| 1. |
- Adeboye, Peter, 1982, et al.
(författare)
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A coniferyl aldehyde dehydrogenase gene from Pseudomonas sp. strain HR199 enhances the conversion of coniferyl aldehyde by Saccharomyces cerevisiae
- 2016
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Ingår i: Bioresource Technology. - : Elsevier BV. - 0960-8524 .- 1873-2976. ; 212:July 2016, s. 11-19
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Tidskriftsartikel (refereegranskat)abstract
- AbstractThe conversion of coniferyl aldehyde to cinnamic acids by Saccharomyces cerevisiae under aerobic growth conditions was previously observed. Bacteria such as Pseudomonas have been shown to harbor specialized enzymes for converting coniferyl aldehyde but no comparable enzymes have been identified in S. cerevisiae. CALDH from Pseudomonas was expressed in S. cerevisiae. An acetaldehyde dehydrogenase (Ald5) was also hypothesized to be actively involved in the conversion of coniferyl aldehyde under aerobic growth conditions in S. cerevisiae. In a second S. cerevisiae strain, the acetaldehyde dehydrogenase (ALD5) was deleted. A prototrophic control strain was also engineered. The engineered S. cerevisiae strains were cultivated in the presence of 1.1 mM coniferyl aldehyde under aerobic condition in bioreactors. The results confirmed that expression of CALDH increased endogenous conversion of coniferyl aldehyde in S. cerevisiae and ALD5 is actively involved with the conversion of coniferyl aldehyde in S. cerevisiae.
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| 2. |
- Adeboye, Peter, 1982, et al.
(författare)
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ALD5, PAD1, ATF1 and ATF2 facilitate the catabolism of coniferyl aldehyde, ferulic acid and p-coumaric acid in Saccharomyces cerevisiae
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- The ability of Saccharomyces cerevisiae to catabolize phenolic compounds remains to be fully elucidated. Conversion of coniferyl aldehyde, ferulic acid and p-coumaric acid by S. cerevisiae under aerobic conditions was previously reported. A conversion pathway was also proposed. In the present study, possible enzymes involved in the reported conversion were investigated. Aldehyde dehydrogenase Ald5, phenylacrylic acid decarboxylase Pad1, and alcohol acetyltransferases Atf1 and Atf2, were hypothesised to be involved. Corresponding genes for the four enzymes were overexpressed in a S. cerevisiae strain named APT_1. The ability of APT_1 to tolerate and convert the three phenolic compounds was tested. APT_1 was also compared to strains B_CALD heterologously expressing coniferyl aldehyde dehydrogenase from Pseudomonas, and an ald5 Delta strain, all previously reported. APT_1 exhibited the fastest conversion of coniferyl aldehyde, ferulic acid and p-coumaric acid. Using the intermediates and conversion products of each compound, the catabolic route of coniferyl aldehyde, ferulic acid and p-coumaric acid in S. cerevisiae was studied in greater detail.
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| 3. |
- Adeboye, Peter, 1982, et al.
