1
|
Tian M, Cheng J, Guo M. Stability, Digestion, and Cellular Transport of Soy Isoflavones Nanoparticles Stabilized by Polymerized Goat Milk Whey Protein. Antioxidants (Basel) 2024; 13:567. [PMID: 38790672 PMCID: PMC11117734 DOI: 10.3390/antiox13050567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 04/28/2024] [Accepted: 04/29/2024] [Indexed: 05/26/2024] Open
Abstract
Soy isoflavones (SIF) are bioactive compounds with low bioavailability due to their poor water solubility. In this study, we utilized polymerized goat milk whey protein (PGWP) as a carrier to encapsulate SIF with encapsulation efficiency of 89%, particle size of 135.53 nm, and zeta potential of -35.16 mV. The PGWP-SIF nanoparticles were evaluated for their stability and in vitro digestion properties, and their ability to transport SIF was assessed using a Caco-2 cell monolayer model. The nanoparticles were resistant to aggregation when subjected to pH changes (pH 2.0 to 8.0), sodium chloride addition (0-200 mM), temperature fluctuations (4 °C, 25 °C, and 37 °C), and long-term storage (4 °C, 25 °C, and 37 °C for 30 days), which was mainly attributed to the repulsion generated by steric hindrance effects. During gastric digestion, only 5.93% of encapsulated SIF was released, highlighting the nanoparticles' resistance to enzymatic digestion in the stomach. However, a significant increase in SIF release to 56.61% was observed during intestinal digestion, indicating the efficient transport of SIF into the small intestine for absorption. Cytotoxicity assessments via the MTT assay showed no adverse effects on Caco-2 cell lines after encapsulation. The PGWP-stabilized SIF nanoparticles improved the apparent permeability coefficient (Papp) of Caco-2 cells for SIF by 11.8-fold. The results indicated that using PGWP to encapsulate SIF was an effective approach for delivering SIF, while enhancing its bioavailability and transcellular transport.
Collapse
Affiliation(s)
- Mu Tian
- College of Food Science and Technology, Southwest Minzu University, Chengdu 610041, China;
- Key Laboratory of Dairy Science, Northeast Agricultural University, Harbin 150030, China;
| | - Jianjun Cheng
- Key Laboratory of Dairy Science, Northeast Agricultural University, Harbin 150030, China;
| | - Mingruo Guo
- Department of Nutrition and Food Sciences, College of Agriculture and Life Sciences, University of Vermont, Burlington, VT 05405, USA
| |
Collapse
|
2
|
Liu Q, Sun Y, Zhang J, Zhang M, Cheng J, Guo M. Physicochemical and in vitro digestion properties of soy isoflavones loaded whey protein nanoparticles using a pH-driven method. INNOV FOOD SCI EMERG 2022. [DOI: 10.1016/j.ifset.2022.103209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
|
3
|
Deciphering Molecular Mechanism Underlying Self-Flocculation of Zymomonas mobilis for Robust Production. Appl Environ Microbiol 2022; 88:e0239821. [PMID: 35465724 DOI: 10.1128/aem.02398-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Zymomonas mobilis metabolizes sugar anaerobically through the Entner-Doudoroff pathway with less ATP generated for lower biomass accumulation to direct more sugar for product formation with improved yield, making it a suitable host to be engineered as microbial cell factories for producing bulk commodities with major costs from feedstock consumption. Self-flocculation of the bacterial cells presents many advantages, such as enhanced tolerance to environmental stresses, a prerequisite for achieving high product titers by using concentrated substrates. ZM401, a self-flocculating mutant developed from ZM4, the unicellular model strain of Z. mobilis, was employed in this work to explore the molecular mechanism underlying this self-flocculating phenotype. Comparative studies between ZM401 and ZM4 indicate that a frameshift caused by a single nucleotide deletion in the poly-T tract of ZMO1082 fused the putative gene with the open reading frame of ZMO1083, encoding the catalytic subunit BcsA of the bacterial cellulose synthase to catalyze cellulose biosynthesis. Furthermore, the single nucleotide polymorphism mutation in the open reading frame of ZMO1055, encoding a bifunctional GGDEF-EAL protein with apparent diguanylate cyclase/phosphodiesterase activities, resulted in the Ala526Val substitution, which consequently compromised in vivo specific phosphodiesterase activity for the degradation of cyclic diguanylic acid, leading to intracellular accumulation of the signaling molecule to activate cellulose biosynthesis. These discoveries are significant for engineering other unicellular strains from Z. mobilis with the self-flocculating phenotype for robust production. IMPORTANCE Stress tolerance is a prerequisite for microbial cell factories to be robust in production, particularly for biorefinery of lignocellulosic biomass to produce biofuels, bioenergy, and bio-based chemicals for sustainable socioeconomic development, since various inhibitors are released during the pretreatment to destroy the recalcitrant lignin-carbohydrate complex for sugar production through enzymatic hydrolysis of the cellulose component, and their detoxification is too costly for producing bulk commodities. Although tolerance to individual stress has been intensively studied, the progress seems less significant since microbial cells are inevitably suffering from multiple stresses simultaneously under production conditions. When self-flocculating, microbial cells are more tolerant to multiple stresses through the general stress response due to enhanced quorum sensing associated with the morphological change for physiological and metabolic advantages. Therefore, elucidation of the molecular mechanism underlying such a self-flocculating phenotype is significant for engineering microbial cells with the unique multicellular morphology through rational design to boost their production performance.
