important plant secondary metabolite compounds. Advances in biotechniques, particularly methods for culturing plant cell cultures, should provide new means for the commercial processing of even rare plants and the chemicals they provide. The advantage of this method is that it can ultimately provide a continuous, reliable source of natural products. The major advantage of the cell cultures includes synthesis of bioactive secondary metabolites, running in controlled environment, independently from climate and soil conditions. The use of in vitro plant cell culture for the production of chemicals and pharmaceuticals has made great strides building on advances in plant science. The increased use of genetic tools and an emerging picture of the structure and regulation of pathways for secondary metabolism will provide the basis for the production of commercially acceptable levels of product. Knowledge of biosynthetic pathways of desired phytochemicals in plants and in cultures is often still in its infancy, and consequently strategies needed to develop an information based on a cellular and molecular level. These results show that in vitro plant cell cultures have potential for commercial production of secondary metabolites. The introduction of newer techniques of molecular biology, so as to produce transgenic cultures and to effect the expression and regulation of biosynthetic pathways, is also likely to be a significant step toward making cell cultures more generally applicable to the commercial production of secondary metabolites. The commercial values of plant secondary metabolites have been the main impetus for the enormous research effort put into understanding and manipulating their biosynthesis using various chemical, physiological, and biotechnological pathways. In vitro propagation of medicinal plants with enriched bioactive principles and cell culture methodologies for selective metabolite production is found to be highly useful for commercial production of medicinally important compounds. The increased use of plant cell culture systems in recent years is perhaps due to an improved understanding of the secondary metabolite pathway in economically important plants. Advances in plant cell cultures could provide new means for the cost-effective, commercial production of even rare or exotic plants, their cells, and the chemicals that they will produce. Knowledge of the biosynthetic pathways of desired compounds in plants as well as of cultures is often still rudimentary, and strategies are consequently needed to develop information based on a cellular and molecular level. A key to the evaluation of strategies to improve productivity is the realization that all the problems must be seen in a holistic context. At any rate, substantial progress in improving secondary metabolite production from plant cell cultures has been made within last few years. These new technologies will serve to extend and enhance the continued usefulness of higher plants as renewable sources of chemicals, especially medicinal compounds. We hope that a continuation and intensification efforts in this field will lead to controllable and successful biotechnological production of specific, valuable, and as yet unknown plant chemicals.
Chemical analysis of yeast extract
Vitamins
mg ⁄100g dry weight
Carbohydrates
mg ⁄100g dry weight
Amino acid
mg ⁄100g dry weight
Arginine 1.99
Carbohydrates 23.2
Vit.B1 2.23
Vit.B2 1.33
Vit.B6 1.25
Vit B12 0.15
Histidine 2.63
Glucose 13.33
Isoleucine 2.31
leucine 3.09
Lysine 2.95
Thimain 2.71
Methionine 0.72
Riboflavin 4.96
2.01 Insitol 0.26
Phenylalanine
Threonine 2.09
Biotin 0.09
Tryptophan 0.45
Nicotinic acid 39.88
Valine 2.19
Panthothenic acid 19.56
Glutamic acid 2.00
Pamino benzoic acid 9.23
Serine 1.59
Folic acid 4.36
Aspartic acid 1.33
Pyridoxine 2.90
Cystine 0.23
Proline 1.53
Tyrosine 1.49
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3283951/
I see yeast extract on a lot of big name supplements, does the actual extract help or is it the carbs and vitamines ect. that are the real key.
In other words is it best to supplement with the extract.
Is it of any value other than what is listed above?
Or just make sure you get the carbs and vitamins,amino's,sugars ect.
