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Öğe Bioactive Metabolites Genetic Regulation and Potential Market Implications(Crc Press-Taylor & Francis Group, 2020) Kose, Ayse; Remacle, Claire; Kim, Young-Woo; Oncel, Suphi S.; Elibol, Murat[No abstract available]Öğe Chemical Composition and Tyrosinase Inhibitory Activities of Fatty Acids Obtained from Heterotrophic Microalgae, S. limacinum and C. cohnii(Springer, 2022) Kose, AyseTyrosinase is the rate-limiting enzyme for melanin production in plant and mammalian cells. Upregulation of this enzyme results in hyperpigmentation disorders. In order to treat pigmentation problems, novel skin whitening compounds are extremely screened. It is found that fatty acids based on their saturation levels either increase or decrease tyrosinase enzyme activity. Thus, fatty acids and their compositions are promising candidates for the treatment of hyperpigmentation or hypopigmentation disorders. Microalgae are rich in both saturated and unsaturated fatty acids, as well. In this study, C. cohnii and S. limacinum fatty acids were evaluated as tyrosinase inhibitor candidates. Mushroom tyrosinase activity studies displayed that both extracts increase tyrosinase enzyme activity dose-dependently. On the other hand, S. limacinum at 200 mu g ml(-1) concentration almost decreased half of tyrosinase enzyme activity in B16-F10 cells. Besides, it was 3 times more efficient for tyrosinase enzyme activity inhibition and 2 times more effective to decrease melanin synthesis compared to C. cohnii. Considering low toxicity to B16-F10 melanoma and healthy keratinocyte cells (HaCaT), S. limacinum fatty acids could be a suitable source for lipid-based tyrosinase inhibitory functional cosmetics products.Öğe Design of a horizontal-dual bladed bioreactor for low shear stress to improve hydrodynamic responses in cell cultures: A pilot study in Chlamydomonas reinhardtii(Elsevier, 2021) Duman, Emre Taylan; Kose, Ayse; Celik, Yunus; Oncel, Suphi S.The aim of this study is to investigate the potential of a novel design considering low shear horizontal bioreactor (LSB-R) with counter rotation U-shape impellers. Bioreactors (LSB-R and STR) were compared under the same mixing time (23 +/- 2 s) using Computational Fluid Dynamics analysis focusing on the shear stresses. The highest shear stress was around the impeller tips with an average shear stress found to reach up to 0.8 Pa for LSB-R a very small value compared to the 100-fold increase inside the STR. Cell wall deficient and motility impaired mutants of Chlamydomonas were used in the experiments to see the effects of shear stress on growth and morphology. Biomass productivities were almost doubled, and specific growth rates were increased by LSB-R. On the other hand, the motility impaired cells aligned as colonies to protect from shear forces in STR and a rapid death occurred in cells with flagella due to continuous deflagellation and cell damage. The results indicate that; LSB-R design has great advantage on lowering shear stress, eliminating excessive hydrodynamic forces, providing mild operation conditions.Öğe Design of melanogenesis regulatory peptides derived from phycocyanin of the microalgae Spirulina platensis(Elsevier Science Inc, 2022) Kose, Ayse; Oncel, Suphi S.Pigmentation issues are common conditions associated with excessive or insufficient production of melanin. Recently peptides are investigated to discover novel melanogenesis regulators as low molecular weight com-pounds to regulate skin pigmentation. In this study, an internal library of peptides obtained through in silico enzymatic digestion of phycocyanin from microalgae S. platensis was tested to apprehend their anti-melanogenic effects. Seven peptides were investigated for their inhibitory potential against mushroom and B16-F10 murine tyrosinase enzymes. According to the results, P5 (SPSWY) and P7 (AADQRGKDKCARDIGY) were effective in lowering the activity of mushroom and B16-F10 tyrosinases. P5 was the most potent (IC50 value, 12.1 mu M) in mushroom which was followed by P2 (MAACLR, 86.9 mu M). Although the peptides were particularly powerful in inhibiting monophenolase activity, only moderate inhibition was observed for diphenolase activity in mushroom tyrosinase assay. Apart from tyrosinase inhibition, P2 and P3 (RCLNGRL) were efficient DPPH radical scavengers at low concentrations (IC50 < 200 mu M). In the mammalian assay system, P5 and P7 were noticeably effective to decrease tyrosinase enzyme activity with IC50 values of 48.9 and 34.2 mu M, respectively. However, although P4 (RYVTYAVF) was a potent mushroom tyrosinase inhibitor, it increased melanin synthesis up to 3-fold in B16-F10 cells. The results indicate that C-terminal tyrosine residue is important for tyrosinase inhibition. This study shows, for the first time, that microalgae proteins can be regarded as sources for melanogenesis regulation.