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Astaxanthin production by freshwater microalgae Chlorella sorokiniana and marine microalgae Tetraselmis sp

Raman R, Mohamad SE

Pak J Biol Sci, 2012 Dec 15;15(24):1182-6.
PMID: 23755409

There are numerous commercial applications of microalgae nowadays owing to their vast biotechnological and economical potential. Indisputably, astaxanthin is one of the high value product synthesized by microalgae and is achieving commercial success. Astaxanthin is a keto-carotenoid pigment found in many aquatic animals including microalgae. Astaxanthin cannot be synthesized by animals and provided in the diet is compulsory. In this study, the production of astaxanthin by the freshwater microalgae Chlorella sorokiniana and marine microalgae Tetraselmis sp. were studied. The relationship between growth and astaxanthin production by marine and freshwater microalgae cultivated under various carbon sources and concentrations, environmental conditions and nitrate concentrations was investigated in this study. Inorganic carbon source and low nitrate concentration favored the growth and production of astaxanthin by the marine microalgae Tetraselmis sp. and the freshwater microalgae Chlorella sorokiniana. Outdoor cultivation enhanced the growth of microalgae, while indoor cultivation promoted the formation of astaxanthin. The results indicated that supplementation of light, inorganic carbon and nitrate could be effectively manipulated to enhance the production of astaxanthin by both microalgae studied.

Matched MeSH terms: Chlorella/metabolism*
Indole-3-acetic acid (IAA) induced changes in oil content, fatty acid profiles and expression of four fatty acid biosynthetic genes in Chlorella vulgaris at early stationary growth phase

Jusoh M, Loh SH, Chuah TS, Aziz A, Cha TS

Phytochemistry, 2015 Mar;111:65-71.
PMID: 25583439 DOI: 10.1016/j.phytochem.2014.12.022

Microalgae lipids and oils are potential candidates for renewable biodiesel. Many microalgae species accumulate a substantial amount of lipids and oils under environmental stresses. However, low growth rate under these adverse conditions account for the decrease in overall biomass productivity which directly influence the oil yield. This study was undertaken to investigate the effect of exogenously added auxin (indole-3-acetic acid; IAA) on the oil content, fatty acid compositions, and the expression of fatty acid biosynthetic genes in Chlorella vulgaris (UMT-M1). Auxin has been shown to regulate growth and metabolite production of several microalgae. Results showed that oil accumulation was highest on days after treatment (DAT)-2 with enriched levels of palmitic (C16:0) and stearic (C18:0) acids, while the linoleic (C18:2) and α-linolenic (C18:3n3) acids levels were markedly reduced by IAA. The elevated levels of saturated fatty acids (C16:0 and C18:0) were consistent with high expression of the β-ketoacyl ACP synthase I (KAS I) gene, while low expression of omega-6 fatty acid desaturase (ω-6 FAD) gene was consistent with low production of C18:2. However, the increment of stearoyl-ACP desaturase (SAD) gene expression upon IAA induction did not coincide with oleic acid (C18:1) production. The expression of omega-3 fatty acid desaturase (ω-3 FAD) gene showed a positive correlation with the synthesis of PUFA and C18:3n3.

Matched MeSH terms: Chlorella vulgaris/genetics*; Chlorella vulgaris/chemistry
Fulltext Transcription Factor ChbZIP1 from Alkaliphilic Microalgae Chlorella sp. BLD Enhancing Alkaline Tolerance in Transgenic Arabidopsis thaliana

Qu D, Show PL, Miao X

Int J Mol Sci, 2021 Feb 27;22(5).
PMID: 33673599 DOI: 10.3390/ijms22052387

Saline-alkali soil has become an important environmental problem for crop productivity. One of the most effective approaches is to cultivate new stress-tolerant plants through genetic engineering. Through RNA-seq analysis and RT-PCR validation, a novel bZIP transcription factor ChbZIP1, which is significantly upregulated at alkali conditions, was obtained from alkaliphilic microalgae Chlorella sp. BLD. Overexpression of ChbZIP1 in Saccharomyces cerevisiae and Arabidopsis increased their alkali resistance, indicating ChbZIP1 may play important roles in alkali stress response. Through subcellular localization and transcriptional activation activity analyses, we found that ChbZIP1 is a nuclear-localized bZIP TF with transactivation activity to bind with the motif of G-box 2 (TGACGT). Functional analysis found that genes such as GPX1, DOX1, CAT2, and EMB, which contained G-box 2 and were associated with oxidative stress, were significantly upregulated in Arabidopsis with ChbZIP1 overexpression. The antioxidant ability was also enhanced in transgenic Arabidopsis. These results indicate that ChbZIP1 might mediate plant adaptation to alkali stress through the active oxygen detoxification pathway. Thus, ChbZIP1 may contribute to genetically improving plants' tolerance to alkali stress.

