scholarly journals The Effects of Alkaline Pretreatment on Agricultural Biomasses (Corn Cob and Sweet Sorghum Bagasse) and Their Hydrolysis by a Termite-Derived Enzyme Cocktail

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1211 ◽  
Author(s):  
Mpho. S. Mafa ◽  
Samkelo Malgas ◽  
Abhishek Bhattacharya ◽  
Konanani Rashamuse ◽  
Brett I. Pletschke
Keyword(s):  
Sweet Sorghum ◽  
Compositional Analysis ◽  
Value Added ◽  
Alkaline Pretreatment ◽  
Sweet Sorghum Bagasse ◽  
Amorphous Cellulose ◽  
Naoh Pretreatment ◽  
Enzyme Cocktail ◽  
Sorghum Bagasse ◽  
Multifunctional Enzymes

Sweet sorghum bagasse (SSB) and corncob (CC) have been identified as promising feedstocks for the production of second-generation biofuels and other value-added chemicals. In this study, lime (Ca(OH)2) and NaOH pretreatment efficacy for decreasing recalcitrance from SSB and CC was investigated, and subsequently, the pretreated biomass was subjected to the hydrolytic action of an in-house formulated holocellulolytic enzyme cocktail (HEC-H). Compositional analysis revealed that SSB contained 29.34% lignin, 17.75% cellulose and 16.28% hemicellulose, while CC consisted of 22.51% lignin, 23.58% cellulose and 33.34% hemicellulose. Alkaline pretreatment was more effective in pretreating CC biomass compared to the SSB biomass. Both Ca(OH)2 and NaOH pretreatment removed lignin from the CC biomass, while only NaOH removed lignin from the SSB biomass. Biomass compositional analysis revealed that these agricultural feedstocks differed in their chemical composition because the CC biomass contained mainly hemicellulose (33–35%), while SSB biomass consisted mainly of cellulose (17–24%). The alkaline pretreated SSB and CC samples were subjected to the hydrolytic action of the holocellulolytic enzyme cocktail, formulated with termite derived multifunctional enzymes (referred to as MFE-5E, MFE-5H and MFE-45) and exoglucanase (Exg-D). The HEC-H hydrolysed NaOH pretreated SSB and CC more effectively than Ca(OH)2 pretreated feedstocks, revealing that NaOH was a more effective pretreatment. In conclusion, the HEC-H cocktail efficiently hydrolysed alkaline pretreated agricultural feedstocks, particularly those which are hemicellulose- and amorphous cellulose-rich, such as CC, making it attractive for use in the bioconversion process in the biorefinery industry.

scholarly journals Optimization of a pretreatment and hydrolysis process for the efficient recovery of recycled sugars and unknown compounds from agricultural sweet sorghum bagasse stem pith solid waste

PeerJ ◽  
2019 ◽  
Vol 6 ◽  
pp. e6186 ◽  
Author(s):  
Ting-Ting Jiang ◽  
Yan Liang ◽  
Xiang Zhou ◽  
Zi-Wei Shi ◽  
Zhi-Jun Xin
Keyword(s):  
Solid Waste ◽  
Sweet Sorghum ◽  
Agricultural Waste ◽  
Value Added ◽  
Raw Material ◽  
Alkali Concentration ◽  
Sweet Sorghum Bagasse ◽  
Amorphous Cellulose ◽  
Sorghum Bagasse ◽  
Value Added Products

Background Sweet sorghum bagasse (SSB), comprising both a dermal layer and pith, is a solid waste generated by agricultural activities. Open burning was previously used to treat agricultural solid waste but is harmful to the environment and human health. Recent reports showed that certain techniques can convert this agricultural waste into valuable products. While SSB has been considered an attractive raw material for sugar extraction and the production of value-added products, the pith root in the SSB can be difficult to process. Therefore, it is necessary to pretreat bagasse before conventional hydrolysis. Methods A thorough analysis and comparison of various pretreatment methods were conducted based on physicochemical and microscopic approaches. The responses of agricultural SSB stem pith with different particle sizes to pretreatment temperature, acid and alkali concentration and enzyme dosage were investigated to determine the optimal pretreatment. The integrated methods are beneficial to the utilization of carbohydrate-based and unknown compounds in agricultural solid waste. Results Acid (1.5−4.5%, v/v) and alkali (5−8%, w/v) reagents were used to collect cellulose from different meshes of pith at 25–100 °C. The results showed that the use of 100 mesh pith soaked in 8% (w/v) NaOH solution at 100 °C resulted in 32.47% ± 0.01% solid recovery. Follow-up fermentation with 3% (v/v) acid and 6.5% (w/v) alkali at 50 °C for enzymolysis was performed with the optimal enzyme ratio. An analysis of the surface topography and porosity before and after pretreatment showed that both the pore size of the pith and the amount of exposed cellulose increased as the mesh size increased. Interestingly, various compounds, including 42 compounds previously known to be present and 13 compounds not previously known to be present, were detected in the pretreatment liquid, while 10 types of monosaccharides, including D-glucose, D-xylose and D-arabinose, were found in the enzymatic solution. The total monosaccharide content of the pith was 149.48 ± 0.3 mg/g dry matter. Discussion An integrated technique for obtaining value-added products from sweet sorghum pith is presented in this work. Based on this technique, lignin and hemicellulose were effectively broken down, amorphous cellulose was obtained and all sugars in the sweet sorghum pith were hydrolysed into monosaccharides. A total of 42 compounds previously found in these materials, including alcohol, ester, acid, alkene, aldehyde ketone, alkene, phenolic and benzene ring compounds, were detected in the pretreatment pith. In addition, several compounds that had not been previously observed in these materials were found in the pretreatment solution. These findings will improve the transformation of lignocellulosic biomass into sugar to create a high-value-added coproduct during the integrated process and to maximize the potential utilization of agricultural waste in current biorefinery processing.

