1
|
Asefi S, Nouri H, Pourmohammadi G, Moghimi H. Comprehensive network of stress-induced responses in Zymomonas mobilis during bioethanol production: from physiological and molecular responses to the effects of system metabolic engineering. Microb Cell Fact 2024; 23:180. [PMID: 38890644 PMCID: PMC11186258 DOI: 10.1186/s12934-024-02459-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 06/13/2024] [Indexed: 06/20/2024] Open
Abstract
Nowadays, biofuels, especially bioethanol, are becoming increasingly popular as an alternative to fossil fuels. Zymomonas mobilis is a desirable species for bioethanol production due to its unique characteristics, such as low biomass production and high-rate glucose metabolism. However, several factors can interfere with the fermentation process and hinder microbial activity, including lignocellulosic hydrolysate inhibitors, high temperatures, an osmotic environment, and high ethanol concentration. Overcoming these limitations is critical for effective bioethanol production. In this review, the stress response mechanisms of Z. mobilis are discussed in comparison to other ethanol-producing microbes. The mechanism of stress response is divided into physiological (changes in growth, metabolism, intracellular components, and cell membrane structures) and molecular (up and down-regulation of specific genes and elements of the regulatory system and their role in expression of specific proteins and control of metabolic fluxes) changes. Systemic metabolic engineering approaches, such as gene manipulation, overexpression, and silencing, are successful methods for building new metabolic pathways. Therefore, this review discusses systems metabolic engineering in conjunction with systems biology and synthetic biology as an important method for developing new strains with an effective response mechanism to fermentation stresses during bioethanol production. Overall, understanding the stress response mechanisms of Z. mobilis can lead to more efficient and effective bioethanol production.
Collapse
Affiliation(s)
- Shaqayeq Asefi
- Department of Microbial Biotechnology, School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Hoda Nouri
- Department of Microbial Biotechnology, School of Biology, College of Science, University of Tehran, Tehran, Iran.
| | - Golchehr Pourmohammadi
- Department of Microbial Biotechnology, School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Hamid Moghimi
- Department of Microbial Biotechnology, School of Biology, College of Science, University of Tehran, Tehran, Iran.
| |
Collapse
|
2
|
Wang B, Zhao X, Fu T, Chen X, Guo X, Li X, Yang F. Glucose Starvation Stimulates the Promoting Strength of a Novel Evolved Suc2 Promoter. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:13838-13847. [PMID: 37669532 DOI: 10.1021/acs.jafc.3c03699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
Abstract
Promoters are essential for designing Saccharomyces cerevisiae cell factories. Identifying novel promoters tuned to produce specific metabolites under increasingly diverse industrial stresses is required to improve the economic feasibility of whole fermentation processes. In this study, a positively evolved Suc2 promoter (SUC 2p) with promoter activity stronger than that of the wild-type Suc2 promoter (SUC 2wtp) was obtained. Quantitative real-time PCR, fluorescence analysis, Western blotting, and a β-galactosidase activity assay revealed that SUC 2p is a medium-strength promoter compared with eight reported promoters at a medium glucose concentration (2% (w/v)). Different glucose concentrations modulated the strength of SUC 2p. Low glucose concentrations (0.05 and 0.5% (w/v)) enhanced the promoter strength of SUC 2p dramatically, with promoter activity higher than that of reported strong promoters. Glucose starvation resulted in the formation of a new Msn2/4 binding site on SUC 2p. Our work should facilitate the development of promoters with novel fine-tuning properties and the construction of S. cerevisiae cell factories suitable for the industrial production of essential chemicals under glucose-deprived conditions.
Collapse
Affiliation(s)
- Biying Wang
- School of Biological Engineering, Dalian Polytechnic University, Ganjingziqu, Dalian 116034, P. R. China
| | - Xiaoya Zhao
- School of Biological Engineering, Dalian Polytechnic University, Ganjingziqu, Dalian 116034, P. R. China
| | - Tong Fu
- School of Biological Engineering, Dalian Polytechnic University, Ganjingziqu, Dalian 116034, P. R. China
| | - Xiaoyi Chen
- School of Biological Engineering, Dalian Polytechnic University, Ganjingziqu, Dalian 116034, P. R. China
| | - Xiaoyu Guo
- School of Biological Engineering, Dalian Polytechnic University, Ganjingziqu, Dalian 116034, P. R. China
| | - Xianzhen Li
- School of Biological Engineering, Dalian Polytechnic University, Ganjingziqu, Dalian 116034, P. R. China
| | - Fan Yang
- School of Biological Engineering, Dalian Polytechnic University, Ganjingziqu, Dalian 116034, P. R. China
| |
Collapse
|
3
|
Ndubuisi IA, Amadi CO, Nwagu TN, Murata Y, Ogbonna JC. Non-conventional yeast strains: Unexploited resources for effective commercialization of second generation bioethanol. Biotechnol Adv 2023; 63:108100. [PMID: 36669745 DOI: 10.1016/j.biotechadv.2023.108100] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 01/13/2023] [Accepted: 01/13/2023] [Indexed: 01/18/2023]
Abstract
The conventional yeast (Saccharomyces cerevisiae) is the most studied yeast and has been used in many important industrial productions, especially in bioethanol production from first generation feedstock (sugar and starchy biomass). However, for reduced cost and to avoid competition with food, second generation bioethanol, which is produced from lignocellulosic feedstock, is now being investigated. Production of second generation bioethanol involves pre-treatment and hydrolysis of lignocellulosic biomass to sugar monomers containing, amongst others, d-glucose and D-xylose. Intrinsically, S. cerevisiae strains lack the ability to ferment pentose sugars and genetic engineering of S. cerevisiae to inculcate the ability to ferment pentose sugars is ongoing to develop recombinant strains with the required stability and robustness for commercial second generation bioethanol production. Furthermore, pre-treatment of these lignocellulosic wastes leads to the release of inhibitory compounds which adversely affect the growth and fermentation by S. cerevisae. S. cerevisiae also lacks the ability to grow at high temperatures which favour Simultaneous Saccharification and Fermentation of substrates to bioethanol. There is, therefore, a need for robust yeast species which can co-ferment hexose and pentose sugars and can tolerate high temperatures and the inhibitory substances produced during pre-treatment and hydrolysis of lignocellulosic materials. Non-conventional yeast strains are potential solutions to these problems due to their abilities to ferment both hexose and pentose sugars, and tolerate high temperature and stress conditions encountered during ethanol production from lignocellulosic hydrolysate. This review highlights the limitations of the conventional yeast species and the potentials of non-conventional yeast strains in commercialization of second generation bioethanol.
Collapse
Affiliation(s)
| | - Chioma O Amadi
- Department of Microbiology, University of Nigeria Nsukka, Nigeria
| | - Tochukwu N Nwagu
- Department of Microbiology, University of Nigeria Nsukka, Nigeria
| | - Y Murata
- Biological Resources and Post-Harvest Division, Japan International Research Center for Agricultural Sciences, 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan
| | - James C Ogbonna
- Department of Microbiology, University of Nigeria Nsukka, Nigeria.
| |
Collapse
|
4
|
Low Indirect Land Use Change (ILUC) Energy Crops to Bioenergy and Biofuels—A Review. ENERGIES 2022. [DOI: 10.3390/en15124348] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Energy crops are dedicated cultures directed for biofuels, electricity, and heat production. Due to their tolerance to contaminated lands, they can alleviate and remediate land pollution by the disposal of toxic elements and polymetallic agents. Moreover, these crops are suitable to be exploited in marginal soils (e.g., saline), and, therefore, the risk of land-use conflicts due to competition for food, feed, and fuel is reduced, contributing positively to economic growth, and bringing additional revenue to landowners. Therefore, further study and investment in R&D is required to link energy crops to the implementation of biorefineries. The main objective of this study is to present a review of the potential of selected energy crops for bioenergy and biofuels production, when cultivated in marginal/degraded/contaminated (MDC) soils (not competing with agriculture), contributing to avoiding Indirect Land Use Change (ILUC) burdens. The selected energy crops are Cynara cardunculus, Arundo donax, Cannabis sativa, Helianthus tuberosus, Linum usitatissimum, Miscanthus × giganteus, Sorghum bicolor, Panicum virgatum, Acacia dealbata, Pinus pinaster, Paulownia tomentosa, Populus alba, Populus nigra, Salix viminalis, and microalgae cultures. This article is useful for researchers or entrepreneurs who want to know what kind of crops can produce which biofuels in MDC soils.
Collapse
|
5
|
Singh RS, Singh T, Hassan M, Larroche C. Biofuels from inulin-rich feedstocks: A comprehensive review. BIORESOURCE TECHNOLOGY 2022; 346:126606. [PMID: 34974098 DOI: 10.1016/j.biortech.2021.126606] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/15/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
Biofuels are considered as a pre-eminent alternate to fossil fuels to meet the demand of future energy supply in a sustainable manner. Conventionally, they are produced from lignocellulosic raw materials. Saccharification of lignocellulosic raw materials for bioethanol production is a cumbersome process as compared to inulin-rich feedstocks. Various inulin-rich feedstocks, viz. jerusalem artichoke, chicory, dahlia, asparagus sp., etc. has also been exploited for the production of biofuels, viz. bioethanol, acetone, butanol, etc. The ubiquitous availability of inulin-rich feedstocks and presence of large amount of inulin makes them a robust substrate for biofuels production. Different strategies, viz. separate hydrolysis and fermentation, simultaneous saccharification and fermentation and consolidated bioprocessing have been explored for the conversion of inulin-rich feedstocks into biofuels. These bioprocess strategies are simple and efficient. The present review elaborates the prospective of inulin-rich feedstocks for biofuels production. Bioprocess strategies exploited for the conversion of inulin-rich feedstocks have also been highlighted.
