Browsing by Author "Ortucu, Serkan"

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Chicken Feather Peptone: A New Alternative Nitrogen Source for Pigment Production by Monascus Purpureus
(Elsevier Science Bv, 2018) Orak, Tugba; Caglar, Ozge; Ortucu, Serkan; Ozkan, Hakan; Taskin, Mesut
Peptones are accepted as one of the most favourable nitrogen sources supporting pigment synthesis in Monascus purpureus. The present study was performed to test the feasibility of chicken feather peptone (CFP) as nitrogen source for pigment production from M. purpureus ATCC16365. CFP was compared with fish peptone (FP) and protease peptone (PP) in order to elucidate its effectiveness on pigment production. CFP was prepared from waste feathers using hydrolysis (KOH) and neutralization (H2SO4) methods. The protein content of CFP was determined as 67.2 g/100 g. Optimal concentrations of CFP and glucose for pigment production were determined as 3 and 20 g/L, respectively. A medium pH of 5.5 and an incubation period of 7-days were found to be more favourable for pigment production. In CFP, PP and FP media, yellow pigment absorbances were 2.819, 2.870 and 2.831, red pigment absorbances were 2.709, 2.304 and 2.748, and orange pigment absorbances were 2.643, 2.132 and 2.743, respectively. Sugar consumption and mycelia growth showed the similar trends in CFP, FP and PP media. This study indicates that the peptone from chicken feathers may be a good nutritional substrate for pigment production from M. purpureus.
Direct Conversion of Waste Loquat Kernels to Pigments Using Monascus Purpureus Atcc16365 with Proteolytic and Amylolytic Activity
(Springer Heidelberg, 2021) Arslan, Nazli Pinar; Yazici, Aysenur; Komesli, Senba; Esim, Nevzat; Ortucu, Serkan
Kernels of loquat (Eriobotrya japonica L.) fruits are rich in protein and starch contents; however, they have no significant application in world. This study was performed to produce pigments from Monascus purpureus ATCC16365 using loquat kernel powder (LKP) as a fermentation substrate and investigate the effect of four mineral salts (CaCl2, KH2PO4, MgSO4, and FeSO4) on pigment production in LKP-based medium. During the experiments, LKP was not subjected to any chemical or enzymatic hydrolysis, and it was tested directly as a substrate in shaking flask and fermenter cultures. It was found that addition of CaCl2 alone decreased red pigment production but did not cause an important change in synthesis of yellow and orange pigments. Supplementation of KH2PO4, MgSO4, or FeSO4 alone decreased the production of yellow pigment but increased the production of red pigments. When three salts (1.0 g/L KH2PO4, 0.3 g/L MgSO4, and 0.03 g/L FeSO4) were added together to the LKP-based medium, more productions of enzymes (protease and amylase) and red pigments were achieved. When experiments were performed in optimized medium (LKP and three mineral salts), maximum concentrations of red, orange, and yellow pigments were determined as 292, 193, and 171 AU/L in flask culture but 327, 241, and 204 AU/L in fermenter culture, respectively. Amylase and protease activities were 93.4 and 52.3 U/L in flask culture but 93.8 and 52.8 U/L in fermenter culture, respectively. This is the first report on the use of LKP as a substrate in production of enzymes and pigments from M. purpureus.
