The aim of this study was to construct Chlorella mutants deficient in chlorophyll synthesis by atmospheric pressure room temperature plasma (ARTP) mutagenesis, and screen novel algal species with very low chlorophyll content which is suitable for protein production by fermentation. Firstly, the lethal rate curve of mixotrophic wild type cells was established by optimizing the mutagenesis treatment time. The mixotrophic cells in early exponential phase were treated by the condition of over 95% lethal rate, and 4 mutants with the visual change of colony color were isolated. Subsequently, the mutants were cultured in shaking flasks heterotrophically for evaluation of their protein production performance. P. ks 4 mutant showed the best performance in Basal medium containing 30 g/L glucose and 5 g/L NaNO₃. The protein content and productivity reached 39.25% dry weight and 1.15 g/(L·d), with an amino acid score of 101.34. The chlorophyll a content decreased 98.78%, whereas chlorophyll b was not detected, and 0.62 mg/g of lutein content made the algal biomass appear golden yellow. This work provides a novel germplasm, the mutant P. ks 4 with high yield and high quality, for alternative protein production by microalgal fermentation.
Chlorella/metabolism* ; Chlorophyll A/metabolism* ; Plant Breeding ; Mutagenesis ; Chlorophyll/metabolism* ; Biomass ; Microalgae

Selenium (Se) is an essential trace element for organisms. Se deficiency will cause diseases such as Keshan disease and Kashin-Beck in human being, and huge loss to animal husbandry. Currently available Se supplements have such problems as low Se content, poor bioavailability, and poor safety. Chlorella pyrenoidosa can produce bioavailable and safe organic Se under suitable conditions, which is thus a promising Se supplement. Therefore, in this study, we tried to improve the Se tolerance and accumulation of C. pyrenoidosa by directional adaptation. To be specific, we gradually increased the concentration of Na₂SeO₃ in medium to domesticate C. pyrenoidosa and optimized the adapting time and concentration gradient of Na₂SeO₃ during the adaptation. The results showed that the adapted C. pyrenoidosa was more tolerant to Se and had stronger Se enrichment ability. In 5 L fermenter, the adapted strains could tolerate 40 mg/L Na₂SeO₃ and the synthesis rate of organic Se was 175.6% higher. Then, Se addition method in the 5 L fermenter was optimized. The result demonstrated that addition of Na₂SeO₃ at 40 mg/L during heterotrophic culture achieved the final dry weight of C. pyrenoidosa cells at 106.4 g/L, content of organic Se at 1 227 mg/kg, and synthesis rate of organic Se at 1.36 mg/(L·h). Compared with the reported highest cell density of 75 g/L and the highest organic Se content of 560 mg/kg, the corresponding figures in this study were 41.9% and 119.1% higher, respectively. In conclusion, directional adaptation can remarkably improve the Se tolerance and enrichment of C. pyrenoidosa.
Animals ; Humans ; Selenium/pharmacology* ; Chlorella ; Heterotrophic Processes

Objective To construct a polymerase chain reaction-capillary electrophoresis （PCR-CE） detection method using ChlB gene and NIES gene, investigate the method's specificity and sensitivity, and to evaluate its application value in drowning diagnosis. Methods The specific primers ChlB and NIES were designed for the conserved sequence of chlorophyte ChlB gene and cyanophyte NIES gene in GenBank to construct PCR-CE detection method; 50 species of standard DNA samples were amplified; the sensitivity was determined by gradient concentration detection of positive standard samples; 25 actual cadaver lung tissue samples （drowned： 20, natural death： 5） were detected, and the simultaneous detection results of microwave digestion-vacuum filtration-automated scanning electron microscopy （MD-VF-Auto SEM） were simultaneously compared. Results The minimum DNA detection concentration of primers ChlB and NIES was 0.161 ng and 0.109 ng, respectively, which could specifically amplify chlorophyte （Chlorella pyrenoidosa） and cyanophyte ［Microcystis aeruginosa （producing and not producing toxin）］ widespread in water. The product fragments were 156 bp and 182 bp, respectively. The results of non-drowning tissues were negative. Conclusion This method has high sensitivity and specificity. It can be applied to the detection of plankton related to drowning and combined with MD-VF-Auto SEM method, can increase the detection range of plankton related to drowning and improve the evidence power of drowning diagnosis.
Chlorella ; Diatoms/genetics* ; Drowning/diagnosis* ; Humans ; Kidney ; Liver ; Lung ; Plankton/genetics*