scholarly journals Alkaline Pretreatment of Sweet Sorghum Bagasse for Bioethanol Production

2016 ◽  
Vol 5 (2) ◽  
Author(s):  
Yanni Sudiyani ◽  
Eka Triwahyuni ◽  
Muryanto Muryanto ◽  
Dian Burhani ◽  
Joko Waluyo ◽  
...  
Keyword(s):  
Sweet Sorghum ◽  
Alkaline Pretreatment ◽  
Sweet Sorghum Bagasse ◽  
Bioethanol Production ◽  
Sorghum Bagasse

Conversion of Sweet Sorghum Bagasse into Value-Added Biochar

Sugar Tech ◽  
2017 ◽  
Vol 19 (5) ◽  
pp. 553-561 ◽  
Author(s):  
Isabel Lima ◽  
Renee Bigner ◽  
Maureen Wright
Keyword(s):  
Sweet Sorghum ◽  
Value Added ◽  
Sweet Sorghum Bagasse ◽  
Sorghum Bagasse

Lignin relocation contributed to the alkaline pretreatment efficiency of sweet sorghum bagasse

Fuel ◽  
2015 ◽  
Vol 158 ◽  
pp. 152-158 ◽  
Author(s):  
Zhipei Yan ◽  
Jihong Li ◽  
Sandra Chang ◽  
Ting Cui ◽  
Yan Jiang ◽  
...  
Keyword(s):  
Sweet Sorghum ◽  
Alkaline Pretreatment ◽  
Sweet Sorghum Bagasse ◽  
Sorghum Bagasse

scholarly journals Impact of Lignin Content on the Sweet Sorghum Bagasse Enzymatic Hydrolysis

2014 ◽  
Vol 61 ◽  
pp. 1957-1960
Author(s):  
Zhipei Yan ◽  
Jihong Li ◽  
Shizhong Li ◽  
Ting Cui ◽  
Yan Jiang ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Sweet Sorghum ◽  
Lignin Content ◽  
Sweet Sorghum Bagasse ◽  
Sorghum Bagasse

scholarly journals Insights into the physiology of Chlorella vulgaris cultivated in sweet sorghum bagasse hydrolysate for sustainable algal biomass and lipid production

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Neha Arora ◽  
George P. Philippidis
Keyword(s):  
Sweet Sorghum ◽  
Lipid Production ◽  
Scale Up ◽  
Cellular Growth ◽  
Sweet Sorghum Bagasse ◽  
Triacylglycerol Synthesis ◽  
Sugar Addition ◽  
Dry Cell Weight ◽  
Sorghum Bagasse ◽  
Mixotrophic Conditions

AbstractSupplementing cultivation media with exogenous carbon sources enhances biomass and lipid production in microalgae. Utilization of renewable organic carbon from agricultural residues can potentially reduce the cost of algae cultivation, while enhancing sustainability. In the present investigation a medium was developed from sweet sorghum bagasse for cultivation of Chlorella under mixotrophic conditions. Using response surface methodology, the optimal values of critical process parameters were determined, namely inoculum cell density (O.D.750) of 0.786, SSB hydrolysate content of the medium 25% v/v, and zero medium salinity, to achieve maximum lipid productivity of 120 mg/L/d. Enhanced biomass (3.44 g/L) and lipid content (40% of dry cell weight) were observed when the alga was cultivated in SSB hydrolysate under mixotrophic conditions compared to heterotrophic and photoautotrophic conditions. A time course investigation revealed distinct physiological responses in terms of cellular growth and biochemical composition of C. vulgaris cultivated in the various trophic modes. The determined carbohydrate and lipid profiles indicate that sugar addition to the cultivation medium boosts neutral lipid synthesis compared to structural lipids, suggesting that carbon flux is channeled towards triacylglycerol synthesis in the cells. Furthermore, the fatty acid profile of lipids extracted from mixotrophically grown cultures contained more saturated and monosaturated fatty acids, which are suitable for biofuel manufacturing. Scale-up studies in a photobioreactor using SSB hydrolysate achieved a biomass concentration of 2.83 g/L consisting of 34% lipids and 26% carbohydrates. These results confirmed that SSB hydrolysate is a promising feedstock for mixotrophic cultivation of Chlorella and synthesis of algal bioproducts and biofuels.

Sweet sorghum bagasse and corn stover serving as substrates for producing sophorolipids

2016 ◽  
Vol 44 (3) ◽  
pp. 353-362 ◽  
Author(s):  
Abdul Samad ◽  
Ji Zhang ◽  
Da Chen ◽  
Xiaowen Chen ◽  
Melvin Tucker ◽  
...  
Keyword(s):  
Corn Stover ◽  
Sweet Sorghum ◽  
Sweet Sorghum Bagasse ◽  
Sorghum Bagasse
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