Collapse
Affiliation(s)
- R S Singh
- Carbohydrate and Protein Biotechnology Laboratory, Department of Biotechnology, Punjabi University, Patiala 147 002, India.
| | - Taranjeet Singh
- Carbohydrate and Protein Biotechnology Laboratory, Department of Biotechnology, Punjabi University, Patiala 147 002, India
| | - Muhammad Hassan
- U.S. - Pakistan Centre for Advanced Studies in Energy, National University of Sciences and Technology (NUST), Islamabad 44000, Pakistan
| | - Christian Larroche
- Université Clermont Auvergne, Institut Pascal, UMR, CNRS 6602, and Labex, IMobS3, 4 Avenue Blaise Pascal, TSA 60026, CS 60026, F-63178 Aubiere Cedex, France
| |
Collapse
|
6
|
Hoffman SM, Alvarez M, Alfassi G, Rein DM, Garcia-Echauri S, Cohen Y, Avalos JL. Cellulosic biofuel production using emulsified simultaneous saccharification and fermentation (eSSF) with conventional and thermotolerant yeasts. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:157. [PMID: 34274018 PMCID: PMC8285809 DOI: 10.1186/s13068-021-02008-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 07/05/2021] [Indexed: 05/16/2023]
Abstract
BACKGROUND Future expansion of corn-derived ethanol raises concerns of sustainability and competition with the food industry. Therefore, cellulosic biofuels derived from agricultural waste and dedicated energy crops are necessary. To date, slow and incomplete saccharification as well as high enzyme costs have hindered the economic viability of cellulosic biofuels, and while approaches like simultaneous saccharification and fermentation (SSF) and the use of thermotolerant microorganisms can enhance production, further improvements are needed. Cellulosic emulsions have been shown to enhance saccharification by increasing enzyme contact with cellulose fibers. In this study, we use these emulsions to develop an emulsified SSF (eSSF) process for rapid and efficient cellulosic biofuel production and make a direct three-way comparison of ethanol production between S. cerevisiae, O. polymorpha, and K. marxianus in glucose and cellulosic media at different temperatures. RESULTS In this work, we show that cellulosic emulsions hydrolyze rapidly at temperatures tolerable to yeast, reaching up to 40-fold higher conversion in the first hour compared to microcrystalline cellulose (MCC). To evaluate suitable conditions for the eSSF process, we explored the upper temperature limits for the thermotolerant yeasts Kluyveromyces marxianus and Ogataea polymorpha, as well as Saccharomyces cerevisiae, and observed robust fermentation at up to 46, 50, and 42 °C for each yeast, respectively. We show that the eSSF process reaches high ethanol titers in short processing times, and produces close to theoretical yields at temperatures as low as 30 °C. Finally, we demonstrate the transferability of the eSSF technology to other products by producing the advanced biofuel isobutanol in a light-controlled eSSF using optogenetic regulators, resulting in up to fourfold higher titers relative to MCC SSF. CONCLUSIONS The eSSF process addresses the main challenges of cellulosic biofuel production by increasing saccharification rate at temperatures tolerable to yeast. The rapid hydrolysis of these emulsions at low temperatures permits fermentation using non-thermotolerant yeasts, short processing times, low enzyme loads, and makes it possible to extend the process to chemicals other than ethanol, such as isobutanol. This transferability establishes the eSSF process as a platform for the sustainable production of biofuels and chemicals as a whole.
Collapse
Affiliation(s)
- Shannon M Hoffman
- Department of Chemical and Biological Engineering, Hoyt Laboratory, Princeton University, 101 Hoyt Laboratory, William Street, Princeton, NJ, 08544, USA
| | - Maria Alvarez
- Department of Chemical and Biological Engineering, Hoyt Laboratory, Princeton University, 101 Hoyt Laboratory, William Street, Princeton, NJ, 08544, USA
- Department of Chemical Engineering, University of Vigo, 36310, Vigo, Spain
| | - Gilad Alfassi
- Department of Biotechnology Engineering, ORT Braude College, Karmiel, Israel
| | - Dmitry M Rein
- Department of Chemical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Sergio Garcia-Echauri
- Department of Chemical and Biological Engineering, Hoyt Laboratory, Princeton University, 101 Hoyt Laboratory, William Street, Princeton, NJ, 08544, USA
| | - Yachin Cohen
- Department of Chemical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - José L Avalos
- Department of Chemical and Biological Engineering, Hoyt Laboratory, Princeton University, 101 Hoyt Laboratory, William Street, Princeton, NJ, 08544, USA.
- The Andlinger Center for Energy and the Environment, Princeton University, Princeton, NJ, USA.
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA.
- Princeton Environmental Institute, Princeton University, Princeton, NJ, 08544, USA.
| |
Collapse
|
7
|
Singh R, Singh T, Hassan M, Kennedy JF. Updates on inulinases: Structural aspects and biotechnological applications. Int J Biol Macromol 2020; 164:193-210. [DOI: 10.1016/j.ijbiomac.2020.07.078] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/30/2020] [Accepted: 07/08/2020] [Indexed: 12/16/2022]
|
8
|
Enhanced production of Aspergillus niger inulinase from sugar beet molasses and its kinetic modeling. Biotechnol Lett 2020; 42:1939-1955. [PMID: 32424732 DOI: 10.1007/s10529-020-02913-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 05/13/2020] [Indexed: 10/24/2022]
Abstract
OBJECTIVE The fermentation medium contains many complex components (vitamins, minerals, etc.) for better growth of the microorganisms. The increasing purity and number of these components used in the medium seriously affect the cost of the microbial process. This study aimed to further optimize the concentration of the components used in the medium (yeast extract and peptone) for inulinase fabrication by Aspergillus niger from sugar-beet molasses in shake flask fermentation by using Central Composite Design (CCD) and to kinetically identify the fermentation. RESULTS The results indicated that the optimal medium composition consisted of only 4.2% (w/v) yeast extract. By using the fermentation environment, the inulinase generation, inulinase/sucrase ratio, maximum inulinase generation rate, maximum sugar depletion rate, and substrate utilization yield were determined as 1294.5 U/mL, 1.2, 159.6 U/mL/day, 7.4 g/L/day, and 98.1%, respectively. The kinetic analysis of the fungal development (logistic model) indicated that a specific development rate and initial biomass concentration were 0.89/day and 1.79 g/L, respectively. Inulinase and sucrase productions are mixed-development associated since the α value ≠ 0 (8.46 and 4.31 U/mgX) and the β value ≠ 0 (5.15 and 4.83 U/mgX day), respectively (Luedeking-Piret model). Besides, the maintenance value (Z) (0.009 gS/gX day) was lower than γ value (1.044 gS/gX), showing that A. niger commonly uses the substrates for enzyme fabrication and fungal development (modified Luedeking-Piret model). CONCLUSIONS The enzyme activity was increased by optimizing the concentration of the components used. It was demonstrated that the proposed kinetic models can victoriously define fungal development, enzyme fabrication, and sugar depletion.
Collapse
|
9
|
Germec M, Turhan I. Evaluation of carbon sources for the production of inulinase by Aspergillus niger A42 and its characterization. Bioprocess Biosyst Eng 2019; 42:1993-2005. [PMID: 31414183 DOI: 10.1007/s00449-019-02192-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 08/07/2019] [Indexed: 11/30/2022]
Abstract
Inulinases are used for the production of high-fructose syrup and fructooligosaccharides, and are widely utilized in food and pharmaceutical industries. In this study, different carbon sources were screened for inulinase production by Aspergillus niger in shake flask fermentation. Optimum working conditions of the enzyme were determined. Additionally, some properties of produced enzyme were determined [activation (Ea)/inactivation (Eia) energies, Q10 value, inactivation rate constant (kd), half-life (t1/2), D value, Z value, enthalpy (ΔH), free energy (ΔG), and entropy (ΔS)]. Results showed that sugar beet molasses (SBM) was the best in the production of inulinase, which gave 383.73 U/mL activity at 30 °C, 200 rpm and initial pH 5.0 for 10 days with 2% (v/v) of the prepared spore solution. Optimum working conditions were 4.8 pH, 60 °C, and 10 min, which yielded 604.23 U/mL, 1.09 inulinase/sucrase ratio, and 2924.39 U/mg. Additionally, Ea and Eia of inulinase reaction were 37.30 and 112.86 kJ/mol, respectively. Beyond 60 °C, Q10 values of inulinase dropped below one. At 70 and 80 °C, t1/2 of inulinase was 33.6 and 7.2 min; therefore, inulinase is unstable at high temperatures, respectively. Additionally, t1/2, D, ΔH, ΔG values of inulinase decreased with the increase in temperature. Z values of inulinase were 7.21 °C. Negative values of ΔS showed that enzymes underwent a significant process of aggregation during denaturation. Consequently, SBM is a promising carbon source for inulinase production by A. niger. Also, this is the first report on the determination of some properties of A. niger A42 (ATCC 204,447) inulinase.
Collapse
Affiliation(s)
- Mustafa Germec
- Department of Food Engineering, Akdeniz University, 07058, Antalya, Turkey
| | - Irfan Turhan
- Department of Food Engineering, Akdeniz University, 07058, Antalya, Turkey.
| |
Collapse
|
10
|
Global Warming Potential of Biomass-to-Ethanol: Review and Sensitivity Analysis through a Case Study. ENERGIES 2019. [DOI: 10.3390/en12132535] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In Europe, ethanol is blended with gasoline fuel in 5 or 10% volume (E5 or E10). In USA the blend is 15% in volume (E15) and there are also pumps that provide E85. In Brazil, the conventional gasoline is E27 and there are pumps that offer E100, due to the growing market of flex fuel vehicles. Bioethanol production is usually by means of biological conversion of several biomass feedstocks (first generation sugar cane in Brazil, corn in the USA, sugar beet in Europe, or second-generation bagasse of sugarcane or lignocellulosic materials from crop wastes). The environmental sustainability of the bioethanol is usually measured by the global warming potential metric (GWP in CO2eq), 100 years time horizon. Reviewed values could range from 0.31 to 5.55 gCO2eq/LETOH. A biomass-to-ethanol industrial scenario was used to evaluate the impact of methodological choices on CO2eq: conventional versus dynamic Life Cycle Assessment; different impact assessment methods (TRACI, IPCC, ILCD, IMPACT, EDIP, and CML); electricity mix of the geographical region/country for different factory locations; differences in CO2eq factor for CH4 and N2O due to updates in Intergovernmental Panel on Climate Change (IPCC) reports (5 reports so far), different factory operational lifetimes and future improved productivities. Results showed that the electricity mix (factory location) and land use are the factors that have the greatest effect (up to 800% deviation). The use of the CO2 equivalency factors stated in different IPCC reports has the least influence (less than 3%). The consideration of the biogenic emissions (uptake at agricultural stage and release at the fermentation stage) and different allocation methods is also influential, and each can make values vary by 250%.