(författare)
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Catabolism of coniferyl aldehyde, ferulic acid and p-coumaric acid by Saccharomyces cerevisiae yields less toxic products
- 2015
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Ingår i: Microbial Cell Factories. - : Springer Science and Business Media LLC. - 1475-2859. ; 14:1, s. 149-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Lignocellulosic substrates and pulping process streams are of increasing relevance to biorefineries for second generation biofuels and biochemical production. They are known to be rich in sugars and inhibitors such as phenolic compounds, organic acids and furaldehydes. Phenolic compounds are a group of aromatic compounds known to be inhibitory to fermentative organisms. It is known that inhibition of Sacchromyces cerevisiae varies among phenolic compounds and the yeast is capable of in situ catabolic conversion and metabolism of some phenolic compounds. In an approach to engineer a S. cerevisiae strain with higher tolerance to phenolic inhibitors, we selectively investigated the metabolic conversion and physiological effects of coniferyl aldehyde, ferulic acid, and p-coumaric acid in Saccharomyces cerevisiae. Aerobic batch cultivations were separately performed with each of the three phenolic compounds. Conversion of each of the phenolic compounds was observed on time-based qualitative analysis of the culture broth to monitor various intermediate and final metabolites. Result: Coniferyl aldehyde was rapidly converted within the first 24 h, while ferulic acid and p-coumaric acid were more slowly converted over a period of 72 h. The conversion of the three phenolic compounds was observed to involved several transient intermediates that were concurrently formed and converted to other phenolic products. Although there were several conversion products formed from coniferyl aldehyde, ferulic acid and p-coumaric acid, the conversion products profile from the three compounds were similar. On the physiology of Saccharomyces cerevisiae, the maximum specific growth rates of the yeast was not affected in the presence of coniferyl aldehyde or ferulic acid, but it was significantly reduced in the presence of p-coumaric acid. The biomass yields on glucose were reduced to 73 and 54 % of the control in the presence of coniferyl aldehyde and ferulic acid, respectively, biomass yield increased to 127 % of the control in the presence of p-coumaric acid. Coniferyl aldehyde, ferulic acid and p-coumaric acid and their conversion products were screened for inhibition, the conversion products were less inhibitory than coniferyl aldehyde, ferulic acid and p-coumaric acid, indicating that the conversion of the three compounds by Saccharomyces cerevisiae was also a detoxification process. Conclusion: We conclude that the conversion of coniferyl aldehyde, ferulic acid and p-coumaric acid into less inhibitory compounds is a form of stress response and a detoxification process. We hypothesize that all phenolic compounds are converted by Saccharomyces cerevisiae using the same metabolic process. We suggest that the enhancement of the ability of S. cerevisiae to convert toxic phenolic compounds into less inhibitory compounds is a potent route to developing a S. cerevisiae with superior tolerance to phenolic compounds.
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| 4. |
- Adeboye, Peter, 1982, et al.
(författare)
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Conversion of lignin-derived phenolic compounds by Saccharomyces cerevisiae
- 2014
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Ingår i: 36th Symposium on Biotechnology for Fuels and Chemicals, April 2-May 1st, Clearwater Beach, Florids, USA.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Lignin breakdown during biomass pretreatment releases a wide array of phenolic compounds in lignocellulose hydrolysates. Phenolic compounds, together with organic acids and furaldehydes are known to be inhibitors of microbial fermentation, thus limiting the efficient bioconversion of lignocellulose biomass. The goal of our study is to improve S. cerevisiae tolerance to phenolic compounds from lignocellulose hydrolysates and investigate its conversion capacities. In particular, we aimed i) to establish a correlation between the phenolic compounds structure and the effect on yeast growth, and ii) to investigate the conversion/detoxification products of selected representative compounds in order to provide strain engineering strategies for enhanced phenolics conversion.First, the effect on S. cerevisiae growth of 13 different phenolic compounds commonly found in lignocellulose hydrolysates was characterized. The compounds could be grouped in three clusters, according to their effect on lag phase duration, specific growth rate and cell density. Next, coniferyl aldehyde, p-coumaric acid and ferulic acid were chosen as representative compounds and their conversion product by S. cerevisiae in aerobic culture in bioreactor were identified and followed throughout the fermentation time. Understanding the effect of different phenolics on yeast and their conversion/ detoxification pathways is the first step not only in strain engineering for enhanced robustness, but also for designing new biorefinery concepts, where the bioconversion of lignin-derived aromatics could potentially be the source of new bio-based chemicals.
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| 5. |
- Adeboye, Peter, 1982, et al.