Collapse
|
4
|
Liu Q, Sun Y, Cheng J, Guo M. Development of whey protein nanoparticles as carriers to deliver soy isoflavones. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2021.112953] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
5
|
Wu S, Li YS, Wang XL. A flow-injection system exploiting focused beam reflectance applied to the determination of high concentrations of sulfate. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2021; 13:1147-1153. [PMID: 33576362 DOI: 10.1039/d0ay01707h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
To evaluate the grain size and particle number formed in a non-equilibrium flow mixing state, flow-injection analysis (FIA) was combined with focused beam reflectance measurement (FBRM). The influence of BaCl2, PEG-4000, ethanol, flowrate, temperature and acidity on the dynamic formation of BaSO4 particles was evaluated. Optimization parameters obtained were 5% BaCl2 as the reagent, 2% PEG-4000 + 6% ethanol as the stabilizer and 0.3 mol L-1 HCl as the carrier with 4 ml min-1 flowrate, and the BaSO4 particle size distribution in the system was in the 1-50 μm range. Under optimized conditions, the system was successfully used for the determination of high sulfate concentrations in the wet-process phosphoric acid process in the 3.2-48 g L-1 (Sct = 55c + 208, r = 0.998, n = 3) range for SO42-. The relative standard deviation was less than 1.86% (n = 11), the detection limit was 0.95 g L-1, the sample throughput reached 30 samples per h, recovery data were within the 97-106% range, and the results were consistent with those of gravimetry (RD < 3%). The system avoids the large error caused by high dilution and the slow analysis speed when measuring high sulfate concentrations.
Collapse
Affiliation(s)
- Su Wu
- School of Chemical Engineering, Sichuan University, Chengdu 610065, China.
| | | | | |
Collapse
|
6
|
Gustavsson R, Mandenius CF, Löfgren S, Scheper T, Lindner P. In situ microscopy as online tool for detecting microbial contaminations in cell culture. J Biotechnol 2019; 296:53-60. [PMID: 30898686 DOI: 10.1016/j.jbiotec.2019.03.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 03/14/2019] [Accepted: 03/15/2019] [Indexed: 11/25/2022]
Abstract
Microbial contamination in mammalian cell cultures causing rejected batches is costly and highly unwanted. Most methods for detecting a contamination are time-consuming and require extensive off-line sampling. To circumvent these efforts and provide a more convenient alternative, we used an online in situ microscope to estimate the cell diameter of the cellular species in the culture to distinguish mammalian cells from microbial cells depending on their size. A warning system was set up to alert the operator if microbial cells were present in the culture. Hybridoma cells were cultured and infected with either Candida utilis or Pichia stipitis as contaminant. The warning system could successfully detect the introduced contamination and alert the operator. The results suggest that in situ microscopy could be used as an efficient online tool for early detection of contaminations in cell cultures.
