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.

Lipid production from sweet sorghum bagasse through yeast fermentation

2012 ◽  
Vol 40 (1) ◽  
pp. 130-136 ◽  
Author(s):  
Yanna Liang ◽  
Tianyu Tang ◽  
Thara Siddaramu ◽  
Ruplal Choudhary ◽  
Arosha Loku Umagiliyage
Keyword(s):  
Sweet Sorghum ◽  
Lipid Production ◽  
Yeast Fermentation ◽  
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 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.

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

Optimization of saccharification of sweet sorghum bagasse using response surface methodology

2013 ◽  
Vol 44 ◽  
pp. 211-219 ◽  
Author(s):  
Jitendra K. Saini ◽  
Rahul K. Anurag ◽  
Arti Arya ◽  
B.K. Kumbhar ◽  
Lakshmi Tewari
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Sweet Sorghum ◽  
Sweet Sorghum Bagasse ◽  
Sorghum Bagasse

scholarly journals THE EFFECTIVENESS OF PHYSICAL AND ALKALI HYDROTHERMAL PRETREATMENT IN IMPROVING ENZYME SUSCEPTIBILITY OF SWEET SORGHUM BAGASSE

2017 ◽  
Vol 6 (2) ◽  
pp. 117-131 ◽  
Author(s):  
Dwi Ajias Pramasari ◽  
Liesbetini Haditjaroko ◽  
Titi Candra Sunarti ◽  
Euis Hermiati ◽  
Khaswar Syamsu
Keyword(s):  
Sweet Sorghum ◽  
Soluble Sugars ◽  
Milling Process ◽  
Reducing Sugar ◽  
Hydrothermal Pretreatment ◽  
Particle Sizes ◽  
Sweet Sorghum Bagasse ◽  
X Ray Diffraction ◽  
Juice Extraction ◽  
Sorghum Bagasse

Sweet sorghum bagasse (SSB) obtained after juice extraction is a potential feedstock for fermentable sugars production that can be further fermented to different kinds of products, such as ethanol or lactic acid. The proper particle size resulted from phsyical pretreatment and different pretreatment processes including water, alkali, hydrothermal, and alkali hydrothermal for improving enzyme susceptibility of SSB have been investigated. After grinding to particle sizes of <250 ?m, 250-420 ?m, and, > 420 ?m the sweet sorghum bagasse was washed to eliminate residual soluble sugars present in the bagasse. Dosages of cellulase enzyme used in saccharification were 60 and 100 FPU/g substrate, respectively. The results showed that SSB with particle sizes of 250-420 ?m had the highest cellulose (38.33%) and hemicellulose content (31.80%). Although the yield of reducing sugar of 250-420 ?m size particles was lower than that of smaller particle (<250 ?m), the former was more economical in the energy consumption for milling process. The yields of reducing sugar obtained from enzymatic hydrolysis of alkali hydrothermal pretreated sweet sorghum bagasse were 1.5 and 0.5 times higher than that from untreated sweet sorghum bagasse at enzyme loading of 100 and 60 FPU/g substrate, respectively. Furthermore, alkali hydrothermal pretreatment was able to remove as much as 85% of lignin. Morphological analysis using SEM (Scanning Electron Microscope) showed that samples treated with alkali hydrothermal have more pores and distorted bundles than that of untreated sweet sorghum bagasse. Meanwhile, XRD (X-ray diffraction) analysis showed that pretreated samples had a higher crystallinity and smaller crystallite size than untreated sweet sorghum bagasse, which might be due to removal of amorphous lignin components.

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