1
|
Process Development for the Detoxification of Fermentation Inhibitors from Acid Pretreated Microalgae Hydrolysate. Molecules 2021; 26:molecules26092435. [PMID: 33922050 PMCID: PMC8122414 DOI: 10.3390/molecules26092435] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 04/04/2021] [Accepted: 04/07/2021] [Indexed: 11/17/2022] Open
Abstract
The aim of this study was to remove 5-hydroxymethyl furfural (5-HMF) and furfural, known as fermentation inhibitors, in acid pretreated hydrolysates (APH) obtained from Scenedesmus obliquus using activated carbon. Microwave-assisted pretreatment was used to produce APH containing glucose, xylose, and fermentation inhibitors (5-HMF, furfural). The response surface methodology was applied to optimize key detoxification variables such as temperature (16.5–58.5 °C), time (0.5–5.5 h), and solid–liquid (S-L) ratio of activated carbon (0.6–7.4 w/v%). Three variables showed significant effects on the removal of fermentation inhibitors. The optimum detoxification conditions with the maximum removal of fermentation inhibitors and the minimum loss of sugars (glucose and xylose) were as follows: temperature of 36.6 °C, extraction time of 3.86 h, and S-L ratio of 3.3 w/v%. Under these conditions, removal of 5-HMF, furfural, and sugars were 71.6, 83.1, and 2.44%, respectively, which agreed closely with the predicted values. When the APH and detoxified APH were used for ethanol fermentation by S. cerevisiae, the ethanol produced was 38.5% and 84.5% of the theoretical yields, respectively, which confirmed that detoxification using activated carbon was effective in removing fermentation inhibitors and increasing fermentation yield without significant removal of fermentable sugars.
Collapse
|
2
|
Guo J, Zhao J, Nawaz A, Haq IU, Chang W, Xu Y. In Situ Chemical Locking of Acetates During Xylo-Oligosaccharide Preparation by Lignocellulose Acidolysis. Appl Biochem Biotechnol 2021; 193:2602-2615. [PMID: 33797025 DOI: 10.1007/s12010-021-03550-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/22/2021] [Indexed: 11/26/2022]
Abstract
Xylo-oligosaccharides with high value could be obtained by acidolysis of lignocellulosic biomass with acetic acid, which was an urgent problem to solve for the separation of acetic acid from crude xylo-oligosaccharides solution. Four neutralizers, CaCO3, CaO, Na2CO3, and NaOH, were used for in situ chemically locking the acetic acid in the acidolyzed hydrolysate of corncob. The chemically locked hydrolysate was analyzed and compared using vacuum evaporation and spray drying. After CaCO3, CaO, Na2CO3, and NaOH treatment, the locking rates of acetic acid were 92.62%, 94.89%, 95.05%, and 95.58%, respectively, and 39.55 g, 41.13 g, 41.78 g, and 41.87 g of the compound of xylo-oligosaccharide and acetate were obtained. Sodium neutralizer had lesser effect on xylo-oligosaccharide content, and Na2CO3 was the best chemical for locking acetic acid among these four neutralizers. This process provides a novel method for effectively utilizing acetic acid during the industrial production of xylo-oligosaccharides via acetic acid.
Collapse
Affiliation(s)
- Jianming Guo
- Key Laboratory of Forestry Genetics & Biotechnology, Nanjing Forestry University, Ministry of Education, Nanjing, 210037, People's Republic of China
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, No. 159 Longpan Road, Nanjing, 210037, People's Republic of China
- Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing, 210037, People's Republic of China
| | - Jianglin Zhao
- Key Laboratory of Forestry Genetics & Biotechnology, Nanjing Forestry University, Ministry of Education, Nanjing, 210037, People's Republic of China
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, No. 159 Longpan Road, Nanjing, 210037, People's Republic of China
- Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing, 210037, People's Republic of China
| | - Ali Nawaz
- Institute of Industrial Biotechnology, GC University, Lahore, 54000, Pakistan
| | - Ikram Ul Haq
- Institute of Industrial Biotechnology, GC University, Lahore, 54000, Pakistan
| | - Wenhuan Chang
- The Key Laboratory of Feed Biotechnology of Ministry of Agriculture, Feed Research Institute of Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Yong Xu
- Key Laboratory of Forestry Genetics & Biotechnology, Nanjing Forestry University, Ministry of Education, Nanjing, 210037, People's Republic of China.
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, No. 159 Longpan Road, Nanjing, 210037, People's Republic of China.
- Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing, 210037, People's Republic of China.
| |
Collapse
|