Collapse
Affiliation(s)
- R Gustavsson
- Division of Biotechnology, Department of Physics, Chemistry and Biology, Linköping University, 581 83, Linköping, Sweden
| | - C F Mandenius
- Division of Biotechnology, Department of Physics, Chemistry and Biology, Linköping University, 581 83, Linköping, Sweden.
| | - S Löfgren
- Division of Biotechnology, Department of Physics, Chemistry and Biology, Linköping University, 581 83, Linköping, Sweden
| | - T Scheper
- Institute of Technical Chemistry, Leibniz University Hannover, 30167, Hanover, Germany
| | - P Lindner
- Institute of Technical Chemistry, Leibniz University Hannover, 30167, Hanover, Germany
| |
Collapse
|
7
|
Liu CG, Li ZY, Hao Y, Xia J, Bai FW, Mehmood MA. Computer Simulation Elucidates Yeast Flocculation and Sedimentation for Efficient Industrial Fermentation. Biotechnol J 2018; 13:e1700697. [DOI: 10.1002/biot.201700697] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 12/31/2017] [Indexed: 11/10/2022]
Affiliation(s)
- Chen-Guang Liu
- State Key Laboratory of Microbial Metabolism; School of Life Sciences & Biotechnology; Shanghai Jiao Tong University; Shanghai 200240 China
| | - Zhi-Yang Li
- School of Information Science and Technology; Dalian Maritime University; Dalian Liaoning 116023 China
| | - Yue Hao
- Key Laboratory of Pollinating Insect Biology of the Ministry of Agriculture; Institute of Apicultural Research; Chinese Academy of Agricultural Sciences; Beijing 100093 China
| | - Juan Xia
- State Key Laboratory of Microbial Metabolism; School of Life Sciences & Biotechnology; Shanghai Jiao Tong University; Shanghai 200240 China
| | - Feng-Wu Bai
- State Key Laboratory of Microbial Metabolism; School of Life Sciences & Biotechnology; Shanghai Jiao Tong University; Shanghai 200240 China
| | - Muhammad Aamer Mehmood
- State Key Laboratory of Microbial Metabolism; School of Life Sciences & Biotechnology; Shanghai Jiao Tong University; Shanghai 200240 China
- Department of Bioinformatics & Biotechnology; Bioenergy Research Centre; Government College University Faisalabad; Faisalabad-38000 Pakistan
| |
Collapse
|
8
|
Lemoine A, Delvigne F, Bockisch A, Neubauer P, Junne S. Tools for the determination of population heterogeneity caused by inhomogeneous cultivation conditions. J Biotechnol 2017; 251:84-93. [DOI: 10.1016/j.jbiotec.2017.03.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 03/17/2017] [Accepted: 03/21/2017] [Indexed: 01/01/2023]
|
9
|
Cheng C, Zhang M, Xue C, Bai F, Zhao X. Development of stress tolerant Saccharomyces cerevisiae strains by metabolic engineering: New aspects from cell flocculation and zinc supplementation. J Biosci Bioeng 2016; 123:141-146. [PMID: 27576171 DOI: 10.1016/j.jbiosc.2016.07.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 07/29/2016] [Indexed: 10/21/2022]
Abstract
Budding yeast Saccharomyces cerevisiae is widely studied for the production of biofuels from lignocellulosic biomass. However, economic production is currently challenged by the repression of cell growth and compromised fermentation performance of S. cerevisiae strains in the presence of various environmental stresses, including toxic level of final products, inhibitory compounds released from the pretreatment of cellulosic feedstocks, high temperature, and so on. Therefore, it is important to improve stress tolerance of S. cerevisiae to these stressful conditions to achieve efficient and economic production. In this review, the latest advances on development of stress tolerant S. cerevisiae strains are summarized, with the emphasis on the impact of cell flocculation and zinc addition. It was found that cell flocculation affected ethanol tolerance and acetic acid tolerance of S. cerevisiae, and addition of zinc to a suitable level improved stress tolerance of yeast cells to ethanol, high temperature and acetic acid. Further studies on the underlying mechanisms by which cell flocculation and zinc status affect stress tolerance will not only enrich our knowledge on stress response and tolerance mechanisms of S. cerevisiae, but also provide novel metabolic engineering strategies to develop robust yeast strains for biofuels production.