Collapse
|
11
|
Abo BO, Gao M, Wang Y, Wu C, Ma H, Wang Q. Lignocellulosic biomass for bioethanol: an overview on pretreatment, hydrolysis and fermentation processes. REVIEWS ON ENVIRONMENTAL HEALTH 2019; 34:57-68. [PMID: 30685745 DOI: 10.1515/reveh-2018-0054] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 12/17/2018] [Indexed: 05/14/2023]
Abstract
Bioethanol is currently the only alternative to gasoline that can be used immediately without having to make any significant changes in the way fuel is distributed. In addition, the carbon dioxide (CO2) released during the combustion of bioethanol is the same as that used by the plant in the atmosphere for its growth, so it does not participate in the increase of the greenhouse effect. Bioethanol can be obtained by fermentation of plants containing sucrose (beet, sugar cane…) or starch (wheat, corn…). However, large-scale use of bioethanol implies the use of very large agricultural surfaces for maize or sugarcane production. Lignocellulosic biomass (LCB) such as agricultural residues for the production of bioethanol seems to be a solution to this problem due to its high availability and low cost even if its growth still faces technological difficulties. In this review, we present an overview of lignocellulosic biomass, the different methods of pre-treatment of LCB and the various fermentation processes that can be used to produce bioethanol from LCB.
Collapse
Affiliation(s)
- Bodjui Olivier Abo
- Department of Environmental Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China
| | - Ming Gao
- Department of Environmental Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China
- Beijing Key Laboratory on Disposal and Resource Recovery of Industry Typical Pollutants, University of Science and Technology Beijing, Beijing, China
| | - Yonglin Wang
- Department of Environmental Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China
| | - Chuanfu Wu
- Department of Environmental Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China
- Beijing Key Laboratory on Disposal and Resource Recovery of Industry Typical Pollutants, University of Science and Technology Beijing, Beijing, China
| | - Hongzhi Ma
- Department of Environmental Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China
- Beijing Key Laboratory on Disposal and Resource Recovery of Industry Typical Pollutants, University of Science and Technology Beijing, Beijing, China
| | - Qunhui Wang
- Department of Environmental Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China
- Beijing Key Laboratory on Disposal and Resource Recovery of Industry Typical Pollutants, University of Science and Technology Beijing, Beijing, China
| |
Collapse
|
12
|
Singh RS, Singh T, Larroche C. Biotechnological applications of inulin-rich feedstocks. BIORESOURCE TECHNOLOGY 2019; 273:641-653. [PMID: 30503580 DOI: 10.1016/j.biortech.2018.11.031] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 11/05/2018] [Accepted: 11/08/2018] [Indexed: 06/09/2023]
Abstract
Inulin is a naturally occurring second largest storage polysaccharide with a wide range of applications in pharmaceutical and food industries. It is a robust polysaccharide which consists of a linear chain of β-2, 1-linked-d-fructofuranose molecules terminated with α-d-glucose moiety at the reducing end. It is present in tubers, bulbs and tuberous roots of more than 36,000 plants belonging to both monocotyledonous and dicotyledonous families. Jerusalem artichoke, chicory, dahlia, asparagus, etc. are important inulin-rich plants. Inulin is a potent substrate and inducer for the production of inulinases. Inulin/inulin-rich feedstocks can be used for the production of fructooligosaccharides and high-fructose syrup. Additionally, inulin-rich feedstocks can also be exploited for the production of other industrially important products like acetone, butanol, bioethanol, single cell proteins, single cell oils, 2, 3-butanediol, sorbitol, mannitol, etc. Current review highlights the biotechnological potential of inulin-rich feedstocks for the production of various industrially important products.
Collapse
Affiliation(s)
- R S Singh
- Carbohydrate and Protein Biotechnology Laboratory, Department of Biotechnology, Punjabi University, Patiala 147 002, Punjab, India.
| | - Taranjeet Singh
- Carbohydrate and Protein Biotechnology Laboratory, Department of Biotechnology, Punjabi University, Patiala 147 002, Punjab, India
| | - Christian Larroche
- Université Clermont Auvergne, Institut Pascal, UMR, CNRS 6602, and Labex, IMobS3, 4 Avenue Blaise Pascal, TSA 60026, CS 60026, F-63178 Aubiere Cedex, France
| |
Collapse
|
13
|
Selection of thermotolerant Saccharomyces cerevisiae for high temperature ethanol production from molasses and increasing ethanol production by strain improvement. Antonie van Leeuwenhoek 2019; 112:975-990. [PMID: 30666530 DOI: 10.1007/s10482-019-01230-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 01/12/2019] [Indexed: 10/27/2022]
Abstract
A thermotolerant ethanol fermenting yeast strain is a key requirement for effective ethanol production at high temperature. This work aimed to select a thermotolerant yeast producing a high ethanol concentration from molasses and increasing its ethanol production by mutagenesis. Saccharomyces cerevisiae DMKU 3-S087 was selected from 168 ethanol producing strains because it produced the highest ethanol concentration from molasses at 40 °C. Optimization of molasses broth composition was performed by the response surface method using Box-Behnken design. In molasses broth containing optimal total fermentable sugars (TFS) of 200 g/L and optimal (NH4)2SO4 of 1 g/L, with an initial pH of 5.5 by shaking flask cultivation at 40 °C ethanol, productivity and yield were 58.4 ± 0.24 g/L, 1.39 g/L/h and 0.29 g/g, respectively. Batch fermentation in a 5 L stirred-tank fermenter with 3 L optimized molasses broth adjusted to an initial pH of 5.5 and fermentation controlled at 40 °C and 300 rpm agitation resulted in 72.4 g/L ethanol, 1.21 g/L/h productivity and 0.36 g/g yield at 60 h. Strain DMKU 3-S087 improvement was performed by mutagenesis using ultraviolet radiation and ethyl methane sulfonate (EMS). Six EMS mutants produced higher ethanol (65.2 ± 0.48-73.0 ± 0.54 g/L) in molasses broth containing 200 g/L TFS and 1 g/L (NH4)2SO4 by shake flask fermentation at 37 °C than the wild type (59.8 ± 0.25 g/L). Among these mutants, only mutant S087E100-265 produced higher ethanol (62.5 ± 0.26 g/L) than the wild type (59.5 ± 0.02 g/L) at 40 °C. In addition, mutant S087E100-265 showed better tolerance to high sugar concentration, furfural, hydroxymethylfurfural and acetic acid than the wild type.
Collapse
|
14
|
Nolasco-Cancino H, Santiago-Urbina JA, Wacher C, Ruíz-Terán F. Predominant Yeasts During Artisanal Mezcal Fermentation and Their Capacity to Ferment Maguey Juice. Front Microbiol 2018; 9:2900. [PMID: 30574125 PMCID: PMC6291486 DOI: 10.3389/fmicb.2018.02900] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 11/12/2018] [Indexed: 11/13/2022] Open
Abstract
Artisanal mezcal is produced by the natural fermentation of maguey juice, which frequently results in a process that becomes stuck or is sluggish. Using selected indigenous starter inoculums of Saccharomyces and non-Saccharomyces yeasts is considered beneficial in overcoming these problems and thereby preserving the essence of the artisanal process. In this work, three hundred and four yeast isolates were recovered from 17 distilleries and then grouped by the ARDRA analysis, their restriction profiles were clustered in 15 groups. Four of them included 90% of all isolates, and these were identified using the sequence of the D1/D2 domain of the large-subunit rDNA. Pichia kudriavzevii, Pichia manshurica, Saccharomyces cerevisiae, and Kluyveromyces marxianus were detected as predominant species. Both species belonging to the Pichia genus were detected in 88% of the distilleries, followed by S. cerevisiae (70%) and K. marxianus (50%). In order to evaluate the fermentative capacity, one strain of each species was assessed in a pure and mixed culture in two culture media, filtered maguey juice (MJ) and maguey juice including its bagasse (MJB). Findings demonstrated that non-Saccharomyces yeast presented better growth than that of S. cerevisiae. K. marxianus PA16 was more efficient for ethanol production than S. cerevisiae DI14. It produced 32 g/L of ethanol with a yield of 0.47 g/g and efficient of 90%. While, P. kudriavzevii produced more ethyl acetate (280 mg/L) than the others species. All fermentations were characterized by the presence of isobutyl and isoamyl alcohol. The presence of K. marxianus in a mixed culture, improved the ethanol production and volatile compounds increased using co-cultures.
Collapse
Affiliation(s)
- Hipócrates Nolasco-Cancino
- Departamento de Alimentos y Biotecnología, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México, Mexico.,Facultad de Ciencias Químicas, Universidad Autónoma Benito Juárez de Oaxaca, Oaxaca, Mexico
| | - Jorge A Santiago-Urbina
- División de Dirección de Carrera de Agricultura Sustentable y Protegida, Universidad Tecnológica de los Valles Centrales de Oaxaca, Oaxaca, Mexico
| | - Carmen Wacher
- Departamento de Alimentos y Biotecnología, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México, Mexico
| | - Francisco Ruíz-Terán
- Departamento de Alimentos y Biotecnología, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México, Mexico
| |
Collapse
|
15
|
Varela JA, Montini N, Scully D, Van der Ploeg R, Oreb M, Boles E, Hirota J, Akada R, Hoshida H, Morrissey JP. Polymorphisms in the LAC12 gene explain lactose utilisation variability in Kluyveromyces marxianus strains. FEMS Yeast Res 2018; 17:3739724. [PMID: 28444380 DOI: 10.1093/femsyr/fox021] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Accepted: 04/16/2017] [Indexed: 01/29/2023] Open
Abstract
Kluyveromyces marxianus is a safe yeast used in the food and biotechnology sectors. One of the important traits that sets it apart from the familiar yeasts, Saccharomyces cerevisiae, is its capacity to grow using lactose as a carbon source. Like in its close relative, Kluyveromyces lactis, this requires lactose transport via a permease and intracellular hydrolysis of the disaccharide. Given the importance of the trait, it was intriguing that most, but not all, strains of K. marxianus are reported to consume lactose efficiently. In this study, primarily through heterologous expression in S. cerevisiae and K. marxianus, it was established that a single gene, LAC12, is responsible for lactose uptake in K. marxianus. Strains that failed to transport lactose showed variation in 13 amino acids in the Lac12p protein, rendering the protein non-functional for lactose transport. Genome analysis showed that the LAC12 gene is present in four copies in the subtelomeric regions of three different chromosomes but only the ancestral LAC12 gene encodes a functional lactose transporter. Other copies of LAC12 may be non-functional or have alternative substrates. The analysis raises some interesting questions regarding the evolution of sugar transporters in K. marxianus.
