scholarly journals Harvesting of Chlorella sorokiniana BR001 cultivated in a low-nitrogen medium using different techniques

2022 ◽  
Vol 52 (1) ◽  
Author(s):  
Rafael de Araújo Lira ◽  
Lucas de Paula Corrêdo ◽  
Jimmy Soares ◽  
Mariana Machado Rocha ◽  
Antonio Teixeira de Matos ◽  
...  

ABSTRACT: The harvesting process is a current challenge for the commercial production of microalgae because the biomass is diluted in the culture medium. Several methods have been proposed to harvest microalgae cells, but there is not a consensus about the optimum method for such application. Herein, the methods based on sedimentation, flocculation, and centrifugation were evaluated on the recovery of Chlorella sorokiniana BR001 cultivated in a low-nitrogen medium. C. sorokiniana BR001 was cultivated using a low-nitrogen medium to trigger the accumulation of neutral lipids and neutral carbohydrates. The biomass of C. sorokiniana BR001 cultivated in a low-nitrogen medium showed a total lipid content of 1.9 times higher (23.8 ± 4.5%) when compared to the biomass produced in a high-nitrogen medium (12.3 ± 1.2%). In addition, the biomass of the BR001 strain cultivated in a low-nitrogen medium showed a high content of neutral carbohydrates (52.1 ± 1.5%). The natural sedimentation-based process was evaluated using a sedimentation column, and it was concluded that C. sorokiniana BR001 is a non-flocculent strain. Therefore, it was evaluated the effect of different concentrations of ferric sulfate (0.005 to 1 g L-1) or aluminum sulfate (0.025 to 0.83 g L-1) on the flocculation process of C. sorokiniana BR001, but high doses of flocculant agents were required for an efficient harvest of biomass. It was evaluated the centrifugation at low speed (300 to 3,000 g) as well, and it was possible to conclude that this process was the most adequate to harvest the non-flocculent strain C. sorokiniana BR001.

1962 ◽  
Vol 40 (1) ◽  
pp. 83-94 ◽  
Author(s):  
M. Kates ◽  
D. J. Kushner ◽  
A. T. James

Cells of Bacillus cereus grown in an alcohol-free medium (control cells) had a lipid content of 2.6 ± 0.4%, on a dry weight basis. About half of the lipids consisted of phosphatides, including phosphatidyl ethanolamine (40%), phosphatidyl glycerol (28%), lecithin (6%), lyso compounds (10%), and three acidic phosphatides of unknown structure. The fatty acids of the total lipids were predominantly saturated, the major components being branched-chain C13, C15, and C17acids. The neutral lipids consisted mostly of diglycerides, with a small amount of triglycerides. Five to ten per cent of the lipids was obtained as unsaponifiable material, consisting chiefly of long-chain (n-C16and n-C18) alcohols, and having traces of long-chain aldehydes (derived from plasmalogens).Cells grown in the presence of alcohols usually had a higher phosphatide content, a correspondingly lower non-phosphatide content, and a higher non-saponifiable content than control cells. Total lipid content or relative proportions of the phosphatide components in alcohol-grown cells did not differ significantly from those of control cells.


1962 ◽  
Vol 40 (1) ◽  
pp. 83-94 ◽  
Author(s):  
M. Kates ◽  
D. J. Kushner ◽  
A. T. James

Cells of Bacillus cereus grown in an alcohol-free medium (control cells) had a lipid content of 2.6 ± 0.4%, on a dry weight basis. About half of the lipids consisted of phosphatides, including phosphatidyl ethanolamine (40%), phosphatidyl glycerol (28%), lecithin (6%), lyso compounds (10%), and three acidic phosphatides of unknown structure. The fatty acids of the total lipids were predominantly saturated, the major components being branched-chain C13, C15, and C17acids. The neutral lipids consisted mostly of diglycerides, with a small amount of triglycerides. Five to ten per cent of the lipids was obtained as unsaponifiable material, consisting chiefly of long-chain (n-C16and n-C18) alcohols, and having traces of long-chain aldehydes (derived from plasmalogens).Cells grown in the presence of alcohols usually had a higher phosphatide content, a correspondingly lower non-phosphatide content, and a higher non-saponifiable content than control cells. Total lipid content or relative proportions of the phosphatide components in alcohol-grown cells did not differ significantly from those of control cells.