Collapse
Affiliation(s)
- Cheng Cheng
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, China
| | - Mingming Zhang
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, China
| | - Chuang Xue
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, China
| | - Fengwu Bai
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, China; State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xinqing Zhao
- State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
| |
Collapse
|
10
|
Liu CG, Hao XM, Lin YH, Bai FW. Redox potential driven aeration during very-high-gravity ethanol fermentation by using flocculating yeast. Sci Rep 2016; 6:25763. [PMID: 27161047 PMCID: PMC4861961 DOI: 10.1038/srep25763] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 04/21/2016] [Indexed: 11/09/2022] Open
Abstract
Ethanol fermentation requires oxygen to maintain high biomass and cell viability, especially under very-high-gravity (VHG) condition. In this work, fermentation redox potential (ORP) was applied to drive the aeration process at low dissolved oxygen (DO) levels, which is infeasible to be regulated by a DO sensor. The performance and characteristics of flocculating yeast grown under 300 and 260 g glucose/L conditions were subjected to various aeration strategies including: no aeration; controlled aeration at -150, -100 and -50 mV levels; and constant aeration at 0.05 and 0.2 vvm. The results showed that anaerobic fermentation produced the least ethanol and had the highest residual glucose after 72 h of fermentation. Controlled aerations, depending on the real-time oxygen demand, led to higher cell viability than the no-aeration counterpart. Constant aeration triggered a quick biomass formation, and fast glucose utilization. However, over aeration at 0.2 vvm caused a reduction of final ethanol concentration. The controlled aeration driven by ORP under VHG conditions resulted in the best fermentation performance. Moreover, the controlled aeration could enhance yeast flocculating activity, promote an increase of flocs size, and accelerate yeast separation near the end of fermentation.
Collapse
Affiliation(s)
- Chen-Guang Liu
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.,School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116023, China
| | - Xue-Mi Hao
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116023, China
| | - Yen-Han Lin
- Department of Chemical and Biological Engineering, University of Saskatchewan, Saskatoon SK S7N 5A9, Canada
| | - Feng-Wu Bai
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.,School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116023, China
| |
Collapse
|
11
|
Zhao N, Bai Y, Liu CG, Zhao XQ, Xu JF, Bai FW. FlocculatingZymomonas mobilisis a promising host to be engineered for fuel ethanol production from lignocellulosic biomass. Biotechnol J 2013; 9:362-71. [DOI: 10.1002/biot.201300367] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 10/31/2013] [Indexed: 11/07/2022]
|
12
|
Display of active beta-glucosidase on the surface of Schizosaccharomyces pombe cells using novel anchor proteins. Appl Microbiol Biotechnol 2013; 97:4343-52. [PMID: 23385477 DOI: 10.1007/s00253-013-4733-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 01/17/2013] [Accepted: 01/20/2013] [Indexed: 10/27/2022]
Abstract
Here, we demonstrate display of beta-glucosidase (BGL) on the surface of Schizosaccharomyces pombe cells using novel anchor proteins. A total of four candidate anchor proteins (SPBC21D10.06c, SPBC947.04, SPBC19C7.05, and SPBC359.04c) were selected from among almost all of S. pombe membrane proteins. The C-terminus of each anchor protein was genetically fused to the N-terminus of BGL, and the fusion protein was expressed using S. pombe as a host. The highest cell surface-associated BGL activity (107 U/10(5) cells was achieved with SPBC359.04c serving as the anchor, followed by SPBC947.04 (44 U/10(5) cells) and SPBC21D10.06c (38 U/10(5) cells). S. pombe displaying BGL with SPBC359.04c as an anchor showed the highest growth on 2 % cellobiose (10.7 × 10(7) cells/mL after 41 h of cultivation from an initial density of 0.1 × 10(7) cells/mL). Additionally, culturing BGL-displaying S. pombe in medium containing cellobiose as the sole carbon source did not affect protein expression, and ethanol fermentation from cellobiose was successfully demonstrated using BGL-displaying S. pombe. This is the first report describing a cell surface display system for the functionalization of S. pombe.
Collapse
|
13
|
Optimization of Insect Cell Based Protein Production Processes - Online Monitoring, Expression Systems, Scale Up. YELLOW BIOTECHNOLOGY II 2013; 136:65-100. [DOI: 10.1007/10_2013_205] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
|
14
|
Ge X, Zhang N, Phillips GC, Xu J. Growing Lemna minor in agricultural wastewater and converting the duckweed biomass to ethanol. BIORESOURCE TECHNOLOGY 2012; 124:485-8. [PMID: 22985823 DOI: 10.1016/j.biortech.2012.08.050] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 08/10/2012] [Accepted: 08/12/2012] [Indexed: 05/16/2023]
Abstract
Duckweed (Lemna minor) was grown in swine lagoon wastewater and Schenk & Hildebrandt medium with a growth rate of 3.5 and 14.1 g m(-2)day(-1) (dry basis), respectively detected. The rapid accumulation of starch in duckweed biomass (10-36%, w/w) was triggered by nutrient starvation or growing in dark with addition of glucose. The harvested duckweed biomass (from culture in wastewater) contained 20.3% (w/w) total glucan, 32.3% (w/w) proteins, trace hemicellulose and undetectable lignin. Without prior thermal-chemical pretreatment, up to 96.2% (w/w) of glucose could be enzymatically released from both the cellulose and starch fractions of duckweed biomass. The enzymatic hydrolysates could be efficiently fermented by two yeast strains (self-flocculating yeast SPSC01 and conventional yeast ATCC 24859) with a high ethanol yield of 0.485 g g(-1) (glucose).
