Limits...
Effects of aromatic compounds on the production of bacterial nanocellulose by Gluconacetobacter xylinus.

Zhang S, Winestrand S, Guo X, Chen L, Hong F, Jönsson LJ - Microb. Cell Fact. (2014)

Bottom Line: However, very little is known about the effect on G. xylinus of specific lignocellulose-derived inhibitors.Vanillin was reduced to vanillyl alcohol with a yield of up to 80%.This is the first investigation of the effect of specific phenolics on the production of BC by G. xylinus, and is also the first demonstration of the ability of G. xylinus to convert phenolic compounds.

View Article: PubMed Central - HTML - PubMed

Affiliation: China-Sweden Associated Research Laboratory in Industrial Biotechnology, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, China. fhong@dhu.edu.cn.

ABSTRACT

Background: Bacterial cellulose (BC) is a polymeric nanostructured fibrillar network produced by certain microorganisms, principally Gluconacetobacter xylinus. BC has a great potential of application in many fields. Lignocellulosic biomass has been investigated as a cost-effective feedstock for BC production through pretreatment and hydrolysis. It is well known that detoxification of lignocellulosic hydrolysates may be required to achieve efficient production of BC. Recent results suggest that phenolic compounds contribute to the inhibition of G. xylinus. However, very little is known about the effect on G. xylinus of specific lignocellulose-derived inhibitors. In this study, the inhibitory effects of four phenolic model compounds (coniferyl aldehyde, ferulic acid, vanillin and 4-hydroxybenzoic acid) on the growth of G. xylinus, the pH of the culture medium, and the production of BC were investigated in detail. The stability of the phenolics in the bacterial cultures was investigated and the main bioconversion products were identified and quantified.

Results: Coniferyl aldehyde was the most potent inhibitor, followed by vanillin, ferulic acid, and 4-hydroxybenzoic acid. There was no BC produced even with coniferyl aldehyde concentrations as low as 2 mM. Vanillin displayed a negative effect on the bacteria and when the vanillin concentration was raised to 2.5 mM the volumetric yield of BC decreased to ~40% of that obtained in control medium without inhibitors. The phenolic acids, ferulic acid and 4-hydroxybenzoic acid, showed almost no toxic effects when less than 2.5 mM. The bacterial cultures oxidized coniferyl aldehyde to ferulic acid with a yield of up to 81%. Vanillin was reduced to vanillyl alcohol with a yield of up to 80%.

Conclusions: This is the first investigation of the effect of specific phenolics on the production of BC by G. xylinus, and is also the first demonstration of the ability of G. xylinus to convert phenolic compounds. This study gives a better understanding of how phenolic compounds and G. xylinus cultures are affected by each other. Investigations in this area are useful for elucidating the mechanism behind inhibition of G. xylinus in lignocellulosic hydrolysates and for understanding how production of BC using lignocellulosic feedstocks can be performed in an efficient way.

Show MeSH

Related in: MedlinePlus

The structure of model inhibitors and related compounds. (A) coniferylaldehyde, (B) ferulic acid, (C) vanillin, (D)4-hydroxybenzoic acid, (E) coniferyl alcohol, (F) vanillyl alcohol,and (G) vanillic acid.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4126184&req=5

Figure 1: The structure of model inhibitors and related compounds. (A) coniferylaldehyde, (B) ferulic acid, (C) vanillin, (D)4-hydroxybenzoic acid, (E) coniferyl alcohol, (F) vanillyl alcohol,and (G) vanillic acid.

Mentions: The influence of four phenolic model inhibitors was investigated with regard to thegrowth of G. xylinus, the sugar consumption, the change of pH duringcultivation, the cell viability, and the yield of BC. The experimental approach appliedsome modern analytical techniques including high-performance liquid chromatographyequipped with a UV detector and a diode array and multiple wavelength detector(HPLC-UV-DAD) for analysis of phenols, fluorescence staining for analysis of cellviability, and enzyme technology for analysis of sugar consumption. Furthermore,potential biotransformation of the inhibitory phenolics during cultivation was alsostudied. The four phenolic model compounds (Figure 1A-D)included two aldehydes, coniferyl aldehyde and vanillin, and two carboxylic acids,ferulic acid and 4-hydroxybenzoic acid. Coniferyl aldehyde has been identified in sprucehydrolysates and has been used extensively as a model compound to study the effect ofinhibition of production of cellulosic ethanol by the yeast Saccharomycescerevisiae[19-21]. Vanillin is one of the most prevalent phenolic compounds in lignocellulosichydrolysates and has been identified in for example hydrolysates from spruce [19,20], pine, poplar, corn stover [22], wheat straw [23], and sugarcane bagasse [24]. Ferulic acid and 4-hydroxybenzoic acid are common in various hydrolysates,for example from spruce, pine, poplar, corn stover and sugarcane bagasse [20,22,24]. This is the first study of the effect of specific phenolics on theproduction of BC by G. xylinus. Investigations in this area are useful forelucidating the mechanism behind inhibition of G. xylinus by lignocellulosichydrolysates and for understanding how production of BC using lignocellulosic feedstockscan be performed in an efficient way.


