1
|
Huang M, Cui X, Zhang P, Jin Z, Li H, Liu J, Jiang Z. Engineered Saccharomyces cerevisiae harbors xylose isomerase and xylose transporter improves co-fermentation of xylose and glucose for ethanol production. Prep Biochem Biotechnol 2024; 54:1058-1067. [PMID: 38349751 DOI: 10.1080/10826068.2024.2315479] [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] [Indexed: 09/04/2024]
Abstract
Saccharomyces cerevisiae cannot assimilate xylose, second to glucose derived from lignocellulosic biomass. Here, the engineered S. cerevisiae strains INVSc-XI and INVSc-XI/XT were constructed using xylA and Xltr1p to co-utilize xylose and glucose, achieving economic viability and sustainable production of fuels. The xylose utilization rate of INVSc-XI/XT was 2.3-fold higher than that of INVSc-XI, indicating that overexpressing Xltr1p could further enhance xylose utilization. In mixed sugar media, a small amount of glucose enhanced the consumption of xylose by INVSc-XI/XT. Transcriptome analysis showed that glucose increased the upregulation of acetate of coenzyme A synthetase (ACS), alcohol dehydrogenase (ADH), and transketolase (TKL) gene expression in INVSc-XI/XT, further promoting xylose utilization and ethanol yield. The highest ethanol titer of 2.91 g/L with a yield of 0.29 g/g at 96 h by INVSc-XI/XT was 56.9% and 63.0% of the theoretical ethanol yield from glucose and xylose, respectively. These results showed overexpression of xylA and Xltr1p is a promising strategy for improving xylose and glucose conversion to ethanol. Although the ability of strain INVSc-XI/XT to produce ethanol was not very satisfactory, glucose was discovered to influence xylose utilization in strain INVSc-XI/XT. Altering the glucose concentration is a promising strategy to improve the xylose and glucose co-utilization.
Collapse
Affiliation(s)
- Mengtian Huang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, P.R. China
- College of Life Science and Technology, Hubei Engineering University, Xiaogan, P.R. China
| | - Xinxin Cui
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, P.R. China
| | - Peining Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, P.R. China
| | - Zhuocheng Jin
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, P.R. China
| | - Huanan Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, P.R. China
| | - Jiashu Liu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, P.R. China
| | - Zhengbing Jiang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, P.R. China
| |
Collapse
|
2
|
Jeyaram K, Murugan D, Velmurugan S, Prabhu AA, Raja S, Bose SA, Balakrishnan D. Investigation of the influence of Candida tropicalis on bioethanol production using sugarcane bagasse: stochastic and in silico analysis. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024:10.1007/s11356-024-34226-5. [PMID: 38987518 DOI: 10.1007/s11356-024-34226-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 06/30/2024] [Indexed: 07/12/2024]
Abstract
This study investigated the impact of Candida tropicalis NITCSK13 on sugarcane bagasse (SCB) consolidated bioprocessing (CSB) using various parameters, such as pH, steam explosion (STEX) pretreatment, and temperature (at two different temperatures, cellulose hydrolysis and ethanol fermentation). The backpropagation neural network (BPNN) method simulated the optimal CSB conditions, achieving a maximum ethanol yield of 44 ± 0.32 g/L (0.443 g of ethanol/g of SCB) from STEX pretreated SCB within 48 h at 55 °C for cellulose hydrolysis and 33 °C for ethanol fermentation and pH 3.5. The simulated conditions were experimentally validated and showed an R2 value of 0.998 and absolute average deviation (AAD) of 1.23%. The strain NITCSK13 also exhibited a high ethanol tolerance of 16% (v/v). The interactions between the inhibitors, cellobiose, furfural, and thermocellulase were assessed through molecular docking. The results revealed a maximum inhibitory constant of 3.7 mM for furfural against the endoglucanase (EnG) of Humicola insolens (2ENG) at 50 °C. Acremonium chrysogenum endoglucanase (5M2D) exhibited a maximum of 88.7 µM for cellobiose at 50 °C. The SWISS homology model of EnG from Candida viswanathii exhibited inhibitory effects similar to those of EnG from Thermoascus and Thermotoga, indicating that the moderately thermophilic yeast Candida sp. cellulase may be capable of efficiently tolerating inhibitors and could be a promising candidate for consolidated bioprocessing of cellulosic ethanol.
