Relevance of microbial coculture fermentations in biotechnology

Bader, Johannes; Mast-Gerlach, Edeltraud; Popović, Milan; Bajpai, Rakesh; Ståhl, Ulf

doi:10.1111/j.1365-2672.2009.04659.x

Cited by 242 publications

(150 citation statements)

References 161 publications

(259 reference statements)

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“…The potential of mixed cultures in biomass degradation has been described for diverse cases and mirrors nature where microbial communities cooperate in degrading plant matter (76,77).…”

Section: Discussionmentioning

confidence: 99%

Activating Intrinsic Carbohydrate-Active Enzymes of the Smut Fungus Ustilago maydis for the Degradation of Plant Cell Wall Components

Geiser

Reindl

Blank

et al. 2016

Appl Environ Microbiol

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The microbial conversion of plant biomass to valuable products in a consolidated bioprocess could greatly increase the ecologic and economic impact of a biorefinery. Current strategies for hydrolyzing plant material mostly rely on the external application of carbohydrate-active enzymes (CAZymes). Alternatively, production organisms can be engineered to secrete CAZymes to reduce the reliance on externally added enzymes. Plant-pathogenic fungi have a vast repertoire of hydrolytic enzymes to sustain their lifestyle, but expression of the corresponding genes is usually highly regulated and restricted to the pathogenic phase. Here, we present a new strategy in using the biotrophic smut fungus Ustilago maydis for the degradation of plant cell wall components by activating its intrinsic enzyme potential during axenic growth. This fungal model organism is fully equipped with hydrolytic enzymes, and moreover, it naturally produces value-added substances, such as organic acids and biosurfactants. To achieve the deregulated expression of hydrolytic enzymes during the industrially relevant yeast-like growth in axenic culture, the native promoters of the respective genes were replaced by constitutively active synthetic promoters. This led to an enhanced conversion of xylan, cellobiose, and carboxymethyl cellulose to fermentable sugars. Moreover, a combination of strains with activated endoglucanase and ␤-glucanase increased the release of glucose from carboxymethyl cellulose and regenerated amorphous cellulose, suggesting that mixed cultivations could be a means for degrading more complex substrates in the future. In summary, this proof of principle demonstrates the potential applicability of activating the expression of native CAZymes from phytopathogens in a biocatalytic process. IMPORTANCEThis study describes basic experiments that aim at the degradation of plant cell wall components by the smut fungus Ustilago maydis. As a plant pathogen, this fungus contains a set of lignocellulose-degrading enzymes that may be suited for biomass degradation. However, its hydrolytic enzymes are specifically expressed only during plant infection. Here, we provide the proof of principle that these intrinsic enzymes can be synthetically activated during the industrially relevant yeast-like growth. The fungus is known to naturally synthesize valuable compounds, such as itaconate or glycolipids. Therefore, it could be suited for use in a consolidated bioprocess in which more complex and natural substrates are simultaneously converted to fermentable sugars and to value-added compounds in the future. O ne central aim of a sustainable bioeconomy is the switch from fossil-to bio-based production of platform chemicals and other valuable substances. To date, the most promising feedstock for biorefineries is lignocellulosic nonfood plant biomass (1). Lignocellulose is a complex composite mainly consisting of cellulose, hemicelluloses, pectin, and lignin (2). The selective conversion of lignocellulosic biomass comprises different steps: pret...

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“…The potential of mixed cultures in biomass degradation has been described for diverse cases and mirrors nature where microbial communities cooperate in degrading plant matter (76,77).…”

Section: Discussionmentioning

confidence: 99%

Activating Intrinsic Carbohydrate-Active Enzymes of the Smut Fungus Ustilago maydis for the Degradation of Plant Cell Wall Components

Geiser

Reindl

Blank

et al. 2016

Appl Environ Microbiol

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show abstract

“…Co-culture fermentations may result in increased yield, improved control of product qualities, possibility of utilizing cheaper substrates and potential of improving existing processes [8]. These methods have been described to improve the efficiency of lignocellulosic biomass fermentation, having a great impact on the development of biofuels, bioenergy and biobased products [4,8,9]. On the other hand, carbohydrates concentrations of agroindustrial residues vary depending on the crop used and cultivation conditions.…”

Section: Introductionmentioning

confidence: 99%

“…have shown the ability to ferment pentoses and hexoses carbohydrates from degradation of hemicellulose and cellulose, individually and in co-culture [5][6][7]. The co-culture system appears to be an advantageous system over individual cultures because of the potential for synergistic utilization of the metabolic pathways of the strains involved [8,9]. Co-culture fermentations may result in increased yield, improved control of product qualities, possibility of utilizing cheaper substrates and potential of improving existing processes [8].…”