(författare)
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DETOXIFICATION AS A STRATEGY FOR DEVELOPING TOLERANCE IN Saccharomyces cerevisiae TO PHENOLIC COMPOUNDS
- 2014
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Ingår i: ISSY31: 31ST INTERNATIONAL SPECIALISED SYMPOSIUM ON YEAST.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Several phenolic compounds are formed as products of lignin breakdown during pretreatment of lignocellulosic biomass. These phenolic compounds are inhibitory to cell growth and function as biocatalysts in the production of second generation biofuels from degraded lignocellulosic biomass. Our research is focused on developing a Saccharomyces cerevisiae strain with improved resistance to phenolic compounds.As part of our study, we have focused on understanding the ability of S. cerevisiae to tolerate and convert phenolic compounds. We aim to understand the conversion mechanisms of phenolic compounds and adapt the knowledge to the engineering and use of S. cerevisiae on a biotechnological platform for bioethanol production and prospective, novel bio-based chemicals.We have investigated toxicity of various phenolic compounds against S. cerevisiae. Our results showed that phenolic compounds have varied toxicity against S. cerevisiae and the toxicity may be dependent on the structure of the compound involved. Under aerobic batch cultivation conditions, we have also studied the conversion of phenolic compounds by S. cerevisiae using coniferyl aldehyde, ferulic acid and p-coumaric acid as representative phenolic compounds. We compiled a list of conversion products of the three starting compounds under investigation and we proposed a possible conversion pathway, currently being investigated.In this talk, we present the proposed conversion pathway through which S. cerevisiae converts and detoxifies coniferyl aldehyde, ferulic acid and p-coumaric acid under aerobic cultivation condition.
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| 6. |
- Adeboye, Peter, 1982, et al.
(författare)
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Detoxification in Saccharomyces cerevisiae under phenolics stress
- 2013
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Ingår i: Conference on Physiology of Yeast and Filamentous Fungi.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Phenolic compounds, commonly found in woods hydrolysates and biorefinery side streams are products of lignin breakdown during wood pretreatment. They are formed alongside other products such as organic acids and furaldehydes. Phenolic compounds are widely varied and are known to be inhibitory to cell performance, thus making the efficient bioconversion of lignocellulose biomass to products such as bioethanol, a difficult task. As part of our aim at developing robust Saccharomyces cerevisiae for lignocellulosic fermentation, we have studied the interaction of S. cerevisiae cells with a selected subset of phenolic compounds. Three phenolic compounds; 3-methoxy-4-hydroxycinnamaldehyde, 3-methoxy-4-hydroxycinnamic acid and 4-hydroxycinnamic acid, were selected as representative phenolic compounds and model substrates. These substances represent phenolic aldehydes and acids thus providing an opportunity to closely compare different phenolic compound groups on the same –cinnamic- structural background, at the same time they offer a chance to probe the influence of side groups such as the methoxy group on the phenolic compound toxicity. Our studies show that when S. cerevisiae is exposed to the selected phenolic compounds, the cells carry out a process of detoxification that involves several conversion steps in transforming the toxic phenolic compounds to other phenolic compounds with much higher toxicity limits that confirm them to be less toxic. The toxicity limit here has been defined as the concentration at which S. cerevisiae performance in the presence of phenolic compounds is decreased to about 20% in comparison to the control in Yeast minimal Mineral medium without phenolic compounds. Furthermore, products and observed patterns of the conversion indicate that S. cerevisiae likely employs a common conversion route for the different phenolic compounds.
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| 7. |
- Adeboye, Peter, 1982, et al.
(författare)
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Fermentation of Biorefinery Streams
- 2011
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Ingår i: Yeast Retreat, Tjärnö, Sweden. August 15-17, 2011..
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Fermentation of biorefinery streams with S. cerevisiaePeter Adeboye, Eva Albers, Maurizio Bettiga and Lisbeth OlssonOur project aims at developing robust bioprocessing steps for the production of materials and energy from biomass, such as second‐generation ethanol by fermentation with Saccharomyces cerevisiae. We will concentrate on the fermentation of different biorefinery streams, generated by innovative biomass treatments. Fermentability of the substrates generated by the other project partner (Innventia AB) will be investigated, as well as maximum ethanol productivity and yield. Since lignocellulosic material can be a nutrient‐(especially nitrogen‐) poor and challenging substrate for the fermenting microorganism, the impact of different substrates on yeast metabolism will be investigated. Therefore, part of the research efforts of the project will be dedicated to fundamental studies on the effect of exposure to lignocellulose hydrolysate on energy metabolism, redox power homeostasis, cell integrity and viability. In addition, the effects of nutrient limitations will also be considered.
