scholarly journals Organic Wastes as Feedstocks for Non-Conventional Yeast-Based Bioprocesses

2019 ◽  
Vol 7 (8) ◽  
pp. 229 ◽  
Author(s):  
Diem T. Hoang Do ◽  
Chrispian W. Theron ◽  
Patrick Fickers
Keyword(s):  
Carbon Sources ◽  
Value Added ◽  
Building Blocks ◽  
Organic Wastes ◽  
Cell Factory ◽  
Microbial Cell Factories ◽  
Cell Factories ◽  
Alternative Feedstocks ◽  
Global Population ◽  
By Products

Non-conventional yeasts are efficient cell factories for the synthesis of value-added compounds such as recombinant proteins, intracellular metabolites, and/or metabolic by-products. Most bioprocess, however, are still designed to use pure, ideal sugars, especially glucose. In the quest for the development of more sustainable processes amid concerns over the future availability of resources for the ever-growing global population, the utilization of organic wastes or industrial by-products as feedstocks to support cell growth is a crucial approach. Indeed, vast amounts of industrial and commercial waste simultaneously represent an environmental burden and an important reservoir for recyclable or reusable material. These alternative feedstocks can provide microbial cell factories with the required metabolic building blocks and energy to synthesize value-added compounds, further representing a potential means of reduction of process costs as well. This review highlights recent strategies in this regard, encompassing knowledge on catabolic pathways and metabolic engineering solutions developed to endow cells with the required metabolic capabilities, and the connection of these to the synthesis of value-added compounds. This review focuses primarily, but not exclusively, on Yarrowia lipolytica as a yeast cell factory, owing to its broad range of naturally metabolizable carbon sources, together with its popularity as a non-conventional yeast.

scholarly journals Engineering Microbes to Bio-Upcycle Polyethylene Terephthalate

2021 ◽  
Vol 9 ◽  
Author(s):  
Lakshika Dissanayake ◽  
Lahiru N. Jayakody
Keyword(s):  
Polyethylene Terephthalate ◽  
Metabolic Pathways ◽  
Aquatic Ecosystems ◽  
Value Added ◽  
Building Blocks ◽  
Chemical Recycling ◽  
Plastic Pollution ◽  
Microbial Cell Factories ◽  
Cell Factories ◽  
Value Added Products

Polyethylene terephthalate (PET) is globally the largest produced aromatic polyester with an annual production exceeding 50 million metric tons. PET can be mechanically and chemically recycled; however, the extra costs in chemical recycling are not justified when converting PET back to the original polymer, which leads to less than 30% of PET produced annually to be recycled. Hence, waste PET massively contributes to plastic pollution and damaging the terrestrial and aquatic ecosystems. The global energy and environmental concerns with PET highlight a clear need for technologies in PET “upcycling,” the creation of higher-value products from reclaimed PET. Several microbes that degrade PET and corresponding PET hydrolase enzymes have been successfully identified. The characterization and engineering of these enzymes to selectively depolymerize PET into original monomers such as terephthalic acid and ethylene glycol have been successful. Synthetic microbiology and metabolic engineering approaches enable the development of efficient microbial cell factories to convert PET-derived monomers into value-added products. In this mini-review, we present the recent progress of engineering microbes to produce higher-value chemical building blocks from waste PET using a wholly biological and a hybrid chemocatalytic–biological strategy. We also highlight the potent metabolic pathways to bio-upcycle PET into high-value biotransformed molecules. The new synthetic microbes will help establish the circular materials economy, alleviate the adverse energy and environmental impacts of PET, and provide market incentives for PET reclamation.

scholarly journals Methane monooxygenases: central enzymes in methanotrophy with promising biotechnological applications

2021 ◽  
Vol 37 (4) ◽  
Author(s):  
May L. K. Khider ◽  
Trygve Brautaset ◽  
Marta Irla
Keyword(s):  
Animal Feed ◽  
Bacterial Species ◽  
Carbon Sources ◽  
Value Added ◽  
Anthropogenic Pollution ◽  
Functional Expression ◽  
Ongoing Research ◽  
Microbial Cell Factories ◽  
Cell Factories ◽  
Food Market

AbstractWorldwide, the use of methane is limited to generating power, electricity, heating, and for production of chemicals. We believe this valuable gas can be employed more widely. Here we review the possibility of using methane as a feedstock for biotechnological processes based on the application of synthetic methanotrophs. Methane monooxygenase (MMO) enables aerobic methanotrophs to utilize methane as a sole carbon and energy source, in contrast to industrial microorganisms that grow on carbon sources, such as sugar cane, which directly compete with the food market. However, naturally occurring methanotrophs have proven to be difficult to manipulate genetically and their current industrial use is limited to generating animal feed biomass. Shifting the focus from genetic engineering of methanotrophs, towards introducing metabolic pathways for methane utilization in familiar industrial microorganisms, may lead to construction of efficient and economically feasible microbial cell factories. The applications of a technology for MMO production are not limited to methane-based industrial synthesis of fuels and value-added products, but are also of interest in bioremediation where mitigating anthropogenic pollution is an increasingly relevant issue. Published research on successful functional expression of MMO does not exist, but several attempts provide promising future perspectives and a few recent patents indicate that there is an ongoing research in this field. Combining the knowledge on genetics and metabolism of methanotrophy with tools for functional heterologous expression of MMO-encoding genes in non-methanotrophic bacterial species, is a key step for construction of synthetic methanotrophs that holds a great biotechnological potential.

