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Butyric acid fermentation from pretreated and hydrolysed wheat straw by an adapted Clostridium tyrobutyricum strain.

Baroi GN, Baumann I, Westermann P, Gavala HN - Microb Biotechnol (2015)

Bottom Line: Butyric acid is a valuable building-block for the production of chemicals and materials and nowadays it is produced exclusively from petroleum.Pretreated (by wet explosion) and enzymatically hydrolysed wheat straw (PHWS), rich in C6 and C5 sugars (71.6 and 55.4 g l(-1) of glucose and xylose respectively), was used as substrate.Specifically, the butyric acid yield at 60-80% PHWS lie between 0.37 and 0.46 g g(-1) of sugar, while the selectivity for butyric acid was as high as 0.9-1.0 g g(-1) of acid.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Bioscience, Aalborg University (AAU), A.C. Meyers Vaenge 15, DK 2450, Copenhagen, SV, Denmark.

No MeSH data available.


Related in: MedlinePlus

Butyric and acetic acid yields and sugar consumption obtained with increasing concentrations of PHWS during the 2nd adaptation phase of C. tyrobutyricum.
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fig01: Butyric and acetic acid yields and sugar consumption obtained with increasing concentrations of PHWS during the 2nd adaptation phase of C. tyrobutyricum.

Mentions: Butyric and acetic acids were the major products observed during the adaptation and the yields as well as sugar consumption are shown in Fig. 1. Glucose was the major sugar consumed while only minor amounts of xylose and arabinose were metabolized. The apparent yield of butyric acid was in the range of 0.32–0.46 g g−1 of sugar with the highest yield obtained at 60% PHWS fermentation. The butyric acid yield at 60–80% PHWS fermented was comparable and even higher than the yields achieved with mutants with inactivated ack and pta genes, 0.42 (Liu et al., 2006b) and 0.38 g g−1 of glucose (Zhu et al., 2005; Liu and Yang, 2006) respectively. Acetic acid apparent yield was decreasing with increasing PHWS concentration leading to increasing selectivity towards butyric acid, which lied between 0.78 and 1 g g−1 of acid. The very low and especially the ‘zero’ net yield of acetic acid during the fermentation with 80% PHWS could be an indication of acetic acid uptake to form butyric acid. Such an activity has been reviewed by Zhang and colleagues (2009) and reported for C. tyrobutyricum in the study of Michel-Savin and colleagues (1990). Also, Clostridium thermobutyricum has shown such potential (Canganella et al., 2002).


Butyric acid fermentation from pretreated and hydrolysed wheat straw by an adapted Clostridium tyrobutyricum strain.

Baroi GN, Baumann I, Westermann P, Gavala HN - Microb Biotechnol (2015)

Butyric and acetic acid yields and sugar consumption obtained with increasing concentrations of PHWS during the 2nd adaptation phase of C. tyrobutyricum.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4554475&req=5

fig01: Butyric and acetic acid yields and sugar consumption obtained with increasing concentrations of PHWS during the 2nd adaptation phase of C. tyrobutyricum.
Mentions: Butyric and acetic acids were the major products observed during the adaptation and the yields as well as sugar consumption are shown in Fig. 1. Glucose was the major sugar consumed while only minor amounts of xylose and arabinose were metabolized. The apparent yield of butyric acid was in the range of 0.32–0.46 g g−1 of sugar with the highest yield obtained at 60% PHWS fermentation. The butyric acid yield at 60–80% PHWS fermented was comparable and even higher than the yields achieved with mutants with inactivated ack and pta genes, 0.42 (Liu et al., 2006b) and 0.38 g g−1 of glucose (Zhu et al., 2005; Liu and Yang, 2006) respectively. Acetic acid apparent yield was decreasing with increasing PHWS concentration leading to increasing selectivity towards butyric acid, which lied between 0.78 and 1 g g−1 of acid. The very low and especially the ‘zero’ net yield of acetic acid during the fermentation with 80% PHWS could be an indication of acetic acid uptake to form butyric acid. Such an activity has been reviewed by Zhang and colleagues (2009) and reported for C. tyrobutyricum in the study of Michel-Savin and colleagues (1990). Also, Clostridium thermobutyricum has shown such potential (Canganella et al., 2002).

Bottom Line: Butyric acid is a valuable building-block for the production of chemicals and materials and nowadays it is produced exclusively from petroleum.Pretreated (by wet explosion) and enzymatically hydrolysed wheat straw (PHWS), rich in C6 and C5 sugars (71.6 and 55.4 g l(-1) of glucose and xylose respectively), was used as substrate.Specifically, the butyric acid yield at 60-80% PHWS lie between 0.37 and 0.46 g g(-1) of sugar, while the selectivity for butyric acid was as high as 0.9-1.0 g g(-1) of acid.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Bioscience, Aalborg University (AAU), A.C. Meyers Vaenge 15, DK 2450, Copenhagen, SV, Denmark.

No MeSH data available.


Related in: MedlinePlus