Efficient Production of L-Lactic Acid from Chicken Feather Protein Hydrolysate and Sugar Beet Molasses by the Newly Isolated Rhizopus Oryzae Ts-61
(Elsevier, 2012) Taskin, Mesut; Esim, Nevzat; Ortucu, Serkan
The aim of this study was to investigate production of L-lactic acid from molasses and chicken feather protein hydrolysate (CFP) by the newly isolated Rhizopus oryzae TS-61. R. oryzae TS-61 was capable of utilizing molasses sucrose and CFP as carbon and nitrogen sources, respectively. In contrast to yeast extract and ammonium sulfate, CFP had potential not only to prevent excessive pH changes and foaming but also to provide smaller uniform pellet formation in during fermentation. Thanks to these properties, it was concluded that CFP might have resulted in higher L-lactic acid production than the other two nitrogen sources (yeast extract and ammonium sulfate). At the end of 42-h optimal cultivation period, the highest (38.5 g/L) and lowest (28.8 g/L) concentrations of L-lactic acid were obtained with CFP and ammonium sulfate, respectively. This is the first report on use of waste chicken feather as a lactic acid production substrate. In addition, a new R. oryzae strain, being capable of using molasses sucrose as carbon source in order to produce L-lactic acid, was isolated. (C) 2012 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
Encapsulation of Crocin Using Low-Molecular Penicillium Expansum-Derived Chitosan and Process Optimization Via Taguchi Orthogonal Array Design
(Springer, 2026) Tasar, Ozden Canli; Ortucu, Serkan; Ustun, Ayse
The aim of this study was to produce fungal chitosan from a potential fungus using a cost-effective substrate (sugar beet molasses) and optimize the growth conditions using Taguchi L9 orthogonal array (OA). The obtained fungal chitinous chitosan (FC) was then used for the microencapsulation of crocin. Optimal conditions were found as 120 mL/L molasses, initial pH at 6 and 5 g/L magnesium sulphate. The dried biomass was weighed as 22.7 g/L, while 8.1 g/L alkali insoluble material (AIM), 5.3 g/L FC and 2.7 g/L native chitosan (NC) were obtained. Deacetylation degree (DD) of the obtained chitosan was calculated as 80.27 and 78.81% for NC and FC, respectively. Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) was employed for molecular weight detection of the chitosan samples. Molecular weights were found for FC and commercial chitosan (CC) as 145 and 219 kDa, respectively. The solubility of NC and FC in 1% acetic acid was found as 84 and 78% respectively. The fungus was isolated from jujube fruit which was identified as Penicillium expansum HNP11 (GenBank Accession Number: PQ057454). To deepen the research, antimicrobial activity was carried out. The zeta potential of crocin loaded alginate-chitosan microparticles was about - 49 mV and loading capacity was found as 46%. Cytotoxicity of FC was found lower than CC at low concentrations. Consequently, P. expansum has higher antimicrobial activity and minimal toxic structure and Taguchi orthogonal array contributes economic chitosan production.
Enhancement of Invertase Production by Aspergillus Niger Oz-3 Using Low-Intensity Static Magnetic Fields
(Taylor & Francis Inc, 2013) Taskin, Mesut; Esim, Nevzat; Genisel, Mucip; Ortucu, Serkan; Hasenekoglu, Ismet; Canli, Ozden; Erdal, Serkan
The aim of this study is to investigate the effect of low-intensity static magnetic fields (SMFs) on invertase activity and growth on different newly identified molds. The most positive effect of SMFs on invertase activity and growth was observed for Aspergillus niger OZ-3. The submerged production of invertase was performed with the spores obtained at the different exposure times (120, 144, 168, and 196hr) and magnetic field intensities (0.45, 3, 5, 7, and 9 mT). The normal magnetic field of the laboratory was assayed as 0.45mT (control). Optimization of magnetic field intensity and exposure time significantly increased biomass production and invertase activity compared to 0.45 mT. The maximum invertase activity (51.14U/mL) and biomass concentration (4.36g/L) were achieved with the spores obtained at the 144hr exposure time and 5mT magnetic field intensity. The effect of low-intensity static magnetic fields (SMFs) on invertase activities of molds was investigated for the first time in the present study. As an additional contribution, a new hyper-invertase-producing mold strain was isolated. Supplemental materials are available for this article. Go to the publisher's online edition of Preparative Biochemistry and Biotechnology to view the supplemental file.
