Designing industrial yeasts for the consolidated bioprocessing of starchy biomass to ethanol

Favaro, Lorenzo; Jooste, Tracey; Basaglia, Marina; Rose, Shaunita H.; Saayman, Maryna; Görgens, Johann F.; Casella, Sergio; Zyl, Willem H. van

doi:10.4161/bioe.22268

Cited by 42 publications

(33 citation statements)

References 28 publications

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“…The total consumption of starch and starch derivatives in 2011 was about 70 million tons, while the applications of starch in EU (30%) are mainly in the paper, cardboard, and corrugating industries. Other application are biofuels, cosmetics, dyes, pharmaceuticals, textiles, and biomaterials such as bioplastics . These starch‐based biopolymers have been produced in Europe (e.g., by BASF SE and Novamont S.p.A.) and the USA (e.g., by Cargill and National Starch).…”

Section: Bacterial Strains Producing Phas Can Be Modified To Use Diffmentioning

confidence: 99%

“…Other application are biofuels, cosmetics, dyes, pharmaceuticals, textiles, and biomaterials such as bioplastics. [77][78][79][80] These starch-based biopolymers have been produced in Europe (e.g., by BASF SE and Novamont S.p.A.) and the USA (e.g., by Cargill and National Starch). As the price of starch is lower than that of glucose, for a production scale of 100 000 tons of PHB per year, costs would decrease from 4.91 to 3.72 US$ per kg by using hydrolyzed corn starch (0.22 US$ per kg) in place of glucose (0.49 US$ per kg).…”

Section: Starchy Residuesmentioning

confidence: 99%

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Improving polyhydroxyalkanoate production from inexpensive carbon sources by genetic approaches: a review

Favaro

Basaglia

Casella

2018

Biofuels Bioprod Bioref

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137

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Polyhydroxyalkanoates (PHAs) are a family of biodegradable intracellular polyesters that a number of Eubacteria and Archaea can accumulate for energy and carbon storage. Most of the genetic modifications to the producing bacterial species have been accomplished to clarify basic biochemical, genetic, and metabolic aspects of PHA metabolism. However, due to its plastic‐like properties and complete biodegradability, this bio‐based polymer has attracted the attention of a variety of manufacturers. A number of genetic approaches have therefore been reported, aimed at improving the performance of the microorganisms with a potential for use in a production process. Indeed, genetic tools may find useful applications in all the phases of the PHA production chain, from the isolation and characterization of new microbial strains through all the production steps until they reach the downstream processes. The substrates generally used for PHA production are expensive, so the search for low‐cost feedstock is necessary. These materials, possibly deriving from agri‐food processes, are unfortunately not easily degraded or converted directly into PHAs. Thus, the development of engineered microbes is in progress to process waste streams and covert them to valuable polymers. This review will summarize the most relevant results obtained through genetic engineering tools for the production of PHAs from cheap carbon sources in view of possible industrial applications. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.

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Section: Bacterial Strains Producing Phas Can Be Modified To Use Diffmentioning

confidence: 99%

Section: Starchy Residuesmentioning

confidence: 99%

Improving polyhydroxyalkanoate production from inexpensive carbon sources by genetic approaches: a review

Favaro

Basaglia

Casella

2018

Biofuels Bioprod Bioref

Self Cite

137

View full text Add to dashboard Cite

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“…In order to implement the large scale ethanol production from raw starch, the development of an industrial yeast http that converts starch to ethanol in one step (called consolidated bioprocessing -CBP) is needed [8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Utilisation of wheat bran as a substrate for bioethanol production using recombinant cellulases and amylolytic yeast