Collapse
Affiliation(s)
- Javier A Varela
- School of Microbiology, University College Cork, Cork T12YN60, Ireland
| | - Noemi Montini
- School of Microbiology, University College Cork, Cork T12YN60, Ireland
| | - Damhan Scully
- School of Microbiology, University College Cork, Cork T12YN60, Ireland
| | | | - Mislav Oreb
- Institute of Molecular Biosciences, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | - Eckhard Boles
- Institute of Molecular Biosciences, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | - Junya Hirota
- Department of Applied Chemistry, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Ube 755-8611, Japan
| | - Rinji Akada
- Department of Applied Chemistry, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Ube 755-8611, Japan.,Biomedical Engineering Center, Yamaguchi University, Ube 755-8611, Japan.,Research Center for Thermotolerant Microbial Resources, Yamaguchi University, Yamaguchi 753-8315, Japan
| | - Hisashi Hoshida
- Department of Applied Chemistry, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Ube 755-8611, Japan.,Biomedical Engineering Center, Yamaguchi University, Ube 755-8611, Japan.,Research Center for Thermotolerant Microbial Resources, Yamaguchi University, Yamaguchi 753-8315, Japan
| | - John P Morrissey
- School of Microbiology/Centre for Synthetic Biology and Biotechnology/Environmental Research Institute/APC Microbiome Institute, University College Cork, Cork T12 YN60, Ireland
| |
Collapse
|
16
|
Nambu-Nishida Y, Nishida K, Hasunuma T, Kondo A. Genetic and physiological basis for antibody production by Kluyveromyces marxianus. AMB Express 2018; 8:56. [PMID: 29651657 PMCID: PMC5897269 DOI: 10.1186/s13568-018-0588-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Accepted: 04/05/2018] [Indexed: 12/20/2022] Open
Abstract
Kluyveromyces marxianus is a thermotolerant, crabtree-negative yeast, which preferentially directs metabolism (e.g., from the tricarboxylic acid cycle) to aerobic alcoholic fermentation. Thus K. marxianus has great potential for engineering to produce various materials under aerobic cultivation conditions. In this study, we engineered K. marxianus to produce and secrete a single-chain antibody (scFv), a product that is highly valuable but has historically proven difficult to generate at large scale. scFv production was obtained with strains carrying either plasmid-borne or genomically integrated constructs using various combinations of promoters (PMDH1 or PACO1) and secretion signal peptides (KmINUss or Scα-MFss). As the wild-type K. marxianus secretes endogenous inulinase predominantly, the corresponding INU1 gene was disrupted using a Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)—associated protein (CRISPR–Cas9) system to re-direct resources to scFv production. Genomic integration was used to replace INU1 with sequences encoding a fusion of the INU1 signal peptide to scFv; the resulting construct yielded the highest scFv production among the strains tested. Optimization of growth conditions revealed that scFv production by this strain was enhanced by incubation at 30 °C in xylose medium containing 200 mM MgSO4. These results together demonstrate that K. marxianus has the potential to serve as a host strain for antibody production.
Collapse
|
17
|
Jiang GL, Zhou LY, Wang YT, Zhu MJ. Astaxanthin from Jerusalem artichoke: Production by fed-batch fermentation using Phaffia rhodozyma and application in cosmetics. Process Biochem 2017. [DOI: 10.1016/j.procbio.2017.08.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
18
|
Zhang G, Lu M, Wang J, Wang D, Gao X, Hong J. Identification of hexose kinase genes in Kluyveromyces marxianus and thermo-tolerant one step producing glucose-free fructose strain construction. Sci Rep 2017; 7:45104. [PMID: 28338054 PMCID: PMC5364472 DOI: 10.1038/srep45104] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 02/16/2017] [Indexed: 01/01/2023] Open
Abstract
In yeast, the hexose assimilation is started at hexose phosphorylation. However, in Kluyveromyces marxianus, the hexokinase (HXK) and glucokinase (GLK) genes were not identified by experiments. Meanwhile, the glucose-free fructose product requires more cost-efficient method. In this study, the KmHXK1 and KmGLK1 genes were functionally identified through gene disruption, over-expression and recombinant enzymes characterization. Both glucose and fructose assimilation ability decreased significantly in KmHXK1 disrupted strain YLM001, however, this ability was not changed obviously in KmGLK1 disrupted strain YLM002. When over-expressing KmGLK1 in YLM001, only the glucose assimilation ability was recovered in obtained strain (YLM005). The kinetic constant analysis of recombinant enzymes also proved that KmHXK1 could phosphorylate glucose (Vmax 553.01 U/mg, Km 0.83 mM) and fructose (Vmax 609.82 U/mg, Km 0.52 mM), and KmGLK1 only phosphorylate glucose with a Vmax of 0.73 U/mg and a Km 4.09 mM. A thermo-tolerant strain YGR003 which produced glucose-free fructose from Jerusalem artichoke tuber in one step was constructed based on the obtained information. The highest production and fastest productivity were 234.44 g/L and 10.26 g/L/h, respectively, which were several folds of the results in previous reports.
Collapse
Affiliation(s)
- Guorong Zhang
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, P. R. China
| | - Min Lu
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, P. R. China
| | - Jichao Wang
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, P. R. China
| | - Dongmei Wang
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, P. R. China
| | - Xiaolian Gao
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, P. R. China
| | - Jiong Hong
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, P. R. China
| |
Collapse
|
19
|
Hughes SR, Qureshi N, López-Núñez JC, Jones MA, Jarodsky JM, Galindo-Leva LÁ, Lindquist MR. Utilization of inulin-containing waste in industrial fermentations to produce biofuels and bio-based chemicals. World J Microbiol Biotechnol 2017; 33:78. [PMID: 28341907 DOI: 10.1007/s11274-017-2241-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Accepted: 03/06/2017] [Indexed: 12/18/2022]
Abstract
Inulins are polysaccharides that belong to an important class of carbohydrates known as fructans and are used by many plants as a means of storing energy. Inulins contain 20 to several thousand fructose units joined by β-2,1 glycosidic bonds, typically with a terminal glucose unit. Plants with high concentrations of inulin include: agave, asparagus, coffee, chicory, dahlia, dandelion, garlic, globe artichoke, Jerusalem artichoke, jicama, onion, wild yam, and yacón. To utilize inulin as its carbon and energy source directly, a microorganism requires an extracellular inulinase to hydrolyze the glycosidic bonds to release fermentable monosaccharides. Inulinase is produced by many microorganisms, including species of Aspergillus, Kluyveromyces, Penicillium, and Pseudomonas. We review various inulinase-producing microorganisms and inulin feedstocks with potential for industrial application as well as biotechnological efforts underway to develop sustainable practices for the disposal of residues from processing inulin-containing crops. A multi-stage biorefinery concept is proposed to convert cellulosic and inulin-containing waste produced at crop processing operations to valuable biofuels and bioproducts using Kluyveromyces marxianus, Yarrowia lipolytica, Rhodotorula glutinis, and Saccharomyces cerevisiae as well as thermochemical treatments.
Collapse
Affiliation(s)
- Stephen R Hughes
- Renewable Product Technology Research Unit, United States Department of Agriculture (USDA), Agricultural Research Service (ARS), National Center for Agricultural Utilization Research (NCAUR), 1815 North University Street, Peoria, IL, 61604, USA.
| | - Nasib Qureshi
- Bioenergy Research Unit, USDA, ARS, NCAUR, 1815 North University Street, Peoria, IL, 61604, USA
| | - Juan Carlos López-Núñez
- National Coffee Research Centre (Cenicafe), National Federation of Coffee Growers of Colombia (FNC), Cenicafé Planalto Km 4 vía Antigua Chinchiná, Manizales, Caldas, Colombia
| | - Marjorie A Jones
- Department of Chemistry, Illinois State University, Normal, IL, 61790, USA
| | - Joshua M Jarodsky
- Department of Chemistry, Illinois State University, Normal, IL, 61790, USA
| | - Luz Ángela Galindo-Leva
- National Coffee Research Centre (Cenicafe), National Federation of Coffee Growers of Colombia (FNC), Cenicafé Planalto Km 4 vía Antigua Chinchiná, Manizales, Caldas, Colombia
| | - Mitchell R Lindquist
- Renewable Product Technology Research Unit, United States Department of Agriculture (USDA), Agricultural Research Service (ARS), National Center for Agricultural Utilization Research (NCAUR), 1815 North University Street, Peoria, IL, 61604, USA
| |
Collapse
|
20
|
Khatun MM, Liu CG, Zhao XQ, Yuan WJ, Bai FW. Consolidated ethanol production from Jerusalem artichoke tubers at elevated temperature by Saccharomyces cerevisiae engineered with inulinase expression through cell surface display. J Ind Microbiol Biotechnol 2016; 44:295-301. [PMID: 27999966 DOI: 10.1007/s10295-016-1881-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 11/26/2016] [Indexed: 12/30/2022]
Abstract
Ethanol fermentation from Jerusalem artichoke tubers was performed at elevated temperatures by the consolidated bioprocessing strategy using Saccharomyces cerevisiae MK01 expressing inulinase through cell surface display. No significant difference was observed in yeast growth when temperature was controlled at 38 and 40 °C, respectively, but inulinase activity with yeast cells was substantially enhanced at 40 °C. As a result, enzymatic hydrolysis of inulin was facilitated and ethanol production was improved with 89.3 g/L ethanol produced within 72 h from 198.2 g/L total inulin sugars consumed. Similar results were also observed in ethanol production from Jerusalem artichoke tubers with 85.2 g/L ethanol produced within 72 h from 185.7 g/L total sugars consumed. On the other hand, capital investment on cooling facilities and energy consumption for running the facilities would be saved, since regular cooling water instead of chill water could be used to cool down the fermentation system.