Collapse
Affiliation(s)
- Xumeng Ge
- Arkansas Biosciences Institute, Arkansas State University, Jonesboro, AR 72401, USA
| | | | | | | |
Collapse
|
15
|
Zhao XQ, Li Q, He LY, Li F, Que WW, Bai FW. Exploration of a natural reservoir of flocculating genes from various Saccharomyces cerevisiae strains and improved ethanol fermentation using stable genetically engineered flocculating yeast strains. Process Biochem 2012. [DOI: 10.1016/j.procbio.2011.06.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
16
|
Liu CG, Wang N, Lin YH, Bai FW. Very high gravity ethanol fermentation by flocculating yeast under redox potential-controlled conditions. BIOTECHNOLOGY FOR BIOFUELS 2012; 5:61. [PMID: 22917193 PMCID: PMC3494525 DOI: 10.1186/1754-6834-5-61] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Accepted: 08/17/2012] [Indexed: 06/01/2023]
Abstract
BACKGROUND Very high gravity (VHG) fermentation using medium in excess of 250 g/L sugars for more than 15% (v) ethanol can save energy consumption, not only for ethanol distillation, but also for distillage treatment; however, stuck fermentation with prolonged fermentation time and more sugars unfermented is the biggest challenge. Controlling redox potential (ORP) during VHG fermentation benefits biomass accumulation and improvement of yeast cell viability that is affected by osmotic pressure and ethanol inhibition, enhancing ethanol productivity and yield, the most important techno-economic aspect of fuel ethanol production. RESULTS Batch fermentation was performed under different ORP conditions using the flocculating yeast and media containing glucose of 201 ± 3.1, 252 ± 2.9 and 298 ± 3.8 g/L. Compared with ethanol fermentation by non-flocculating yeast, different ORP profiles were observed with the flocculating yeast due to the morphological change associated with the flocculation of yeast cells. When ORP was controlled at -100 mV, ethanol fermentation with the high gravity (HG) media containing glucose of 201 ± 3.1 and 252 ± 2.9 g/L was completed at 32 and 56 h, respectively, producing 93.0 ± 1.3 and 120.0 ± 1.8 g/L ethanol, correspondingly. In contrast, there were 24.0 ± 0.4 and 17.0 ± 0.3 g/L glucose remained unfermented without ORP control. As high as 131.0 ± 1.8 g/L ethanol was produced at 72 h when ORP was controlled at -150 mV for the VHG fermentation with medium containing 298 ± 3.8 g/L glucose, since yeast cell viability was improved more significantly. CONCLUSIONS No lag phase was observed during ethanol fermentation with the flocculating yeast, and the implementation of ORP control improved ethanol productivity and yield. When ORP was controlled at -150 mV, more reducing power was available for yeast cells to survive, which in turn improved their viability and VHG ethanol fermentation performance. On the other hand, controlling ORP at -100 mV stimulated yeast growth and enhanced ethanol production under the HG conditions. Moreover, the ORP profile detected during ethanol fermentation with the flocculating yeast was less fluctuated, indicating that yeast flocculation could attenuate the ORP fluctuation observed during ethanol fermentation with non-flocculating yeast.