Section: Introductionmentioning

confidence: 99%

“…The co-culture system appears to be an advantageous system over individual cultures because of the potential for synergistic utilization of the metabolic pathways of the strains involved [8,9]. Co-culture fermentations may result in increased yield, improved control of product qualities, possibility of utilizing cheaper substrates and potential of improving existing processes [8]. These methods have been described to improve the efficiency of lignocellulosic biomass fermentation, having a great impact on the development of biofuels, bioenergy and biobased products [4,8,9].…”

Section: Introductionmentioning

confidence: 99%

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Capability of Candidas to Ferment Mixtures of Carbohydrates to Alcohol in Free Cells and Co-Culture

Estrada-Martínez¹,

Pacheco-López²,

Ramírez‐Sucre³

et al. 2017

JFSE

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Abstract:Organic biomass is an attractive feedstock for second generation alcohol production. Wild-type strains of the genus Candida showed capabilities different to produce alcohol fermenting a carbohydrates mixture (synthetic medium), individually and in co-culture. Therefore, the main objective of this work was to evaluate the capability of Candida wild-type strains isolated from termite gut and rumen liquid, to ferment the most commonly carbohydrates presented in citrus residues, individually and in co-culture to alcohol production. C. Tropicalis (LR4) presented higher percentage of carbohydrate consumption (74.20% ± 4.60%), alcohol production (44.53 ± 0.01 gL -1 ) and maximal alcohol productivity (6.40 ± 0.01 gL -1 day) than C. Glabrata (T1). Co-culture schemas, CC1 (LR4: 60%; T1: 40%) and CC3 (first LR4 alone and 2 days later T1) presented the highest alcohol production (45.20 ± 1.30 gL -1 and 46.80 ± 2.60 gL -1 , respectively). Maximal alcohol productivity was obtained with CC2 (LR4: 80%; T1: 20%) and CC3 schemas, 7.70 ± 0.29 gL -1 day and 7.80 ± 0.44 gL -1 day, respectively. The results suggest the usefulness of these wild-type strains in co-culture as an alternative to alcohol production from carbohydrates mixtures at concentrations commonly found in citrus waste.

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“…In nature, the majority of biotransformations happen due to combined metabolic pathways of diverse microbes such as the natural fermentation of saps containing sugars, compost piles, mammalian gut, aerobic and anaerobic water zones, human skin, and forest soils [19,20]. Utilization of substrates in co-culture occurs via collective metabolic action of the recognized strains of microbes [21].…”

Section: Introductionmentioning

confidence: 99%

Enhanced Agarose and Xylan Degradation for Production of Polyhydroxyalkanoates by Co-Culture of Marine Bacterium, Saccharophagus degradans and Its Contaminant, Bacillus cereus

et al. 2017

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Over reliance on energy or petroleum products has raised concerns both in regards to the depletion of their associated natural resources as well as their increasing costs. Bioplastics derived from microbes are emerging as promising alternatives to fossil fuel derived petroleum plastics. The development of a simple and eco-friendly strategy for bioplastic production with high productivity and yield, which is produced in a cost effective manner utilising abundantly available renewable carbon sources, would have the potential to result in an inexhaustible global energy source. Here we report the biosynthesis of bioplastic polyhydroxyalkanoates (PHAs) in pure cultures of marine bacterium, Saccharophagus degradans 2-40 (Sde 2-40), its contaminant, Bacillus cereus, and a co-culture of these bacteria (Sde 2-40 and B. cereus) degrading plant and algae derived complex polysaccharides. Sde 2-40 degraded the complex polysaccharides agarose and xylan as sole carbon sources for biosynthesis of PHAs. The ability of Sde 2-40 to degrade agarose increased after co-culturing with B. cereus. The association of Sde 2-40 with B. cereus resulted in increased cell growth and higher PHA production (34.5% of dry cell weight) from xylan as a carbon source in comparison to Sde 2-40 alone (22.7% of dry cell weight). The present study offers an innovative prototype for production of PHA through consolidated bioprocessing of complex carbon sources by pure and co-culture of microorganisms.

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Relevance of microbial coculture fermentations in biotechnology

Cited by 242 publications

References 161 publications

Activating Intrinsic Carbohydrate-Active Enzymes of the Smut Fungus Ustilago maydis for the Degradation of Plant Cell Wall Components

Activating Intrinsic Carbohydrate-Active Enzymes of the Smut Fungus Ustilago maydis for the Degradation of Plant Cell Wall Components

Capability of Candidas to Ferment Mixtures of Carbohydrates to Alcohol in Free Cells and Co-Culture

Enhanced Agarose and Xylan Degradation for Production of Polyhydroxyalkanoates by Co-Culture of Marine Bacterium, Saccharophagus degradans and Its Contaminant, Bacillus cereus

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