Collapse
Affiliation(s)
- M Mahfuza Khatun
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, 116023, China
| | - Chen-Guang Liu
- School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xin-Qing Zhao
- School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Wen-Jie Yuan
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, 116023, China
| | - Feng-Wu Bai
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, 116023, China. .,School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
| |
Collapse
|
21
|
A panorama of bacterial inulinases: Production, purification, characterization and industrial applications. Int J Biol Macromol 2016; 96:312-322. [PMID: 27932256 DOI: 10.1016/j.ijbiomac.2016.12.004] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Revised: 12/01/2016] [Accepted: 12/01/2016] [Indexed: 11/23/2022]
Abstract
Inulinases are important hydrolysing enzymes which specifically act on β-2, 1 linkages of inulin to produce fructose or fructooligosaccharides. Fungi, yeasts and bacteria are the potent microbial sources of inulinases. The data on bacterial inulinases is scarce as compared to other microbial sources. Inulinases yield from bacteria is very less as compared to fungal and yeast sources of inulinases. Submerged fermentation (SmF) is the method of choice for the production of inulinases from bacterial sources. Moreover, inulin is a potent substrate for the production of inulinases in SmF. Many bacterial inulinases have been reported to display magnificent environment abiding features and variability in their biophysical and biochemical properties. These properties have attracted intention of many researchers towards exploring adverse ecological niches for more distinctive inulinase producing bacterial strains. Inulinases are substantially important in current biotechnological era due to their numerous industrial applications. High fructose syrup and fructooligosaccharides are two major industrial applications of inulinases. Additionally, there are many reports on the production of various metabolites like citric acid, lactic acid, ethanol, biofuels, butanediol etc. using mixed cultures of inulinase producing organisms with other microorganisms. The present review mainly envisages inulinase producing bacterial sources, inulinase production, purification, characterization and their applications.
Collapse
|
22
|
Gao J, Yuan W, Li Y, Bai F, Zhong S, Jiang Y. Application of redox potential control to improve ethanol productivity from inulin by consolidated bioprocessing. Process Biochem 2016. [DOI: 10.1016/j.procbio.2016.07.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
23
|
|
24
|
Li QM, Shi Z, Xiong XY, Wen Q, Hu QL, Su XJ. Ethanol production from xylose by Fusarium oxysporum and the optimization of culture conditions. BIOCATAL BIOTRANSFOR 2016. [DOI: 10.1080/10242422.2016.1212848] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Qing-ming Li
- College of Food Science and Technology, Hunan Agricultural University, Changsha, Hunan, PR China,
- Hunan Provincial Key Laboratory of Crop Germplasm Innovation and Utilization, Hunan Agricultural University, Changsha, Hunan, PR China,
| | - Zhuo Shi
- College of Food Science and Technology, Hunan Agricultural University, Changsha, Hunan, PR China,
| | - Xing-yao Xiong
- The Institute of Vegetables and Flowers, Chinese Academy of Agriculture Sciences, Beijing, PR China, and
| | - Qian Wen
- College of Food Science and Technology, Hunan Agricultural University, Changsha, Hunan, PR China,
| | - Qiu-long Hu
- Hunan Provincial Key Laboratory of Crop Germplasm Innovation and Utilization, Hunan Agricultural University, Changsha, Hunan, PR China,
| | - Xiao-jun Su
- Hunan Provincial Key Laboratory of Crop Germplasm Innovation and Utilization, Hunan Agricultural University, Changsha, Hunan, PR China,
- Hunan Collaborative Innovation for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, Hunan, PR China
| |
Collapse
|
25
|
Galindo-Leva LÁ, Hughes SR, López-Núñez JC, Jarodsky JM, Erickson A, Lindquist MR, Cox EJ, Bischoff KM, Hoecker EC, Liu S, Qureshi N, Jones MA. Growth, ethanol production, and inulinase activity on various inulin substrates by mutant Kluyveromyces marxianus strains NRRL Y-50798 and NRRL Y-50799. J Ind Microbiol Biotechnol 2016; 43:927-39. [PMID: 27130462 PMCID: PMC4902847 DOI: 10.1007/s10295-016-1771-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 04/11/2016] [Indexed: 10/26/2022]
Abstract
Economically important plants contain large amounts of inulin. Disposal of waste resulting from their processing presents environmental issues. Finding microorganisms capable of converting inulin waste to biofuel and valuable co-products at the processing site would have significant economic and environmental impact. We evaluated the ability of two mutant strains of Kluyveromyces marxianus (Km7 and Km8) to utilize inulin for ethanol production. In glucose medium, both strains consumed all glucose and produced 0.40 g ethanol/g glucose at 24 h. In inulin medium, Km7 exhibited maximum colony forming units (CFU)/mL and produced 0.35 g ethanol/g inulin at 24 h, while Km8 showed maximum CFU/mL and produced 0.02 g ethanol/g inulin at 96 h. At 24 h in inulin + glucose medium, Km7 produced 0.40 g ethanol/g (inulin + glucose) and Km8 produced 0.20 g ethanol/g (inulin + glucose) with maximum CFU/mL for Km8 at 72 h, 40 % of that for Km7 at 36 h. Extracellular inulinase activity at 6 h for both Km7 and Km8 was 3.7 International Units (IU)/mL.
Collapse
Affiliation(s)
| | - Stephen R Hughes
- United States Department of Agriculture (USDA) Agricultural Research Service (ARS) National Center for Agricultural Utilization Research (NCAUR) Renewable Product Technology Research Unit, 1815, North University Street, Peoria, IL, 61604, USA.
| | - Juan Carlos López-Núñez
- National Coffee Research Centre (Cenicafe) National Federation of Coffee Growers of Colombia (FNC), Cenicafé Planalto Km 4 vía Antigua Chinchiná, Manizales, Caldas, Colombia
| | - Joshua M Jarodsky
- Department of Chemistry, Illinois State University, Normal, IL, 61790-4160, USA
| | - Adam Erickson
- Department of Chemistry, Illinois State University, Normal, IL, 61790-4160, USA
| | - Mitchell R Lindquist
- United States Department of Agriculture (USDA) Agricultural Research Service (ARS) National Center for Agricultural Utilization Research (NCAUR) Renewable Product Technology Research Unit, 1815, North University Street, Peoria, IL, 61604, USA
| | - Elby J Cox
- United States Department of Agriculture (USDA) Agricultural Research Service (ARS) National Center for Agricultural Utilization Research (NCAUR) Renewable Product Technology Research Unit, 1815, North University Street, Peoria, IL, 61604, USA
| | - Kenneth M Bischoff
- United States Department of Agriculture (USDA) Agricultural Research Service (ARS) National Center for Agricultural Utilization Research (NCAUR) Renewable Product Technology Research Unit, 1815, North University Street, Peoria, IL, 61604, USA
| | - Eric C Hoecker
- United States Department of Agriculture (USDA) Agricultural Research Service (ARS) National Center for Agricultural Utilization Research (NCAUR) Renewable Product Technology Research Unit, 1815, North University Street, Peoria, IL, 61604, USA
| | - Siqing Liu
- United States Department of Agriculture (USDA) Agricultural Research Service (ARS) National Center for Agricultural Utilization Research (NCAUR) Renewable Product Technology Research Unit, 1815, North University Street, Peoria, IL, 61604, USA
| | - Nasib Qureshi
- United States Department of Agriculture (USDA) Agricultural Research Service (ARS) National Center for Agricultural Utilization Research (NCAUR) Renewable Product Technology Research Unit, 1815, North University Street, Peoria, IL, 61604, USA
| | - Marjorie A Jones
- Department of Chemistry, Illinois State University, Normal, IL, 61790-4160, USA
| |
Collapse
|
26
|
Choudhary J, Singh S, Nain L. Thermotolerant fermenting yeasts for simultaneous saccharification fermentation of lignocellulosic biomass. ELECTRON J BIOTECHN 2016. [DOI: 10.1016/j.ejbt.2016.02.007] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
27
|
Wang D, Li FL, Wang SA. Engineering a natural Saccharomyces cerevisiae strain for ethanol production from inulin by consolidated bioprocessing. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:96. [PMID: 27134653 PMCID: PMC4851821 DOI: 10.1186/s13068-016-0511-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 04/19/2016] [Indexed: 05/23/2023]
Abstract
BACKGROUND The yeast Saccharomyces cerevisiae is an important eukaryotic workhorse in traditional and modern biotechnology. At present, only a few S. cerevisiae strains have been extensively used as engineering hosts. Recently, an astonishing genotypic and phenotypic diversity of S. cerevisiae was disclosed in natural populations. We suppose that some natural strains can be recruited as superior host candidates in bioengineering. This study engineered a natural S. cerevisiae strain with advantages in inulin utilization to produce ethanol from inulin resources by consolidated bioprocess. Rational engineering strategies were employed, including secretive co-expression of heterologous exo- and endo-inulinases, repression of a protease, and switch between haploid and diploid strains. RESULTS Results from co-expressing endo- and exo-inulinase genes showed that the extracellular inulinase activity increased 20 to 30-fold in engineered S. cerevisiae strains. Repression of the protease PEP4 influenced cell physiology in late stationary phase. Comparison between haploid and diploid engineered strains indicated that diploid strains were superior to haploid strains in ethanol production albeit not in production and secretion of inulinases. Ethanol fermentation from both inulin and Jerusalem artichoke tuber powder was dramatically improved in most engineered strains. Ethanol yield achieved in the ultimate diploid strain JZD-InuMKCP was close to the theoretical maximum. Productivity achieved in the strain JZD-InuMKCP reached to 2.44 and 3.13 g/L/h in fermentation from 200 g/L inulin and 250 g/L raw Jerusalem artichoke tuber powder, respectively. To our knowledge, these are the highest productivities reported up to now in ethanol fermentation from inulin resources. CONCLUSIONS Although model S. cerevisiae strains are preferentially used as hosts in bioengineering, some natural strains do have specific excellent properties. This study successfully engineered a natural S. cerevisiae strain for efficient ethanol production from inulin resources by consolidated bioprocess, which indicated the feasibility of natural strains used as bioengineering hosts. This study also presented different properties in enzyme secretion and ethanol fermentation between haploid and diploid engineering strains. These findings provided guidelines for host selection in bioengineering.
