Despite many publications about Chlorella-like algae, their reliable and accurate identification is still difficult due to their simplicity and high phenotypic plasticity. The molecular approach has revolutionized our understanding of the diversity of ’small green balls’, and a natural classification of this group is currently being developed. This work is aimed at providing a detailed study of the phylogenetic position, morphology, ultrastructure, and physiology of the biotechnologically remarkable Chlorella-like strain IPPAS C-1210. Based on the SSU–ITS1–5.8S–ITS2 phylogeny, genetic distances, and the presence of compensatory base changes (CBCs) in ITS1 and conserved regions of ITS2 secondary structures, we describe a new genus, Neochlorella, with IPPAS C-1210 as the authentic strain of the type species, N. semenenkoi gen. and sp. nov. In addition, we justify the reassignment of the strain C. thermophila ITBB HTA 1–65 into N. thermophila comb. nov. The distinctive ultrastructural and physiological traits of the new species are discussed.

Currently, microalgae and cyanobacteria attract the attention of researchers as potential producers of various valuable substances. To increase the profitability of biotechnological processes using these organisms, it is necessary to select highly effective strains and choose the optimal conditions for their growth and maximum productivity. Growth optimization should be carried out, on the one hand, under intensive conditions, as close as possible to large-scale cultivation, and, on the other hand, in small volumes in order to be able to check many different parameters in parallel at minimal cost. In this paper, the authors present a description and characteristics of their laboratory system for intensive cultivation (LSIC—Laboratory System for Intensive Cultivation) with thermo-, light-, and gas regulation and the possibility of cultivation in four repetitions in eight different conditions, differing in light, temperature, and CO 2 concentration. As an example, the results of a number of experiments using the installation are also presented.

Strain Сhlorella sp. IPPAS C-1210 is an effective lipid and triacilglycerols (TAG) producer. The strain could be used eventually in such industries as bioenergetics, food industry and agriculture. The objective of this work was investigation of conditions in which the strain Сhlorella sp. IPPAS C-1210 accumulates the most starch and TAG in cells with a view to optimise its growth and productivity. The following cultivation parameters were investigated in order to figure out their influence on accumulation of starch and TAG: nitrogen- and phosphorous-starvation and cultivation on media with different nitrogen (nitrate, urea) and carbon (carbon dioxide, bicarbonate) sources. Pigments, starch, protein and lipid content in cells were measured. The exclusion of nitrogen or phosphorus source from medium decreased the biomass productivity significantly, caused chlorosis and reduction of protein content. Total lipid content increased slightly after phosphorous starvation and stayed almost constant under nitrogen starvation, however a greater TAG increase was observed during nitrogen starvation. Both nitrogen and phosphorous starvations caused the increase of the amount of reserve carbohydrates: during phosphorous starvation increase was insignificant, whereas the latter almost doubled the amount of reserve carbohydrates. The highest biomass and lipid productivity was observed in cells grown in bicarbonate supplement medium and the highest starch productivity was observed in cells grown in standard BBM-3N medium.

Микроводоросли накапливают в качестве основных запасных веществ крахмал и триацилглицерины (ТАГ). При этом соотношения этих запасных продуктов могут сильно варьироваться и в значительной степени оказываются видо- и даже штамм-специфичны. Кроме того, различные стрессовые воздействия могут способствовать запасанию крахмала или же ТАГ, открывая возможности для биотехнологического «управления» процессами запасания в клетках культивируемых микроводорослей Microalgae accumulate starch and triacylglycerols (TAG) as the main reserve substances. At the same time, the ratios of these reserve products can vary greatly and, to a large extent, turn out to be species- and even strain-specific. In addition, various stress effects can promote the storage of starch or TAG, opening up opportunities for biotechnological "management" of storage processes in the cells of cultivated microalgae.