Matched MeSH terms: Chlorella/genetics; Chlorella/metabolism*
A metabolomic approach to investigate effects of ocean acidification on a polar microalga Chlorella sp

Tan YH, Lim PE, Beardall J, Poong SW, Phang SM

Aquat Toxicol, 2019 Dec;217:105349.
PMID: 31734626 DOI: 10.1016/j.aquatox.2019.105349

Ocean acidification, due to increased levels of anthropogenic carbon dioxide, is known to affect the physiology and growth of marine phytoplankton, especially in polar regions. However, the effect of acidification or carbonation on cellular metabolism in polar marine phytoplankton still remains an open question. There is some evidence that small chlorophytes may benefit more than other taxa of phytoplankton. To understand further how green polar picoplankton could acclimate to high oceanic CO2, studies were conducted on an Antarctic Chlorella sp. Chlorella sp. maintained its growth rate (∼0.180 d-1), photosynthetic quantum yield (Fv/Fm = ∼0.69) and chlorophyll a (0.145 fg cell-1) and carotenoid (0.06 fg cell-1) contents under high CO2, while maximum rates of electron transport decreased and non-photochemical quenching increased under elevated CO2. GCMS-based metabolomic analysis reveal that this polar Chlorella strain modulated the levels of metabolites associated with energy, amino acid, fatty acid and carbohydrate production, which could favour its survival in an increasingly acidified ocean.

Matched MeSH terms: Chlorella/drug effects; Chlorella/metabolism*
Rapid magnetophoretic separation of microalgae

Lim JK, Chieh DC, Jalak SA, Toh PY, Yasin NH, Ng BW, et al.

Small, 2012 Jun 11;8(11):1683-92.
PMID: 22438107 DOI: 10.1002/smll.201102400

Magnetic collection of the microalgae Chlorella sp. from culture media facilitated by low-gradient magnetophoretic separation is achieved in real time. A removal efficiency as high as 99% is accomplished by binding of iron oxide nanoparticles (NPs) to microalgal cells in the presence of the cationic polyelectrolyte poly(diallyldimethylammonium chloride) (PDDA) as a binder and subsequently subjecting the mixture to a NdFeB permanent magnet with surface magnetic field ≈6000 G and magnetic field gradient <80 T m(-1) . Surface functionalization of magnetic NPs with PDDA before exposure to Chlorella sp. is proven to be more effective in promoting higher magnetophoretic removal efficiency than the conventional procedure, in which premixing of microalgal cells with binder is carried out before the addition of NPs. Rodlike NPs are a superior candidate for enhancing the magnetophoretic separation compared to spherical NPs due to their stable magnetic moment that originates from shape anisotropy and the tendency to form large NP aggregates. Cell chaining is observed for nanorod-tagged Chlorella sp. which eventually fosters the formation of elongated cell clusters.

Matched MeSH terms: Chlorella
Fulltext Enhancement of targeted microalgae species growth using aquaculture sludge extracts

Arumugam K, Ahmad MF, Yaacob NS, Ikram WM, Maniyam MN, Abdullah H, et al.