Effects of aromatic compounds on the production of bacterial nanocellulose by Gluconacetobacter xylinus.

Zhang S, Winestrand S, Guo X, Chen L, Hong F, Jönsson LJ - Microb. Cell Fact. (2014)

The structure of model inhibitors and related compounds. (A) coniferylaldehyde, (B) ferulic acid, (C) vanillin, (D)4-hydroxybenzoic acid, (E) coniferyl alcohol, (F) vanillyl alcohol,and (G) vanillic acid.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4126184&req=5

Figure 1: The structure of model inhibitors and related compounds. (A) coniferylaldehyde, (B) ferulic acid, (C) vanillin, (D)4-hydroxybenzoic acid, (E) coniferyl alcohol, (F) vanillyl alcohol,and (G) vanillic acid.
Mentions: The influence of four phenolic model inhibitors was investigated with regard to thegrowth of G. xylinus, the sugar consumption, the change of pH duringcultivation, the cell viability, and the yield of BC. The experimental approach appliedsome modern analytical techniques including high-performance liquid chromatographyequipped with a UV detector and a diode array and multiple wavelength detector(HPLC-UV-DAD) for analysis of phenols, fluorescence staining for analysis of cellviability, and enzyme technology for analysis of sugar consumption. Furthermore,potential biotransformation of the inhibitory phenolics during cultivation was alsostudied. The four phenolic model compounds (Figure 1A-D)included two aldehydes, coniferyl aldehyde and vanillin, and two carboxylic acids,ferulic acid and 4-hydroxybenzoic acid. Coniferyl aldehyde has been identified in sprucehydrolysates and has been used extensively as a model compound to study the effect ofinhibition of production of cellulosic ethanol by the yeast Saccharomycescerevisiae[19-21]. Vanillin is one of the most prevalent phenolic compounds in lignocellulosichydrolysates and has been identified in for example hydrolysates from spruce [19,20], pine, poplar, corn stover [22], wheat straw [23], and sugarcane bagasse [24]. Ferulic acid and 4-hydroxybenzoic acid are common in various hydrolysates,for example from spruce, pine, poplar, corn stover and sugarcane bagasse [20,22,24]. This is the first study of the effect of specific phenolics on theproduction of BC by G. xylinus. Investigations in this area are useful forelucidating the mechanism behind inhibition of G. xylinus by lignocellulosichydrolysates and for understanding how production of BC using lignocellulosic feedstockscan be performed in an efficient way.

Bottom Line: However, very little is known about the effect on G. xylinus of specific lignocellulose-derived inhibitors.Vanillin was reduced to vanillyl alcohol with a yield of up to 80%.This is the first investigation of the effect of specific phenolics on the production of BC by G. xylinus, and is also the first demonstration of the ability of G. xylinus to convert phenolic compounds.

View Article: PubMed Central - HTML - PubMed

Affiliation: China-Sweden Associated Research Laboratory in Industrial Biotechnology, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, China. fhong@dhu.edu.cn.

ABSTRACT

Background: Bacterial cellulose (BC) is a polymeric nanostructured fibrillar network produced by certain microorganisms, principally Gluconacetobacter xylinus. BC has a great potential of application in many fields. Lignocellulosic biomass has been investigated as a cost-effective feedstock for BC production through pretreatment and hydrolysis. It is well known that detoxification of lignocellulosic hydrolysates may be required to achieve efficient production of BC. Recent results suggest that phenolic compounds contribute to the inhibition of G. xylinus. However, very little is known about the effect on G. xylinus of specific lignocellulose-derived inhibitors. In this study, the inhibitory effects of four phenolic model compounds (coniferyl aldehyde, ferulic acid, vanillin and 4-hydroxybenzoic acid) on the growth of G. xylinus, the pH of the culture medium, and the production of BC were investigated in detail. The stability of the phenolics in the bacterial cultures was investigated and the main bioconversion products were identified and quantified.

Results: Coniferyl aldehyde was the most potent inhibitor, followed by vanillin, ferulic acid, and 4-hydroxybenzoic acid. There was no BC produced even with coniferyl aldehyde concentrations as low as 2 mM. Vanillin displayed a negative effect on the bacteria and when the vanillin concentration was raised to 2.5 mM the volumetric yield of BC decreased to ~40% of that obtained in control medium without inhibitors. The phenolic acids, ferulic acid and 4-hydroxybenzoic acid, showed almost no toxic effects when less than 2.5 mM. The bacterial cultures oxidized coniferyl aldehyde to ferulic acid with a yield of up to 81%. Vanillin was reduced to vanillyl alcohol with a yield of up to 80%.

Conclusions: This is the first investigation of the effect of specific phenolics on the production of BC by G. xylinus, and is also the first demonstration of the ability of G. xylinus to convert phenolic compounds. This study gives a better understanding of how phenolic compounds and G. xylinus cultures are affected by each other. Investigations in this area are useful for elucidating the mechanism behind inhibition of G. xylinus in lignocellulosic hydrolysates and for understanding how production of BC using lignocellulosic feedstocks can be performed in an efficient way.

Show MeSH
Related in: MedlinePlus