The aim of this study was to establish a novel technology using microalgae for NO₃⁻ removal from high concentration wastewater and conversion to algal proteins. The effects of cultivation modes and illumination modes on the biomass yield, NO₃⁻ assimilation rate and algal protein yield were first investigated in shaking flasks for mixotrophic cultivation of Chlorella pyrenoidosa, and subsequently the scale-up verification in 5-L photo fermenter was successfully conducted. Fed-batch cultivation without medium recycling was the best cultivation mode in shaking flask system, in which the highest biomass yield (35.95 g/L), the average NO₃⁻ assimilation rate (2.06 g/(L·d)) and algal protein content (up to 42.44% of dry weight) were achieved. By using a staged increase of light intensity as illumination modes, the specific growth rate of cells could be significantly promoted to the highest (0.65 d⁻¹). After a 128-hour continuous cultivation in a 5-L photo fermenter, the highest biomass yield and the average NO₃⁻ assimilation rate were reached to 66.22 g/L and 4.38 g/(L·d) respectively, with the highest algal protein content at 47.13% of dry weight. Our study could provide a photo fermentation technology of microalgae for highly efficient treatment of waste industrial nitric acid and/or high concentration nitrate wastewater. This microalgae-based bioconversion process could coproduce protein-rich microalgal biomass, which facilitates the resource utilization of these type wastewater by trash-to-treasure conversion.
Algal Proteins ; biosynthesis ; Biomass ; Chlorella ; Nitrates ; isolation & purification ; metabolism ; Nitrogen ; metabolism ; Waste Water ; chemistry ; Water Purification ; methods

OBJECTIVE: To study the effects of aerobic exercise combined with chlorella pyrenoidos of disintegrated cell wall on the lipid metabolism in rats with high-fat diet. METHODS: Fifty-five male Wistar rats were subjected to adaptive feeding for 4 days and weight-free swimming training for 3 days, 20 min/d. After eliminating 5 rats that were not suitable for swimming training, the other rats were randomly divided into 5 groups according to their body weight:control group (C group), high fat diet group (H group), high-fat diet + chlorella group(HC group), high fat diet + aerobic exercise group (HM group), high fat diet + chlorella + aerobic exercise group (HMC group), 10 in each group. The HM and HMC group were subjected to 60 min/d swimming training for 6 weeks with non-weight-bearing. Group C were fed regular diet. The other groups were fed with high-fat diet, the rats in group HC and HMC were intragastrically treated with chlorella pyrenoidos of disintegrated cell wall at the dose of 3.9 g/(kg·d), the volume was 5 ml/kg, and the other groups are given equivalent saline. The Lee's index and biochemical indexes of blood and liver were measured after 6 weeks. RESULTS: Compared with group C, Lee's index, serum levels of free fatty acids(FFA), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-c), liver FFA and interleukin-10 (IL-10) were increased significantly (<0.01), the serum level of high-density lipoprotein cholesterol (HDL-c) was decreased significantly (<0.01) in group H. Compared with group H, Lee's index, serum FFA, IL-6, TNF-α, TC, TG, LDL-c, liver FFA and IL-10 were decreased significantly (<0.05 or <0.01), serum level of HDL-c was increased significantly (<0.05 or <0.01) in group HC, HM and HMC. Compared with group HC and HM, Lee's index, serum FFA, IL-6, TNF-α, TC, TG, LDL-c, liver FFA and IL-10 were decreased significantly (<0.05), serum level of HDL-c was increased significantly (<0.05) in group HMC. CONCLUSIONS Aerobic exercise and chlorella pyrenoidos of disintegrated cell wall can improve lipid metabolism in rats with high-fat diet and reduce the lipid toxicity caused by obesity. Joint intervention is more effective than single intervention.
Animals ; Cell Wall ; Chlorella ; Diet, High-Fat ; Lipid Metabolism ; Male ; Physical Conditioning, Animal ; Rats ; Rats, Wistar

Flashing light effect on microalgae could significantly improve the light efficiency and biomass productivity of microalgae. In this paper, the baffles were introduced into the traditional flat plate photobioreactor so as to enhance the flashing light effect of microalgae. Making Chlorella sp. as the model microalgae, the effect of light intensity and inlet velocity on the biomass concentration of Chlorella sp. and light efficiency were evaluated. The results showed that, when the inlet velocity was 0.16 m/s, with the increase of light intensity, the cell dry weight of Chlorella sp. increased and light efficiency decreased. With increasing the inlet velocity, the cell dry weight of Chlorella sp. and light efficiency both increased under the condition of 500 μmol/(m2 x s) light intensity. The cell dry weight of Chlorella sp. cultivated in the novel flat plate photobioreactor was 39.23% higher than that of the traditional one, which showed that the flashing light effect of microalgae could be improved in the flat plate photobioreactor with inclined baffles built-in.
Biomass ; Chlorella ; growth & development ; Culture Techniques ; instrumentation ; Light ; Microalgae ; growth & development ; Photobioreactors