Heliyon, 2020 Jul;6(7):e04556.
PMID: 32775725 DOI: 10.1016/j.heliyon.2020.e04556

Natural growth-promoting nutrients extracted from aquaculture sludge waste can be used to maximise microalgal growth. This study identified the influence of aquaculture sludge extract (SE) on four microalgae species. Conway or Bold's Basal Media (BBM) was supplemented with SE collected from a Sabak Bernam shrimp pond (SB) and Kota Puteri fish pond (KP), and tested using a novel microplate-incubation technique. Five different autoclave extraction treatment parameters were assessed for both collected SE, i.e., 1-h at 105 °C, 2-h at 105 °C, 1-h at 121 °C, 2-h at 121 °C, and 24-h at room temperature (natural extraction). Microalgae culture in the microplates containing control (media) and enriched (media + SE) samples were incubated for nine days, at 25 °C with the light intensity of 33.75 μmol photons m-2 s-1 at 12-h light/dark cycle. The total dissolved nitrogen (TDN) and total dissolved phosphorus (TDP) in KP SE were 44.0-82.0 mg L-1 and 0.96-8.60 mg L-1. TDN (8.0%-515.0%) and TDP (105%-186 %) were relatively higher in KP SE compared to SB SE. The growth of microalgae species Nannochloropsis ocenica showed significant differences (p < 0.05) between the five extraction treatments from SB and the control. However, Chlorella vulgaris, Neochloris conjuncta, and Nephroclamys subsolitaria showed no significant differences (p > 0.05) in SB SE. N. ocenica, C. vulgaris, and N. conjuncta showed significant differences (p < 0.05) between five extraction treatments from KP and the control while N. subsolitaria showed no significant difference (p > 0.05). The specific growth rate (SGR) in the exponential phase of all microalgae species were relatively higher in SB SE compared to KP SE. While the organic matter content of KP SE was relatively higher, there were no significant differences in microalgae growth compared to SB SE. Nonetheless, modified SE did influence microalgae growth compared to the control. This study shows that modified SE could be used as enrichment media for microalgae cultivation.

Matched MeSH terms: Chlorella vulgaris
Monitoring of Water Quality and Microalgae Species Composition of Penaeus monodon Ponds in Pulau Pinang, Malaysia

Shaari AL, Surif M, Latiff FA, Omar WM, Ahmad MN

Trop Life Sci Res, 2011 May;22(1):51-69.
PMID: 24575209

Many reports have revealed that the abundance of microalgae in shrimp ponds vary with changes in environmental factors such as light, temperature, pH, salinity and nutrient level throughout a shrimp culture period. In this study, shrimp cultivation period was divided into three stages (initial = week 0-5, mid = week 6-10 and final = week 11-15). Physical and chemical parameters throughout the cultivation period were studied and species composition of microalgae was monitored. Physical parameters were found to fluctuate widely with light intensity ranging between 182.23-1278 μmol photon m(-2)s(-1), temperature between 29.56°C -31.59°C, dissolved oxygen (DO) between 4.56-8.21 mg/l, pH between 7.65-8.49 and salinity between 20‰-30‰. Ammonium (NH4 (+)-N), nitrite (NO2 (-)-N), nitrate (NO3 (-)-N), and orthophosphate (PO4 (3-)-P) concentrations in the pond at all cultivation stages ranged from 0.017 to 0.38 mg/l, 0.24 to 2.12 mg/l, 0.06 to 0.98 mg/l and 0.16 to 1.93 mg/l respectively. Statistical test (ANOVA) showed that there were no significant difference (p<0.05) in nutrients concentrations among the cultivation stages. All nutrients concentrations however were still in the tolerable level and safe for shrimp culture. The chlorophyll a contents were found to range from 5.03±2.17 to 32.61±0.35 μg/l throughout the cultivation period. A total of 19 microalgae species were found in the shrimp pond, with diatoms contributing up to 72% of the species followed by Chlorophyta (11%) and Cyanophyta (11%). However, weekly species abundance varied through the study period. At the initial stage, when there were no shrimps in the pond, Anabaena spp. and Oscillatoria spp. (Cyanophyta) were the dominant species, followed by Chlorella sp. and Dunaliella sp. (Chlorophyta). When shrimps were introduced into the pond, Amphora sp., Navicula sp. Gyrosigma sp. and Nitzschia sp. (diatoms) started to exist. At the middle and towards the final stage of the shrimp culture period diatoms were the dominant species. The Chlorophyta (Chlorella sp.) domination took place only twice, which was at week 2 and 13. The absence of some of the coastal water microalgae species in the shrimp pond was most likely due to the fact that they could not tolerate the physicochemical factors of harsh environment. In this study, Cylindrotheca closterium was regarded as the most tolerant species among the microalgae due to its ability to exist for 6 weeks out of the 15 weeks of cultivation.

