Developing an economically efficient LED light regime for Arthrospira platensis cultivation

Lighting technologies develop rapidly and the energy efficiency of LEDs quadrupled between prices have decreased more than 60% in the last decade. The cyanobacterium Arthrospira platensis, commercially known as food supplement Spirulina, has great potential for urban indoor farming due to its high growth rate and low resources needed. This study investigates the combined effects of photoperiod (16–24 h light), light intensity (100–400 μmol photons m−2 s−1), and temperature (27–35℃) on production and energy efficiency in the cultivation of A. platensis in 0.5 L bubble column photobioreactor. This study aimed to develop a cost-efficient LED light regime for attaining maximal production of A. platensis. All experiments under cold white (6500 K) light show higher light energy efficiency than those under warm white (3000 K) light (p < 0.05). The light saturation point was at 261 μmol photons m−2 s−1 for warm white light and was not reached for cold white light. The maximum specific growth rate (µmax) was 2.2 day−1, 30% higher than reported in the literature. This growth rate was obtained at 24:00 light:dark photoperiod 33–35℃ and cold white light; light efficiency was 3 kW g−1 DW. Cultivation under warm white light resulted in 22% lower µmax, and light efficiency was 9 kW g−1 DW. The most economical light intensity was 193 μmol photons m−2 s−1 of cold white light

Comparison of antioxidant activity in various spirulina containing products and factors affecting it

© 2023. The Author(s).Spirulina is a popular food supplement known for its high antioxidant activity. Several studies have shown that antioxidant activity fluctuates depending on the combination of ingredients in the food. Fresh spirulina is a growing market trend; however, pure spirulina short shelf life is a strong limitation. This study aims to investigate antioxidant activity of various novel commercial fresh spirulina-containing products and the factors affecting it. Antioxidant activity and total phenolic content of each ingredient and binary combinations of spirulina and apple juices, Japanese quince syrup, or cranberry syrup were measured. Synergic, antagonistic, and additive interactions between samples were determined and expressed using the synergy coefficient. FRAP assay showed apparent synergism of spirulina and all the studied ingredients whereas ABTS and Folin–Ciocalteu methods revealed an antagonistic interaction between spirulina and apple juice. Despite the antagonistic interactions, all the products demonstrated at least the same antioxidant activity as pure fresh spirulina and had longer shelf life than, pointing to their commercial potential.publishersversionPeer reviewe

An in vitro and in vivo study on the intensity of adhesion and colonization by Staphylococcus epidermidis and Pseudomonas aeruginosa on originally synthesized biomaterials with different chemical composition and modified surfaces and their effect on expression of TNF-α, β-defensin 2 and IL-10 in tissues

The aim of this study was to determine adhesion and colonization of bacteria on the surface of originally synthesized glass-ceramic biomaterials and their effect on inflammation reactions in tissues surrounding the implant. Materials and Methods: Biomaterial discs were contaminated with bacterial suspensions of 10, 102, and 103 colony forming units (CFU)/mL (P. aeruginosa ATCC 27853 and S. epidermidis ATCC 12228), and after 2 hours of cultivation, the intensity of bacterial adhesion was determined. For in vivo tests, the samples were contaminated with 102, and 103 CFU/mL cultivated at 37°C for 2 h to ensure bacterial adhesion. Contaminated biomaterial samples were implanted in the interscapular area of chinchilla rabbits for 2 and 4 weeks. The biomaterials were removed, and using plate count and sonification methods, bacterial colonization on the surface of biomaterials was determined. Moreover, the expression of TNF-α, β-defensin 2, and IL-10 in the surrounding tissues was assessed by using immunohistochemistry methods. Results: P. aeruginosa more intensively colonized biomaterials in the in vivo study as compared with S. epidermidis. Il-10 is a regulatory cytokine, which reduces the intensity of inflammatory cell activity, thus reducing nonspecific resistance of the organism. Conclusions: The expression of TNF-α and IL-10 was not affected by short (2 and 4 weeks) biomaterial implantation. Pronounced cytokine expression in tissues around implanted biomaterials contaminated with P. aeruginosa was observed.publishersversionPeer reviewe

An In Vitro and In Vivo Study on the Intensity of Adhesion and Colonization by Staphylococcus epidermidis and Pseudomonas aeruginosa on Originally Synthesized Biomaterials With Different Chemical Composition and Modified Surfaces and Their Effect on Expression of TNF-alpha, beta-Defensin 2 and IL-10 in Tissues

publishersversionPeer reviewe

Investigation of Crystallization of Na+ and Nb5+ Containing Ca2+ Phosphate Glass Ceramics

Investigation of crystallization of Na+ and Nb5+ containing Ca2+ phosphate glass ceramic

Komerciālo kosmētisko mālu minerālā un granulometriskā sastāva noteikšana

Komerciālo kosmētisko mālu minerālā un granulometriskā sastāva noteikšan

1A un 2A grupas modifikatoru ietekme uz niobofosfātu stiklu struktūru

Stiklu īpašības nosaka to sastāvs. Atkarībā no pievienotā modifikatora katjona rādiusa, iespējams izmainīt stiklu fizikālās un ķīmiskās īpašības

Šķīdināšanas nozīme niobofosfātu stikla keramikas sastāva noteikšanā

Šķīdināšanas nozīme niobofosfātu stikla keramikas sastāva noteikšan

Mālu minerālus saturoši komerciālie kosmētikas produkti

Mālu minerālus saturoši komerciālie kosmētikas produkt