2017 ◽  
Vol 10 (1) ◽  
pp. 92-99 ◽  
Author(s):  
Hércules Rezende Freitas

Polyunsaturated fatty acids (PUFAs) comprise about 35-40% of the total lipid content from green algaeChlorella, reaching up to 24% linoleic acid and 27% α-linolenic acid inC. vulgaris. Also, microalgae nutrient composition may be modulated by changes in the culture medium, increasing fatty acid and microelement concentrations in the algae biomass. PUFAs, such as α-linolenic (n-3) and linoleic (n-6) acids, as well as its derivatives, are considered essential for dietary consumption, and their ability to regulate body chemistry has been recently explored in depth. A balanced fatty acid consumption is shown to counteract the negative effects of western diets, such as chronic inflammation and glucose intolerance. In this brief commentary, technological and practical uses ofC. vulgarisare explored as means to improve dietary quality and, ultimately, human health.


Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 463 ◽  
Author(s):  
Ali Nawaz Kumbhar ◽  
Meilin He ◽  
Abdul Razzaque Rajper ◽  
Khalil Ahmed Memon ◽  
Muhammad Rizwan ◽  
...  

The decline in fossil fuel reserves has forced researchers to seek out alternatives to fossil fuels. Microalgae are considered to be a promising feedstock for sustainable biofuel production. Previous studies have shown that urea is an important nitrogen source for cell growth and the lipid production of microalgae. The present study investigated the effect of different concentrations of urea combined with kelp waste extract on the biomass and lipid content of Chlorella sorokiniana. The results revealed that the highest cell density, 20.36 × 107 cells−1, and maximal dry biomass, 1.70 g/L, were achieved in the presence of 0.5 g/L of urea combined with 8% kelp waste extract. Similarly, the maximum chlorophyll a, b and beta carotenoid were 10.36 mg/L, 7.05, and 3.01 mg/L, respectively. The highest quantity of carbohydrate content, 290.51 µg/mL, was achieved in the presence of 0.2 g/L of urea and 8% kelp waste extract. The highest fluorescence intensity, 40.05 × 107 cells−1, and maximum total lipid content (30%) were achieved in the presence of 0.1 g/L of urea and 8% kelp waste extract. The current study suggests that the combination of urea and kelp waste extract is the best strategy to enhance the biomass and lipid content in Chlorella sorokiniana.


2020 ◽  
Vol 5 (1) ◽  
pp. 49
Author(s):  
Dina Soes Putri ◽  
Desy Ambar Sari ◽  
Lulu Diani Zuhdia

Microalgae-based researches are one of the interesting topics to date due to its wide applications for commercial industries. One of the vital issues that remain in the production of large-scale microalgae is the harvesting process of microalgae culture. There are several techniques that can be used in harvesting microalgae and each algae will be showing a different result. In this research, the microalgae Haematococcus pluvialis were harvested using flocculation-filtration method. Alum in different dosages, range from 0.25-2 g/L, was used as flocculants and the mixing duration was investigated to seek out the best harvesting efficiency. Based on the research, it can be concluded that the optimum flocculation process was alum addition of 1 g/L culture that continuously stirring for 5 minutes long. In which the flocculation efficiency reaches 94.5%.


OENO One ◽  
1988 ◽  
Vol 22 (1) ◽  
pp. 25
Author(s):  
Catherine Desens ◽  
Aline Lonvaud-Funel

<p style="text-align: justify;">Les lipides extraits des membranes de bactéries lactiques du vin sont séparés par chromatographie sur couche mince en phospholipides, glycolipides et lipides neutres. Le pourcentage de répartition de chaque classe varie, non seulement en fonction des souches, mais aussi selon leurs conditions de culture.</p><p style="text-align: justify;">+++</p><p style="text-align: justify;">Lactic and bacteria of wines are inhibited in fermenting must. Éthanol, fatty acids and other unknow yeast metabolites are responsible for the loss of viability and malolactic activity. Prior results suggest that they induce an alteration of the plasma membrane. Owing to their nature, we assume the lipid constituants to be the target of the inhibitors. So, we have undertaken the study of the membrane lipids of two strains, <em>L. plantarum</em> and <em>L. oenos</em>.</p><p style="text-align: justify;">After extraction, the samples are analysed by HPTLC. Comparing the strains, the patterns reveal small differences in the distribution of phospholipids, glycolipids and neutral lipids.</p><p style="text-align: justify;">Some culture factors were investigated for their influence. Within the cell cycle, the distribution of the various classes changes according to the period of incubation. If ethanol is added in the culture medium, neutral lipids decrease by 25 to 50 per cent and glycolipids increase by 30 per cent depending on the age of the culture. Phospholipids remain quite constant.</p><p style="text-align: justify;">Further researchs are in progress to test the influence of others factors. These results might explain the loss of viability of the bacteria varies when they are added to wine, as well as the variable response to yeast antagonism according to the strains.</p>