Metabolic engineering of glycosylated polyketide biosynthesis

2018 ◽  
Vol 2 (3) ◽  
pp. 389-403 ◽  
Author(s):  
Ramesh Prasad Pandey ◽  
Prakash Parajuli ◽  
Jae Kyung Sohng
Keyword(s):  
Natural Products ◽  
Metabolic Engineering ◽  
Value Added ◽  
Chemical Diversity ◽  
Yeast Cells ◽  
Microbial Cell Factories ◽  
Cell Factories ◽  
Modification Method ◽  
Post Modification ◽  
Microbial Biosynthesis

Microbial cell factories are extensively used for the biosynthesis of value-added chemicals, biopharmaceuticals, and biofuels. Microbial biosynthesis is also realistic for the production of heterologous molecules including complex natural products of plant and microbial origin. Glycosylation is a well-known post-modification method to engineer sugar-functionalized natural products. It is of particular interest to chemical biologists to increase chemical diversity of molecules. Employing the state-of-the-art systems and synthetic biology tools, a range of small to complex glycosylated natural products have been produced from microbes using a simple and sustainable fermentation approach. In this context, this review covers recent notable metabolic engineering approaches used for the biosynthesis of glycosylated plant and microbial polyketides in different microorganisms. This review article is broadly divided into two major parts. The first part is focused on the biosynthesis of glycosylated plant polyketides in prokaryotes and yeast cells, while the second part is focused on the generation of glycosylated microbial polyketides in actinomycetes.

scholarly journals A Case of Adaptive Laboratory Evolution (ALE): Biodegradation of Furfural by Pseudomonas pseudoalcaligenes CECT 5344

Genes ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 499 ◽  
Author(s):  
M. Isabel Igeño ◽  
Daniel Macias ◽  
Rafael Blasco
Keyword(s):  
Carbon Sources ◽  
Value Added ◽  
Cost Effective ◽  
Building Blocks ◽  
Yeast Fermentation ◽  
Adaptive Laboratory Evolution ◽  
Pseudomonas Pseudoalcaligenes ◽  
Hydroxymethyl Furfural ◽  
Double Recombination ◽  
Lag Period

Pseudomonas pseudoalcaligenes CECT 5344 is a bacterium able to assimilate cyanide as a nitrogen source at alkaline pH. Genome sequencing of this strain allowed the detection of genes related to the utilization of furfurals as a carbon and energy source. Furfural and 5-(hydroxymethyl) furfural (HMF) are byproducts of sugars production during the hydrolysis of lignocellulosic biomass. Since they inhibit the yeast fermentation to obtain bioethanol from sugars, the biodegradation of these compounds has attracted certain scientific interest. P. pseudoalcaligenes was able to use furfuryl alcohol, furfural and furoic acid as carbon sources, but after a lag period of several days. Once adapted, the evolved strain (R1D) did not show any more prolonged lag phases. The transcriptomic analysis (RNA-seq) of R1D revealed a non-conservative punctual mutation (L261R) in BN5_2307, a member of the AraC family of activators, modifying the charge of the HTH region of the protein. The inactivation of the mutated gene in the evolved strain by double recombination reverted to the original phenotype. Although the bacterium did not assimilate HMF, it transformed it into value-added building blocks for the chemical industry. These results could be used to improve the production of cost-effective second-generation biofuels from agricultural wastes.

Genome-scale metabolic modeling to provide insight into the production of storage compounds during feast–famine cycles of activated sludge

2013 ◽  
Vol 67 (3) ◽  
pp. 469-476 ◽  
Author(s):  
Mohammad Tajparast ◽  
Dominic Frigon
Keyword(s):  
Activated Sludge ◽  
Carbon Sources ◽  
Value Added ◽  
Growth Cycle ◽  
Glycogen Accumulation ◽  
Storage Compounds ◽  
Metabolic Models ◽  
K 12 ◽  
Genome Scale ◽  
By Products

