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Evaluation of ammonia fibre expansion (AFEX) pretreatment for enzymatic hydrolysis of switchgrass harvested in different seasons and locations.

Bals B, Rogers C, Jin M, Balan V, Dale B - Biotechnol Biofuels (2010)

Bottom Line: All hydrolysates were highly fermentable, although xylose utilisation in the July CIR hydrolysate was poor.Each harvest type and location responded differently to AFEX pretreatment, although all harvests successfully produced fermentable sugars.Thus, it is necessary to consider an integrated approach between agricultural production and biochemical processing in order to insure optimal productivity.

View Article: PubMed Central - HTML - PubMed

Affiliation: Biomass Conversion Research Laboratory, Department of Chemical Engineering and Material Science, Michigan State University, Lansing, MI, USA.

ABSTRACT

Background: When producing biofuels from dedicated feedstock, agronomic factors such as harvest time and location can impact the downstream production. Thus, this paper studies the effectiveness of ammonia fibre expansion (AFEX) pretreatment on two harvest times (July and October) and ecotypes/locations (Cave-in-Rock (CIR) harvested in Michigan and Alamo harvested in Alabama) for switchgrass (Panicum virgatum).

Results: Both harvest date and ecotype/location determine the pretreatment conditions that produce maximum sugar yields. There was a high degree of correlation between glucose and xylose released regardless of the harvest, pretreatment conditions, or enzyme formulation. Enzyme formulation that produced maximum sugar yields was the same across all harvests except for the CIR October harvest. The least mature sample, the July harvest of CIR switchgrass, released the most sugars (520 g/kg biomass) during enzymatic hydrolysis while requiring the least severe pretreatment conditions. In contrast, the most mature harvest released the least amount of sugars (410 g/kg biomass). All hydrolysates were highly fermentable, although xylose utilisation in the July CIR hydrolysate was poor.

Conclusions: Each harvest type and location responded differently to AFEX pretreatment, although all harvests successfully produced fermentable sugars. Thus, it is necessary to consider an integrated approach between agricultural production and biochemical processing in order to insure optimal productivity.

No MeSH data available.


Rate of hydrolysis. Glucose (right) and xylose (left) released during enzymatic hydrolysis between 3 and 168 h of residence time. Pretreatments were performed at the conditions listed in Table 2 and enzyme addition as listed in Table 3. Hydrolysis was performed at 3% solid loading, 50°C, and 200 rpm rotation.
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Figure 3: Rate of hydrolysis. Glucose (right) and xylose (left) released during enzymatic hydrolysis between 3 and 168 h of residence time. Pretreatments were performed at the conditions listed in Table 2 and enzyme addition as listed in Table 3. Hydrolysis was performed at 3% solid loading, 50°C, and 200 rpm rotation.

Mentions: All harvests of switchgrass showed a rapid response to enzyme addition, as seen in Figure 3. As expected, both glucose and xylose released during hydrolysis rose rapidly within the first 24 h, with a slow release afterwards. Interestingly, xylose was released faster than glucose for all samples except the July harvest of CIR switchgrass. The initial rate (defined as sugar release within the first 3 h) for xylose was between 35 to 45 g/kg/h for xylose compared to 25 to 30 g/kg/h for glucose. In addition, glucose released after 168 h was 25% higher than 24 h for all harvests except for the CIR July harvest (which was 16% higher). Xylose at 168 h compared to 24 h was only 8% to 14% higher for all harvests. The xylan appears to be readily accessible to enzymes after AFEX pretreatment relative to cellulose and responds rapidly to enzymatic attack with high xylanase addition.


Evaluation of ammonia fibre expansion (AFEX) pretreatment for enzymatic hydrolysis of switchgrass harvested in different seasons and locations.

Bals B, Rogers C, Jin M, Balan V, Dale B - Biotechnol Biofuels (2010)

Rate of hydrolysis. Glucose (right) and xylose (left) released during enzymatic hydrolysis between 3 and 168 h of residence time. Pretreatments were performed at the conditions listed in Table 2 and enzyme addition as listed in Table 3. Hydrolysis was performed at 3% solid loading, 50°C, and 200 rpm rotation.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2823726&req=5

Figure 3: Rate of hydrolysis. Glucose (right) and xylose (left) released during enzymatic hydrolysis between 3 and 168 h of residence time. Pretreatments were performed at the conditions listed in Table 2 and enzyme addition as listed in Table 3. Hydrolysis was performed at 3% solid loading, 50°C, and 200 rpm rotation.
Mentions: All harvests of switchgrass showed a rapid response to enzyme addition, as seen in Figure 3. As expected, both glucose and xylose released during hydrolysis rose rapidly within the first 24 h, with a slow release afterwards. Interestingly, xylose was released faster than glucose for all samples except the July harvest of CIR switchgrass. The initial rate (defined as sugar release within the first 3 h) for xylose was between 35 to 45 g/kg/h for xylose compared to 25 to 30 g/kg/h for glucose. In addition, glucose released after 168 h was 25% higher than 24 h for all harvests except for the CIR July harvest (which was 16% higher). Xylose at 168 h compared to 24 h was only 8% to 14% higher for all harvests. The xylan appears to be readily accessible to enzymes after AFEX pretreatment relative to cellulose and responds rapidly to enzymatic attack with high xylanase addition.

Bottom Line: All hydrolysates were highly fermentable, although xylose utilisation in the July CIR hydrolysate was poor.Each harvest type and location responded differently to AFEX pretreatment, although all harvests successfully produced fermentable sugars.Thus, it is necessary to consider an integrated approach between agricultural production and biochemical processing in order to insure optimal productivity.

View Article: PubMed Central - HTML - PubMed

Affiliation: Biomass Conversion Research Laboratory, Department of Chemical Engineering and Material Science, Michigan State University, Lansing, MI, USA.

ABSTRACT

Background: When producing biofuels from dedicated feedstock, agronomic factors such as harvest time and location can impact the downstream production. Thus, this paper studies the effectiveness of ammonia fibre expansion (AFEX) pretreatment on two harvest times (July and October) and ecotypes/locations (Cave-in-Rock (CIR) harvested in Michigan and Alamo harvested in Alabama) for switchgrass (Panicum virgatum).

Results: Both harvest date and ecotype/location determine the pretreatment conditions that produce maximum sugar yields. There was a high degree of correlation between glucose and xylose released regardless of the harvest, pretreatment conditions, or enzyme formulation. Enzyme formulation that produced maximum sugar yields was the same across all harvests except for the CIR October harvest. The least mature sample, the July harvest of CIR switchgrass, released the most sugars (520 g/kg biomass) during enzymatic hydrolysis while requiring the least severe pretreatment conditions. In contrast, the most mature harvest released the least amount of sugars (410 g/kg biomass). All hydrolysates were highly fermentable, although xylose utilisation in the July CIR hydrolysate was poor.

Conclusions: Each harvest type and location responded differently to AFEX pretreatment, although all harvests successfully produced fermentable sugars. Thus, it is necessary to consider an integrated approach between agricultural production and biochemical processing in order to insure optimal productivity.

No MeSH data available.