Öğe The effect of medium and light wavelength towards Stichococcus bacillaris fatty acid production and composition(Elsevier Sci Ltd, 2019) Mutaf, Tugce; Oz, Yagmur; Kose, Ayse; Elibol, Murat; Oncer, Suphi S.Introduction of novel species will highlight technical feasibility of microalgae-based biofuels for commercial applications. This paper reports the effect of culture medium and light wavelength on biomass and fatty acid production of S. bacillaris which holds some advantages as short life cycle, easy cultivation, high lipid content, diversity of fatty acids and stability under harsh environmental conditions. the results displayed that, soil extract (SE) greatly enhance growth rate of cultures. Maximum biomass and lipid productivity were achieved in TAP medium as 81 mg/L.day, 19.44 mg/L.day; respectively. Light wavelength didn't significantly change growth kinetics but played a critical role on chlorophyll-a accumulation. C14:0, C16:0 and C18:0 fatty acids were abundant which are suitable for biodiesel conversion. Interestingly, blue and red light increased longer chain fatty acids content. These results indicated that; S. bacillaris holds potential for further development of biodiesel production and feasibility of algal biodiesel for fundamental and applied sciences.Öğe Evaluation of Several Microalgal Extracts as Bioactive Metabolites as Potential Pharmaceutical Compounds(Springer, 2020) Gurlek, Ceren; Yarkent, Cagla; Kose, Ayse; Oral, Izel; Oncel, Suphi S.; Elibol, MuratThe nature derived therapeutics is getting intense attention rather than chemical synthesis and synthetic ones. Today the expansion of natural bioactive molecule market is started to be dominated and generic drug and therapeutic understanding looks like to leave its place to a new horizon. Thus, natural originated therapeutics under controlled production conditions are of importance. Besides the public attention on natural molecules are also gain advance and the demand on this bioactive molecules is also increasing dramatically. the bioactive molecules from microalgae show antioxidant, antibacterial, antiviral, anticancer, skin regenerative, sunscreen, antihypertensive, neuroprotective and immunostimulatory effects which are favorable for pharmaceutical, nutraceutical and cosmetics industry. Also a new concept known as functional nutrition also broaden the acceptability and utilization of microalgae derived bioactive metabolites in new dietary formulations. the expansion of microalgal biotechnology and the number of research gained from the role of biologically active microalgal metabolites display the emergence of the microalgae farming for new pharmaceutical formulations. in this study, we prepared solvent and water extracts of G. sulphuraria, N. texensis, S. bacillaris, E. carotinosa, C. minutissima, S. limacinum, C. cohnii, and C. vulgaris. Antioxidant activity using DPPH radical scavenging activity and total phenolic compounds were measured from the methanolic extracts and water extracts. With the bioactive extracts cytotoxicity test were performed on Hep-G2 and B16-F10 cell lines. the results display potential onset of novel therapeutic compounds derived from microalgae.Öğe The heat is on: a simple method to increase genome editing efficiency in plants(Bmc, 2022) Blomme, Jonas; Develtere, Ward; Kose, Ayse; Ribera, Julia Arraiza; Brugmans, Christophe; Jaraba-Wallace, Jessica; Decaestecker, WardBackground Precision genome mutagenesis using CRISPR/Cas has become the standard method to generate mutant plant lines. Several improvements have been made to increase mutagenesis efficiency, either through vector optimisation or the application of heat stress. Results Here, we present a simplified heat stress assay that can be completed in six days using commonly-available laboratory equipment. We show that three heat shocks (3xHS) efficiently increases indel efficiency of LbCas12a and Cas9, irrespective of the target sequence or the promoter used to express the nuclease. The generated indels are primarily somatic, but for three out of five targets we demonstrate that up to 25% more biallelic mutations are transmitted to the progeny when heat is applied compared to non-heat controls. We also applied our heat treatment to lines containing CRISPR base editors and observed a 22-27% increase in the percentage of C-to-T base editing. Furthermore, we test the effect of 3xHS on generating large deletions and a homologous recombination reporter. Interestingly, we observed no positive effect of 3xHS treatment on either approach using our conditions. Conclusions Together, our experiments show that heat treatment is consistently effective at increasing the number of somatic mutations using many CRISPR approaches in plants and in some cases can increase the recovery of mutant progeny.Öğe In Silico Bioactive Peptide Prediction from The Enzymatic Hydrolysates of Edible Seaweed Rubisco Large Chain(Central Fisheries Research Inst, 2021) Kose, AyseSeaweeds are one of the ancient food supplements on Earth. Especially Asian countries use seaweeds as the fundamental ingredient in their cuisine. Seaweeds are photosynthetic organisms living in aquatic ecosystems and in the coastal territories. Seaweeds out of farm areas are frequently observed as coastal wastes. However, seaweeds are outstanding sources for bioactive substances and investigation bioactive properties of seaweed RuBisCO has never been done. RuBisCO is the most abundant protein on Earth but a vast amount of RuBisCO goes through waste. In this study, bioactive peptide prediction of frequently consumed seaweed RuBisCO proteins were analyzed in silico to identify possible bioactive peptides as substitute or support for grain, meat, and dairy based bioactive peptides. A huge portion of peptides were di-, tri- peptides with IC50 values less than 300 mu M according to the comparison of BIOPEP database. Including gastric digestion, more than half of the peptides showed DDP-IV and ACE inhibitory activity followed by antioxidant properties. Also, novel anti-inflammatory and anti-cancer peptides were found through in silico analysis.