{"title":"Biochemical changes due to photothermal acclimation of Oedogonium and associated implications for photosynthetic growth and biomass utilisation","authors":"","doi":"10.1016/j.algal.2024.103666","DOIUrl":null,"url":null,"abstract":"<div><p>Freshwater filamentous algae have potential for wastewater bioremediation and bioproduct generation. This study investigated the separate and combined effects of growth irradiance regime (300 ± 25 μmol.m<sup>−2</sup>.s<sup>−1</sup> with 13:11 dark:light cycle or 775 ± 25 μmol.m<sup>−2</sup>.s<sup>−1</sup> with 8:16 dark:light cycle) and temperature (15 ± 1 or 25 ± 1 °C) during acclimation on the adaptive biochemistry and photosynthetic activity of <em>Oedogonium</em> with the higher and lower levels representing average outdoor conditions in summer and winter in Melbourne, Australia, respectively. Photoprotective pigments were upregulated in response to either high irradiance regime or temperature, while the chlorophyll content was also reduced when both stressors were combined. The upregulation of protective adaptations slightly lowered photosynthetic efficiency, which was more dramatically impaired by the reduced chlorophyll at high temperature and irradiance. The polar lipid content increased from ~10% to ~30% of total lipid content, the protein content decreased by ~10% and the starch content increased by 30% in response to higher irradiance and temperature, with implications for biomass utilisation. These changes in biochemical composition due to long-term acclimation suggests the potential for compositional stratification in stable floating filamentous algae mats due to the presence of self-shading. Further, the shading created by the upper layers in the mat can be expected to provide further protection to the biomass at the lower levels against photooxidative stress. The results reveal the impact of variations on seasonal growth conditions and filamentous mat depth on the composition and productivity of the algae.</p></div>","PeriodicalId":7855,"journal":{"name":"Algal Research-Biomass Biofuels and Bioproducts","volume":null,"pages":null},"PeriodicalIF":4.6000,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2211926424002789/pdfft?md5=5879c72a84904af7984a012bb0cc5aed&pid=1-s2.0-S2211926424002789-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Algal Research-Biomass Biofuels and Bioproducts","FirstCategoryId":"99","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2211926424002789","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"BIOTECHNOLOGY & APPLIED MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Freshwater filamentous algae have potential for wastewater bioremediation and bioproduct generation. This study investigated the separate and combined effects of growth irradiance regime (300 ± 25 μmol.m−2.s−1 with 13:11 dark:light cycle or 775 ± 25 μmol.m−2.s−1 with 8:16 dark:light cycle) and temperature (15 ± 1 or 25 ± 1 °C) during acclimation on the adaptive biochemistry and photosynthetic activity of Oedogonium with the higher and lower levels representing average outdoor conditions in summer and winter in Melbourne, Australia, respectively. Photoprotective pigments were upregulated in response to either high irradiance regime or temperature, while the chlorophyll content was also reduced when both stressors were combined. The upregulation of protective adaptations slightly lowered photosynthetic efficiency, which was more dramatically impaired by the reduced chlorophyll at high temperature and irradiance. The polar lipid content increased from ~10% to ~30% of total lipid content, the protein content decreased by ~10% and the starch content increased by 30% in response to higher irradiance and temperature, with implications for biomass utilisation. These changes in biochemical composition due to long-term acclimation suggests the potential for compositional stratification in stable floating filamentous algae mats due to the presence of self-shading. Further, the shading created by the upper layers in the mat can be expected to provide further protection to the biomass at the lower levels against photooxidative stress. The results reveal the impact of variations on seasonal growth conditions and filamentous mat depth on the composition and productivity of the algae.
期刊介绍:
Algal Research is an international phycology journal covering all areas of emerging technologies in algae biology, biomass production, cultivation, harvesting, extraction, bioproducts, biorefinery, engineering, and econometrics. Algae is defined to include cyanobacteria, microalgae, and protists and symbionts of interest in biotechnology. The journal publishes original research and reviews for the following scope: algal biology, including but not exclusive to: phylogeny, biodiversity, molecular traits, metabolic regulation, and genetic engineering, algal cultivation, e.g. phototrophic systems, heterotrophic systems, and mixotrophic systems, algal harvesting and extraction systems, biotechnology to convert algal biomass and components into biofuels and bioproducts, e.g., nutraceuticals, pharmaceuticals, animal feed, plastics, etc. algal products and their economic assessment