Collapse
Affiliation(s)
- Kanimozhi Jeyaram
- Department of Biotechnology, School of Bio, Chemical and Processing Engineering, Kalasalingam Academy of Research and Education, Krishnankoil, Tamil Nadu, India.
| | - Dharanidharan Murugan
- Department of Biotechnology, School of Bio, Chemical and Processing Engineering, Kalasalingam Academy of Research and Education, Krishnankoil, Tamil Nadu, India
| | | | - Ashish A Prabhu
- Department of Biotechnology, National Institute of Technology, Warangal, Telangana, India
| | - Sivashankar Raja
- Department of Biotechnology, Vel Tech Dr Rangarajan Dr Sagunthala R&D Institute of Science and Technology, Chennai, Tamilnadu, India
| | - Sathya A Bose
- Department of Biotechnology, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, Chennai, India
| | - Deepanraj Balakrishnan
- Department of Mechanical Engineering, College of Engineering, Prince Mohammad Bin Fahd University, Al-Khobar, Saudi Arabia
| |
Collapse
|
3
|
Zhang JX, Liu XL, Wang L, Fang Z. Two-stage process production of microbial lipid by co-fermentation of glucose and N-acetylglucosamine from food wastes with Cryptococcus curvatus. BIORESOURCE TECHNOLOGY 2023; 387:129685. [PMID: 37595808 DOI: 10.1016/j.biortech.2023.129685] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/12/2023] [Accepted: 08/14/2023] [Indexed: 08/20/2023]
Abstract
Microbial lipids were produced through a two-stage process with Cryptococcus curvatus by co-fermenting rice and shrimp shells hydrolysates. In the first stage, biomass production of glucose and N-acetylglucosamine was optimized by response surface methodology with the maximum biomass yield (17.60 g/L) under optimum conditions (43.2 g/L mixed sugar concentration, pH 5.8, 200 rpm, and 28 °C). In the second stage, according to a single-factor optimization setting (43.2 g/L sugar mixture solutions, pH 5.5, and shift time of 36 h), lipid titer of 10.08 g/L with content of 55.30 % was achieved. Scaling up to a 5-L bioreactor increased lipid content to 60.07 % with 0.233 g/g yield. When Cryptococcus curvatus was cultured in the blends of rice hydrolysates and shrimp shells hydrolysate, lipid content and yield were 52.25 % and 0.204 g/g. The fatty acid compositions of lipid were similar to those of typical vegetable oils.
Collapse
Affiliation(s)
- Jia-Xuan Zhang
- Biomass Group, College of Engineering, Nanjing Agricultural University, 40 Dianjiangtai Road, Nanjing, Jiangsu 210031, China
| | - Xiao-le Liu
- Biomass Group, College of Engineering, Nanjing Agricultural University, 40 Dianjiangtai Road, Nanjing, Jiangsu 210031, China
| | - Li Wang
- Biomass Group, College of Engineering, Nanjing Agricultural University, 40 Dianjiangtai Road, Nanjing, Jiangsu 210031, China
| | - Zhen Fang
- Biomass Group, College of Engineering, Nanjing Agricultural University, 40 Dianjiangtai Road, Nanjing, Jiangsu 210031, China.
| |
Collapse
|
4
|
Ran Y, Yang Q, Zeng J, Li F, Cao Y, Xu Q, Qiao D, Xu H, Cao Y. Potential xylose transporters regulated by CreA improved lipid yield and furfural tolerance in oleaginous yeast Saitozyma podzolica zwy-2-3. BIORESOURCE TECHNOLOGY 2023; 386:129413. [PMID: 37390935 DOI: 10.1016/j.biortech.2023.129413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 06/26/2023] [Accepted: 06/27/2023] [Indexed: 07/02/2023]
Abstract
Lignocellulose's hydrolysate, a significant renewable source, contains xylose and furfural, making it challenging for industrial production of oleaginous yeast. On xylose fermentation with furfural treatment, OE::DN7263 and OE::DN7661 increased lipid yield and furfural tolerance versus WT, while, which of OE::CreA were decreased owing to CreA regulating DN7263 and DN7661 negatively. OE::CreA generated reactive oxygen species (ROS) causing oxidative damage. OE::DN7263, OE::DN7661, and ΔCreA reduced furfural via NADH; while ΔCreA produced less ROS and OE::DN7263, and OE::DN7661 scavenged ROS quickly, minimizing oxidative damage. Overall, CreA knockout increased DN7263 and DN7661 expression to facilitate xylose assimilation, enhancing NADH generation and ROS clearance. Finally, with mixed sugar fermentation, ΔCreA and OE::DN7263's biomass and lipid yield rose without furfural addition, while that of ΔCreA remained higher than WT after furfural treatment. These findings revealed how oleaginous yeast zwy-2-3 resisted furfural stress and indicated ΔCreA and OE::DN7263 might develop into robust industrial chassis strains.
