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Fermentative polyhydroxybutyrate production from a novel feedstock derived from bakery waste.

Pleissner D, Lam WC, Han W, Lau KY, Cheung LC, Lee MW, Lei HM, Lo KY, Ng WY, Sun Z, Melikoglu M, Lin CS - Biomed Res Int (2014)

Bottom Line: These include: (1) use of crude enzyme extracts from Aspergillus awamori, (2) Aspergillus awamori solid mashes, and (3) commercial glucoamylase.In both cases, the final glucose concentration was around 130-150 g L(-1).The present work has generated promising information contributing to the sustainable production of bioplastic using bakery waste hydrolysate.

View Article: PubMed Central - PubMed

Affiliation: School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.

ABSTRACT
In this study, Halomonas boliviensis was cultivated on bakery waste hydrolysate and seawater in batch and fed-batch cultures for polyhydroxybutyrate (PHB) production. Results demonstrated that bakery waste hydrolysate and seawater could be efficiently utilized by Halomonas boliviensis while PHB contents between 10 and 30% (w/w) were obtained. Furthermore, three methods for bakery waste hydrolysis were investigated for feedstock preparation. These include: (1) use of crude enzyme extracts from Aspergillus awamori, (2) Aspergillus awamori solid mashes, and (3) commercial glucoamylase. In the first method, the resultant free amino nitrogen (FAN) concentration in hydrolysates was 150 and 250 mg L(-1) after 20 hours at enzyme-to-solid ratios of 6.9 and 13.1 U g(-1), respectively. In both cases, the final glucose concentration was around 130-150 g L(-1). In the second method, the resultant FAN and glucose concentrations were 250 mg L(-1) and 150 g L(-1), respectively. In the third method, highest glucose and lowest FAN concentrations of 170-200 g L(-1) and 100 mg L(-1), respectively, were obtained in hydrolysates after only 5 hours. The present work has generated promising information contributing to the sustainable production of bioplastic using bakery waste hydrolysate.

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Fermentative PHB production. Profile of glucose (closed circle), fructose (open square), free amino nitrogen (FAN, open triangle), and biomass (closed triangle) concentrations as well as weight specific PHB content (open circle) during fermentation of Halomonas boliviensis on bakery waste hydrolysate ((a) and (b)). Fermentations were initially performed as batch cultures and later changed to fed-batch cultures. Start of feeding is indicated by an arrow.
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fig1: Fermentative PHB production. Profile of glucose (closed circle), fructose (open square), free amino nitrogen (FAN, open triangle), and biomass (closed triangle) concentrations as well as weight specific PHB content (open circle) during fermentation of Halomonas boliviensis on bakery waste hydrolysate ((a) and (b)). Fermentations were initially performed as batch cultures and later changed to fed-batch cultures. Start of feeding is indicated by an arrow.

Mentions: The feasibility of using bakery waste hydrolysate and seawater as medium for fermentative PHB production with Halomonas boliviensis was examined. Figure 1(a) shows the fermentation of Halomonas boliviensis on hydrolyzed bakery waste and seawater at initial glucose and FAN concentrations of 50.5 g L−1 and 172.2 mg L−1, respectively. After 30 hours, the FAN concentration was reduced to 32 mg L−1 and the PHB content increased to 14% (w/w) due to nitrogen limitation of Halomonas boliviensis cells. When glucose concentration became below 5 g L−1, a hydrolysate consisting of 103.0 g L−1 glucose and 606.2 mg L−1 FAN was fed continuously at a rate of 0.029 L h−1 for 20 hours in order to prevent glucose depletion. During fed-batch phase, cells consumed all the glucose (59.7 g) and FAN (351.6 mg) supplied. The feeding resulted in a further increase in biomass concentration from 5 to 25 g L−1 due to the supply of glucose and FAN in excess. The PHB content of cells, however, remained unchanged at 10–14% (Table 1).