Collapse
Affiliation(s)
- Da Wang
- />Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 China
- />University of Chinese Academy of Sciences, Beijing, 100039 China
| | - Fu-Li Li
- />Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 China
| | - Shi-An Wang
- />Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 China
| |
Collapse
|
28
|
Ethanol Production from Sweet Sorghum Juice at High Temperatures Using a Newly Isolated Thermotolerant Yeast Saccharomyces cerevisiae DBKKU Y-53. ENERGIES 2016. [DOI: 10.3390/en9040253] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
29
|
Rawat HK, Soni H, Treichel H, Kango N. Biotechnological potential of microbial inulinases: Recent perspective. Crit Rev Food Sci Nutr 2016; 57:3818-3829. [DOI: 10.1080/10408398.2016.1147419] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Hemant Kumar Rawat
- Department of Applied Microbiology and Biotechnology, Dr. Harisingh Gour University, Sagar (M.P.), India
| | - Hemant Soni
- Department of Applied Microbiology and Biotechnology, Dr. Harisingh Gour University, Sagar (M.P.), India
| | - Helen Treichel
- Universidade Federal da Fronteira Sul-Campus de Erechim, Erechim, Brazil
| | - Naveen Kango
- Department of Applied Microbiology and Biotechnology, Dr. Harisingh Gour University, Sagar (M.P.), India
| |
Collapse
|
30
|
Celińska E, Borkowska M, Białas W. Evaluation of a recombinant insect-derived amylase performance in simultaneous saccharification and fermentation process with industrial yeasts. Appl Microbiol Biotechnol 2015; 100:2693-707. [PMID: 26545757 PMCID: PMC4761610 DOI: 10.1007/s00253-015-7098-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 10/11/2015] [Accepted: 10/13/2015] [Indexed: 12/18/2022]
Abstract
Starch is the dominant feedstock consumed for the bioethanol production, accounting for 60 % of its global production. Considering the significant contribution of bioethanol to the global fuel market, any improvement in its major operating technologies is economically very attractive. It was estimated that up to 40 % of the final ethanol unit price is derived from the energy input required for the substrate pre-treatment. Application of raw starch hydrolyzing enzymes (RSHE), combined with operation of the process according to a simultaneous saccharification and fermentation (SSF) strategy, constitutes the most promising solutions to the current technologies limitations. In this study, we expressed the novel RSHE derived from an insect in Saccharomyces cerevisiae strain dedicated for the protein overexpression. Afterwards, the enzyme performance was assessed in SSF process conducted by industrial ethanologenic or thermotolerant yeast species. Comparison of the insect-derived RSHE preparation with commercially available amylolytic RSH preparation was conducted. Our results demonstrate that the recombinant alpha-amylase from rice weevil can be efficiently expressed and secreted with its native signal peptide in S. cerevisiae INVSc-pYES2-Amy1 expression system (accounting for nearly 72 % of the strain’s secretome). Application of the recombinant enzyme-based preparation in SSF process secured sufficient amylolytic activity for the yeast cell propagation and ethanol formation from raw starch. (Oligo)saccharide profiles generated by the compared preparations differed with respect to homogeneity of the sugar mixtures. Concomitantly, as demonstrated by a kinetic model developed in this study, the kinetic parameters describing activity of the compared preparations were different.
Collapse
Affiliation(s)
- Ewelina Celińska
- Department of Biotechnology and Food Microbiology, Poznań University of Life Sciences, ul. Wojska Polskiego 48, 60-627, Poznań, Poland.
| | - Monika Borkowska
- Department of Biotechnology and Food Microbiology, Poznań University of Life Sciences, ul. Wojska Polskiego 48, 60-627, Poznań, Poland
| | - Wojciech Białas
- Department of Biotechnology and Food Microbiology, Poznań University of Life Sciences, ul. Wojska Polskiego 48, 60-627, Poznań, Poland
| |
Collapse
|
31
|
Zheng YL, Wang SA. Stress Tolerance Variations in Saccharomyces cerevisiae Strains from Diverse Ecological Sources and Geographical Locations. PLoS One 2015; 10:e0133889. [PMID: 26244846 PMCID: PMC4526645 DOI: 10.1371/journal.pone.0133889] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 07/03/2015] [Indexed: 11/17/2022] Open
Abstract
The budding yeast Saccharomyces cerevisiae is a platform organism for bioethanol production from various feedstocks and robust strains are desirable for efficient fermentation because yeast cells inevitably encounter stressors during the process. Recently, diverse S. cerevisiae lineages were identified, which provided novel resources for understanding stress tolerance variations and related shaping factors in the yeast. This study characterized the tolerance of diverse S. cerevisiae strains to the stressors of high ethanol concentrations, temperature shocks, and osmotic stress. The results showed that the isolates from human-associated environments overall presented a higher level of stress tolerance compared with those from forests spared anthropogenic influences. Statistical analyses indicated that the variations of stress tolerance were significantly correlated with both ecological sources and geographical locations of the strains. This study provides guidelines for selection of robust S. cerevisiae strains for bioethanol production from nature.
Collapse
Affiliation(s)
- Yan-Lin Zheng
- College of Mathematics and Systems Science, Shandong University of Science and Technology, Qingdao, 266590, China
| | - Shi-An Wang
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
| |
Collapse
|
32
|
Gou Y, Li J, Zhu J, Xu W, Gao J. Enhancing inulinase yield by irradiation mutation associated with optimization of culture conditions. Braz J Microbiol 2015; 46:911-20. [PMID: 26413078 PMCID: PMC4568880 DOI: 10.1590/s1517-838246320140918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 01/27/2015] [Indexed: 11/29/2022] Open
Abstract
A new inulinase-producing strain was isolated from rhizosphere soils of Jerusalem
artichoke collected from Shihezi (Xinjiang, China) using Jerusalem artichoke power
(JAP) as sole carbon source. It was identified as an Aspergillus
niger strain by analysis of 16S rRNA. To improve inulinase production,
this fungus was subjected to mutagenesis induced by 60Co γ-irradiation. A
genetically stable mutant (designated E12) was obtained and it showed 2.7-fold higher
inulinase activity (128 U/mL) than the parental strain in the supernatant of a
submerged culture. Sequential methodology was used to optimize the inulinase
production of stain E12. A screening trial was first performed using Plackett-Burman
design and variables with statistically significant effects on inulinase
bio-production were identified. These significant factors were further optimized by
central composite design experiments and response surface methodology. Finally, it
was found that the maximum inulinase production (185 U/mL) could be achieved under
the optimized conditions namely pH 7.0, yeast extract concentration of 5.0 g/L, JAP
concentration of 66.5 g/L, peptone concentration of 29.1 g/L, solution volume of 49.4
mL in 250-mL shake flasks, agitation speed of 180 rpm, and fermentation time of 60 h.
The yield of inulinase under optimized culture conditions was approximately 1.4-fold
of that obtained by using basal culture medium. These findings are of significance
for the potential industrial application of the mutant E12.
Collapse
Affiliation(s)
- Yafeng Gou
- College of Life Science, Shihezi University, Xinjiang, China
| | - Jianhua Li
- College of Life Science, Shihezi University, Xinjiang, China
| | - Junbao Zhu
- College of Life Science, Shihezi University, Xinjiang, China
| | - Wanyun Xu
- College of Life Science, Shihezi University, Xinjiang, China
| | - Jianfeng Gao
- College of Life Science, Shihezi University, Xinjiang, China
| |
Collapse
|
33
|
Radecka D, Mukherjee V, Mateo RQ, Stojiljkovic M, Foulquié-Moreno MR, Thevelein JM. Looking beyond Saccharomyces: the potential of non-conventional yeast species for desirable traits in bioethanol fermentation. FEMS Yeast Res 2015; 15:fov053. [PMID: 26126524 DOI: 10.1093/femsyr/fov053] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2015] [Indexed: 01/18/2023] Open
Abstract
Saccharomyces cerevisiae has been used for millennia in the production of food and beverages and is by far the most studied yeast species. Currently, it is also the most used microorganism in the production of first-generation bioethanol from sugar or starch crops. Second-generation bioethanol, on the other hand, is produced from lignocellulosic feedstocks that are pretreated and hydrolyzed to obtain monomeric sugars, mainly D-glucose, D-xylose and L-arabinose. Recently, S. cerevisiae recombinant strains capable of fermenting pentose sugars have been generated. However, the pretreatment of the biomass results in hydrolysates with high osmolarity and high concentrations of inhibitors. These compounds negatively influence the fermentation process. Therefore, robust strains with high stress tolerance are required. Up to now, more than 2000 yeast species have been described and some of these could provide a solution to these limitations because of their high tolerance to the most predominant stress conditions present in a second-generation bioethanol reactor. In this review, we will summarize what is known about the non-conventional yeast species showing unusual tolerance to these stresses, namely Zygosaccharomyces rouxii (osmotolerance), Kluyveromyces marxianus and Ogataea (Hansenula) polymorpha (thermotolerance), Dekkera bruxellensis (ethanol tolerance), Pichia kudriavzevii (furan derivatives tolerance) and Z. bailii (acetic acid tolerance).
Collapse
Affiliation(s)
- Dorota Radecka
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, Department of Biology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
| | - Vaskar Mukherjee
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, Department of Biology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium Laboratory for Process Microbial Ecology and Bioinspirational Management, Cluster for Bioengineering Technology (CBeT), Department of Microbial and Molecular Systems (M2S), KU Leuven, Campus De Nayer, B-2860 Sint-Katelijne-Waver, Flanders, Belgium
| | - Raquel Quintilla Mateo
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, Department of Biology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
| | - Marija Stojiljkovic
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, Department of Biology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
| | - María R Foulquié-Moreno
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, Department of Biology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
| | - Johan M Thevelein
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, Department of Biology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
| |
Collapse
|
34
|
Charoensopharat K, Thanonkeo P, Thanonkeo S, Yamada M. Ethanol production from Jerusalem artichoke tubers at high temperature by newly isolated thermotolerant inulin-utilizing yeast Kluyveromyces marxianus using consolidated bioprocessing. Antonie van Leeuwenhoek 2015; 108:173-90. [DOI: 10.1007/s10482-015-0476-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Accepted: 05/08/2015] [Indexed: 10/23/2022]
|
35
|
Yang F, Liu ZC, Wang X, Li LL, Yang L, Tang WZ, Yu ZM, Li X. Invertase Suc2-mediated inulin catabolism is regulated at the transcript level in Saccharomyces cerevisiae. Microb Cell Fact 2015; 14:59. [PMID: 25890240 PMCID: PMC4404613 DOI: 10.1186/s12934-015-0243-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 04/08/2015] [Indexed: 11/10/2022] Open
Abstract
Background Invertase Suc2 was recently identified as a key hydrolase for inulin catabolism in Saccharomyces cerevisiae, whereas the Suc2 activity degrading inulin varies greatly in different S. cerevisiae strains. The molecular mechanism causing such variation remained obscure. The aim of this study is to investigate how Suc2 activity is regulated in S. cerevisiae. Results The effect of SUC2 expression level on inulin hydrolysis was investigated by introducing different SUC2 genes or their corresponding promoters in S. cerevisiae strain BY4741 that can only weakly catabolize inulin. Both inulinase and invertase activities were increased with the rising SUC2 expression level. Variation in the promoter sequence has an obvious effect on the transcript level of the SUC2 gene. It was also found that the high expression level of SUC2 was beneficial to inulin degradation and ethanol yield. Conclusions Suc2-mediated inulin catabolism is regulated at transcript level in S. cerevisiae. Our work should be valuable for engineering advanced yeast strains in application of inulin for ethanol production. Electronic supplementary material The online version of this article (doi:10.1186/s12934-015-0243-3) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Fan Yang
- School of Biological Engineering, Dalian Polytechnic University, Dalian, 116034, PR China.