Matched MeSH terms: Chlorella
Fulltext Influence of nitrogen source on the growth and biochemical composition of an antarctic chlorella

Chu, W.L., Phang, S.M., Lim, S.L., Teoh, M.L., Wong, C.Y.

ASM Science Journal, 2009;3(2):178-183.
MyJurnal

Chlorella is one of the common microalgae found in a wide range of habitats, including Antarctica. Chlorella UMACC 234 is an interesting isolate in the collection of Antarctic microalgae in the University of Malaya algae culture collection (UMACC) as it grows well at temperatures much higher than the ambience. The alga was isolated from snow samples collected from Casey, Antarctica. This study investigates the influence of nitrogen source on the growth, biochemical composition and fatty acid profile of Chlorella UMACC 234. The cultures were grown in Bold’s Basal Medium with 3.0 mM NaNO3, NH4Cl or urea. The cultures grown on NaNO3 attained the highest specific growth rate (μ = 0.43 day–1) while the specific growth rates of those grown on NH4Cl and urea were not significantly different (p > 0.05). The urea-grown cells produced the highest amounts of lipids (25.7% dry weight) and proteins (52.5% dry weight) compared to those grown on other nitrogen sources. The cell numbers attained by the cultures grown at NaNO3 levels between 0.3 and 3.0 mM were similar but decreased markedly at 9.0 mM NaNO3. The fatty acids of Chlorella UMACC 234 were dominated by saturated fatty acids, especially 16:0 and 18:0. The percentage of polyunsaturated fatty acids was very low, especially in cells grown on urea (0.9% total fatty acids). Characterisation of the growth and biochemical composition of this Antarctic Chlorella is important to our studies on the relationship of Chorella isolates from tropical, temperate and polar regions, especially in terms of phylogeny and stress adaptation.

Matched MeSH terms: Chlorella
Fulltext Biotechnological applications of microalgae

Chu, Wan-Loy

International e-Journal of Science, Medicine & Education, 2012;6(10):0-0.
MyJurnal

Microalgae are important biological resources that have a wide range of biotechnological
applications. Due to their high nutritional value, microalgae such as Spirulina and Chlorella are being mass cultured for health food. A variety of high-value products including polyunsaturated fatty acids (PUFA), pigments such as carotenoids and phycobiliproteins, and bioactive compounds are useful as nutraceuticals and pharmaceuticals, as well as for industrial applications. In terms of environmental biotechnology, microalgae are useful for bioremediation of agro-industrial wastewater, and as a biological tool for assessment and monitoring of environmental toxicants such as heavy metals, pesticides and pharmaceuticals. In recent years, microalgae have attracted much interest due to their potential use as feedstock for biodiesel production. In Malaysia, there has been active research on microalgal biotechnology for the past 30 years, tapping into the potential of our
rich microalgal resources for high-value products and applications in wastewater treatment and assessment of environmental toxicants. A culture collection of microalgae has been established, and this serves as an important resource for microalgal biotechnology
research. Microalgal biotechnology should continue to be regarded as a priority area of research in this country.

Matched MeSH terms: Chlorella
Tackling membrane fouling in microalgae filtration using nylon 6,6 nanofiber membrane

Bilad MR, Azizo AS, Wirzal MDH, Jia Jia L, Putra ZA, Nordin NAHM, et al.

J Environ Manage, 2018 Oct 01;223:23-28.
PMID: 29885561 DOI: 10.1016/j.jenvman.2018.06.007

Microalgae technology, if managed properly, has promising roles in solving food-water-energy nexus. The Achilles' heel is, however, to lower the costs associated with cultivation and harvesting. As a favorable technique, application of membrane process is strongly limited by membrane fouling. This study evaluates performance of nylon 6,6 nanofiber membrane (NFM) to a conventional polyvinylidene fluoride phase inverted membrane (PVDF PIM) for filtration of Chlorella vulgaris. Results show that nylon 6,6 NFM is superhydrophilic, has higher size of pore opening (0.22 vs 0.18 μm) and higher surface pore density (23 vs 18 pores/μm2) leading to higher permeance (1018 vs 493 L/m2hbar) and better fouling resistant. Such advantages help to outperform the filterability of PVDF PIM by showing much higher steady-state permeance (286 vs 120 L/m2hbar), with comparable biomass retention. In addition, unlike for PVDF PIM, imposing longer relaxation cycles further enhances the performance of the NFM (i.e., 178 L/m2hbar for 0.5 min and 236 L/m2hbar for 5 min). Overall findings confirm the advantages of nylon 6,6 NFM over the PVDF PIM. Such advantages can help to reduce required membrane area and specific aeration demand by enabling higher flux and lowering aeration rate. Nevertheless, developments of nylon 6,6 NFM material with respect to its intrinsic properties, mechanical strength and operational conditions of the panel can still be explored to enhance its competitiveness as a promising fouling resistant membrane material for microalgae filtration.