Collapse
Affiliation(s)
- Yulu Ran
- Microbiology and Metabolic Engineering Key Laboratory of Sichuan Province, College of Life Science, Sichuan University, Chengdu, Sichuan Province 610065, PR China
| | - Qingzhuoma Yang
- Microbiology and Metabolic Engineering Key Laboratory of Sichuan Province, College of Life Science, Sichuan University, Chengdu, Sichuan Province 610065, PR China
| | - Jie Zeng
- Microbiology and Metabolic Engineering Key Laboratory of Sichuan Province, College of Life Science, Sichuan University, Chengdu, Sichuan Province 610065, PR China
| | - Fazhi Li
- Microbiology and Metabolic Engineering Key Laboratory of Sichuan Province, College of Life Science, Sichuan University, Chengdu, Sichuan Province 610065, PR China
| | - Yu Cao
- Microbiology and Metabolic Engineering Key Laboratory of Sichuan Province, College of Life Science, Sichuan University, Chengdu, Sichuan Province 610065, PR China
| | - Qingrui Xu
- Microbiology and Metabolic Engineering Key Laboratory of Sichuan Province, College of Life Science, Sichuan University, Chengdu, Sichuan Province 610065, PR China
| | - Dairong Qiao
- Microbiology and Metabolic Engineering Key Laboratory of Sichuan Province, College of Life Science, Sichuan University, Chengdu, Sichuan Province 610065, PR China
| | - Hui Xu
- Microbiology and Metabolic Engineering Key Laboratory of Sichuan Province, College of Life Science, Sichuan University, Chengdu, Sichuan Province 610065, PR China.
| | - Yi Cao
- Microbiology and Metabolic Engineering Key Laboratory of Sichuan Province, College of Life Science, Sichuan University, Chengdu, Sichuan Province 610065, PR China.
| |
Collapse
|
5
|
Chen L, Peng Q, Chen Y, Wang C, Li K, Nian H. Enhancement production of lipid and unsaturation of fatty acids in Cryptococcus humicola via addition of calcium ion. World J Microbiol Biotechnol 2022; 39:50. [PMID: 36542152 DOI: 10.1007/s11274-022-03502-2] [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: 10/12/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
Lipids synthesized by oleaginous yeasts are considered to be the best candidates for biodiesel production. Cryptococcus humicola as an oleaginous yeast accumulated lipid in cells. In order to optimize the conditions for lipid production, different carbon and nitrogen sources were used and metals were added into the medium. Ca2+ addition increased the lipid production greatly. Xylose and peptone were optimal carbon source and nitrogen source, respectively for lipid accumulation. Response surface experiment results revealed that the accumulation of lipid could be maximized when the xylose, peptone and Ca2+ concentration was 61 g/L, 4.31 g/L, 0.67 mmol/L. C16 and C18 fatty acid account for about 91% of the total fatty acids. The most abundant fatty acid was oleic acid (42.68%), followed by palmitic acid (29.7%) and stearic acid (13.87%). The addition of Ca2+ increased the content of unsaturated fatty acids (such as C16:1 and C18:1) and improved the unsaturation of fatty acids. Quantitative real time PCR analysis revealed that expression of genes related to lipid biosynthesis showed up-regulated by Ca2+ treatment. This study provided a strategy for increase in lipid production and content of unsaturated fatty acids.
Collapse
Affiliation(s)
- Lu Chen
- Faculty of Life Science and Technology, Kunming University of Science and Technology, 650500, Kunming, China
| | - Qianyun Peng
- Faculty of Life Science and Technology, Kunming University of Science and Technology, 650500, Kunming, China
| | - Yuner Chen
- Faculty of Life Science and Technology, Kunming University of Science and Technology, 650500, Kunming, China
| | - Chengsong Wang
- Faculty of Life Science and Technology, Kunming University of Science and Technology, 650500, Kunming, China
| | - Kunzhi Li
- Faculty of Life Science and Technology, Kunming University of Science and Technology, 650500, Kunming, China
| | - Hongjuan Nian
- Faculty of Life Science and Technology, Kunming University of Science and Technology, 650500, Kunming, China.