et al. 2015

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Wheat bran, generated from the milling of wheat, represents a promising feedstock for the production of bioethanol. This substrate consists of three main components: starch, hemicellulose and cellulose. The optimal conditions for wheat bran hydrolysis have been determined using a recombinant cellulase cocktail (RCC), which contains two cellobiohydrolases, an endoglucanase and a beta-glucosidase. The 10% (w/v, expressed in terms of dry matter) substrate loading yielded the most glucose, while the 2% loading gave the best hydrolysis efficiency (degree of saccharification) using unmilled wheat bran. The ethanol production of two industrial amylolytic Saccharomyces cerevisiae strains, MEL2[TLG1-SFA1] and M2n [TLG1-SFA1], were compared in a simultaneous saccharification and fermentation (SSF) for 10% wheat bran loading with or without the supplementation of optimised RCC. The recombinant yeasts. cerevisiae MEL2[TLG1-SFA1] and M2n[TLG1-SFA1] completely hydrolysed wheat bran's starch producing similar amounts of ethanol (5.3 +/- 0.14 g/L and 5.0 +/- 0.09 g/L, respectively). Supplementing SSF with RCC resulted in additional ethanol production of about 2.0 g/L. Scanning electron microscopy confirmed the effectiveness of both RCC and engineered amylolytic strains in terms of cellulose and starch depolymerisatio

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“…CBP requires robust microbes able to: (i) degrade lignocellulosic materials in the absence of supplementary exogenous enzymes, (ii) utilise at high efficiency both hexose and pentose sugars including their conversion into high-titer ethanol and (iii) tolerate toxic compounds notably the primary alcohol product formed during fermentation [16]. Whereas the endogenous ability of F. oxysporum to tolerate inhibitory compounds encountered during CBP including lignocellulosic hydrosylates (carboxylic acids, phenolic compounds, furan derivatives) [17] and the fermentation by-product acetic acid [18] has been reported, a knowledge deficit exists in regards to F. oxysporum ’s capability to tolerate ethanol.…”

Section: Introductionmentioning

confidence: 99%

Generating Phenotypic Diversity in a Fungal Biocatalyst to Investigate Alcohol Stress Tolerance Encountered during Microbial Cellulosic Biofuel Production

2013

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Consolidated bioprocessing (CBP) of lignocellulosic biomass offers an alternative route to renewable energy. The crop pathogen Fusarium oxysporum is a promising fungal biocatalyst because of its broad host range and innate ability to co-saccharify and ferment lignocellulose to bioethanol. A major challenge for cellulolytic CBP-enabling microbes is alcohol inhibition. This research tested the hypothesis that Agrobacterium tumefaciens - mediated transformation (ATMT) could be exploited as a tool to generate phenotypic diversity in F. oxysporum to investigate alcohol stress tolerance encountered during CBP. A random mutagenesis library of gene disruption transformants (n=1,563) was constructed and screened for alcohol tolerance in order to isolate alcohol sensitive or tolerant phenotypes. Following three rounds of screening, exposure of select transformants to 6% ethanol and 0.75% n-butanol resulted respectively in increased (≥11.74%) and decreased (≤43.01%) growth compared to the wild –type (WT). Principal component analysis (PCA) quantified the level of phenotypic diversity across the population of genetically transformed individuals and isolated candidate strains for analysis. Characterisation of one strain, Tr. 259, ascertained a reduced growth phenotype under alcohol stress relative to WT and indicated the disruption of a coding region homologous to a putative sugar transporter (FOXG_09625). Quantitative PCR (RT-PCR) showed FOXG_09625 was differentially expressed in Tr. 259 compared to WT during alcohol-induced stress (P<0.05). Phylogenetic analysis of putative sugar transporters suggests diverse functional roles in F. oxysporum and other filamentous fungi compared to yeast for which sugar transporters form part of a relatively conserved family. This study has confirmed the potential of ATMT coupled with a phenotypic screening program to select for genetic variation induced in response to alcohol stress. This research represents a first step in the investigation of alcohol tolerance in F. oxysporum and has resulted in the identification of several novel strains, which will be of benefit to future biofuel research.

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Designing industrial yeasts for the consolidated bioprocessing of starchy biomass to ethanol

Cited by 42 publications

References 28 publications

Improving polyhydroxyalkanoate production from inexpensive carbon sources by genetic approaches: a review

Improving polyhydroxyalkanoate production from inexpensive carbon sources by genetic approaches: a review

Utilisation of wheat bran as a substrate for bioethanol production using recombinant cellulases and amylolytic yeast

Generating Phenotypic Diversity in a Fungal Biocatalyst to Investigate Alcohol Stress Tolerance Encountered during Microbial Cellulosic Biofuel Production

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