Matched MeSH terms: Chlorella vulgaris
Chlorella vulgaris menunjukkan kesan antioksidan dan antitumor terhadap kanser hepar dalam kajian in vivo dan in vitro

Nor Ashikeen Mukti, Suhaniza Sulaiman, Suhana Md Saad, Junaida @ Maimunah Hassan Basari, Mariati Abdul Rahman, Wan Zurinah Wan Ngah, et al.

Sains Malaysiana, 2009;38.

Chlorella vulgaris (ChV), sejenis alga hijau unisel telah dilaporkan mempunyai khasiat kesihatan pada penyakit tertentu termasuk kanser. Objektif utama kajian ialah untuk mengukur dan menilai kesan antioksidan dan antitumor ekstrak air panas ChV ke atas sel kanser hepar yang dijalankan secara in vivo dan in vitro. Asai DPPH yang dijalankan menunjukkan peratus pengautan ChV yang tinggi. Dalam kajian in vivo, tikus Wistar jantan (200-250 g) dibahagikan kepada lapan kumpulan: tikus kawalan (diet normal), tikus diaruh kanser hepar (diet kurang kolin + 0.1% etionin dalam air minuman) atau singkatannya CDE, tikus diberi rawatan ChV pada tiga dos berbeza (50, 150 dan 300 mg/kg berat badan) dan tikus CDE diberi rawatan ChV pada tiga dos berbeza. Sampel darah dan tisu diambil dari semua kumpulan tikus pada minggu 0, 4, 8 dan 12 untuk penentuan kadar proliferasi dan apoptosis sel untuk melihat kesan antitumor ChV. Peratus pembentukan nodul praneoplasia adalah tinggi pada tikus diaruh kanser hepar (CDE) tetapi ChV pada semua dos berjaya mengurangkannya. Pertambahan jumlah sel kanser semasa hepatokarsinogenesis ditunjukkan dengan peningkatan proliferasi hepatosit yang signifikan (p<0.05) pada tikus CDE berbanding kawalan tetapi ChV pada semua dos berjaya mengurangkan proliferasi secara signifikan (p<0.05). Peratus apoptosis sel didapati meningkat secara signifikan (p<0.05) pada tikus CDE, tetapi peningkatan yang lebih ketara berlaku pada tikus CDE diberi ChV (300 mg/kg berat badan). Dalam kajian in vitro pula, aktiviti antitumor ekstrak air panas ChV telah ditentukan dengan melihat perubahan dalam proliferasi dan apoptosis sel kanser hepar HepG2 yang dikultur di makmal. Ekstrak air panas ChV berjaya menurunkan kadar proliferasi sel HepG2 dengan signifikan secara berkadar terus dengan dos yang digunakan dengan nilai IC50 1.6 mg/ml. Hasil analisis TUNEL pula menunjukkan ekstrak air panas ChV berjaya mengaruh apoptosis dalam sel HepG2. Keputusan ini disokong oleh hasil pemblotan Western dengan peningkatan pengekspresan protein P53 dan protein proapoptosis BAX dan Kaspase-3. Daripada hasil-hasil kajian, dapatlah dicadangkan bahawa ChV berpotensi tinggi sebagai antioksidan serta berupaya memberi kesan antitumor kepada kanser hepar pada kajian in vivo dan in vitro.

