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BackgroundThe differentiation between wild type of Parachlorella kessleri and its mutant strains PC Mut2, PC Mut4 by using the Multi-functional Plant Efficiency Analyzer (М-РЕА-2) was studied. Mutant algal cells of P. kessleri have been obtained by UV-C during 3 and 10 min respectively.ResultsLight-induced kinetics of prompt fluorescence (OJIP transients), delayed fluorescence and modulated reflection at 820 nm (redox transitions of P700 in PSI) showed disturbance of electron transport flow in photosystem II (PSII) and an increase fraction of non-reducing centers of secondary quinone acceptors of electron (QB). In addition, the amplitudes of the fast and slow peak in the kinetics of the delayed light emission and non-photochemical fluorescence quenching ( NPQ) were significantly reduced in mutant cells, indicating low level of the membrane energization of photosynthetic membranes. Changes of photosynthetic reactions of mutants may lead to an increase of the carotenoids content, which protect cells against the light stress.ConclusionIt is suggested to use parameters of induction curves of prompt and delayed fluorescence to characterize mutant algal cells in biotechnological studies.Electronic supplementary materialThe online version of this article (doi:10.1186/s40529-014-0053-7) contains supplementary material, which is available to authorized users.

The induced mutagenesis method for deriving pigment mutants of a green microalga, Chlamydomonas reinhardtii CC-124 and their pigment composition as well as ability to assess mutability of contaminated aquatic ecosystems were studied. In the present study, 14086 mutants (colonies) were obtained by exposure of the wild strain, C. reinhardtii CC-124, to 1, 2, 3, 5 min of ultraviolet (UV) irradiation. After screening, these mutants (colonies) revealed four pigmented mutants (124y-1, 124p-1, 124y-2 and 124p-2). Compared to the wild CC-124, these mutants are characterized by a decrease in chlorophyll a & b content and an increase in carotenoids. The lowest decrease in chlorophyll a was three to four folds, while the highest increase in carotenoids was two to four folds. The result of bio-test, using the resulting pigment mutant of C. reinhardtii 124y-1 showed that mutagenic activity was observed significantly in both Tekeli River and Pavlodar Oil Refinery in Kazakhstan; the waste water of the Pavlodar Oil Refinery had high-toxicity while the water of the Tekeli River had medium-toxicity.

he objective of the present investigation was to study the effect of two supplemented algae on nutritive value of lactating Damascus goats rations and its effect on performance of kids, milk production, milk composition, digestion coefficients, feed intake and feed conversion. Twenty seven Damascus lactating goats of 2-4 years old and average live body weight of 48.5±1.4kg were chosen divided and into three similar groups (9 animals each) R1 (control), R2 and R3. The groups were assigned at random to receive one of the three experimental rations. Animals of group R1 were fed 50% concentrate feed mixture (CFM) + 30% berseem hay + 20% wheat straw (control), R2 were fed 50% CFM + 30% berseem hay + 20% wheat straw with supplemented algae (Spirulina) and R3 were fed 50% CFM + 30%berseem hay + 20% wheat straw with supplemented algae (Ulva rigida) 0.2% of feed intake. At the end of the trial, three digestibility trials were conducted to determine digestibility coefficients and nutritive value of experimental rations. In addition, rumen liquor and blood samples were taken to determine some parameters. All supplemented in the present study decreased (P<0.05) CF, ash, ADL and hemicelluloses, but CP content had increased. The results revealed that the algae supplementation recorded highest digestibility coefficients (P<0.05) for all nutrients fiber fractions and nutritive value of R2 (P<0.05) compared with control. Nutrients digestibility coefficients, concentrations of ruminal ammonia nitrogen and total volatile were significantly (P<0.05) higher, which ruminal pH values were significantly (P<0.05) lower for rams fed algae supplemented diets than control at the sampling times 4 hrs. The highest body weight was recorded with R2. The algae supplemented recorded better feed conversion (DMI/daily milk yield) for R2 and R3, respectively compared with the control (R1). It could be concluded that supplemented goats ration with algae tended to increase digestibility coefficients and nutritive values, increased milk yield and improved feed conversion as kg DM intake per kg milk yield.