Evaluation of Nisin-Loaded PLGA Nanoparticles Prepared with Rhamnolipid Cosurfactant Against S. Aureus Biofilms
(MDPI, 2022) Ustun, Ayse; Ortucu, Serkan
In this article, nisin(N)-loaded poly lactic-co-glycolic acid (PLGA) nanoparticles (NPs) were prepared using the single-solvent evaporation method with a rhamnolipid(R) cosurfactant. The antibacterial-antibiofilm effects of the prepared formulation and free nisin were evaluated against S. aureus (ATCC 25923). The characterization of NPs was analyzed using scanning electron microscopy (SEM), Zetasizer and Fourier-transform infrared spectroscopy (FTIR). The drug encapsulation efficiency and loading capacity percentages of NPs were calculated by the spectrophotometric method. The drug release of N-loaded PVA-R-PLGA NPs was determined by the dialysis bag method. The antibacterial and antibiofilm activity of N-PVA-R-PLGA NPs was determined. PVA-R-PLGA-NPs were found to be spherical with sizes of similar to 140 nm, according to the SEM analysis and surface charge of N-PVA-R-PLGA NPs -53.23 +/- 0.42 mV. The sustained release of N (>= 72% after 6 h) was measured in PVA-R-PLGA-NPs. The encapsulation efficiency percentage of N-PVA-R-PLGA NP was 78%. The MIC values of free nisin and N-PVA-R-PLGA NPs were 256 mu g/mL and 64 mu g/mL, respectively. The antibiofilm inhibition percentages of free nisin and N-PVA-R-PLGA NPs were 28% and 72%, respectively. These results reveal that N-PVA-R-PLGA NPs are a promising formulation for use in infections caused by S. aureus compared to free nisin.
Evaluation of the Antibiofilm Effect of Fluconazole Loaded PLGA Nanoparticles Prepared Using Rhamnolipid on Candida Albicans
(Trakya Univ Balkan Yerlesesi Enstituler Binasi, 2022) Ustun, Ayse; Ortucu, Serkan
In this study, fluconazole (FLZ) loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) were prepared with two different formulations consisting of polyvinyl alcohol (PVA) and PVA-rhamnolipid (R) in order to improve antibiofilm activity against Candida albicans ATCC 90028. The encapsulation efficiency, drug loading capacity, in-vitro release, characterization and antibiofilm activity of these formulations were compared. Characterization of NPs were analyzed by scanning electron microscopy (SEM) and Zetasizer. Drug loading capacity and encapsulation efficiency percentages were measured by spectrophotometric method. PLGA-NPs were spherical in shape with mean sizes of similar to 300 nm and surface charge of FLZ loaded PVA and PVA-R-PLGA NPs -25,9 +/- 1.99, -48,1 +/- 2.46, respectively. Sustained release of FLZ (>= 60% after 6 h) were obtained in PVA-R PLGA-NPs. The encapsulation efficiency percentages of PVA-FLZ-PLGA and PVA-R-FLZ-PLGA were 50% and 85%, respectively. Antibiofilm inhibition percentages are 55% and 63%, respectively. These results show that the PVA-R-FLZ-PLGA drug delivery system is a new therapeutic approach that can be used in infections caused by C. albicans.
Evaluation of Waste Loquat Kernels as Substrate for Lipid Production by Rhodotorula Glutinis SO28
(Springer, 2017) Ortucu, Serkan; Yazici, Aysenur; Taskin, Mesut; Cebi, Kadir
This study was performed to produce lipids from the isolated oleaginous yeast Rhodotorula glutinis SO28 using loquat kernel extract (LKE) as substrate. LKE was prepared using acid hydrolysis and alkaline neutralization steps. Lipid production was performed in shaking flaks culture. Even if LKE was used as a sole source of nutritional substances, it could support cell growth and lipid synthesis in the yeast. Additional carbon, nitrogen and phosphorus sources were found to significantly alter the lipid accumulation potential of the yeast. Optimal concentrations of additional carbon (glucose) and nitrogen (ammonium sulphate) sources for lipid accumulation were determined as 15 and 0.5 g/L, respectively. On the other hand, all the concentrations of additional phosphorus source were found to significantly reduce the lipid accumulation. Optimal incubation time was determined as 132 h. Under the optimized culture conditions, the lipid concentration and lipid content of the yeast were determined as 7.82 g/L and 62 %, respectively. Fatty acid methyl ester analysis exhibited that this yeast strain could produce high proportions of C16:0 and C18 fatty acids, which are ideal for biodiesel production. This is the first report on the use of waste loquat kernels as substrate for microbial lipid production.