Öğe Investigation of in vitro digestibility of dietary microalga Chlorella vulgaris and cyanobacterium Spirulina platensis as a nutritional supplement(Springer Heidelberg, 2017) Kose, Ayse; Ozen, Mehmet O.; Elibol, Murat; Oncel, Suphi S.Microalgal proteins are promising sources for functional nutrition and a sustainable candidate for nutraceutical formulations. They also gain importance due to emerging focus on a healthy nutrition and increase in the number of chronic diseases. In this study, dried dietary species of microalga, Chlorella vulgaris, and cyanobacterium Spirulina platensis were hydrolyzed with pancreatin enzyme to obtain protein hydrolysates. The hydrolysis yield of biomass was 55.1 +/- 0.1 and 64.8 +/- 3.6% for C. vulgaris and S. platensis; respectively. Digestibility, as an indicator for dietary utilization, was also investigated. In vitro protein digestibility (IVPD) values depicted that cell wall structure due to the taxonomical differences affected both hydrolysis and digestibility yield of the crude biomass (p < 0.05). Epithelial cells (Vero) maintained their viability around 70%, even in relatively higher concentrations of hydrolysates in the culture. The protein hydrolysates showed no any antimicrobial activities. This study clearly shows that the conventional protein sources in nutraceutical formulations such as soy, whey, and fish proteins can be replaced by enzymatic hydrolysates of microalgae, which shows elevated digestibility values as a sustainable and reliable source.Öğe Nutraceutical Aspects of Microalgae Will Our Future Space Foods Be Microalgae Based?(Crc Press-Taylor & Francis Group, 2020) Gurlek, Ceren; Yarkent, Cagla; Oral, Izel; Kose, Ayse; Oncel, Suphi S.[No abstract available]Öğe Preparation of electrospun polycaprolactone nanofiber mats loaded with microalgal extracts(Wiley, 2019) Cetmi, Serffe Dilara; Renkler, Nergis Zeynep; Kose, Ayse; Celik, Cenk; Oncel, Suphi S.Sustainable, ecological, and biocompatible materials are emerging for the development of novel components for tissue engineering. Microalgae being one of the unique organisms on Earth to provide various novel compounds with certain bioactivities are also a good source for the development of novel tissue scaffold materials. In this study, electrospinning technique was utilized to fabricate nanofibers from polycaprolactone loaded with microalgal extracts obtained from Haematococcus pluvialis (vegetative and carotenoid producing form) and Chlorella vulgaris. The FTIR results showed that, blending microalgae with polycaprolactone give unique bands rooted from microalgae and polycaprolactone structure. The samples were not diversified from each other, however stable bands were observed. SEM analysis revealed a uniform fiber fabrication with an average diameter of 810 +/- 55 nm independent from microalgal extracts. MTT assay was done on HUVEC cell lines and results showed that nanofiber mats helped cell proliferation with extended time. Biodegradation resulted with mineral accumulation on the surface of same samples however the fiber degradation was uniform. With slow but stable biodegradation characteristics, microalgal extract loaded nanofiber mats holds great potential to be novel tissue scaffold material.Öğe Screening of antioxidant and cytotoxic activities of several microalgal extracts with pharmaceutical potential(Springer Heidelberg, 2020) Gurlek, Ceren; Yarkent, Cagla; Kose, Ayse; Tugcu, Basak; Gebeloglu, Ilgin Kimiz; Oncel, Suphi S.; Elibol, MuratThe bioactive molecules from microalgae have important properties such as antioxidant, anticancer, antiviral, antibacterial, antihypertensive, skin regenerative, neuroprotective, sunscreen, and, immunostimulatory effects. Bioactive molecules derived from microalgae is getting intense attention from pharmaceuticals, cosmetics and nutraceuticals industries because of these properties and numerous researches have been done to investigate the role of these bioactive molecules that can enlighten microalgal biotechnology to result in new nature derived pharmaceutical formulations. in this study we investigate antioxidant activities of crude extracts of G. Galdieria sulphuraria, Ettlia carotinosa, Neochloris texensis, Chlorella minutissima, Stichococcus bacillaris, Schizochytrium limacinum, Crypthecodinium cohnii, and Chlorella vulgaris with determining radical scavenging activity (RSA) by DPPH (2,2-diphenyl-1-picrylhydrazyl hydrate radical) method and total phenolic content by Folin-Ciocalteu method. Selected extracts according to their antioxidant activities cytotoxicity was evaluated after exposure to human hepatocellular liver carcinoma cells (HepG2) for 48 h. Antioxidant activities of these species ranged from 89 to 95% RSA (radical scavenging activity) while their phenolic contents were also very high, varied from 41 to 312 mg GAE (gallic acid equivalents)/mg extract. MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay also showed microalgae has a potential to be used as a novel therapeutic compound.