Collapse
Affiliation(s)
- Chen-Guang Liu
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, 116023, China
| | - Na Wang
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, 116023, China
| | - Yen-Han Lin
- Department of Chemical Engineering, University of Saskatchewan, Saskatoon, SK S7N5A9, Canada
| | - Feng-Wu Bai
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, 116023, China
| |
Collapse
|
17
|
Ge X, Green VS, Zhang N, Sivakumar G, Xu J. Eastern gamagrass as an alternative cellulosic feedstock for bioethanol production. Process Biochem 2012. [DOI: 10.1016/j.procbio.2011.11.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
18
|
Whelan J, Murphy E, Pearson A, Jeffers P, Kieran P, McDonnell S, Raposo S, Lima-Costa ME, Glennon B. Use of focussed beam reflectance measurement (FBRM) for monitoring changes in biomass concentration. Bioprocess Biosyst Eng 2012; 35:963-75. [PMID: 22246535 DOI: 10.1007/s00449-012-0681-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Accepted: 01/05/2012] [Indexed: 11/28/2022]
Abstract
The potential of focussed beam reflectance measurement (FBRM) as a tool to monitor changes in biomass concentration was investigated in a number of biological systems. The measurement technique was applied to two morphologically dissimilar plant cell suspension cultures, Morinda citrifolia and Centaurea calcitrapa, to a filamentous bacteria, Streptomyces natalensis, to high density cultures of Escherichia coli and to a murine Sp2/0 hybridoma suspension cell line, 3-2.19. In all cases, the biomass concentration proved to be correlated with total FBRM counts. The nature of the correlation varied between systems and was influenced by the concentration, nature, size and morphology of the particle under investigation.
Collapse
Affiliation(s)
- Jessica Whelan
- UCD School of Chemical and Bioprocess Engineering, UCD, Belfield, Dublin 4, Ireland
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Ethanol-induced yeast flocculation directed by the promoter of TPS1 encoding trehalose-6-phosphate synthase 1 for efficient ethanol production. Metab Eng 2011; 14:1-8. [PMID: 22178744 DOI: 10.1016/j.ymben.2011.12.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 11/13/2011] [Accepted: 12/02/2011] [Indexed: 01/03/2023]
Abstract
Yeast flocculation is an important trait in the brewing industry as well as in ethanol production, through which biomass can be recovered by cost-effective sedimentation. However, mass transfer limitation may affect yeast growth and ethanol fermentation if the flocculation occurs earlier before fermentation is completed. In this article, a novel type of cell-cell flocculation induced by trehalose-6-phosphate synthase 1 (TPS1) promoter was presented. The linear cassette HO-P(TPS1)-FLO1(SPSC01)-KanMX4-HO was constructed to transform the non-flocculating industrial yeast S. cerevisiae 4126 by chromosome integration to obtain a new flocculating yeast strain, ZLH01, whose flocculation was induced by ethanol produced during fermentation. The experimental results illustrated that flocculation of ZLH01 was triggered by 3% (v/v) ethanol and enhanced as ethanol concentration increased till complete flocculation was achieved at ethanol concentration of 8% (v/v). Real time PCR analysis confirmed that the expression of FLO1(SPSC01) was dependent on ethanol concentration. The growth and ethanol fermentation of ZLH01 were improved significantly, compared with the constitutive flocculating yeast BHL01 engineered with the same FLO gene but directed by the constitutive 3-phosphoglycerate kinase promoter PGK1, particularly under high temperature conditions. These characteristics make the engineered yeast more suitable for ethanol production from industrial substrates under high gravity and temperature conditions. In addition, this strategy offers advantage in inducing differential expression of other genes for metabolic engineering applications of S. cerevisiae.
Collapse
|
20
|
|
21
|
|
22
|
Sivakumar G, Vail DR, Xu J, Burner DM, Lay JO, Ge X, Weathers PJ. Bioethanol and biodiesel: Alternative liquid fuels for future generations. Eng Life Sci 2010. [DOI: 10.1002/elsc.200900061] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
|
23
|
Xue C, Zhao X, Bai F. Effect of the size of yeast flocs and zinc supplementation on continuous ethanol fermentation performance and metabolic flux distribution under very high concentration conditions. Biotechnol Bioeng 2010; 105:935-44. [DOI: 10.1002/bit.22610] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
24
|
Zhao X, Bai F. Yeast flocculation: New story in fuel ethanol production. Biotechnol Adv 2009; 27:849-856. [DOI: 10.1016/j.biotechadv.2009.06.006] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2009] [Revised: 06/09/2009] [Accepted: 06/20/2009] [Indexed: 11/26/2022]
|
25
|
Zhao XQ, Bai FW. Mechanisms of yeast stress tolerance and its manipulation for efficient fuel ethanol production. J Biotechnol 2009; 144:23-30. [PMID: 19446584 DOI: 10.1016/j.jbiotec.2009.05.001] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Revised: 04/28/2009] [Accepted: 05/06/2009] [Indexed: 11/17/2022]
Abstract
Yeast strains of Saccharomyces cerevisiae have been extensively studied in recent years for fuel ethanol production, in which yeast cells are exposed to various stresses such as high temperature, ethanol inhibition, and osmotic pressure from product and substrate sugars as well as the inhibitory substances released from the pretreatment of lignocellulosic biomass. An in-depth understanding of the mechanism of yeast stress tolerance contributes to breeding more robust strains for ethanol production, especially under very high gravity conditions. Taking advantage of the "omics" technology, the stress response and defense mechanism of yeast cells during ethanol fermentation were further explored, and the newly emerged tools such as genome shuffling and global transcription machinery engineering have been applied to breed stress resistant yeast strains for ethanol production. In this review, the latest development of stress tolerance mechanisms was focused, and improvement of yeast stress tolerance by both random and rational tools was presented.