Matched MeSH terms: Chlorella vulgaris
Stability improvement of algal-alginate beads by zeolite molecular sieves 13X

Emami Moghaddam SA, Harun R, Mokhtar MN, Zakaria R

Int J Biol Macromol, 2019 Jul 01;132:592-599.
PMID: 30922914 DOI: 10.1016/j.ijbiomac.2019.03.191

This research aimed to improve the stability of Chlorella-Alginate Beads (CABs) by zeolite molecular sieves 13X. Dissolution time of synthesized Zeolite-Algal-Alginate Beads (ZABs) in a chelating agent revealed a significant improvement on the beads stability (78.5 ± 0.5 min) compared to the control beads (51.5 ± 0.5 min) under the optimum conditions of zeolite/alginate (1.5:1), pH 5 and 2% of beads. Monitoring cell growth during 5 days of incubation showed good biocompatibility of zeolite 13X. Scanning electron microscopy (SEM) indicated rough surface and spherical shapes of ZABs. Energy dispersive X-ray spectroscopy (EDX) and Fourier transform infrared spectroscopy (FTIR) of ZABs confirmed the presence of zeolite 13X within the matrix. The zeta potential value of ZABs indicated that the beads were relatively stable. The findings of this research showed that zeolite molecular sieves 13X have the potential to improve the stability of algal-alginate beads compared to common beads.

Matched MeSH terms: Chlorella
Integrated palm oil mill effluent treatment and co2 sequestration by microalgae

Nur Anira Syafiqah Hazman, Hassimi Abu Hasan, Kamrul Fakir Kamarudin, Nazlina Haiza Mohd Yasin, Mohd Sobri Takriff, Noor Irma Nazashida Mohd Hakimi

Sains Malaysiana, 2018;47:1455-1464.

Malaysian economy relies on palm oil industries as a driver for rural development. However, palm oil mill effluent
(POME) that is generated from palm oil processing stages causes major environmental challenges. Before being
released to the environment, POME treatment is crucial to comply with standard discharge limit. Microalgae have
demonstrated excellent potential for phycoremediating POME and capturing CO2
. In this study, local microalgae isolate
such as Chlamydomonas sp. UKM 6 and Chlorella spp. UKM 8 were used for POME treatment in 21 days with different
inoculum sizes (5%, 10% and 15%). In addition, an integrated treatment process was performed by taking the treated
POME supernatant for cultivation of Chorella spp. UKM 2, Chorella sorokiniana UKM 3 and Chlorella vulgaris for CO2
sequestration study. Different CO2
concentrations (5%, 10% and 15%) were used and the experiments were carried
out in 10 days under continuous illumination. The results showed that among two species involves in POME treatment,
Chlamydomonas sp. UKM 6 showed a great potential to remove pollutant such as COD (56%), nitrogen (65%) and
phosphorus (34%). The biomass after POME treatment and CO2
biofixation content high lipid (90 mg lipid/g biomass)
which can be the potential source for biodiesel production. In CO2
sequestration study, C. sorokininana UKM3 able
to takes up to 15% CO2
with CO2
uptake rate of 273 mgL-1d-1. In this study, the integrated system of POME treatment
and CO2
sequestration were feasible using microalgae.

Matched MeSH terms: Chlorella vulgaris
Isolation, characterization and the potential use of starch from jackfruit seed wastes as a coagulant aid for treatment of turbid water

Choy SY, Prasad KM, Wu TY, Raghunandan ME, Yang B, Phang SM, et al.

Environ Sci Pollut Res Int, 2017 Jan;24(3):2876-2889.
PMID: 27838910 DOI: 10.1007/s11356-016-8024-z

Fruit wastes constituting up to half of total fruit weight represent a large pool of untapped resources for isolation of starch with diverse applications. In this work, the possibility of isolating starch from tropical fruit wastes and its extended application as a natural coagulant was elucidated. Amongst the 12 various parts of fruit wastes selected, only jackfruit seeds contained more than 50% of total starch content. Using alkaline extraction procedures, starch has been successfully isolated from local jackfruit seeds with a yield of approximately 18%. Bell-shaped starch granules were observed under SEM with a granule size ranging from 1.1 to 41.6 μm. Detailed starch characteristics were performed to provide a comparison between the isolated seed starch and also conventional starches. Among them, chemical properties such as the content of starch, amylose, amylopectin and the corresponding molecular weights are some of the key characteristics which governed their performance as natural coagulants. The potential use of isolated seed starch as an aid was then demonstrated in both suspensions of kaolin (model synthetic system) and Chlorella sp. microalga (real-time application) with plausible outcomes. At optimized starch dosage of 60 mg/L, the overall turbidity removal in kaolin was enhanced by at least 25% at a fixed alum dosage of 2.1 mg/L. Positive turbidity and COD removals were also observed in the treatment of Chlorella suspensions. Starches which served as bridging agents aided in the linkage of neighbouring microflocs and subsequently, forming macroflocs through a secondary coagulation mechanism: adsorption and bridging.

