Enzymatic Hydrolysis Of Bamboo Research Articles

Efficient removal of surface-deposited pseudo-lignin and lignin droplets by isothermal phase separation during hydrolysis

During the traditional autohydrolysis, formation and deposition of “pseudo-lignin” and lignin droplets on the surface of biomass had a detrimental effect on the subsequent biomass conversion. In this study, isothermal phase separation was introduced into autohydrolysis, and the effects of isothermal phase separation on the dissolution of components and enzymatic hydrolysis of bamboo were studied. The research showed that isothermal phase separation after autohydrolysis without cooling had an effective reduction in the deposition of “pseudo-lignin” and lignin droplets on the residues surface. After isothermal phase separation, the contents of sugar (14.05 g/L) and lignin (6.16 g/L) in pre-hydrolysates increased by 20% and 19% compared with control, respectively. Moreover, the efficient removal of “pseudo-lignin” and lignin droplets from cell wall surface could further promote the biological conversion of pretreated biomass (22% higher than that of control) during the subsequent enzymatic hydrolysis.

Part I: Enzymatic treatment of Bamboo, Bamboo/Cotton knitted fabric using brewer’s yeast suspension

In this paper, the optimization of the bio-treatment of bamboo and bamboo/cotton knitted fabrics using brewer’s yeast suspension has been accomplished. After enzymatic treatment, the dyeing operation by using Brazilwood natural type was applied. This comprehensive paper is focused on studying the factors that could influence the bio-treatment like concentration of enzyme, pH value of the bio-treatment bath, temperature and duration of treatment to set the best conditions of the treatment process. The influence of changing these factors on fabric colour strength and wettability was investigated. Scanning Electronic Microscope (SEM) analysis was performed for bamboo and bamboo/cotton samples after pre-treatment and enzymatic hydrolysis of bamboo, in order to have a better understanding of the morphology. This microscopic inspection was carried out to inspect the surface features of the fabrics. Results have shown that the growing in colour strength caused by the bio-treatment with enzymes is referred to the enzyme extract which includes primarily lipase, amylase and protease enzymes that develop the fabric dyeability. Furthermore, the wettability was improved by applying enzymatic treatment, where the diffusion rate of the natural dye is increased for the bamboo and bamboo/cotton fabrics.

Improvement of the Enzymatic Hydrolysis of Bamboo by White Liquor and Alkaline Sulfite Pretreatments

Improvement of the Enzymatic Hydrolysis of Bamboo by White Liquor and Alkaline Sulfite Pretreatments

Comparison of dilute acid and alkali pretreatments in production of fermentable sugars from bamboo: Effect of Tween 80

As a fast growing woody grass with high sugar contents, bamboo is a potential material for the production of bio-ethanol, and the saccharification of bamboo has been extensively investigated. However, the role of surfactants on the pretreatment and enzymatic hydrolysis of bamboo has not been clearly elucidated. In this work, effects of aqueous ammonia (SAA), dilute acid (DA), and NaOH pretreatments on the chemical composition, structural features, and enzymatic hydrolysis of bamboo were compared and the effects of Tween 80 on the pretreatments and hydrolysis were explored. NaOH pretreatment showed strong delignification and gave the highest sugar recovery, followed by severe SAA pretreatment (70°C, 72h). Total reducing sugars from bamboo with NaOH pretreated bamboo samples were 42.3g per 100g dry biomass. With the addition of 3% (w/w) Tween 80, the removal of lignin increased from 9.3% and 54.2% to 13.5% and 57.9% after DA and NaOH pretreatments, respectively. The effectiveness of Tween 80 in enzymatic hydrolysis of different pretreated bamboo was high at a cellulase loading less than 20FPU/g DM. Addition of Tween 80 both before and after enzymatic saccharification increased hydrolysis yield of bamboo compared to the hydrolysis without Tween 80. The removal of xylan in bamboo by xylanase could further improve the effectiveness of Tween 80, suggesting the importance of the combination of xylanase and Tween 80 in enzymatic hydrolysis of bamboo by cellulases.

High-temperature heating and microwave pretreatments: A new light in bamboo's enzymatic hydrolysis

A combined technology of high-temperature heating and microwave is proposed to treat bamboo substrates prior to enzymatic hydrolysis to overcome the limits of ei- ther technology. The combined technology helps to promote the reducing sugar yield from enzymatic hydrolysis of bamboo. The protein adsorption test indicated that more enzyme proteins could adsorb on the surface of bamboo pretreated by the combined technology. Thus, the possibility of enzymes to hydrolyze bamboo increased. Meanwhile, X-ray diffractometry tested revealed that the combined technology benefited the removal of non-cellulosic substances from bamboo and resulted in a higher crystallinity.

Effect of pretreatment severity on the enzymatic hydrolysis of bamboo in hydrothermal deconstruction

Bamboo was subjected to hydrothermal deconstruction to release xylans for the enhancement of enzymatic hydrolysis. The de-waxed and de-starched bamboo culm was non-isothermally pretreated in a batch reactor at a solid to liquid ratio of 1:10 g/mL at 120–240 °C. With the increase of the maximum heating temperature from 120 to 240 °C, the pH value of the liquor decreased from 5.98 to 2.71. A maximum yield of the non-volatile components in the liquid was achieved at a pretreatment severity of 4.20. With the increase of the pretreatment severity from 1.18 to 4.82, the yield of the solid residue decreased from 99.52 to 59.91 %, accompanying a decrease of xylan content from 28.86 to 0 %, an increase of glucan content from 42.80 to 59.14 % and an increase of lignin content from 28.10 to 40.57 %. The solid residues after the hydrothermal pretreatment were comprehensively characterized by FT IR, XRD, and element analysis. Enzymatic hydrolysis of the solid residues was assayed by commercial cellulase. Under enzymatic hydrolysis for 96 h, the enzymatic hydrolysis of the pretreated bamboo at the pretreatment severity of 4.82 was 81.16 %, which equaled to 4.7 times of that of the untreated bamboo. This study provided an environmentally friendly process to pretreat biomass for the production of energy.

Enzymatic Hydrolysis of Bamboo and Larch Alkaline Sulfite Pulps for Glucose Production

Enzymatic Hydrolysis of Bamboo and Larch Alkaline Sulfite Pulps for Glucose Production