Limits...
Pretreatment of garden biomass by alkali-assisted ultrasonication: effects on enzymatic hydrolysis and ultrastructural changes.

Gabhane J, William SP, Vaidya AN, Anand D, Wate S - J Environ Health Sci Eng (2014)

Bottom Line: The present investigation aims at studying the effectiveness of alkali-assisted ultrasonication on pretreatment of garden biomass (GB).The results also indicated that alkali-assisted ultrasonication is an efficient means of pretreatment of GB at moderate (45-50°C) working temperature and low (1%) concentration of alkali.The yield of reducing sugar after enzymatic hydrolysis increased almost six times as compared to control due to alkali-assisted ultrasonication.

View Article: PubMed Central - HTML - PubMed

Affiliation: Solid and Hazardous Waste Management Division, National Environmental Engineering Research Institute, Nehru marg, Nagpur, Maharashtra, India.

ABSTRACT
The present investigation aims at studying the effectiveness of alkali-assisted ultrasonication on pretreatment of garden biomass (GB). Dry and powdered GB suspended in 1% NaOH was ultrasonicated for 15, 30 and 60 minutes at a frequency of 25 KHZ. The mode of action and effectiveness of alkali-assisted ultrasonication on GB was established through microscopic, scanning electron microscopic and X-ray diffraction studies. A perusal of results showed that alkali-assisted ultrasonication led to fibrillation of GB which ultimately facilitated enzymatic hydrolysis. The results also indicated that alkali-assisted ultrasonication is an efficient means of pretreatment of GB at moderate (45-50°C) working temperature and low (1%) concentration of alkali. The yield of reducing sugar after enzymatic hydrolysis increased almost six times as compared to control due to alkali-assisted ultrasonication.

No MeSH data available.


Related in: MedlinePlus

Light and scanning electron microscopic views of control and pretreated GB. A: Polarized light microscopic view of raw garden biomass. B: Polarized light microscopic view of alkali-microwave pretreated garden biomass showing fragmentation. C: Polarized light microscopic view of alkali-sonication pretreated garden biomass showing fibrillation. D: Scanning electron microscopic view (500 X) of untreated garden biomass. E: Scanning electron microscopic view (500 X) of garden biomass pretreated with alkali (1% NaOH)-sonication. F: Scanning electron microscopic view (500 X) of garden biomass pretreated with alkali (1% NaOH)-microwave.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4008385&req=5

Figure 1: Light and scanning electron microscopic views of control and pretreated GB. A: Polarized light microscopic view of raw garden biomass. B: Polarized light microscopic view of alkali-microwave pretreated garden biomass showing fragmentation. C: Polarized light microscopic view of alkali-sonication pretreated garden biomass showing fibrillation. D: Scanning electron microscopic view (500 X) of untreated garden biomass. E: Scanning electron microscopic view (500 X) of garden biomass pretreated with alkali (1% NaOH)-sonication. F: Scanning electron microscopic view (500 X) of garden biomass pretreated with alkali (1% NaOH)-microwave.

Mentions: The mode of action and impact of alkali-assisted ultrasonication on garden biomass was analyzed through microscopic studies using both polarized light microscope (PLM) and scanning electron microscope (SEM). For a clear understanding and precise evaluation of the impact, we compared the ultra structural changes in GB due to alkali-assisted ultrasonication with alkali-microwave treatment. Figure 1A-1F illustrate the results of microscopic studies of both alkali-microwave and alkali-assisted ultrasonication pretreatments. While comparing the mode of action of both alkali-microwave and alkali- assisted ultrasonication pretreatments, it was found that alkali-microwave at higher temperatures (200°C) developed fragmentation (Figure 1B & 1E) in GB, whereas, alkali- assisted ultrasonication resulted in defibration and fibrillation (Figure 1C and 1F). Defibration of GB is mainly because of alkali action that removed lignin from lignocellulose and sonication forked cellulose fibers into fine fibrils (Fibrillation). Such kind of splitting of cellulose fibers due to sonication has already been documented. Cheng et al. [36] reported that after high intensity ultrasonic treatment, most particles of Avicel cellulose were split into smaller fibrils. Tang and Liang [37] also suggested that ultrasonication can crack the cell wall, dislocating the secondary wall of the middle layer and resulting in fibrillation. Further, it was observed that ultrasonication even at longer duration did not produce any chaotic damage on tissue structure; instead, it resulted in fibrillation (Figure 1C & 1F) facilitating the enzymatic hydrolysis. Whereas, alkali-microwave treatment at high temperature led to complete tissue collapse (Figure 1B & 1E), which may hinder enzymatic hydrolysis process as it leaves less space of enzyme action on substrate.