Matched MeSH terms: Chlorella
Fulltext Modulation of Cell Cycle Profile by Chlorella vulgaris Prevents Replicative Senescence of Human Diploid Fibroblasts

Saberbaghi T, Abbasian F, Mohd Yusof YA, Makpol S

Evid Based Complement Alternat Med, 2013;2013:780504.
PMID: 23573154 DOI: 10.1155/2013/780504

In this study, the effects of Chlorella vulgaris (CV) on replicative senescence of human diploid fibroblasts (HDFs) were investigated. Hot water extract of CV was used to treat HDFs at passages 6, 15, and 30 which represent young, presenescence, and senescence ages, respectively. The level of DNA damage was determined by comet assay while apoptosis and cell cycle profile were determined using FACSCalibur flow cytometer. Our results showed direct correlation between increased levels of damaged DNA and apoptosis with senescence in untreated HDFs (P < 0.05). Cell cycle profile showed increased population of untreated senescent cells that enter G0/G1 phase while the cell population in S phase decreased significantly (P < 0.05). Treatment with CV however caused a significant reduction in the level of damaged DNA and apoptosis in all age groups of HDFs (P < 0.05). Cell cycle analysis showed that treatment with CV increased significantly the percentage of senescent HDFs in S phase and G2/M phases but decreased the population of cells in G0/G1 phase (P < 0.05). In conclusion, hot water extract of Chlorella vulgaris effectively decreased the biomarkers of ageing, indicating its potential as an antiageing compound.

Matched MeSH terms: Chlorella vulgaris
Fulltext Comparative effect of Piper betle, Chlorella vulgaris and tocotrienol-rich fraction on antioxidant enzymes activity in cellular ageing of human diploid fibroblasts

Makpol S, Yeoh TW, Ruslam FA, Arifin KT, Yusof YA

BMC Complement Altern Med, 2013;13:210.
PMID: 23948056 DOI: 10.1186/1472-6882-13-210

Human diploid fibroblasts (HDFs) undergo a limited number of cellular divisions in culture and progressively reach a state of irreversible growth arrest, a process termed cellular ageing. Even though beneficial effects of Piper betle, Chlorella vulgaris and tocotrienol-rich fraction (TRF) have been reported, ongoing studies in relation to ageing is of interest to determine possible protective effects that may reverse the effect of ageing. The aim of this study was to evaluate the effect of P. betle, C. vulgaris and TRF in preventing cellular ageing of HDFs by determining the activity of antioxidant enzymes viz.; catalase, superoxide dismutase (SOD) and glutathione peroxidase.

Matched MeSH terms: Chlorella vulgaris/chemistry*
Assessment of factors affecting Agrobacterium-mediated genetic transformation of the unicellular green alga, Chlorella vulgaris

Cha TS, Yee W, Aziz A

World J Microbiol Biotechnol, 2012 Apr;28(4):1771-9.
PMID: 22805959 DOI: 10.1007/s11274-011-0991-0

The successful establishment of an Agrobacterium-mediated transformation method and optimisation of six critical parameters known to influence the efficacy of Agrobacterium T-DNA transfer in the unicellular microalga Chlorella vulgaris (UMT-M1) are reported. Agrobacterium tumefaciens strain LBA4404 harbouring the binary vector pCAMBIA1304 containing the gfp:gusA fusion reporter and a hygromycin phosphotransferase (hpt) selectable marker driven by the CaMV35S promoter were used for transformation. Transformation frequency was assessed by monitoring transient β-glucuronidase (GUS) expression 2 days post-infection. It was found that co-cultivation temperature at 24°C, co-cultivation medium at pH 5.5, 3 days of co-cultivation, 150 μM acetosyringone, Agrobacterium density of 1.0 units (OD(600)) and 2 days of pre-culture were optimum variables which produced the highest number of GUS-positive cells (8.8-20.1%) when each of these parameters was optimised individually. Transformation conducted with the combination of all optimal parameters above produced 25.0% of GUS-positive cells, which was almost a threefold increase from 8.9% obtained from un-optimised parameters. Evidence of transformation was further confirmed in 30% of 30 randomly-selected hygromycin B (20 mg L(-1)) resistant colonies by polymerase chain reaction (PCR) using gfp:gusA and hpt-specific primers. The developed transformation method is expected to facilitate the genetic improvement of this commercially-important microalga.