| | - Zhi-Cheng Liu
- School of Biological Engineering, Dalian Polytechnic University, Dalian, 116034, PR China.
| | - Xue Wang
- School of Biological Engineering, Dalian Polytechnic University, Dalian, 116034, PR China.
| | - Li-Li Li
- School of Biological Engineering, Dalian Polytechnic University, Dalian, 116034, PR China.
| | - Lan Yang
- School of Biological Engineering, Dalian Polytechnic University, Dalian, 116034, PR China.
| | - Wen-Zhu Tang
- School of Biological Engineering, Dalian Polytechnic University, Dalian, 116034, PR China.
| | - Zhi-Min Yu
- School of Biological Engineering, Dalian Polytechnic University, Dalian, 116034, PR China.
| | - Xianzhen Li
- School of Biological Engineering, Dalian Polytechnic University, Dalian, 116034, PR China.
| |
Collapse
|
36
|
Hu G, Ji S, Yu Y, Wang S, Zhou G, Li F. Organisms for biofuel production: natural bioresources and methodologies for improving their biosynthetic potentials. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2015; 147:185-224. [PMID: 24085385 DOI: 10.1007/10_2013_245] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
In order to relieve the pressure of energy supply and environment contamination that humans are facing, there are now intensive worldwide efforts to explore natural bioresources for production of energy storage compounds, such as lipids, alcohols, hydrocarbons, and polysaccharides. Around the world, many plants have been evaluated and developed as feedstock for bioenergy production, among which several crops have successfully achieved industrialization. Microalgae are another group of photosynthetic autotroph of interest due to their superior growth rates, relatively high photosynthetic conversion efficiencies, and vast metabolic capabilities. Heterotrophic microorganisms, such as yeast and bacteria, can utilize carbohydrates from lignocellulosic biomass directly or after pretreatment and enzymatic hydrolysis to produce liquid biofuels such as ethanol and butanol. Although finding a suitable organism for biofuel production is not easy, many naturally occurring organisms with good traits have recently been obtained. This review mainly focuses on the new organism resources discovered in the last 5 years for production of transport fuels (biodiesel, gasoline, jet fuel, and alkanes) and hydrogen, and available methods to improve natural organisms as platforms for the production of biofuels.
Collapse
Affiliation(s)
- Guangrong Hu
- Shandong Provincial Key Laboratory of Energy Genetics, Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
| | | | | | | | | | | |
Collapse
|
37
|
Yang L, He QS, Corscadden K, Udenigwe CC. The prospects of Jerusalem artichoke in functional food ingredients and bioenergy production. BIOTECHNOLOGY REPORTS (AMSTERDAM, NETHERLANDS) 2015; 5:77-88. [PMID: 28626686 PMCID: PMC5466194 DOI: 10.1016/j.btre.2014.12.004] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 11/24/2014] [Accepted: 12/08/2014] [Indexed: 01/09/2023]
Abstract
Jerusalem artichoke, a native plant to North America has recently been recognized as a promising biomass for bioeconomy development, with a number of advantages over conventional crops such as low input cultivation, high crop yield, wide adaptation to climatic and soil conditions and strong resistance to pests and plant diseases. A variety of bioproducts can be derived from Jerusalem artichoke, including inulin, fructose, natural fungicides, antioxidant and bioethanol. This paper provides an overview of the cultivation of Jerusalem artichoke, derivation of bioproducts and applicable production technologies, with an expectation to draw more attention on this valuable crop for its applications as biofuel, functional food and bioactive ingredient sources.
Collapse
Affiliation(s)
- Linxi Yang
- Department of Engineering, Faculty of Agriculture, Dalhousie University, Truro, NS B2N 5E3, Canada
| | - Quan Sophia He
- Department of Engineering, Faculty of Agriculture, Dalhousie University, Truro, NS B2N 5E3, Canada
| | - Kenneth Corscadden
- Department of Engineering, Faculty of Agriculture, Dalhousie University, Truro, NS B2N 5E3, Canada
| | - Chibuike C. Udenigwe
- Department of Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, NS B2N 5E3, Canada
| |
Collapse
|
38
|
Naumov GI, Naumova ES. Invertase overproduction may provide for inulin fermentation by selection strains of Saccharomyces cerevisiae. Microbiology (Reading) 2015. [DOI: 10.1134/s0026261715020095] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
39
|
Li H, Wu M, Xu L, Hou J, Guo T, Bao X, Shen Y. Evaluation of industrial Saccharomyces cerevisiae strains as the chassis cell for second-generation bioethanol production. Microb Biotechnol 2015; 8:266-74. [PMID: 25616171 PMCID: PMC4353340 DOI: 10.1111/1751-7915.12245] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 10/13/2014] [Accepted: 10/22/2014] [Indexed: 11/26/2022] Open
Abstract
To develop a suitable Saccharomyces cerevisiae industrial strain as a chassis cell for ethanol production using lignocellulosic materials, 32 wild-type strains were evaluated for their glucose fermenting ability, their tolerance to the stresses they might encounter in lignocellulosic hydrolysate fermentation and their genetic background for pentose metabolism. The strain BSIF, isolated from tropical fruit in Thailand, was selected out of the distinctly different strains studied for its promising characteristics. The maximal specific growth rate of BSIF was as high as 0.65 h(-1) in yeast extract peptone dextrose medium, and the ethanol yield was 0.45 g g(-1) consumed glucose. Furthermore, compared with other strains, this strain exhibited superior tolerance to high temperature, hyperosmotic stress and oxidative stress; better growth performance in lignocellulosic hydrolysate; and better xylose utilization capacity when an initial xylose metabolic pathway was introduced. All of these results indicate that this strain is an excellent chassis strain for lignocellulosic ethanol production.
Collapse
Affiliation(s)
- Hongxing Li
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, China
| | | | | | | | | | | | | |
Collapse
|
40
|
Distinct roles for carbohydrate-binding modules of glycoside hydrolase 10 (GH10) and GH11 xylanases from Caldicellulosiruptor sp. strain F32 in thermostability and catalytic efficiency. Appl Environ Microbiol 2015; 81:2006-14. [PMID: 25576604 DOI: 10.1128/aem.03677-14] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Xylanases are crucial for lignocellulosic biomass deconstruction and generally contain noncatalytic carbohydrate-binding modules (CBMs) accessing recalcitrant polymers. Understanding how multimodular enzymes assemble can benefit protein engineering by aiming at accommodating various environmental conditions. Two multimodular xylanases, XynA and XynB, which belong to glycoside hydrolase families 11 (GH11) and GH10, respectively, have been identified from Caldicellulosiruptor sp. strain F32. In this study, both xylanases and their truncated mutants were overexpressed in Escherichia coli, purified, and characterized. GH11 XynATM1 lacking CBM exhibited a considerable improvement in specific activity (215.8 U nmol(-1) versus 94.7 U nmol(-1)) and thermal stability (half-life of 48 h versus 5.5 h at 75°C) compared with those of XynA. However, GH10 XynB showed higher enzyme activity and thermostability than its truncated mutant without CBM. Site-directed mutagenesis of N-terminal amino acids resulted in a mutant, XynATM1-M, with 50% residual activity improvement at 75°C for 48 h, revealing that the disordered region influenced protein thermostability negatively. The thermal stability of both xylanases and their truncated mutants were consistent with their melting temperature (Tm), which was determined by using differential scanning calorimetry. Through homology modeling and cross-linking analysis, we demonstrated that for XynB, the resistance against thermoinactivation generally was enhanced through improving both domain properties and interdomain interactions, whereas for XynA, no interdomain interactions were observed. Optimized intramolecular interactions can accelerate thermostability, which provided microbes a powerful evolutionary strategy to assemble catalysts that are adapted to various ecological conditions.
Collapse
|
41
|
Meng DD, Ying Y, Zhang KD, Lu M, Li FL. Depiction of carbohydrate-active enzyme diversity in Caldicellulosiruptor sp. F32 at the genome level reveals insights into distinct polysaccharide degradation features. MOLECULAR BIOSYSTEMS 2015; 11:3164-73. [DOI: 10.1039/c5mb00409h] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Diverse and distinctive encoding sequences of CAZyme in the genome of Caldicellulosiruptor sp. F32 enable the deconstruction of unpretreated lignocellulose.
