Night LED illumination in the temperate regions as a model of polar day for algal cultivation in field-installed photobioreactors: Comparison of Svalbard and Central Europe

The low-temperature algal biotechnology starts to develop in the Polar Regions, and especially in the Arctic. Light is crucial environmental factor in algal mass cultivation, therefore knowledge of the light environment and its modeling is crucial for design of the photobioreactors. The light conditions in three different environments were compared: natural diel light cycle during the polar summer (June-August) in Svalbard and in winter/spring (January – March) in the Central Europe outdoor and in the greenhouse photobioreactor, and in greenhouse photobioreactor equipped by additional night LED illumination in central Europe in winter/spring. In Svalbard, the monthly mean diel PAR values ranger from 126 to 395 µmol m-2 s-1, and the monthly diel sums of the PAR ranged from 2.38 to 7.47 MJ m-2 d-1. In the Central Europe in natural diel light cycle, the monthly mean diel PAR values and monthly diel sums of the PAR were generally lower, 57 - 248 µmol m-2 s-1 and 1.08 and 4.69 MJ m-2 d-1 in outdoor and 26 – 107 µmol m-2 s-1 and 0.50 – 2.03 69 MJ m-2 d-1 in the sun-illuminated photobioreactor. When additional night LED illumination, lasting from 12 to 14.7 hrs and from 12 to 15.3 hrs in 2021 and 2022, respectively, was provided, the monthly mean diel PAR values and monthly diel sums of the PAR increased to 479 – 598 µmol m-2 s-1 and 9.06 – 11.31 MJ m-2 d-1, respectively. Since the Svalbard maxima of diel sum of PAR are comparable to the values found in the night LED illuminated greenhouse photobioreactor, the night LED illumination in winter/spring in Central Europe should be proposed for model cultivations in the Polar Region in summer

Algae of Černé Lake in the Bohemian Forest

Algae and Cyanobacteria of Bohemian Forest are presented, as an important part of plant communities. Streams, bogs, arophytic ans subaerophytic standorts, phytoplankton of lakes and cryoseston are discussed and presented in tables and microphotographs.Bohemian Forest is an important refugium of oligotrophic species and a classic locality for therir study

Miniaturizovaný řasový biotest

Growth algal bioassay is based on long-term cultivation of a testing alga with tested substance in nutrient solution, or in a sample from nature. The bioassay is at least 3 generations and also chronic affects or influence of repruction process can be so detected. The yield of biomass of testing alga in a sample from nature represent the maximal biomass which could be expected in nature without limitation with light, temperature, CO2 and predation.Miniaturized bioassay is exploating cultivation of algae in wells of an immunological plate in volumes of 0.2 ml. In a plate 9x13 cm, there are 96 wells which enables us to expose 10 samples every in 6 replicates, 2x25 plates in a cultivation unit of size of a common table has capacity of 3 000 miniaturized cultures. Their filling, inoculation and evaluation can be facilitated with a great spectrum of tools and equipments for immunological assays

Mikroprocedura řasového testu

Growth algal bioassay is based on long-term cultivation of a testing alga with tested substance in nutrient solution, or in a sample from nature. The bioassay is at least 3 generations and also chronic affects or influence of repruction process can be so detected. The yield of biomass of testing alga in a sample from nature represent the maximal biomass which could be expected in nature without limitation with light, temperature, CO2 and predation.Miniaturized bioassay is exploating cultivation of algae in wells of an immunological plate in volumes of 0.2 ml. In a plate 9x13 cm, there are 96 wells which enables us to expose 10 samples every in 6 replicates, 2x25 plates in a cultivation unit of size of a common table has capacity of 3 000 miniaturized cultures. Their filling, inoculation and evaluation can be facilitated with a great spectrum of tools and equipments for immunological assay