Expression of Human β-Defensin 2 (hbd-2) in Pichia Pastoris and Investigation of Its Binding Efficiency with ACE-2
(Springer, 2023) Cobanoglu, Seymanur; Arslan, Elif; Yazici, Aysenur; Ortucu, Serkan
COVID-19 is a disease that have affected the entire world, and it continues to spread with new variants. A patient's innate immune system plays a critical role in the mild and severe transition of COVID-19. Antimicrobial peptides (AMPs), which are important components of the innate immune system, are potential molecules to fight pathogenic bacteria, fungi, and viruses. Human beta-defensin 2 (hBD-2), a 41-amino-acid antimicrobial peptide, is one of the defensins inducibly expressed in the skin, lungs, and trachea in humans. In this study, it was aimed to investigate the interaction of hBD-2 produced recombinantly in Pichia pastoris with the human angiotensin-converting enzyme 2 (ACE-2) under in vitro conditions. First, hBD-2 was cloned in P. pastoris X-33 via the pPICZaA vector, a yeast expression platform, and its expression was confirmed by SDS-PAGE, western blotting, and qRT-PCR. Then, the interaction between recombinant hBD-2 and ACE-2 proteins was revealed by a pull-down assay. In light of these preliminary experiments, we suggest that the recombinantly produced hBD-2 may be protective against SARS-CoV-2 and be used as a supplement in treatment. However, current findings need to be supported by cell culture studies, toxicity analyses, and in vivo experiments.
The First Study on Bacterial Flora and Biological Control Agent of the Little Spruce Sawfly, Pristiphora Abietina (Christ.) (Hymenoptera: Tenthredinidae)
(Ars Docendi, 2017) Iskender, Nurcan Albayrak; Ortucu, Serkan; Algur, Omer Faruk; Aksu, Yasar; Saral, Aysegul
The aim of this study was to determine the bacterial flora of Pristiphora abietina and to find the performance of the members of this flora as a biocontrol agent for this pest. For this purpose, eleven bacteria were isolated from living, diseased and dead larvae. Morphological and biochemical properties, metabolic enzyme profiles by BIOLOG microtiter plate system and total cellular fatty acid profile by Microbial Identification Systems (MIS) of the bacterial isolates were determined. In addition, 16S rRNA gene sequence analysis was performed. The isolates were identified as Bacillus pumilus (Pa1), Lysinibacillus fusiformis (Pa2, Pa10), Stenotrophomonas maltophilia (Pa3), Acinetobacter johnsonii (Pa4, Pa9), Bacillus cereus (Pa5), Rhodococcus sp. (Pa6), Staphylococcus sciuri (Pa7), Ralstonia pickettii (Pa8), Neisseria perflava (Pa11). All these bacteria were tested against P. abietina larvae. The highest insecticidal activity was obtained from S. maltophilia and L. fusiformis (65.47%, 60.71%, respectively), (p < 0.05), whereas the lowest insecticidal activity (17.26%) was obtained from N. perflava within seven days. Our result indicates that L. fusiformis (Pa2, Pa10) show potential to be used as biological control agents of P. abietina.