2006 ◽  
Vol 17 (2) ◽  
pp. 134-138 ◽  
Author(s):  
Carlos Estrela ◽  
Cyntia R.A. Estrela ◽  
Daniel de Almeida Decurcio ◽  
Julio Almeida Silva ◽  
Lili Luschke Bammann

The aim of this study was to evaluate the antimicrobial potential of ozone applied to 3 different solutions in an ultrasonic cleaning system against Staphylococcus aureus. A total of 120 mL of S. aureus were mixed in 6 L of the experimental solutions (sterilie distilled water, vinegar and sterile distilled water + Endozime AWpluz) used in a ultrasonic cleaning system (UCS). Ozone was produced by an electric discharge through a current of oxygen and bubbling with flow rate at 7g/h ozone (1.2%) into the microbial suspensions. Ten mL of each experimental suspension were collected and 5 fold dilutions were made in 9 mL of BHI and incubated at 37°C for 48 h. Bacterial growth was evaluated by turbidity of the culture medium. At the same time, 1 mL of bacterial samples was collected and inoculated in BHIA plates. After incubation at 37°C for 48 h, the number of colony forming units (cfu) per mL on BHIA surface was counted. In dilution test in BHI tubes and in BHIA plates (cfu/mL), bacterial growth was not observed in any of the experimental solutions when ozone was added. Under the tested conditions, it may be concluded that the addition of ozone to a ultrasonic cleaning system containing different experimental solutions resulted in antibacterial activity against S. aureus.


Author(s):  
Е.В. Фефелова ◽  
П.П. Терешков ◽  
Н.Н. Цыбиков ◽  
М.В. Максименя

Цель исследования - изучение изменения фенотипа лимфоцитов периферической крови под влиянием гомоцистеина и гомоцистеина-тиолактона в краткосрочной культуре клеток. Методика. Исследована венозная кровь 15 относительно здоровых, некурящих добровольцев - мужчин в возрасте 30 - 40 лет и 16 больных ишемической болезнью сердца (стабильная стенокардия 2-го функционального класса), сопоставимых по возрасту с донорами. Кровь брали из локтевой вены в пробирки с добавлением антикоагулянта гепарина Li. В 3 стерильные пластиковые пробирки, содержащие по 1 мл крови, добавляли по 1 мл культуральной среды RPMI-1640 (Miltenyi BiotecGmbH, Германия) с 10% содержанием сыворотки, в 2 из них вносили растворы либо гомоцистеина (50 мкмоль/л), либо гомоцистеин-тиолактона (50 нмоль/л). 3-я и 4-я (контрольные) пробирки содержали эквивалентный объем физиологического раствора или культуральной среды. Фенотип лейкоцитов определяли после 4-часовой инкубации в 4,8% СО2 при 37 ºС. Результаты. Общее количество лейкоцитов, моноцитов и нейтрофилов в исследуемых группах не имело значимых различий. Было зафиксировано лишь увеличение содержания лимфоцитов в образцах периферической крови больных ишемической болезнью сердца за счет увеличения числа всех субпопуляций лимфоцитов. При изучении фенотипа лимфоцитов в культуре под воздействием высоких доз гомоцистеина и гомоцистеин-тиолактона количественные сдвиги наблюдались только в субпопуляции Т-лимфоцитов: в образцах крови условно здоровых добровольцев наблюдалось снижение количества Т-лимфоцитов за счет фракции Т-хелперов. В пробах больных ишемической болезнью сердца под воздействием гипергомоцистеинемии число Т-лимфоцитов не имело значимых различий по сравнению с контролем, но при этом содержание Т-хелперов снижалось на 20%, так же как в образцах крови условно здоровых добровольцев. Уровень цитотоксических лимфоцитов при добавлении гомоцистеина в культуру клеток условно здоровых добровольцев увеличивался на 50%, а при добавлении гомоцистеин-тиолактона - практически в 2 раза, в то же время у больных ишемической болезнью сердца эта фракция лимфоцитов увеличивалась на 70% как под воздействием гомоцистеина, так и гомоцистеин-тиолактона. Заключение. Высокие дозы гомоцистеина снижают количество Т-хелперов и увеличивают число цитотоксических лимфоцитов. Изменения более выражены в образцах крови лиц, страдающих атеросклерозом. Механизмы развития данного феномена требуют дальнейшего изучения. Aim. To study changes in the phenotype of peripheral blood lymphocyte induced by homocysteine and homocysteine thiolactone in a short-term cell culture. Methods. Venous blood was obtained from 15 conventionally healthy, non-smoking male volunteers aged 35.4 ± 4.7 years and 16 patients with ischemic heart disease (functional class II stable angina). Blood was collected from the ulnar vein into tubes containing heparin Li as an anticoagulant. Then 1 ml of RPMI-1640 culture medium (Miltenyi BiotecGmbH, Germany) with 10% of serum was added to each of 3 sterile plastic tubes containing 1 ml of blood each. A solution of either homocysteine (50 μmol/l) or homocysteine-thiolactone (50 nmol/l) was added to two of these tubes. The remaining two tubes (control) contained an equivalent volume of saline or the culture medium. The leukocyte phenotype was determined after 4 hours of incubation at 37°C in 4.8% CO2. Results. Total counts of leukocytes, monocytes and neutrophils did not significantly differ between the study groups. Only an increase in lymphocyte count was observed in blood samples from IHD patients due to increases in all lymphocyte subpopulations. Quantitative changes in the phenotype of lymphocytes exposed to high doses of homocysteine and homocysteine thiolactone were found only for the T-lymphocyte subpopulation; in blood samples from conventionally healthy volunteers, the T-lymphocyte count was decreased due to a decrease in the T-helper fraction. In blood samples from IHD patients exposed to hyperhomocysteinemia, the number of T-lymphocytes did not differ from the control. However, the T-helper level was decreased by 20% similar to that in blood samples of healthy volunteers. The level of cytotoxic lymphocytes in the cell culture from conditionally healthy volunteers exposed to homocysteine was increased by 50% and in the culture exposed to homocysteine thiolactone, it practically doubled. In the blood from IHD patients exposed to homocysteine or homocysteine thiolactone, this lymphocyte fraction was increased by 70%. Conclusion. High doses of homocysteine reduced the number of T-helpers and increased the number of cytotoxic lymphocytes. These changes were more pronounced in blood samples from patients with atherosclerosis. Mechanisms of this phenomenon require a further study.


