This scientometric review and bibliometric analysis aimed to characterize trends in scientific research related to algae, photobioreactors and astaxanthin. Scientific articles published between 1995 and 2020 in the Web of Science and Scopus bibliographic databases were analyzed. The article presents the number of scientific articles in particular years and according to the publication type (e.g., articles, reviews and books). The most productive authors were selected in terms of the number of publications, the number of citations, the impact factor, affiliated research units and individual countries. Based on the number of keyword occurrences and a content analysis of 367 publications, seven leading areas of scientific interest (clusters) were identified: (1) techno-economic profitability of biofuels, bioenergy and pigment production in microalgae biorefineries, (2) the impact of the construction of photobioreactors and process parameters on the efficiency of microalgae cultivation, (3) strategies for increasing the amount of obtained lipids and obtaining biodiesel in Chlorella microalgae cultivation, (4) the production of astaxanthin on an industrial scale using Haematococcus microalgae, (5) the productivity of biomass and the use of alternative carbon sources in microalgae culture, (6) the effect of light and carbon dioxide conversion on biomass yield and (7) heterotrophy. Analysis revealed that topics closely related to bioenergy production and biofuels played a dominant role in scientific research. This publication indicates the directions and topics for future scientific research that should be carried out to successfully implement economically viable technology based on microalgae on an industrial scale.

An increasing number of microalgae strains are used for commercial production of metabolites. When conducting research, the moment of the process scaling tends to be very difficult. One of the most complex issues is related to planning and designing an efficient system for propagation of appropriately high amounts of inoculum required for inoculating cultures on a semi-technical and industrial scale. The following paper aimed at designing an automated station for the preparation of microalgae inoculation material intended for inoculation of the system, comprising of six 90 dm³ volume photobioreactors. The system, comprised of eight airlift photobioreactors of 12 dm³ volume each, installed in mobile storage units connected to the control system in the form of a docking station. Each of the photobioreactors had a separate system used for monitoring temperature and pH, mixing, and LED lighting. The station constituted the last stage of preparing the inoculation material for inoculating technical-scale photobioreactors, used for conducting experiments with Haematococcus pluvialis microalgae. Achieved results, repeatability of the processes, and the ergonomics of the station increased the productivity and quality of the research and development processes.

Vinasse is the waste product from the production of ethanol that is most loaded with pollutants. Known methods of treating vinasse allow for a reduction in the pollution load, but do not remove the brown colour. The aim of this study was to investigate the effect of the addition of yeast extract (YE) on the decolourization of sugar beet molasses vinasse by lactic acid bacteria (Lactobacillus plantarum, L. casei, and Pediococcus parvulus). Experiments were performed in batch mode in a BioStat B bioreactor (working volume of 2 dm3) for 72 h at 35.8ºC and pH0 of 6.5. The medium consisted of 25% v/v vinasse, glucose (38.67 g dm-3), and different amounts of yeast extract addition (2.24, 4.48, and 8.96 g dm-3). It was observed that an increase in the YE dose in the medium was followed by a decrease in decolourization of the vinasse. The maximum decolourization was 28.36% (YE = 2.24 g dm-3). Regardless of the YE amount added to the medium, removal of invert alkaline degradation products content in all experiments was at a similar level (approx. 13%). With an increased dose of YE, an increase in the caramel content was observed. The biggest melanoidins removal (62.3%) was found in the process with the highest YE dose. The acrylamide, 4-methylimidazole, furfural, 5-hydroxymethylfurfural, and 2-acetyl-4-(1,2,3,4)- tetrahydroxy-butylimidazole were completely assimilated.

Streszczenie: Pszczelarstwo stanowi bardzo ważny element gospodarki żywnościowej państwa