Gene Expression and Characterization of an Antimicrobial Peptide from Medicago Sativa "sazova" Cultivar
(Academic Press Inc Elsevier Science, 2025) Turgut, Busra Albayrak; Ortucu, Serkan; Bezirganoglu, Ismail
In recent years, the discovery of new antimicrobial agents has become necessary because of the increase in antibiotic resistance, the development of herbicides and fungicides resistance. Among the antimicrobial agents, antimicrobial peptides (AMPs) stand out due to their stable structure. In this study, the aim was to identify a thermostable AMP from the seeds of M. sativa "Sazova" cultivar and to analyze gene expression during germination. Antimicrobial tests were performed for the seed peptides after heat treatment (85 degrees C for 10 min), revealing antimicrobial effects against S. aureus, E. coli, and C. albicans. Subsequently, the peptide band corresponding to the inhibition zone was identified as M. sativa Defensin 2.1 (MsDef2.1, MW: 5.2048 kDa). The gene expression analysis of MsDef2.1 in Sazova cultivar showed that the gene was expressed different plant organs, and the expression was decreased over time. As a result of the gene analysis of two cultivars (Sazova and LegenDairy) it was found that there are 5 base differences in the coding sequence and 3 amino acid differences between the sequences of MsDef2.1 isoforms from the LegenDairy and Sazova cultivars. The physiochemical properties, secondary, and tertiary structure of the Sazova Defensin 2.1 were predicted by using bioinformatic tools. Due to the amino acid substitutions in gamma-core structures, the antimicrobial activity of the isoforms is expected to differ from each other. These findings demonstrated that the defensin MsDef2.1 can differ in M. sativa cultivars in respect of the gene and amino acid sequences and has a potential for future applications.
In Vitro Evaluation of Probiotic and Antioxidant Potential of Lacticaseibacillus Paracasei Ed25
(Springer, 2024) Dasdemir, Elanur; Arslan, Nazli P.; Ortucu, Serkan; Aykutoglu, Gurkan; Ozkan, Hakan; Adiguzel, Ahmet; Taskin, Mesut
This study aimed to assess the in vitro probiotic and antioxidant potential of lactic acid bacteria (LAB) isolated from different white cheeses, also known as "Beyaz Peynir" in Turkey. A total of 58 bacterial strains were isolated from 11 different white cheeses obtained from small-scale dairies. According to some preselection criteria (having the distinctive features of LAB, exhibiting non-haemolytic property, and resisting the simulated gastrointestinal conditions such as low pH, pepsin, pancreatin and bile salt tolerance), four (ED13, ED20, ED25 and ED36) out of 58 isolates were selected for the subsequent experiments. Among the four isolates, ED25 exhibited the maximum lactase production and cholesterol removal potential, the highest biological activity (antimicrobial and antioxidant activity) and the lowest antibiotic resistance. In addition, the second highest B12-producing capacity were measured for ED25. The isolate ED25 was found to possess antimicrobial effectiveness against all tested microorganisms (S. aureus, E. coli, S. Typhimurium, L. monocytogenes and C. albicans) according to the agar well diffusion method. In vitro antioxidant activity assay demonstrated that the culture supernatant of the ED25 had the ability to scavenge DPPH (49%), ABTS (37%), OH center dot (51%) and O-2(center dot-) (38%) radicals. According to the sequences analysis of the 16 S rRNA gene, the isolate ED25 was identified as Lacticaseibacillus paracasei (GenBank accesion number: OP036674.1). Due to strong biological activities, L. paracasei ED25 may be used as a probiotic agent against gastrointestinal disorders, infections and oxidative stress-mediated diseases.