| |
Collapse
|
6
|
Zan X, Sun J, Chu L, Cui F, Huo S, Song Y, Koffas MAG. Improved glucose and xylose co-utilization by overexpression of xylose isomerase and/or xylulokinase genes in oleaginous fungus Mucor circinelloides. Appl Microbiol Biotechnol 2021; 105:5565-5575. [PMID: 34215904 DOI: 10.1007/s00253-021-11392-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/28/2021] [Accepted: 06/07/2021] [Indexed: 12/17/2022]
Abstract
Most of the oleaginous microorganisms cannot assimilate xylose in the presence of glucose, which is the major bottleneck in the bioconversion of lignocellulose to biodiesel. Our present study revealed that overexpression of xylose isomerase (XI) gene xylA or xylulokinase (XK) gene xks1 increased the xylose consumption by 25 to 37% and enhanced the lipid content by 8 to 28% during co-fermentation of glucose and xylose. In xylA overexpressing strain Mc-XI, the activity of XI was 1.8-fold higher and the mRNA level of xylA at 24 h and 48 h was 11- and 13-fold higher than that of the control, respectively. In xks1 overexpressing strain Mc-XK, the mRNA level of xks1 was 4- to 11-fold of that of the control strain and the highest XK activity of 950 nmol min-1 mg-1 at 72 h which was 2-fold higher than that of the control. Additionally, expression of a translational fusion of xylA and xks1 further enhanced the xylose utilization rate by 45%. Our results indicated that overexpression of xylA and/or xks1 is a promising strategy to improve the xylose and glucose co-utilization, alleviate the glucose repression, and produce lipid from lignocellulosic biomass in the oleaginous fungus M. circinelloides. KEY POINTS: • Overexpressing xylA or xks1 increased the xylose consumption and the lipid content. • The xylose isomerase activity and the xylA mRNA level were enhanced in strain Mc-XI. • Co-expression of xylA and xks1 further enhanced the xylose utilization rate by 45%.
Collapse
Affiliation(s)
- Xinyi Zan
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, People's Republic of China
| | - Jianing Sun
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, People's Republic of China
| | - Linfang Chu
- School of Food Science and Technology, Jiang University, Wuxi, 214000, People's Republic of China
| | - Fengjie Cui
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, People's Republic of China
| | - Shuhao Huo
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, People's Republic of China
| | - Yuanda Song
- Colin Ratledge Center for Microbial Lipids, School of Agriculture Engineering and Food Science, Shandong University of Technology, Zibo, 255049, People's Republic of China.
| | - Mattheos A G Koffas
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| |
Collapse
|
7
|
Sanya DRA, Onésime D, Passoth V, Maiti MK, Chattopadhyay A, Khot MB. Yeasts of the Blastobotrys genus are promising platform for lipid-based fuels and oleochemicals production. Appl Microbiol Biotechnol 2021; 105:4879-4897. [PMID: 34110474 DOI: 10.1007/s00253-021-11354-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 04/29/2021] [Accepted: 05/16/2021] [Indexed: 12/31/2022]
Abstract
Strains of the yeast genus Blastobotrys (subphylum Saccharomycotina) represent a valuable biotechnological resource for basic biochemistry research, single-cell protein, and heterologous protein production processes. Species of this genus are dimorphic, non-pathogenic, thermotolerant, and can assimilate a variety of hydrophilic and hydrophobic substrates. These can constitute a single-cell oil platform in an emerging bio-based economy as oleaginous traits have been discovered recently. However, the regulatory network of lipogenesis in these yeasts is poorly understood. To keep pace with the growing market demands for lipid-derived products, it is critical to understand the lipid biosynthesis in these unconventional yeasts to pinpoint what governs the preferential channelling of carbon flux into lipids instead of the competing pathways. This review summarizes information relevant to the regulation of lipid metabolic pathways and prospects of metabolic engineering in Blastobotrys yeasts for their application in food, feed, and beyond, particularly for fatty acid-based fuels and oleochemicals. KEY POINTS: • The production of biolipids by heterotrophic yeasts is reviewed. • Summary of information concerning lipid metabolism regulation is highlighted. • Special focus on the importance of diacylglycerol acyltransferases encoding genes in improving lipid production is made.