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| 8. |
- Adeboye, Peter, 1982, et al.
(författare)
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FERMENTATION OF BIOREFINERY STREAMS
- 2011
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Ingår i: PHD COURSE ON INDUSTRIAL BIOTECHNOLOGY FOR LIGNOCELLULOSE BASED PROCESSED.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Side streams generated from pulping processes have been of interest in the generation of alternative fuels due to the various wood compositional residues such as fermentable sugars leached out with it during the pulping process. These streams, due to their composition of fermentable sugars and other wood carbohydrate residues and the potential to ferment such carbohydrate residues in them for bioethanol production are in that case Biorefinery streams. Although these streams contain several growth inhibitory compounds such as furfural, numerous phenolic derivatives of lignin, several organic acids and are also known to be nutrient- (especially nitrogen-) poor thus constituting a challenging type of substrates for the fermenting microorganism, these traits however make for interesting grey areas for research on cell response to stress . Using biorefinery streams generated by innovative biomass treatments, our project aims at developing robust bioprocessing steps for the production of materials and energy, such as second-generation ethanol by fermentation with Saccharomyces cerevisiae. Fermentability of the substrates generated by the other project partner (Innventia AB) will be investigated, as well as maximum ethanol productivity and yield. The impact of different substrates on yeast metabolism will be investigated. Therefore, part of the research efforts of the project will be dedicated to fundamental studies on the effect of exposure to lignocellulose hydrolysate on energy metabolism, redox power homeostasis, cell integrity and viability. In addition, the effects of nutrient limitations will also be considered.
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| 9. |
- Adeboye, Peter, 1982, et al.
(författare)
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In situ conversion of phenolic compounds as a tool to phenolic tolerance development by S. cerevisiae
- 2015
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Phenolic compounds in hydrolysates are degradation products from the lignin component of wood. They are diverse in nature and they account for some of the inhibitory activities observed during lignocellulosic fermentation. S. cerevisiae possesses the ability to convert some phenolic compounds. We are currently studying the interaction between S. cerevisiae and selected phenolic compounds namely; coniferyl aldehyde, ferulic acid and p-coumaric acid to understand the ability of S. cerevisiae to convert the selected compounds. Preliminary results show that the three phenolic compounds are being converted into several other less inhibitory phenolic compounds common to the three compounds. We hypothesised a conversion route and engineered S. cerevisiae strains to test the hypothesis, the preliminary result shows faster conversion in an engineered strain.
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| 10. |
- Adeboye, Peter, 1982, et al.
(författare)
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The chemical nature of phenolic compounds determines their toxicity and induces distinct physiological responses in Saccharomyces cerevisiae in lignocellulosic hydrolysates
- 2014
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Ingår i: AMB Express. - : Springer Science and Business Media LLC. - 2191-0855. ; 4:46, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the severity of the inhibitory effects of 13 phenolic compounds usually found in spruce hydrolysates (4-hydroxy-3-methoxycinnamaldehyde, homovanilyl alcohol, vanillin, syringic acid, vanillic acid, gallic acid, dihydroferulic acid, p-coumaric acid, hydroquinone, ferulic acid, homovanillic acid, 4-hydroxybenzoic acid and vanillylidenacetone). The effects of the selected compounds on cell growth, biomass yield and ethanol yield were studied and the toxic concentration threshold was defined for each compound. Using Ethanol Red, the popular industrial strain of Saccharomyces cerevisiae, we found the most toxic compound to be 4-hydroxy-3-methoxycinnamaldehyde which inhibited growth at a concentration of 1.8 mM. We also observed that toxicity did not generally follow a trend based on the aldehyde, acid, ketone or alcohol classification of phenolic compounds, but rather that other structural properties such as additional functional groups attached to the compound may determine its toxicity. Three distinctive growth patterns that effectively clustered all the compounds involved in the screening into three categories. We suggest that the compounds have different cellular targets, and that. We suggest that the compounds have different cellular targets and inhibitory mechanisms in the cells, also compounds who share similar pattern on cell growth may have similar inhibitory effect and mechanisms of inhibition.
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