Invertase Production and Molasses Decolourization by Cold-Adapted Filamentous Fungus Cladosporium Herbarum Er-25 in Non-Sterile Molasses Medium
(Elsevier, 2016) Taskin, Mesut; Ortucu, Serkan; Unver, Yagmur; Tasar, Ozden Canli; Ozdemir, Mustafa; Kaymak, Haluk Caglar
This study was undertaken to remove the coloring compounds of molasses as well as produce extracellular (exo) invertase in sterile and non-sterile molasses medium by using cold-adapted filamentous fungus Cladosporium herbarum ER-25. It was determined that a combination of low culture pH (5.5), temperature (20 degrees C) and high molasses concentration (6%) could completely prevent undesired bacterial contamination during the cultivation of C. herbarum ER-25. Under the optimized non-sterile culture conditions, the maximum invertase activity (36.1 U/mL) was attained after 72 h. On the other hand, the fungus could remove toxical dark brown pigments (melanoidins) in non-sterilized molasses medium through biodegradation and bioadsorption mechanisms. A color removal rate of 64.8% in non-sterile medium could be achieved at the end of 144-h cultivation period. It was found that lac case and manganese peroxidase were responsible for biodegradation. No ligninase activity was detected for the fungus during the cultivation. Maximum laccase (4.6 U/mL) and manganese peroxidase (3.5 U/mL) activities could be reached after 120 h. Higher invertase activity and color removal rate were achieved in non-sterilized medium compared to sterilized one. This is the first report on invertase production from cold-adapted microorganisms under non-sterile culture conditions. As an additional contribution, use of cold-adapted fungi for molasses decolourization was investigated for the first time in the present study. (C) 2016 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
Investigation on the Biological Control of Alternaria Alternata
(Indian Council of Agricultural Research, 2018) Tozlu, Elif; Tekiner, Nasibe; Kotan, Recep; Ortucu, Serkan
Alternaria alternata (Fr.) Keissl. which has a wide host range is an important fungal pathogen causing losses in yield in agricultural crops. The chemicals used for controlling this disease are directly toxic to beneficial microorganisms in soil. This study was carried out to determine the antifungal activities of a total 13 candidate bioagent bacterial isolates of Bacillus subtilis (TV-6F, TV-12H, TV-17C and TV 125 A), Bacillus megaterium (TV 87 A and TV 91 C), Bacillus pumilus (TV 67 C), Paenibacillus polyntyxa (TV 12E), Pantoea agglomerans (RK 92 and BRT-B), Pseudomonas flumrscens Biotip F (FDG 37), Bacillus thuringiensis subsp. kurstakii (BAB-410) and Bacillus sphaericus GC subgroup D (FD 49) and bioagent fungal isolates of Trichoderma harzianum (ET 4 and ET 14) against two isolates of A. alternata isolated from strawberry and cucumber on petri plate assays. B. pumilus TV 67C (87.63%-65.89%), B. subtilis TV 6F (77.61%-63.11%) and B. megaterium TV 87A (72.93%-68.87%) bacterial isolates were the most effective isolates against pathogenic fungi in in vitro and bioagent fungal isolates ET 4 and ET 14 inhibited pathogenic fungi grown in in vitro respectively 73.87% -83.33% and 55.85% -74.44%, too. Our results indicated that B. subtilis, B. pumilus, B. megaterium and T harzianum should be tested against A. alternata in field condition.
Isolation of a Novel Antimicrobial Polypeptide from an Aspergillus Niger Isolate
(Trakya University Balkan Yerlesesi Enstituler Binasi, 2023) Ustun, Ayse; Yazici, Aysenur; Ortucu, Serkan
In this study the extracellular proteins from the isolate LC3 belonging to Aspergillus were purified for new antimicrobial polypeptide (AMP) discovery and then tested for antimicrobial activity against Staphylococcus aureus (ATCC 25923) and Methicillinresistant S. aureus (MRSA). Antimicrobial activity was determined by the trypsin/proteinase K assay, which was polypeptide-based, and it was observed that this protein was a protein of about 11 kDa by gel overlay assay. The minimum inhibitory concentration of purified AMP molecule against S. aureus ATCC 25923 and MRSA was 8 mu g/ml and 32 mu g/ml, respectively and the AMP molecule was confirmed. ITS sequence analysis showed that isolate LC3 was identified as Aspergillus niger, using the Bioedit sequence assembly program. The sequence was deposited with the GenBank database with accession number MK332597. The results indicate that the purified AMP molecule has the potential to be used in infections caused by S. aureus.