Collapse
Affiliation(s)
- Daniel Ruben Akiola Sanya
- Université Paris-Saclay, Institut Micalis, Diversité génomique et fonctionnelle des levures, domaine de Vilvert, 78350, Jouy-en-Josas, France.
| | - Djamila Onésime
- Université Paris-Saclay, Institut Micalis, Diversité génomique et fonctionnelle des levures, domaine de Vilvert, 78350, Jouy-en-Josas, France
| | - Volkmar Passoth
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, PO Box 7015, SE-750 07, Uppsala, Sweden
| | - Mrinal K Maiti
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India
| | - Atrayee Chattopadhyay
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India
| | - Mahesh B Khot
- Laboratorio de Recursos Renovables, Centro de Biotecnologia, Universidad de Concepcion, Barrio Universitario s/n, Concepcion, Chile
| |
Collapse
|
8
|
Chattopadhyay A, Maiti MK. Lipid production by oleaginous yeasts. ADVANCES IN APPLIED MICROBIOLOGY 2021; 116:1-98. [PMID: 34353502 DOI: 10.1016/bs.aambs.2021.03.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Microbial lipid production has been studied extensively for years; however, lipid metabolic engineering in many of the extraordinarily high lipid-accumulating yeasts was impeded by inadequate understanding of the metabolic pathways including regulatory mechanisms defining their oleaginicity and the limited genetic tools available. The aim of this review is to highlight the prominent oleaginous yeast genera, emphasizing their oleaginous characteristics, in conjunction with diverse other features such as cheap carbon source utilization, withstanding the effect of inhibitory compounds, commercially favorable fatty acid composition-all supporting their future development as economically viable lipid feedstock. The unique aspects of metabolism attributing to their oleaginicity are accentuated in the pretext of outlining the various strategies successfully implemented to improve the production of lipid and lipid-derived metabolites. A large number of in silico data generated on the lipid accumulation in certain oleaginous yeasts have been carefully curated, as suggestive evidences in line with the exceptional oleaginicity of these organisms. The different genetic elements developed in these yeasts to execute such strategies have been scrupulously inspected, underlining the major types of newly-found and synthetically constructed promoters, transcription terminators, and selection markers. Additionally, there is a plethora of advanced genetic toolboxes and techniques described, which have been successfully used in oleaginous yeasts in the recent years, promoting homologous recombination, genome editing, DNA assembly, and transformation at remarkable efficiencies. They can accelerate and effectively guide the rational designing of system-wide metabolic engineering approaches pinpointing the key targets for developing industrially suitable yeast strains.
Collapse
Affiliation(s)
- Atrayee Chattopadhyay
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Mrinal K Maiti
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, India.
| |
Collapse
|
9
|
Kieliszek M, Dourou M. Effect of Selenium on the Growth and Lipid Accumulation of Yarrowia lipolytica Yeast. Biol Trace Elem Res 2021; 199:1611-1622. [PMID: 32632749 PMCID: PMC7886723 DOI: 10.1007/s12011-020-02266-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 06/21/2020] [Indexed: 12/13/2022]
Abstract
Nowadays, there is an increase attention on the effect of selenium (Se) on metabolic processes of microorganisms. Strains belonging to the genus of Yarrowia are of great biotechnological interest for various industries. In this study, we evaluated the effect of 10 mg/L of Se on the growth and lipid production of two Yarrowia lipolytica strains: the ACA DC 50109 and one more with increased oleagenicity, derived after ALE methodology (referred here as Y. lipolytica ALE_70). The presence of Se in the growth medium negatively affected both cell mass production and total lipid accumulation, for both Y. lipolytica strains. Fractionation of total lipids showed an inhibition on neutral lipid (NL) synthesis and consequently, an increase of polar lipids (glycolipids plus sphingolipids, and phospholipids) on the lipids of the Se-enriched ACA DC 50109 strain; however, the NL/polar ratio of the Se-enriched ALE_70 indicated that Se, apart from the inhibition of NL synthesis, provoked also the accumulation of polar lipids in this strain. In addition, the fatty acid (FA) composition was differently affected by Se. Se-enriched total lipids of the ALE_70 strain were enriched in linoleic acid (C18:2 n-6), which resulted in increase of the unsaturated index. On the other hand, Se-enriched lipids of the ACA DC 50109 strain were more saturated, as the percentage of palmitic (C16:0) and stearic (C18:0) acids increased in the total FAs. Moreover, it seems that Se influenced the activity or the expression of desaturases and elongase in both strains. Finally, the supplementation of growth medium with Se affected cell morphology, as well as the size and distribution of lipid droplets inside the yeast cells. According to our opinion, Se caused stress conditions and the consequence of that was the occurrence of metabolic disorders that affected cell mass, lipid content, and/or morphological structures. The results of the present study suggest that further research should be carried out to understand the background of the lipogenesis process in yeast cells cultured under stress conditions.