Studying storage metabolism during feast–famine cycles of activated sludge treatment systems provides profound insight in terms of both operational issues (e.g., foaming and bulking) and process optimization for the production of value added by-products (e.g., bioplastics). We examined the storage metabolism (including poly-β-hydroxybutyrate [PHB], glycogen, and triacylglycerols [TAGs]) during feast–famine cycles using two genome-scale metabolic models: Rhodococcus jostii RHA1 (iMT1174) and Escherichia coli K-12 (iAF1260) for growth on glucose, acetate, and succinate. The goal was to develop the proper objective function (OF) for the prediction of the main storage compound produced in activated sludge for given feast–famine cycle conditions. For the flux balance analysis, combinations of three OFs were tested. For all of them, the main OF was to maximize growth rates. Two additional sub-OFs were used: (1) minimization of biochemical fluxes, and (2) minimization of metabolic adjustments (MoMA) between the feast and famine periods. All (sub-)OFs predicted identical substrate–storage associations for the feast–famine growth of the above-mentioned metabolic models on a given substrate when glucose and acetate were set as sole carbon sources (i.e., glucose–glycogen and acetate–PHB), in agreement with experimental observations. However, in the case of succinate as substrate, the predictions depended on the network structure of the metabolic models such that the E. coli model predicted glycogen accumulation and the R. jostii model predicted PHB accumulation. While the accumulation of both PHB and glycogen was observed experimentally, PHB showed higher dynamics during an activated sludge feast–famine growth cycle with succinate as substrate. These results suggest that new modeling insights between metabolic predictions and population ecology will be necessary to properly predict metabolisms likely to emerge within the niches of activated sludge communities. Nonetheless, we believe that the development of this approach will help guide the optimization of the production of storage compounds as valuable by-products of wastewater treatment.

scholarly journals A common approach for absolute quantification of short chain CoA thioesters in industrially relevant gram-positive and gram-negative prokaryotic and eukaryotic microbes

2020 ◽  
Author(s):  
Lars Gläser ◽  
Martin Kuhl ◽  
Sofija Jovanovic ◽  
Michel Fritz ◽  
Bastian Vögeli ◽  
...  
Keyword(s):  
Building Blocks ◽  
Absolute Quantification ◽  
Microbial Cell ◽  
Short Chain ◽  
Enzymatic Reactions ◽  
Gram Positive ◽  
Gram Negative ◽  
Microbial Cell Factories ◽  
Cell Factories ◽  
Coa Thioesters

Abstract Background: Thioesters of coenzyme A participate in 5% of all enzymatic reactions and at least one third of all cellular carbon is typically metabolized through a CoA thioester. In microbial cell factories, they function as building blocks for products of recognized commercial value, including natural products such as polyketides, polyunsaturated fatty acids, biofuels, and biopolymers. A core spectrum of approximately 5 – 10 short chain thioesters is present in many microbes, as inferred from their genomic repertoire. The relevance these metabolites explains the high interest to trace and quantify them in microbial cells.Results: Here, we describe a common workflow for extraction and absolute quantification of short chain CoA thioesters in different gram-positive and gram-negative bacteria and eukaryotic yeast, i.e. Corynebacterium glutamicum, Streptomyces albus, Pseudomonas putida, and Yarrowia lipolytica. The approach detected CoA thioesters down to the level of 40 attomole and exhibited high precision and reproducibility for all microbes as shown by principal component analysis. Furthermore, it provided interesting insights into microbial CoA-spectra. A succinyl-CoA synthase defective mutant of C. glutamicum, exhibited an unaffected level of succinyl-CoA, which indicated a complete compensation of the l-lysine pathway to bypass the disrupted TCA cycle. Methylmalonyl-CoA, an important building block of high-value polyketides, was identified as dominant CoA thioester in the microbe. S. albus revealed a more than 10,000-fold difference in the abundance of intracellular CoA thioesters. A recombinant strain of S. albus, which produced different derivatives of the antituberculosis polyketide pamamycin, revealed a significant depletion of CoA thioesters of the ethylmalonyl CoA pathway, influencing product level and spectrum. Conclusions: The high relevance of short chain CoA thioesters to synthetize industrial products and the interesting insights gained from the examples shown in this work, suggest analyzing these metabolites in microbial cell factories more routinely than done so far. Due to its broad application range, the developed approach appears useful to be applied this purpose. Hereby, the possibility to use on single protocol promises to facilitate automatized efforts, which rely on standardized workflows.

scholarly journals Modular, synthetic chromosomes as new tools for large scale engineering of metabolism

2021 ◽  
Author(s):  
Eline Postma ◽  
Else-Jasmijn Hassing ◽  
Venda Mangkusaputra ◽  
Jordi Geelhoed ◽  
Pilar de la Torre ◽  
...  
Keyword(s):  
Copy Number ◽  
Large Scale ◽  
Metabolic Networks ◽  
De Novo ◽  
Microbial Cell ◽  
Cell Factory ◽  
Microbial Cell Factory ◽  
Microbial Cell Factories ◽  
Cell Factories