Isolation, Characterization and Pathogenicity of Fungi from Pristiphora Abietina (Hymenoptera: Tenthredinidae)
(Parlar Research & Technology Ug, 2017) Iskender, Nurcan Albayrak; Ortucu, Serkan; Aksu, Yasar; Saral, Aysegul
This study was conducted to isolate and characterize pathogenic fungi for possible use in biocontrol of P. abietina and to determine their pathogenicity. Eleven fungal isolates were obtained from larvae. Based on traditional and molecular methods, fungal isolates were identified as Beauveria bassiana, Penicillium corylophilum, P. glabrum, P. polonicum, Aspergillus niger, A. versicolor, Cladosporium sphaerospermum, Alternaria sp. and Trichoderma asperellum. At first, all these fungal isolates were tested against P. abietina larvae for isolate selection at 106 conidia/ml and 100% relative humidity (RH). Three fungal isolates ((PaF 004, PaF 009, PaF 076) belonging to Beauveria genus were determined to be pathogen against P. abietina. Then, mortality of these three isolates, on P. abietina larvae were investigated at three conidial concentrations as 10(6), 10(7) and 10(8), and at the degree of humidity as in the 65 5% and 100% RH, respectively. In 100% RH and at 10(7)-10(8) conidia/ml, three fungal isolates have shown a mortality rate of 100%. On the other hand, in 65 5% RH and at 10(7)-10(8) conidia/ml, three fungal isolates have shown a mortality rate between 49.1 +/- 4.52% - 91.1 +/- 7.2% and 63,3 +/- 4,5 - 95,3 +/- 2,7, respectively (p<0.05). The present results indicated that PaF 009 has an excellent potential for biological control of P. abietina larvae. This is also the first report on the larvacidal effect of B. bassiana on P. abietina.
L-Lactic Acid Production by Rhizopus Oryzae Mbg-10 Using Starch-Rich Waste Loquat Kernels as Substrate
(Wiley-V C H Verlag GmbH, 2013) Taskin, Mesut; Ortucu, Serkan; Unver, Yagmur; Arslan, Nazli Pinar; Algur, Omer Faruk; Saghafian, Amir
The objective of this work was to perform production of L-lactic acid from starch-rich waste loquat kernels by newly isolated Rhizopus oryzae MBG-10 fungus. Loquat kernel flour (LKF) was used as substrate (mainly as carbon source). The most favorable conditions for L-lactic acid production were LKF concentration of 80g/L, CaCO3 concentration of 20g/L, ammonium sulfate concentration of 3g/L and incubation time of 108h. Under these conditions, L-lactic acid and biomass concentrations were 45.4 and 8.2g/L, respectively, and -amylase activity was 81.6U/mL. No significant pH changes were observed in the medium thanks to the buffering capacity of LKF. L-lactic acid could be produced in a single-stage from starch-rich LKF without prior saccharification by the fungus with high amylolytic enzyme activity. This is the first report on use of waste loquat kernels as a lactic acid production substrate.