Pretreatment of garden biomass by alkali-assisted ultrasonication: effects on enzymatic hydrolysis and ultrastructural changes.

Gabhane J, William SP, Vaidya AN, Anand D, Wate S - J Environ Health Sci Eng (2014)

Light and scanning electron microscopic views of control and pretreated GB. A: Polarized light microscopic view of raw garden biomass. B: Polarized light microscopic view of alkali-microwave pretreated garden biomass showing fragmentation. C: Polarized light microscopic view of alkali-sonication pretreated garden biomass showing fibrillation. D: Scanning electron microscopic view (500 X) of untreated garden biomass. E: Scanning electron microscopic view (500 X) of garden biomass pretreated with alkali (1% NaOH)-sonication. F: Scanning electron microscopic view (500 X) of garden biomass pretreated with alkali (1% NaOH)-microwave.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4008385&req=5

Figure 1: Light and scanning electron microscopic views of control and pretreated GB. A: Polarized light microscopic view of raw garden biomass. B: Polarized light microscopic view of alkali-microwave pretreated garden biomass showing fragmentation. C: Polarized light microscopic view of alkali-sonication pretreated garden biomass showing fibrillation. D: Scanning electron microscopic view (500 X) of untreated garden biomass. E: Scanning electron microscopic view (500 X) of garden biomass pretreated with alkali (1% NaOH)-sonication. F: Scanning electron microscopic view (500 X) of garden biomass pretreated with alkali (1% NaOH)-microwave.
Mentions: The mode of action and impact of alkali-assisted ultrasonication on garden biomass was analyzed through microscopic studies using both polarized light microscope (PLM) and scanning electron microscope (SEM). For a clear understanding and precise evaluation of the impact, we compared the ultra structural changes in GB due to alkali-assisted ultrasonication with alkali-microwave treatment. Figure 1A-1F illustrate the results of microscopic studies of both alkali-microwave and alkali-assisted ultrasonication pretreatments. While comparing the mode of action of both alkali-microwave and alkali- assisted ultrasonication pretreatments, it was found that alkali-microwave at higher temperatures (200°C) developed fragmentation (Figure 1B & 1E) in GB, whereas, alkali- assisted ultrasonication resulted in defibration and fibrillation (Figure 1C and 1F). Defibration of GB is mainly because of alkali action that removed lignin from lignocellulose and sonication forked cellulose fibers into fine fibrils (Fibrillation). Such kind of splitting of cellulose fibers due to sonication has already been documented. Cheng et al. [36] reported that after high intensity ultrasonic treatment, most particles of Avicel cellulose were split into smaller fibrils. Tang and Liang [37] also suggested that ultrasonication can crack the cell wall, dislocating the secondary wall of the middle layer and resulting in fibrillation. Further, it was observed that ultrasonication even at longer duration did not produce any chaotic damage on tissue structure; instead, it resulted in fibrillation (Figure 1C & 1F) facilitating the enzymatic hydrolysis. Whereas, alkali-microwave treatment at high temperature led to complete tissue collapse (Figure 1B & 1E), which may hinder enzymatic hydrolysis process as it leaves less space of enzyme action on substrate.

Bottom Line: The present investigation aims at studying the effectiveness of alkali-assisted ultrasonication on pretreatment of garden biomass (GB).The results also indicated that alkali-assisted ultrasonication is an efficient means of pretreatment of GB at moderate (45-50°C) working temperature and low (1%) concentration of alkali.The yield of reducing sugar after enzymatic hydrolysis increased almost six times as compared to control due to alkali-assisted ultrasonication.

View Article: PubMed Central - HTML - PubMed

Affiliation: Solid and Hazardous Waste Management Division, National Environmental Engineering Research Institute, Nehru marg, Nagpur, Maharashtra, India.

ABSTRACT
The present investigation aims at studying the effectiveness of alkali-assisted ultrasonication on pretreatment of garden biomass (GB). Dry and powdered GB suspended in 1% NaOH was ultrasonicated for 15, 30 and 60 minutes at a frequency of 25 KHZ. The mode of action and effectiveness of alkali-assisted ultrasonication on GB was established through microscopic, scanning electron microscopic and X-ray diffraction studies. A perusal of results showed that alkali-assisted ultrasonication led to fibrillation of GB which ultimately facilitated enzymatic hydrolysis. The results also indicated that alkali-assisted ultrasonication is an efficient means of pretreatment of GB at moderate (45-50°C) working temperature and low (1%) concentration of alkali. The yield of reducing sugar after enzymatic hydrolysis increased almost six times as compared to control due to alkali-assisted ultrasonication.

No MeSH data available.


Related in: MedlinePlus