Collapse
Affiliation(s)
- Marek Kieliszek
- Department of Food Biotechnology and Microbiology, Institute of Food Sciences, Warsaw University of Life Sciences—SGGW, Nowoursynowska 159 C, 02-776 Warsaw, Poland
| | - Marianna Dourou
- Unit of Microbiology, Division of Genetics, Cell and Developmental Biology, Department of Biology, University of Patras, 26504 Patras, Greece
| |
Collapse
|
10
|
Chattopadhyay A, Mitra M, Maiti MK. Recent advances in lipid metabolic engineering of oleaginous yeasts. Biotechnol Adv 2021; 53:107722. [PMID: 33631187 DOI: 10.1016/j.biotechadv.2021.107722] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 02/15/2021] [Accepted: 02/15/2021] [Indexed: 01/12/2023]
Abstract
With the increasing demand to develop a renewable and sustainable biolipid feedstock, several species of non-conventional oleaginous yeasts are being explored. Apart from the platform oleaginous yeast Yarrowia lipolytica, the understanding of metabolic pathway and, therefore, exploiting the engineering prospects of most of the oleaginous species are still in infancy. However, in the past few years, enormous efforts have been invested in Rhodotorula, Rhodosporidium, Lipomyces, Trichosporon, and Candida genera of yeasts among others, with the rapid advancement of engineering strategies, significant improvement in genetic tools and techniques, generation of extensive bioinformatics and omics data. In this review, we have collated these recent progresses to make a detailed and insightful summary of the major developments in metabolic engineering of the prominent oleaginous yeast species. Such a comprehensive overview would be a useful resource for future strain improvement and metabolic engineering studies for enhanced production of lipid and lipid-derived chemicals in oleaginous yeasts.
Collapse
Affiliation(s)
- Atrayee Chattopadhyay
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Mohor Mitra
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Mrinal K Maiti
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
| |
Collapse
|
11
|
Characterization of two sugar transporters responsible for efficient xylose uptake in an oleaginous yeast Candida tropicalis SY005. Arch Biochem Biophys 2020; 695:108645. [PMID: 33122161 DOI: 10.1016/j.abb.2020.108645] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 10/02/2020] [Accepted: 10/17/2020] [Indexed: 01/01/2023]
Abstract
Microbial conversion of lignocellulosic feedstock to the target bioproduct requires efficient assimilation of its constituent sugars, a large part of which comprises of glucose and xylose. This study aims to identify and characterize sugar transporters capable of xylose uptake in an oleaginous strain of the industrially relevant yeast Candida tropicalis. In silico database mining resulted in two sugar transporter proteins- CtStp1 and CtStp2, containing conserved amino acid residues and motifs that have been previously reported to be involved in xylose transport in other organisms. Several softwares predicted the likelihood of 10-12 transmembrane (TM) helices to be present in both the Stps, while molecular modelling showed 12 TM helices that were organized into a typical structure found in the major facilitator superfamily of transporters. Docking with different sugars also predicted favorable interactions. Heterologous expression in a Saccharomyces cerevisiae strain harboring functional xylose metabolic genes validated the broad substrate specificity of the two Stps. Each transporter supported prominent growth of recombinant S. cerevisiae strains on six sugars including xylose at various concentrations. Expression of CtSTP1 and CtSTP2 along with the xylose metabolic genes in yeast transformants grown in presence of xylose was confirmed by transcript detection. Growth curve and sugar consumption profiles revealed uptake of both glucose and xylose simultaneously by the recombinant yeast strains, though CtStp1 showed relatively less effect of glucose repression in mixed sugars and was a better transporter of xylose than CtStp2. Such glucose-xylose utilizing efficient transporters can be effective tools for developing co-fermenting yeasts through genetic engineering in future, with noteworthy applications in renewable biomass utilization.
Collapse
|
12
|
Engineering an oleaginous yeast Candida tropicalis SY005 for enhanced lipid production. Appl Microbiol Biotechnol 2020; 104:8399-8411. [DOI: 10.1007/s00253-020-10830-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 07/23/2020] [Accepted: 08/11/2020] [Indexed: 12/23/2022]
|