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Chang Y, Wang Z, Li H, Dang W, Song Y, Kang X, Zhang H. Morphological Changes and Strong Cytotoxicity in Yarrowia lipolytica by Overexpressing Delta-12-Desaturase. J Fungi (Basel) 2024; 10:126. [PMID: 38392798 PMCID: PMC10890566 DOI: 10.3390/jof10020126] [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: 12/22/2023] [Revised: 01/26/2024] [Accepted: 01/31/2024] [Indexed: 02/24/2024] Open
Abstract
In this study, delta-12 desaturase was overexpressed in Yarrowia lipolytica using the single-copy integrative vector pINA1312 and multicopy integrative vector pINA1292, resulting in the engineered yeast strains 1312-12 and 1292-12, respectively. The content of intracellular linoleic acid (LA) in the 1292-12 strain was much higher than in the 1312-12 strain and the control group. One interesting finding was that the 1292-12 strain showed obvious changes in surface morphology. The 1292-12 colonies were much smaller and smoother, whereas their single cells became much larger compared to the control strain. In addition, the dry cell weight (DCW) of the 1292-12 strain was obviously increased from 8.5 to 12.7 g/L, but the viable cell number sharply decreased from 107 to 105/mL. These results indicated that increased LA content in Yarrowia lipolytica could induce morphological changes or even oxidative stress-dependent cell death. The reactive oxygen species (ROS) and malondialdehyde (MDA) were accumulated in the 1292-12 strain, while the antioxidant activities of intracellular catalase (CAT) and superoxide dismutase (SOD) were significantly decreased by 27.6 and 32.0%, respectively. Furthermore, it was also revealed that these issues could be ameliorated by the exogenous supplementation of vitamin C, fish and colza oil.
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Affiliation(s)
- Yufei Chang
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo 255049, China
| | - Zhen Wang
- School of Public Health, Qilu Medical University, Zibo 255300, China
| | - Hequn Li
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo 255049, China
| | - Wenrui Dang
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo 255049, China
| | - Yuanda Song
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo 255049, China
| | - Xinxin Kang
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo 255049, China
| | - Huaiyuan Zhang
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo 255049, China
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Ni FJ, Bhavsar SP, Poirier D, Branfireun B, Petro S, Arts MT, Chong-Kit R, Mitchell CPJ, Arhonditsis GB. Impacts of water level fluctuations on mercury concentrations in hydropower reservoirs: A microcosm experiment. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 220:112354. [PMID: 34116335 DOI: 10.1016/j.ecoenv.2021.112354] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 04/02/2021] [Accepted: 05/15/2021] [Indexed: 06/12/2023]
Abstract
Hydropower generation, a renewable source of electricity, has been linked to elevated methylmercury (MeHg) concentrations in impoundments and aquatic biota. This study investigates the impact of water level fluctuations (WLF) on MeHg concentrations in water, sediment, and fish. Using a set of controlled microcosm experiments emulating the drawdown/refill dynamics and subsequent sediment exposure to air experienced in reservoirs, we demonstrate that less frequent WLFs, and/or increased exposure of sediment to air, can lead to elevated MeHg concentrations in sediment, and total mercury (THg) and MeHg concentrations in water. In examining the effects of WLF frequency (two-day, weekly, and monthly), the monthly treatment displayed the highest THg and MeHg water levels, while the weekly treatment was characterized by the highest MeHg levels in the sediment. Our work supports emerging evidence that longer duration between WLF creates a larger surface area of sediment exposed to air leading to conditions conducive to higher MeHg concentrations in sediments and water. In contrast, THg, MeHg, and fatty acid trends in fish were largely inconclusive characterized by similar among-treatment effects and minimal temporal variability over the course of our experiment. This result could partly be attributed to overall low mercury levels and simple "worm-forage fish" food web in our experiment. To elucidate the broader impacts of water fluctuations on aquatic chemistry and biota, other factors (e.g., longer WLF cycles, dissolved organic matter, temperature, more complex food webs) which modulate both methylation rates and food web dynamics must be considered.
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Affiliation(s)
- Felicity J Ni
- Department of Physical & Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada
| | - Satyendra P Bhavsar
- Department of Physical & Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada; Ontario Ministry of Environment, Conservation, and Parks, Toronto, Ontario M9P 3V6, Canada.
| | - David Poirier
- Ontario Ministry of Environment, Conservation, and Parks, Toronto, Ontario M9P 3V6, Canada
| | - Brian Branfireun
- Department of Biology and Centre for Environment & Sustainability, Western University, London, Ontario N6A 3K7, Canada
| | - Steve Petro
- Ontario Ministry of Environment, Conservation, and Parks, Toronto, Ontario M9P 3V6, Canada
| | - Michael T Arts
- Department of Chemistry & Biology, Ryerson University, Toronto, Ontario M5B 2K3, Canada
| | - Richard Chong-Kit
- Ontario Ministry of Environment, Conservation, and Parks, Toronto, Ontario M9P 3V6, Canada
| | - Carl P J Mitchell
- Department of Physical & Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada
| | - George B Arhonditsis
- Department of Physical & Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada.
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Zhang M, Liu Z, Yu Q, Mao J, Zhang B, Xing L, Li M. Deletion of genes encoding fatty acid desaturases leads to alterations in stress sensitivity in Pichia pastoris. FEMS Yeast Res 2015; 15:fov020. [DOI: 10.1093/femsyr/fov020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/17/2015] [Indexed: 12/13/2022] Open
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