Matched MeSH terms: Chlorella vulgaris/genetics*
Comparison of Chlorella vulgaris dressing and sodium alginate dressing: an experimental study in rats

Zailan N, Abdul Rashid AH, Das S, Abdul Mokti NA, Hassan Basri J, Teoh SL, et al.

Clin Ter, 2010;161(6):515-21.
PMID: 21181079

Chlorella vulgaris (CV) is a green microalgae enriched with nutrients, vitamins, minerals and chlorophyll. The aim of our study was to evaluate the potential wound healing effects of CV as a dressing while comparing it to sodium alginate dressing.

Matched MeSH terms: Chlorella vulgaris*
Fulltext Chlorella vulgaris triggers apoptosis in hepatocarcinogenesis-induced rats

Mohd Azamai ES, Sulaiman S, Mohd Habib SH, Looi ML, Das S, Abdul Hamid NA, et al.

J Zhejiang Univ Sci B, 2009 Jan;10(1):14-21.
PMID: 19198018 DOI: 10.1631/jzus.B0820168

Chlorella vulgaris (CV) has been reported to have antioxidant and anticancer properties. We evaluated the effect of CV on apoptotic regulator protein expression in liver cancer-induced rats. Male Wistar rats (200~250 g) were divided into eight groups: control group (normal diet), CDE group (choline deficient diet supplemented with ethionine in drinking water to induce hepatocarcinogenesis), CV groups with three different doses of CV (50, 150, and 300 mg/kg body weight), and CDE groups treated with different doses of CV (50, 150, and 300 mg/kg body weight). Rats were sacrificed at various weeks and liver tissues were embedded in paraffin blocks for immunohistochemistry studies. CV, at increasing doses, decreased the expression of anti-apoptotic protein, Bcl-2, but increased the expression of pro-apoptotic protein, caspase 8, in CDE rats, which was correlated with decreased hepatocytes proliferation and increased apoptosis as determined by bromodeoxy-uridine (BrdU) labeling and terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) assay, respectively. Our study shows that CV has definite chemopreventive effect by inducing apoptosis via decreasing the expression of Bcl-2 and increasing the expression of caspase 8 in hepatocarcinogenesis-induced rats.

Matched MeSH terms: Chlorella vulgaris/chemistry*
Fulltext In vitro evaluation of the synergistic antioxidant and anti-inflammatory activities of the combined extracts from Malaysian Ganoderma lucidum and Egyptian Chlorella vulgaris

Abu-Serie MM, Habashy NH, Attia WE

BMC Complement Altern Med, 2018 May 10;18(1):154.
PMID: 29747629 DOI: 10.1186/s12906-018-2218-5

BACKGROUND: Since oxidative stress and inflammation are two linked factors in the pathogenesis of several human diseases. Thus identification of effective treatment is of great importance. Edible mushroom and microalgae are rich in the effective antioxidant phytochemicals. Hence, their beneficial effects on oxidative stress-associated inflammation are extremely required to be investigated.
METHODS: This study evaluated the functional constituents, antioxidant and anti-inflammatory activities of Malaysian Ganoderma lucidum aqueous extract (GLE) and Egyptian Chlorella vulgaris ethanolic extract (CVE). Also, the synergistic, addictive or antagonistic activities of the combination between the two extracts (GLE-CVE) were studied. Expression of inducible nitric oxide synthase, cyclooxygenase-2, and nuclear factor-kappa B, as well as levels of nitric oxide, tumor necrosis factor (TNF)-α, lipid peroxidation, reduced glutathione and antioxidant enzymes were determined using in vitro model of lipopolysaccharide-stimulated white blood cells.

Matched MeSH terms: Chlorella vulgaris/chemistry*

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