Chlorella is nutritious and has been used as a functional food much earlier than the other microalgae. C. pyrenoidosa, the potential microalgae which is currently cultured and developed for the new strategic industry of biofuels production and biological CO2 fixation, is a new resource food announced by the Ministry of Health of the People's Republic of China late 2012. Accumulation of high value-added substances in C. pyrenoidosa during the cultivation for lipid makes it possible to reduce the costs for C. pyrenoidosa-based biofuels production. Among these potential substances, hot water extract of Chlorella (CE), commercially known as "Chlorella growth factor", is the unique one that makes Chlorella more precious than the other algae, and the market price of CE is high. It is believed that CE is effective in growth promotion and immunoregulation. However, there is no systematic analysis on the research status of CE and its bioactivity. The present report summarized recent research progress of CE and its bioactivity. Generally, besides the main effect on immunoregulation and tumor inhibition, CE was efficient in improving metabolic syndrome, scavenging for free radicals, protecting against ultraviolet damage, chelating heavy metals, and protecting liver and bowel. Several major challenges in CE research as well as its prospects were also analysed in the present report.
Biofuels ; Chlorella ; chemistry ; Humans ; Lipids ; chemistry ; Plant Extracts ; chemistry ; pharmacology ; Water

Chemical constituents of Chlorella sorokiniana were isolated and purified by repeated column chromatographies, over silicagel and Sephadex LH-20. Their structures were identified on the basis of physicochemical properties and spectroscopic data analysis. Five compounds were obtained from the petroleum ether extract of Chlorella sorokiniana, and their structures were identified as (22E, 24R)-5alpha, 3beta-epidioxiergosta-6, 22-dien-3beta-ol(1),(24S)-ergosta-7-en-3beta-ol(2), loliolide(3), stigmasta-7,22-dien-3beta,5alpha,6alpha-triol(4), and 3beta-hydroxy-5alpha,6alpha-epoxy-7-megastigmen-9-one(5). The main liposoluble fractions from Chlorella sorokiniana maiuly contain fatty acids, alkyl acids and olefine acids. Components 1-5 were isolated from the genus Chlorella for the first time.
Biological Factors ; chemistry ; Chlorella ; chemistry ; Gas Chromatography-Mass Spectrometry ; Molecular Structure

Photoautotrophic cultivation with heterotrophic cells as seeds (heterotrophic cells/photoautotrophic cultivation) is an effective way for the development of microalgal biofuel, but its development potential from the point of process optimization has not been investigated in literatures. To evaluate this, the optimizations of medium and culture conditions for Chlorella ellipsoidea were studied. In the heterotrophic stage, the biomass concentration reached 11.04 g/L with the optimized medium in flask, which were 28.0% higher than that with the original medium, and the biomass concentration reached 73.89 g/L in 5-L fermenter. In the photoautotrophic stage, the culture medium and conditions were studied in a 2-L column photobioreactor. The maximum biomass concentration, lipid content and lipid productivity reached 1.62 g/L, 36.34% and 6.1 mg/(L·h) under the optimal photoautotrophic conditions. The lipids were mainly composed of C16-C18 fatty acids, which were raw material suitable for biodiesel. After optimization, heterotrophic cells/photoautotrophic cultivation can significantly improve the capacity of biofuel production by Chlorella ellipsoidea, this method is also expected to be an efficient way for the cultivation of other microalgae that can grow heterotrophically.
Biofuels ; Biomass ; Cell Culture Techniques ; Chlorella ; metabolism ; Culture Media ; Fatty Acids ; biosynthesis ; Heterotrophic Processes ; Lipids ; biosynthesis ; Photobioreactors

A dietary supplement, also known as a food supplement or nutritional supplement, is a preparation intended to supplement the diet and provide nutrients, such as vitamins, minerals, fiber, fatty acids, or amino acids. A health functional food is a food where one or more new ingredients have been added to a food and the new product has an additional function. Physicians and patients need information on current evidence on the efficacy and safety of selected dietary supplements that are commonly used. The current evidence on the efficacy and safety of selected dietary supplements (beta-carotene, vitamin C, D, E, calcium, selenium, omega 3, ginseng, glucosamine, chlorella, saw palmetto, gingko, gamma linolenic acid, echinacea) for specific conditions is assessed by an evidence-based approach. With an increase in income and the aging of the population, spending on dietary supplements is steadily increasing, but concern about the safety and efficacy of dietary supplements may be relatively low. Recently, many domestic and international clinical trials on nutritional supplements have been performed. As a result, the evidence on the efficacy and safety of dietary supplements may be changed or recommendations may also be changed. Greater efforts should be made to acquire the latest knowledge about dietary supplements.
Aging ; Amino Acids ; Ascorbic Acid ; Calcium ; Chlorella ; Diet ; Dietary Supplements ; Evidence-Based Medicine ; Fatty Acids ; Functional Food ; gamma-Linolenic Acid ; Ginkgo biloba ; Glucosamine ; Humans ; Minerals ; Panax ; Selenium ; Vitamins