Collapse
Affiliation(s)
- Dong-Dong Meng
- Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Energy Genetics
- Qingdao Institute of Bioenergy and Bioprocess Technology
- Chinese Academy of Sciences
- Qingdao
| | - Yu Ying
- Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Energy Genetics
- Qingdao Institute of Bioenergy and Bioprocess Technology
- Chinese Academy of Sciences
- Qingdao
| | - Kun-Di Zhang
- Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Energy Genetics
- Qingdao Institute of Bioenergy and Bioprocess Technology
- Chinese Academy of Sciences
- Qingdao
| | - Ming Lu
- Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Energy Genetics
- Qingdao Institute of Bioenergy and Bioprocess Technology
- Chinese Academy of Sciences
- Qingdao
| | - Fu-Li Li
- Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Energy Genetics
- Qingdao Institute of Bioenergy and Bioprocess Technology
- Chinese Academy of Sciences
- Qingdao
| |
Collapse
|
42
|
Current Trends in Bioethanol Production by Saccharomyces cerevisiae: Substrate, Inhibitor Reduction, Growth Variables, Coculture, and Immobilization. INTERNATIONAL SCHOLARLY RESEARCH NOTICES 2014; 2014:532852. [PMID: 27379305 PMCID: PMC4897133 DOI: 10.1155/2014/532852] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 11/18/2014] [Indexed: 11/24/2022]
Abstract
Bioethanol is one of the most commonly used biofuels in transportation sector to reduce greenhouse gases. S. cerevisiae is the most employed yeast for ethanol production at industrial level though ethanol is produced by an array of other yeasts, bacteria, and fungi. This paper reviews the current and nonmolecular trends in ethanol production using S. cerevisiae. Ethanol has been produced from wide range of substrates such as molasses, starch based substrate, sweet sorghum cane extract, lignocellulose, and other wastes. The inhibitors in lignocellulosic hydrolysates can be reduced by repeated sequential fermentation, treatment with reducing agents and activated charcoal, overliming, anion exchanger, evaporation, enzymatic treatment with peroxidase and laccase, in situ detoxification by fermenting microbes, and different extraction methods. Coculturing S. cerevisiae with other yeasts or microbes is targeted to optimize ethanol production, shorten fermentation time, and reduce process cost. Immobilization of yeast cells has been considered as potential alternative for enhancing ethanol productivity, because immobilizing yeasts reduce risk of contamination, make the separation of cell mass from the bulk liquid easy, retain stability of cell activities, minimize production costs, enable biocatalyst recycling, reduce fermentation time, and protect the cells from inhibitors. The effects of growth variables of the yeast and supplementation of external nitrogen sources on ethanol optimization are also reviewed.
Collapse
|
43
|
Enhanced expression of the codon-optimized exo-inulinase gene from the yeast Meyerozyma guilliermondii in Saccharomyces sp. W0 and bioethanol production from inulin. Appl Microbiol Biotechnol 2014; 98:9129-38. [DOI: 10.1007/s00253-014-6079-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 08/30/2014] [Accepted: 09/02/2014] [Indexed: 10/24/2022]
|
44
|
Optimizing promoters and secretory signal sequences for producing ethanol from inulin by recombinant Saccharomyces cerevisiae carrying Kluyveromyces marxianus inulinase. Bioprocess Biosyst Eng 2014; 38:263-72. [DOI: 10.1007/s00449-014-1265-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 07/29/2014] [Indexed: 10/24/2022]
|
45
|
Yang F, Liu Z, Dong W, Zhu L, Chen X, Li X. Ethanol production using a newly isolated Saccharomyces cerevisiae strain directly assimilating intact inulin with a high degree of polymerization. Biotechnol Appl Biochem 2014; 61:418-25. [PMID: 24237352 DOI: 10.1002/bab.1181] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 10/28/2013] [Indexed: 11/11/2022]
Abstract
An inulin-degrading strain L610, which was competent to directly convert inulin into ethanol, was isolated and identified as a strain of Saccharomyces cerevisiae according to physiological and phylogenetic analysis. Ion chromatography results showed that isolate L610 could assimilate the intact inulin completely without acidic or enzymatic pretreatment in contrast to the previously reported strains of S. cerevisiae, which could only ferment the fructo-oligosaccharides with a degree of polymerization less than 15. Strain L610 yielded 37.2 g/L ethanol within 48 H at a shake flask level under the evaluated culture conditions (11% inulin, 0.4% yeast extract, and 0.05% MgSO4 at 30 °C and pH 6.0). The conversion efficiency of inulin-type sugar to ethanol was 60% of the theoretical ethanol yield. Strain L610 produced 40.0 g/L of ethanol when directly fermented in Jerusalem artichoke (Helianthus tuberosus L.) powder suspension within 24 H, which was higher than the reported data, 28.9 g/L, produced by S. cerevisiae KCCM 50549.
Collapse
Affiliation(s)
- Fan Yang
- School of Biological Engineering, Dalian Polytechnic University, Ganjingqu, Dalian, People's Republic of China
| | - Zhicheng Liu
- School of Biological Engineering, Dalian Polytechnic University, Ganjingqu, Dalian, People's Republic of China
| | - Weifeng Dong
- Liaoning Entry-Exit Inspection and Quarantine Bureau, Zhongshanqu, Dalian, People's Republic of China
| | - Linghuan Zhu
- School of Biological Engineering, Dalian Polytechnic University, Ganjingqu, Dalian, People's Republic of China
| | - Xiaoyi Chen
- School of Biological Engineering, Dalian Polytechnic University, Ganjingqu, Dalian, People's Republic of China
| | - Xianzhen Li
- School of Biological Engineering, Dalian Polytechnic University, Ganjingqu, Dalian, People's Republic of China
| |
Collapse
|
46
|
Castro RCA, Roberto IC. Selection of a Thermotolerant Kluyveromyces marxianus Strain with Potential Application for Cellulosic Ethanol Production by Simultaneous Saccharification and Fermentation. Appl Biochem Biotechnol 2013; 172:1553-64. [DOI: 10.1007/s12010-013-0612-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Accepted: 10/28/2013] [Indexed: 11/25/2022]
|
47
|
Flores JA, Gschaedler A, Amaya-Delgado L, Herrera-López EJ, Arellano M, Arrizon J. Simultaneous saccharification and fermentation of Agave tequilana fructans by Kluyveromyces marxianus yeasts for bioethanol and tequila production. BIORESOURCE TECHNOLOGY 2013; 146:267-273. [PMID: 23941710 DOI: 10.1016/j.biortech.2013.07.078] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 07/16/2013] [Accepted: 07/18/2013] [Indexed: 06/02/2023]
Abstract
Agave tequilana fructans (ATF) constitute a substrate for bioethanol and tequila industries. As Kluyveromyces marxianus produces specific fructanases for ATF hydrolysis, as well as ethanol, it can perform simultaneous saccharification and fermentation. In this work, fifteen K. marxianus yeasts were evaluated to develop inoculums with fructanase activity on ATF. These inoculums were added to an ATF medium for simultaneous saccharification and fermentation. All the yeasts, showed exo-fructanhydrolase activity with different substrate specificities. The yeast with highest fructanase activity in the inoculums showed the lowest ethanol production level (20 g/l). Five K. marxianus strains were the most suitable for the simultaneous saccharification and fermentation of ATF. The volatile compounds composition was evaluated at the end of fermentation, and a high diversity was observed between yeasts, nevertheless all of them produced high levels of isobutyl alcohol. The simultaneous saccharification and fermentation of ATF with K. marxianus strains has potential for industrial application.
Collapse
Affiliation(s)
- Jose-Axel Flores
- Unidad de Biotecnología Industrial, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, A.C. Avenida Normalistas 800, Col. Colinas de la Normal, C.P. 44270 Guadalajara, Jal., Mexico
| | - Anne Gschaedler
- Unidad de Biotecnología Industrial, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, A.C. Avenida Normalistas 800, Col. Colinas de la Normal, C.P. 44270 Guadalajara, Jal., Mexico
| | - Lorena Amaya-Delgado
- Unidad de Biotecnología Industrial, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, A.C. Avenida Normalistas 800, Col. Colinas de la Normal, C.P. 44270 Guadalajara, Jal., Mexico
| | - Enrique J Herrera-López
- Unidad de Biotecnología Industrial, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, A.C. Avenida Normalistas 800, Col. Colinas de la Normal, C.P. 44270 Guadalajara, Jal., Mexico
| | - Melchor Arellano
- Unidad de Biotecnología Industrial, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, A.C. Avenida Normalistas 800, Col. Colinas de la Normal, C.P. 44270 Guadalajara, Jal., Mexico
| | - Javier Arrizon
- Unidad de Biotecnología Industrial, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, A.C. Avenida Normalistas 800, Col. Colinas de la Normal, C.P. 44270 Guadalajara, Jal., Mexico.
| |
Collapse
|
48
|
Yuan WJ, Li NN, Zhao XQ, Chen LJ, Kong L, Bai FW. Engineering an industrialSaccharomyces cerevisiaestrain with the inulinase gene for more efficient ethanol production from Jerusalem artichoke tubers. Eng Life Sci 2013. [DOI: 10.1002/elsc.201200199] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Wen-Jie Yuan
- School of Life Science and Biotechnology; Dalian University of Technology; Dalian China
| | - Nan-Nan Li
- School of Life Science and Biotechnology; Dalian University of Technology; Dalian China
| | - Xin-Qing Zhao
- School of Life Science and Biotechnology; Dalian University of Technology; Dalian China
| | - Li-Jie Chen
- School of Life Science and Biotechnology; Dalian University of Technology; Dalian China
| | - Liang Kong
- College of Marine Technology and Environment; Dalian Ocean University; Dalian China
| | - Feng-Wu Bai
- School of Life Science and Biotechnology; Dalian University of Technology; Dalian China
| |
Collapse
|
49
|
Yuan B, Wang SA, Li FL. Improved ethanol fermentation by heterologous endoinulinase and inherent invertase from inulin by Saccharomyces cerevisiae. BIORESOURCE TECHNOLOGY 2013; 139:402-405. [PMID: 23683966 DOI: 10.1016/j.biortech.2013.04.076] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 04/17/2013] [Accepted: 04/19/2013] [Indexed: 06/02/2023]
Abstract
It is hypothesized that introduction of an endoinulinase gene into Saccharomyces cerevisiae will improve its inulin utilization and ethanol fermentation through collaboration between the heterologous endoinulinase and the inherent invertase SUC2. The aim of this work was to test the hypothesis by introducing the endoinulinase gene inuA from Aspergillus niger into S. cerevisiae. The results showed that heterologous inuA expressed in S. cerevisiae selectively digested long chains of inulin into short fructooligosaccharides and parts of these fructooligosaccharides could be efficiently utilized by the yeast. This study demonstrated that collaboration between heterologous endoinulinase and inherent invertase improved inulin degradation and ethanol fermentation in S. cerevisiae.
Collapse
Affiliation(s)
- Bo Yuan
- Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
| | | | | |
Collapse
|
50
|
Expression of exoinulinase genes in Saccharomyces cerevisiae to improve ethanol production from inulin sources. Biotechnol Lett 2013; 35:1589-92. [DOI: 10.1007/s10529-013-1251-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 05/24/2013] [Indexed: 11/26/2022]
|