The construction of powerful cell factories requires intensive genetic engineering for the addition of new functionalities and the remodeling of native pathways and processes. The present study demonstrates the feasibility of extensive genome reprogramming using modular, specialized de novo-assembled neochromosomes in yeast. The in vivo assembly of linear and circular neochromosomes, carrying 20 native and 21 heterologous genes, enabled the first de novo production in a microbial cell factory of anthocyanins, plant compounds with a broad range pharmacological properties. Turned into exclusive expression platforms for heterologous and essential metabolic routes, the neochromosomes mimic native chromosomes regarding mitotic and genetic stability, copy number, harmlessness for the host and editability by CRISPR/Cas9. This study paves the way for future microbial cell factories with modular genomes in which core metabolic networks, localized on satellite, specialized neochromosomes can be swapped for alternative configurations and serve as landing pads for the addition of functionalities.

scholarly journals Synthesizing ginsenoside Rh2 in Saccharomyces cerevisiae cell factory at high-efficiency

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Pingping Wang ◽  
Wei Wei ◽  
Wei Ye ◽  
Xiaodong Li ◽  
Wenfang Zhao ◽  
...  
Keyword(s):  
Yeast Cell ◽  
Batch Fermentation ◽  
Cell Factory ◽  
Ginsenoside Rh2 ◽  
Fed Batch ◽  
Microbial Cell Factories ◽  
Cell Factories ◽  
Fed Batch Fermentation ◽  
Shake Flasks ◽  
Produce Plant

AbstractSynthetic biology approach has been frequently applied to produce plant rare bioactive compounds in microbial cell factories by fermentation. However, to reach an ideal manufactural efficiency, it is necessary to optimize the microbial cell factories systemically by boosting sufficient carbon flux to the precursor synthesis and tuning the expression level and efficiency of key bioparts related to the synthetic pathway. We previously developed a yeast cell factory to produce ginsenoside Rh2 from glucose. However, the ginsenoside Rh2 yield was too low for commercialization due to the low supply of the ginsenoside aglycone protopanaxadiol (PPD) and poor performance of the key UDP-glycosyltransferase (UGT) (biopart UGTPg45) in the final step of the biosynthetic pathway. In the present study, we constructed a PPD-producing chassis via modular engineering of the mevalonic acid pathway and optimization of P450 expression levels. The new yeast chassis could produce 529.0 mg/L of PPD in shake flasks and 11.02 g/L in 10 L fed-batch fermentation. Based on this high PPD-producing chassis, we established a series of cell factories to produce ginsenoside Rh2, which we optimized by improving the C3–OH glycosylation efficiency. We increased the copy number of UGTPg45, and engineered its promoter to increase expression levels. In addition, we screened for more efficient and compatible UGT bioparts from other plant species and mutants originating from the direct evolution of UGTPg45. Combining all engineered strategies, we built a yeast cell factory with the greatest ginsenoside Rh2 production reported to date, 179.3 mg/L in shake flasks and 2.25 g/L in 10 L fed-batch fermentation. The results set up a successful example for improving yeast cell factories to produce plant rare natural products, especially the glycosylated ones.

scholarly journals Navigating the Valley of Death: Perceptions of Industry and Academia on Production Platforms and Opportunities

2020 ◽  
Author(s):  
Linde FC Kampers ◽  
Enrique Asin Garcia ◽  
Peter J Schaap ◽  
Annemarie Wagemakers ◽  
Vitor AP Martins dos Santos
Keyword(s):  
Industrial Applications ◽  
Third Party ◽  
Cell Factory ◽  
Microbial Cell Factories ◽  
Cell Factories ◽  
Start Up ◽  
Industrial Performance ◽  
Research Choices ◽  
Depth Interviews ◽  
Valley Of Death

AbstractRational lifestyle engineering using computational methods and synthetic biology has made it possible to genetically improve industrial performance of microbial cell factories for the production of a range of biobased chemicals. However, only an estimated 1 in 5,000 to 10,000 innovations make it through the Valley of Death to market implementation.To gain in-depth insights into the views of industry and academia on key bottlenecks and opportunities to reach market implementation, a qualitative and exploratory study was performed by conducting 12 in depth interviews with 8 industrial and 4 academic participants. The characteristics that any cell factory must have were schematically listed, and commonly recognised opportunities were identified.We found that academics are limited by only technical factors in their research, while industry is restricted in their research choices and flexibility by a series of technical, sector dependent and social factors. This leads to a misalignment of interest of academics and funding industrial partners, often resulting in miscommunication. Although both are of the opinion that academia must perform curiosity-driven research to find innovative solutions, there is a certain pressure to aim for short-term industrial applications. All these factors add up to the Valley of Death; the gap between development and market implementation.A third party, in the form of start-up companies, could be the answer to bridging the Valley of Death.

Sign in / Sign up

Export Citation Format

Share Document