Author(s):  
Ilmi Rizki Imaduddin Imaduddin

The rice thresher machine is an important part of the rice processing process. Before the harvesting process, the rice fields are drained for 7-10 days before the harvest period by using a sharp sickle to cut the base of the stems, then the harvest is stored in a container or lined place. The low application of cultivation technology can be seen from the large potential gap between production. With the creation of this system, the process of threshing rice from the stalks can be done automatically, so that this system is expected to be able to provide the process of threshing rice from the stalks to be faster, easier, more efficient and safe for workers. data from the presentation of rice tresher slender yields 223.17 S, at puly rpm the average value produced is 32.82 S, with an average voltage of 11 V and an average current of 0.18 A. 9.13 minutes, with initial grain weight of 15 kg with an average threshing yield of 6.6 kg, with a threshing capacity of 42.2 kg / hour. And the current and voltage data on the solar panel and the resulting charging, the highest voltage is 12 V with a current of 1.69 A which occurs at 12.30 Wib.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Seung Hwan Oh ◽  
Yong Keun Chang ◽  
Jay Hyung Lee

Abstract Background Current efforts on the optimization of the two-stage cultivation using stress-induced lipid accumulation have mostly focused only on the lipid induction stage. Although recent studies have shown that stress-induced lipid accumulation is affected by the physiological status of the cells harvested at the preceding cultivation stage, this issue has hardly been examined hitherto. Such a study needs to be carried out in a systematic way in order to induce lipid accumulation in a consistent and predictable manner with regard for variances seen at the cultivation stage. Results After a photoautotrophic cultivation of Chlorella sorokiniana HS1 in a modified BG11, harvested cells were re-suspended in the fresh medium, and then NaCl was added as the sole stress inducer with light illumination to induce additional accumulation of lipid. Effects of culture temperature on the lipid accumulation were analyzed by the Kruskal–Wallis test. From the microscopic observation, we had observed a definite increase in lipid body induced by the stress since the cell entered a stationary phase. A multiple linear regression model was developed so as to identify significant parameters to be included for the estimation of lipid induction. As a result, several key parameters at the end of cultivation, such as cell weight, total lipid content, chlorophyll a in a cell, and Fv/Fm, were identified as the important proxy variables for the cell’s physiological status, and the modeling accuracy was achieved by 87.6%. In particular, the variables related to Fv/Fm were shown to have the largest influence, accounting for 65.7% of the total variance, and the Fv/Fm had an optimal point of maximum induction at below its average. Clustering analysis using the K-means algorithm indicated that the algae which are 0.15 pg cell−1 or less in chlorophyll concentration, regardless of other conditions, had achieved high induction results. Conclusion Experimental results showed that it usually achieves high lipid induction after the cells naturally end their division and begin to synthesize lipid. The amount of lipid induction could be estimated by the selected proxy variables, and the estimation method can be adapted according to practical situations such as those with limited measurements.


Sign in / Sign up

Export Citation Format

Share Document