Maintenance of eukaryotic microalgae strains for the long term is generally carried out using serial subculture techniques which require labour, time and cost. Cryopreservation techniques provide long-term storage of up to years for numerous microorganism strains and cell cultures. Ssu930ijn vbvbhnn8;l,n is related to a successfully designed mass and heat transfer balance throughout the cell. In this study, optimization of the cryopreservation process was carried out for two commercially used microalgal strains. The parameters to be optimized were DMSO percentage (0–25%), incubation time (1–15 min) and cryopreservation term (7–180 days) using a central composite design (CCD). Long-term storage up to 123.17 and 111.44 days corresponding to high cell viabilities was achieved for Chlorella vulgaris and Neochloris texensis, respectively. Generated models were found to be in good agreement with experimental results. The study also revealed holistic results for storage of microalgal strains in a stable state for industrial applications.

The beneficial effects of high-intensity interval training (HIIT) and chlorella vulgaris (CV) on body composition and mitochondrial biogenesis have been shown in some mechanistic studies. This study aimed to determine the effects of CV and/or HIIT on mitochondrial biogenesis, performance and body composition among overweight/obese women. There was a significant reduction in the fat mass (FM) of the CV + HIIT group, as compared with the placebo group (P = 0·005). A marginal significant increase in body water (P = 0·050) and PPAR-γ coactivator-1α (P = 0·050) was also found only in the CV + HIIT group, as compared with the placebo. Relative (P < 0·001) and absolute (P < 0·001) VO2max, as well as Bruce MET (P < 0·001), were significantly increased in the HIIT and HIIT + CV groups. Besides, the synergistic effect of CV and HIIT on the Bruce MET increment was found (interaction P-value = 0·029). No significant changes were observed in BMI, fat-free mass, visceral fat, silent information regulator 1 and fibroblast growth factor-21. In this randomised clinical trial, forty-six overweight/obese women were assigned to four groups including CV + HIIT and HIIT + placebo groups that received three capsules of CV (300 mg capsules, three times a day) or corn starch, in combination with three sessions/week of HIIT. CV and placebo groups only received 900 mg of CV or corn starch, daily, for 8 weeks. Biochemical assessments, performance assessment and body composition were obtained at the beginning and end of the intervention. HIIT may be, therefore, effective in improving mitochondrial biogenesis, performance and body composition in overweight/obese women.

Chlorella (vulgaris spp.; CLV) is a genus of unicellular freshwater microalgae that are fit for human consumption and are used as additives with high nutritional value in feed for agriculturally important animals. Chlorella spp. are characterised by their simple cultivation, high productivity and levels of protein and other nutrients. Investigations have shown that the growth performance of broilers can be positively affected by the addition of very low amounts of CLV biomass (0.5-1.0% of the diet) to feed. The effect of CLV on growth and development is considered to stem from its high protein content (60.6%) and nutritional value. Results have shown enhanced body weight gain (2.7%), better feed conversion ratio (lowered by 2.8%), meat colour and breast muscle weight (20.1%) in CLV-supplemented chicks compared to control birds (control breast weight 19.1%). Additionally, a significant decrease in drip loss (2.26%) from breast muscle was observed with CLV supplementation and levels of blood total protein, albumin, and high-density lipoprotein (HDL) cholesterol significantly increased (P<0.05), while the levels of liver enzymes indicative of oxidative damage (alanine aminotransferase, ALT) decreased by 23.2%, indicating better liver function. In terms of immunity, blood lymphocytes were increased in broilers fed a diet supplemented with liquid CLV (17.9 x 103/µl) compared with birds supplemented with dry CLV (13.5 x 103/µl). Additionally, the levels of IgA, IgG, and IgM were elevated by 29.7%, 69.1%, and 32.3%, respectively, in broilers that consumed feed containing CLV. Similarly, the intestinal diversity and abundance of Lactobacillus spp. were significantly increased (9.9 ± 1.88 and 8.99 log10 CFU/g, respectively) by dietary supplementation with liquid CLV compared to that in non-treated chicks (8.7 ± 1.22 and 8.51 log10 CFU/g, respectively). Energy digestibility was increased significantly by 1.29% in CLV-treated chicks compared to the control chicks. This review highlights the findings associated with the utilisation of CLV biomass as a feed supplement and its effect on broiler growth and health.

The influence of buthidazole {3-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-4-hydroxy-1-methyl-2-imidazolidinone}, diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea], and atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] on fluorescence emission and post-luminescence decay in chlorella (Chlorella vulgaris Beyer) was studied. All three herbicides blocked photosynthetic electron transport and thus enhanced fluorescence. Buthidazole was the most active, a 79% increase in fluorescence being observed when algal cultures were exposed to 1 × 10-6 M herbicide for 5 min, and a 206% increase with an exposure time of 60 min. Postluminescence in chlorella exposed to 1 × 10-6 M buthidazole for 5, 10, 20, and 60 min was inhibited 15, 34, 58, and 69%, respectively. Diuron and atrazine inhibition of postluminescence was much less than that of buthidazole. The ratio of relative fluorescence to relative postluminescence can be sued to give a numerical value (C) for the phytotoxicity of this type of herbicide to a given plant species.

Exposure of Chlorella vulgaris to elevated concentrations of copper, chromium, nickel and zinc led to intracellular accumulation of high concentrations of these metals. Concomitantly, accumulation of free proline occurred, depending on the concentration of metals in the external medium or in the cell. The greater the toxicity or accumulation of a metal, the greater the amount of intracellular proline in algal cells. However, higher concentrations of copper and chromium were inhibitory to proline accumulation by the test organism. The accumulation of proline was triggered within a few hours of metal treatment. Test metals also induced lipid peroxidation; copper was the most efficient inducer whereas zinc was the least. Pretreatment of C. vulgaris with proline counteracted metal-induced lipid peroxidation and potassium ion efflux. Thus the present work shows a protective effect of proline on metal toxicity through inhibition of lipid peroxidation.