Thiamine and Pyridoxine Alleviate Oxidative Damage by Copper Stress in Green Alga Chlorella vulgaris

The green seaweed Ulva depends on its associated bacteria for morphogenesis and is an important model to study algal-bacterial interactions. Ulva-associated bacteria exhibit high turnover across environmental gradients, leading to the hypothesis that bacteria contribute to the acclimation potential of the host. Yet little is known about the variation in the functional profile of Ulva-associated bacteria in relation to environmental changes. To test which microbial functions shift alongside a strong environmental gradient, we analysed microbial communities of 91 Ulva samples across a 2,000 km Atlantic–Baltic Sea salinity gradient using metagenomic sequencing. Metabolic reconstruction of 639 metagenome-assembled genomes revealed widespread potential for carbon, sulphur, nitrogen, and vitamin metabolism, including amino acid and vitamin B biosynthesis. While salinity explained 70% of taxonomic variation, it only accounted for 17% of functional variation, indicating extensive functional stability. The limited variation was attributed to typical high-salinity bacteria exhibiting enrichment in genes for thiamine, pyridoxal, and betaine biosynthesis. These metabolic modules likely contribute to oxidative stress mitigation, cellular osmotic homeostasis, and membrane stabilization in response to salinity variations. Our results emphasise the importance of functional profiling to understand the seaweed holobiont and its collective response to environmental change.

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Obtaining Fat-Soluble Pigments—Carotenoids from the Biomass of Chlorella Microalgae

Bazarnova

Smyatskaya

Shlykova

et al. 2022

Applied Sciences

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The aim of this study was to use a directed mode of cultivation of the microalgae Chlorella for biomass production, followed by the subsequent extraction of carotenoids. The effect of a stress inducer of carotenogenesis (hydrogen peroxide) and a growth stimulator (pyridoxine, vitamin B6) on the accumulation of photosynthetic pigments by the biomass of the microalga C. vulgarisBIN in the process of directed cultivation was studied. It was revealed that the combination of these additives in the culture medium increases the content of chlorophylls and carotenoids in the biomass twofold compared to the control sample. The preliminary activation of the biomass by high-speed ultra-homogenization (a rotor rotation range from 6000 to 12,000 rpm) was also investigated. Using ultrasound extraction, the pigment complex was isolated from the activated biomass. The saponification and subsequent neutralization of carotenoids were carried out in an inert medium. The resulting sample contained carotenoids in the amount of 52 ± 3 mg/mL. The chemical profile of the carotenoids in the biomass of the microalga Chlorella vulgaris BIN was also established. The major carotenoid was lutein (45%), followed by fucoxanthin (12%) and β-carotene (4.3%). The oil extract of the carotenoids may be used for the further production of a microencapsulated product with the aim of targeted delivery to the lower parts of the gastrointestinal tract.

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Thiamine and Pyridoxine Alleviate Oxidative Damage by Copper Stress in Green Alga Chlorella vulgaris

Cited by 4 publications

References 34 publications

Transcriptomic analysis suggests the inhibition of DNA damage repair in green alga Raphidocelis subcapitata exposed to roxithromycin

Transcriptomic analysis suggests the inhibition of DNA damage repair in green alga Raphidocelis subcapitata exposed to roxithromycin

Functional stability despite high taxonomic turnover characterizes the Ulva microbiome across a 2,000 km salinity gradient

Obtaining Fat-Soluble Pigments—Carotenoids from the Biomass of Chlorella Microalgae

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