Pigment analysis in Sphingomonas glacialis strain S2U11 and its light exposure effect
Authors
Date
2023Copyright
© The Author(s)
Hapellisissa oloissa happea tuottamattomat fotosynteettiset (AAP-) bakteerit saavat kemiallista energiaa hyödyntämällä valoa happea tuottamattomassa fotosynteesissä. Hapellinen ympäristö on tarpeellinen bakteeriklorofyllien ja karotenoidien valmistukseen, jotka absorboivat valoa valonkeräyskomplekseissa, mistä valon virittämä energia siirretään reaktiokeskuksiin eksitaatioenergiansiirto-prosessilla. Bakteeriklorofylli absorboi valoa infrapuna-alueelta ja karotenoidit 400–550 nm alueelta. Karotenoidit voivat siirtää viritysenergian bakteeriklorofylleille. Toisaalta, karotenoidit suojelevat komplekseja reaktiiviselta hapelta poistamalla ylimääräisen viritysenergian. AAP-bakteereja sekä niiden pigmenttien tutkimus on vähäistä, tämä tutkimus kehittää menetelmää pigmenttien analysointiin. Pigmentit eluoitiin Sphingomonas glacialis -bakteereista. Identifiointi tehtiin korkean erottelykyvyn nestekromatografian retentioajoilla sekä absorptiospektreillä. Fotosynteettisten pigmenttien kartoitus tehtiin fluoresenssieksitaatiolla. Valo-olosuhteiden muutokset vaikuttivat pigmentteihin ja runsain kasvu tapahtui pimeässä. Pigmenttejä löytyi runsaasti, mutta yksikään ei ollut fotosynteettinen. Pigmenttien analysointimenetelmä on toimiva ja käytettävissä muihin AAP-bakteereihin, mutta karotenoidien tunnistamisessa on vielä käytännön haasteita.
...
Aerobic anoxygenic photosynthetic (AAP) bacteria gain chemical energy from light through non-oxygen producing photosynthesis. The presence of the oxygen is required to produce pigments, bacteriochlorophyll a (BChla a) and carotenoids. During photosynthesis pigment constituting light harvesting (LH) complexes gather absorbed light and transfer it to reaction centre (RC) as excitation energy with process called singlet state energy transfer. BChl a is an essential pigment to both the LH complex and RC and its main light absorption area is in near infrared area. Photosynthetic carotenoids absorb light from 400 to 550 nm area and transfer it to the BChls. Carotenoids can act as photoprotectors and quench the excess light energy before it creates high energetic singlet oxygen, that is detrimental to BChl synthesis. The research of AAP bacteria, especially their pigment content, is scarce. This thesis works to find possible method for the pigment analysis and identification. The pigments were extracted from Sphingomonas glacialis and identified with high performance liquid chromatography retention times and absorption spectra. The presence of photosynthetic carotenoids was studied with fluorescence excitation. The light exposure examination addressed effect of light changes to the pigment composition. Pigment synthesis takes place in the darkness. Photosynthetic carotenoids were not present in Sphingomonas glacialis, but multiple carotenoids were found. Identification of the pigments is challenging but the method for pigment analysis is functional and can be utilized in other carotenoid containing AAP bacteria.
...
Keywords
BChl a HPLC carotenoids fluorescence excitation singlet state energy transfer anoxygenic photosynthesis anoxygenic photosynthetic bacteria yhteyttäminen karotenoidit bakteerit valotus pigmentit (värijauheet) fluoresenssi imeytyminen photosynthesis bacteria exposure to light pigments fluorescence absorption
Metadata
Show full item recordCollections
- Pro gradu -tutkielmat [29616]
License
Related items
Showing items with similar title or keywords.
-
Aerobic anoxygenic phototrophic bacteria and their photosynthetic membranes : imaging from macro- to nanoscale
Franz, Ole (2022)While anaerobic anoxygenic phototrophic green or purple bacteria have been extensively researched, little is known about the ubiquity and function of aerobic anoxygenic phototrophic (AAP) bacteria in different environments. ... -
Structural basis for light control of cell development revealed by crystal structures of a myxobacterial phytochrome
Woitowich, Nicole C.; Halavaty, Andrei S.; Waltz, Patricia; Kupitz, Christopher; Valera, Joseph; Tracy, Gregory; Gallagher, Kevin D.; Claesson, Elin; Nakane, Takanori; Pandey, Suraj; Nelson, Garrett; Tanaka, Rie; Nango, Eriko; Mizohata, Eiichi; Owada, Shigeki; Tono, Kensure; Joti, Yasumasa; Nugent, Angela C.; Patel, Hardik; Mapara, Ayesha; Hopkins, James; Duong, Phu; Bizhga, Dorina; Kovaleva, Svetlana E.; Peter, Rachael St.; Hernandez, Cynthia N.; Ozarowski, Wesley B.; Roy-Chowdhuri, Shatabdi; Yang, Jay-How; Edlund, Petra; Takala, Heikki; Ihalainen, Janne; Brayshaw, Jennifer; Norwood, Tyler; Poudyal, Ishwor; Fromme, Petra; Spence, John C. H.; Moffat, Keith; Westenhoff, Sebastian; Schmidt, Marius; Stojković, Emina A. (International Union of Crystallography, 2018)Phytochromes are red-light photoreceptors that were first characterized in plants, with homologs in photosynthetic and non-photosynthetic bacteria known as bacteriophytochromes (BphPs). Upon absorption of light, BphPs ... -
The reduction of selenium(IV) by boreal Pseudomonas sp. strain T5-6-I : Effects on selenium(IV) uptake in Brassica oleracea
Lusa, Merja; Help, Hanna; Honkanen, Ari-Pekka; Knuutinen, Jenna; Parkkonen, Joni; Kalasová, Dominika; Bomberg, Malin (Elsevier, 2019)Selenium (Se) is an essential micronutrient but toxic when taken in excessive amounts. Therefore, understanding the metabolic processes related to selenium uptake and bacteria-plant interactions coupled with selenium ... -
The impact of life stage and pigment source on the evolution of novel warning signal traits
Lindstedt, Carita; Bagley, Robin; Calhim, Sara; Jones, Mackenzie; Linnen, Catherine (Wiley-Blackwell, 2022)Our understanding of how novel warning color traits evolve in natural populations is largely based on studies of reproductive stages and organisms with endogenously produced pigmentation. In these systems, genetic drift ... -
Predictive First-principles Modeling of a Photosynthetic Antenna Protein : The Fenna-Matthews-Olson Complex
Kim, Yongbin; Morozov, Dmitry; Stadnytskyi, Valentyn; Savikhin, Sergei; Slipchenko, Lyudmila (American Chemical Society, 2020)High efficiency of light harvesting in photosynthetic pigment-protein complexes is governed by evolutionary-perfected protein-assisted tuning of individual pigment properties and inter-pigment interactions. Due to the large ...