Fermentative polyhydroxybutyrate production from a novel feedstock derived from bakery waste.

Pleissner D, Lam WC, Han W, Lau KY, Cheung LC, Lee MW, Lei HM, Lo KY, Ng WY, Sun Z, Melikoglu M, Lin CS - Biomed Res Int (2014)

Fermentative PHB production. Profile of glucose (closed circle), fructose (open square), free amino nitrogen (FAN, open triangle), and biomass (closed triangle) concentrations as well as weight specific PHB content (open circle) during fermentation of Halomonas boliviensis on bakery waste hydrolysate ((a) and (b)). Fermentations were initially performed as batch cultures and later changed to fed-batch cultures. Start of feeding is indicated by an arrow.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4127261&req=5

fig1: Fermentative PHB production. Profile of glucose (closed circle), fructose (open square), free amino nitrogen (FAN, open triangle), and biomass (closed triangle) concentrations as well as weight specific PHB content (open circle) during fermentation of Halomonas boliviensis on bakery waste hydrolysate ((a) and (b)). Fermentations were initially performed as batch cultures and later changed to fed-batch cultures. Start of feeding is indicated by an arrow.
Mentions: The feasibility of using bakery waste hydrolysate and seawater as medium for fermentative PHB production with Halomonas boliviensis was examined. Figure 1(a) shows the fermentation of Halomonas boliviensis on hydrolyzed bakery waste and seawater at initial glucose and FAN concentrations of 50.5 g L−1 and 172.2 mg L−1, respectively. After 30 hours, the FAN concentration was reduced to 32 mg L−1 and the PHB content increased to 14% (w/w) due to nitrogen limitation of Halomonas boliviensis cells. When glucose concentration became below 5 g L−1, a hydrolysate consisting of 103.0 g L−1 glucose and 606.2 mg L−1 FAN was fed continuously at a rate of 0.029 L h−1 for 20 hours in order to prevent glucose depletion. During fed-batch phase, cells consumed all the glucose (59.7 g) and FAN (351.6 mg) supplied. The feeding resulted in a further increase in biomass concentration from 5 to 25 g L−1 due to the supply of glucose and FAN in excess. The PHB content of cells, however, remained unchanged at 10–14% (Table 1).

Bottom Line: These include: (1) use of crude enzyme extracts from Aspergillus awamori, (2) Aspergillus awamori solid mashes, and (3) commercial glucoamylase.In both cases, the final glucose concentration was around 130-150 g L(-1).The present work has generated promising information contributing to the sustainable production of bioplastic using bakery waste hydrolysate.

View Article: PubMed Central - PubMed

Affiliation: School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.

ABSTRACT
In this study, Halomonas boliviensis was cultivated on bakery waste hydrolysate and seawater in batch and fed-batch cultures for polyhydroxybutyrate (PHB) production. Results demonstrated that bakery waste hydrolysate and seawater could be efficiently utilized by Halomonas boliviensis while PHB contents between 10 and 30% (w/w) were obtained. Furthermore, three methods for bakery waste hydrolysis were investigated for feedstock preparation. These include: (1) use of crude enzyme extracts from Aspergillus awamori, (2) Aspergillus awamori solid mashes, and (3) commercial glucoamylase. In the first method, the resultant free amino nitrogen (FAN) concentration in hydrolysates was 150 and 250 mg L(-1) after 20 hours at enzyme-to-solid ratios of 6.9 and 13.1 U g(-1), respectively. In both cases, the final glucose concentration was around 130-150 g L(-1). In the second method, the resultant FAN and glucose concentrations were 250 mg L(-1) and 150 g L(-1), respectively. In the third method, highest glucose and lowest FAN concentrations of 170-200 g L(-1) and 100 mg L(-1), respectively, were obtained in hydrolysates after only 5 hours. The present work has generated promising information contributing to the sustainable production of bioplastic using bakery waste hydrolysate.

Show MeSH