Collapse
Affiliation(s)
- X Q Zhao
- Department of Bioscience and Bioengineering, Dalian University of Technology, China
| | | |
Collapse
|
26
|
Impact of zinc supplementation on the improvement of ethanol tolerance and yield of self-flocculating yeast in continuous ethanol fermentation. J Biotechnol 2009; 139:55-60. [DOI: 10.1016/j.jbiotec.2008.08.013] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Revised: 07/23/2008] [Accepted: 08/31/2008] [Indexed: 11/18/2022]
|
27
|
Xue C, Zhao X, Ge X, Yuan W, Bai F. Modulation of floc size distribution and ethanol tolerance of the self-flocculating yeast by metal ion supplementation. J Biotechnol 2008. [DOI: 10.1016/j.jbiotec.2008.07.968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
28
|
On-line monitoring and the mechanism of the de-flocculation of flocculating yeast cells during continuous yeast culture processes. J Biotechnol 2008. [DOI: 10.1016/j.jbiotec.2008.07.975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
29
|
Ethanol fermentation technologies from sugar and starch feedstocks. Biotechnol Adv 2007; 26:89-105. [PMID: 17964107 DOI: 10.1016/j.biotechadv.2007.09.002] [Citation(s) in RCA: 601] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2006] [Revised: 08/26/2007] [Accepted: 09/04/2007] [Indexed: 11/22/2022]
Abstract
This article critically reviews some ethanol fermentation technologies from sugar and starch feedstocks, particularly those key aspects that have been neglected or misunderstood. Compared with Saccharomyces cerevisiae, the ethanol yield and productivity of Zymomonas mobilis are higher, because less biomass is produced and a higher metabolic rate of glucose is maintained through its special Entner-Doudoroff pathway. However, due to its specific substrate spectrum as well as the undesirability of its biomass to be used as animal feed, this species cannot readily replace S. cerevisiae in ethanol production. The steady state kinetic models developed for continuous ethanol fermentations show some discrepancies, making them unsuitable for predicting and optimizing the industrial processes. The dynamic behavior of the continuous ethanol fermentation under high gravity or very high gravity conditions has been neglected, which needs to be addressed in order to further increase the final ethanol concentration and save the energy consumption. Ethanol is a typical primary metabolite whose production is tightly coupled with the growth of yeast cells, indicating yeast must be produced as a co-product. Technically, the immobilization of yeast cells by supporting materials, particularly by gel entrapments, is not desirable for ethanol production, because not only is the growth of the yeast cells restrained, but also the slowly growing yeast cells are difficult to be removed from the systems. Moreover, the additional cost from the consumption of the supporting materials, the potential contamination of some supporting materials to the quality of the co-product animal feed, and the difficulty in the microbial contamination control all make the immobilized yeast cells economically unacceptable. In contrast, the self-immobilization of yeast cells through their flocculation can effectively overcome these drawbacks.
Collapse
|
30
|
Lei J, Zhao X, Ge X, Bai F. Ethanol tolerance and the variation of plasma membrane composition of yeast floc populations with different size distribution. J Biotechnol 2007; 131:270-5. [PMID: 17723249 DOI: 10.1016/j.jbiotec.2007.07.937] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2007] [Revised: 07/09/2007] [Accepted: 07/13/2007] [Indexed: 11/16/2022]
Abstract
The ethanol tolerance of a self-flocculating yeast strain SPSC01 was investigated in an oxygen-limited fed-batch bioreactor. Employing Focused Beam Reflectance Measurement (FBRM) on-line monitoring system, four yeast floc populations with the average size ranging from 100 to 400mum were obtained. It was found that ethanol tolerance increased with the increasing floc size in the 100, 200, and 300mum floc populations, while increasing the average floc size further to 400mum resulted in lower ethanol tolerance. Examination of the membrane composition of different floc populations revealed that the plasma membrane composition of the floc populations was significantly different in the contents of ergosterol, phosphatidylinositol, as well as phospholipid palmitoleic acid. What's more, the plasma membrane of more ethanol tolerant floc population was less permeable when subjected to 15% (v/v) ethanol shock treatment, and the plasma membrane ATPase activities were higher in the floc populations with higher ethanol tolerance. These results indicate that the average size distribution of the floc populations exerted great influence on the physiological status of yeast cells during the ethanol production process, leading to the changes in plasma membrane composition that contributed to improved ethanol tolerance in self-flocculating yeast SPSC01.