A Laboratory Assessment of Two Local Strains of the Beauveria Bassiana (Bals.) Vuill. Against the Tetranychus Urticae (Acari: Tetranychidae) and Their Potential as a Mycopesticide
(Hindawi Ltd, 2017) Ortucu, Serkan; Algur, Omer Faruk
This study was conducted to assess highly pathogenic Beauveria bassiana isolates to be used in biocontrol and to determine their potentials as mycopesticide. For this purpose, two B. bassiana isolates, which were locally isolated from T. urticae, were chosen. Firstly, three suspensions were investigated at the degree of humidity of 65 +/- 5% and 100% RH. Secondly, these strains were selected according to their tendency to mass production, tolerance to UV radiation, and capability of producing spore at the different temperatures. Finally, identification of the selected isolate was performed by using ITS rDNA analysis. Both tested fungal isolates were pathogenic to the T. urticae. Mycelial growths of isolate AT076 at 20 degrees C and 30 degrees C were found to be greater than isolate AT007. It was observed that isolate AT076 had more spore production with 1.61 x 107 spore/disc at 30 degrees C and 44.33% germination after UV radiation for 15 min. The numbers of spores per 5mm disk area for isolates AT076 and AT007 were found to be 1.2 x 106 and 1.0 x 106. These results show that isolate AT076 was more virulent and more UV-tolerant and had higher tendency to mass production compared to isolate AT007 against T. urticae. As a result of this study, isolate AT076 can be used in the biocontrol as mycopesticide.
Lipase Production with Free and Immobilized Cells of Cold-Adapted Yeast Rhodotorula Glutinis HL25
(Elsevier Science BV, 2016) Taskin, Mesut; Ucar, Muhammed Hanifi; Unver, Yagmur; Kara, Ayse Aydan; Ozdemir, Mustafa; Ortucu, Serkan
This study was undertaken to produce the lipase by free and immobilized cells of cold-adapted yeast Rhodotorula glutinis HL25 using waste frying oils as substrate. The optimization of culture parameters was performed using traditional one-factor-at-a-time protocol. The temperature 20 degrees C and initial pH 6.0 were optimal for lipase production by both free and immobilized cells. An inoculum size of 40 mL/L for free cells and beads number of 150 g/L for immobilized cells were optimal for lipase production. Optimal waste frying oil concentration and incubation time were 30 mL/L and 84 h for free cells but 40 mL/L and 72 h for immobilized cells, respectively. The maximum increases for free and immobilized cells were achieved at the Triton X-100 concentrations of 5 and 7.5 mL/L, respectively. The maximum lipase activities were determined as 54.4 and 75.2 U/L for free and immobilized cells, respectively. Immobilized cells could be used in five successive reaction cycles without any loss in the maximum activity. Immobilized cells could retained about 70% of their maximum activity by the end of the cycle 10. This is the first attempt on lipase production potential of a cold-adapted strain of the yeast R. glutinis. Furthermore, lipase production using immobilized cells of cold-adapted yeasts was investigated for the first time. (C) 2016 Elsevier Ltd. All rights reserved.
Lipid Production from Sugar Beet Molasses Under Non-Aseptic Culture Conditions Using the Oleaginous Yeast Rhodotorula Glutinis Tr29
(Pergamon-Elsevier Science Ltd, 2016) Taskin, Mesut; Ortucu, Serkan; Aydogan, Mehmet Nuri; Arslan, Nazli Pinar
In this study the lipid production potential of the isolated yeast Rhodotorula glutinis TR29 in molasses medium under non-aseptic culture conditions was investigated. Different molasses concentrations and initial pH values were tested to make R. glutinis TR29 cells more dominant population in the medium, thereby preventing undesired microbial contaminants. Contamination could be prevented by selecting the high molasses concentration (20%) and low initial pH (5.0). When these parameters were kept constant, the optimum temperature, additional nitrogen source concentration and incubation time for the lipid production were found to be 25 degrees C, 4 g/L and 168 h, respectively. Under these culture conditions, the cell mass and lipid concentration were determined as 16.2 and 10.5 g/L, respectively. The lipid content was determined as 64.8%. The main cellular fatty acids of the yeast were oleic (63.5%), politic acid (15.4%), stearic acid (9.1%) and palmiteloic acid (7.2%). The yeast lipids seems to be a promising feedstock for biodiesel production due to a high content of C16 and C18 fatty acids. To our best knowledge, this is the first work on lipid production by yeasts in non-sterile molasses medium. (C) 2016 Elsevier Ltd. All rights reserved.