Collapse
Affiliation(s)
- Juanjuan Lei
- Department of Bioscience and Bioengineering, Dalian University of Technology, No. 2 Longgong Road, Dalian 116024, China
| | | | | | | |
Collapse
|
31
|
Impacts of temperature, pH, divalent cations, sugars and ethanol on the flocculating of SPSC01. Enzyme Microb Technol 2006. [DOI: 10.1016/j.enzmictec.2005.12.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
32
|
Ge XM, Bai FW. Intrinsic kinetics of continuous growth and ethanol production of a flocculating fusant yeast strain SPSC01. J Biotechnol 2006; 124:363-72. [PMID: 16494960 DOI: 10.1016/j.jbiotec.2005.12.029] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2005] [Revised: 12/11/2005] [Accepted: 12/23/2005] [Indexed: 10/25/2022]
Abstract
The intrinsic kinetics of continuous yeast cell growth and ethanol production for a self-flocculating fusant yeast strain SPSC01 was investigated by means of mechanically dispersing the flocs and correspondingly established floc size distribution on-line monitoring technique using the focused beam reflectance measurement system, through which the floc intra-particle mass transfer limitation was effectively eliminated, but its ethanol formation metabolism was not affected. Modified kinetic models were developed, which can be used to predict the continuous kinetic behaviors of SPSC01, especially when low dilution rates are applied and limiting substrate concentrations are undetectable and almost all kinetic models developed previously are failed in predicting corresponding kinetic behaviors. Both substrate and product inhibitions reported for freely suspended yeast cell ethanol production were also observed for SPSC01 when high gravity media were fed and relatively high levels of residual sugar and ethanol presented. Model parameters were evaluated through numerical calculation method and validated by experimental data mu = 0.584C(s)/0.155 + C(s) + C(2)(s)/160.7(1 -P/125)(3.68) + 0.004 for growth, nu = 1.998C(s)/0.427 + C(s) + C(2)(s)/366.7(1- P/125)(1.72) + 0.060 for ethanol production These intrinsic kinetic models can be further used to develop the observed kinetic models that quantitatively correlate the impact of the self-flocculating yeast cell size distributions on their apparent rates for yeast cell growth, substrate uptake and ethanol production and optimize the ethanol production process.
Collapse
Affiliation(s)
- X M Ge
- Department of Bioscience and Bioengineering, Dalian University of Technology, China
| | | |
Collapse
|
33
|
Impacts of yeast floc size distributions on their observed rates for substrate uptake and product formation. Enzyme Microb Technol 2006. [DOI: 10.1016/j.enzmictec.2005.10.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
34
|
Abstract
The development of a fully automated on-line monitoring and control system is very important in bioprocesses. One of the most important parameters in these processes is biomass. This review discusses different methods for biomass quantification. A general definition of biomass and biovolume are presented. Interesting concepts about active but not culturable cells considerations are included as well as concepts that must be taken into account when selecting biomass quantification technology. Chemical methods have had few applications in biomass measurement to date; however, bioluminescence can selectively enumerate viable cells. Photometric methods including fluorescence and scattered light measurements are presented. Reference methods including dry and wet weight, viable counts and direct counts are discussed, as well as the physical methods of flow cytometry, impedancimetric and dielectric techniques.
Collapse
Affiliation(s)
- R E Madrid
- Departamento de Bioingeniería, FACET/INSIBIO, Universidad Nacional de Tucumán, Consejo Nacional de Investigaciones Científicas y Técnicas, Tucuman, Argentina.
| | | |
Collapse
|
35
|
Current awareness on yeast. Yeast 2005; 22:1249-56. [PMID: 16320446 DOI: 10.1002/yea.1170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|