Pınar Aytar Çelik

Innovation of Strategies and Challenges for Fungal Nanobiotechnology

Nanotechnology involves the study and use of materials under the 100 nm scale, exploiting the different physiochemical properties exhibited by these materials at the nanoscale level. Microorganisms are the best model and role of action for the nano/biotechnological applications. This technology has become increasingly important for the biotechnology and the related sectors. Promising applications have been already employed in the areas of drug delivery systems using bioactive nanoencapsulation, biosensors to detect and quantify pathogens, chemical and organic compounds, alteration of food compositions, and high-performance sensors and film to preserve fruits and vegetables. Moreover, the taste of food and food safety can be improved by new nano-materials from the microbiological sources. The huge benefits from this technology have led to increases in the market investments in nanoscience and nanoproducts in several areas.

Optimization of hyaluronic acid production and its cytotoxicity and degradability characteristics

Abstract In the present study, culture conditions of Streptococcus equi was optimized through Box–Behnken experimental design for hyaluronic acid production. About 0.87 gL−1 of hyaluronic acid was produced under the determined conditions and optimal conditions were found as 38.42 °C, 24 hr and 250 rpm. The validity and practicability of this statistical optimization strategy were confirmed relation between predicted and experimental values. The hyaluronic acid obtained under optimal conditions was characterized. The effects of different conditions such as ultraviolet light, temperature and enzymatic degradation on hyaluronic acid produced under optimal conditions were determined. 118 °C for 32 min of autoclaved HA sample included 63.09 µg mL−1 of d-glucuronic acid, which is about two-fold of enzymatic effect. Cytotoxicity of hyaluronic acid on human dermal cells (HUVEC, HaCaT), L929 and THP-1 cells was studied. In vitro effect on pro or anti-inflammatory cytokine release of THP-1 cells was determined. Although it varies depending on the concentration, cytotoxicity of hyaluronic acid is between 5 and 30%. However, it varies depending on the concentration of hyaluronic acid, TNF-α release was not much increased compared to control study. Consequently, purification procedure is necessary to develop and it is worth developing the bacterial hyaluronic acid.

Higher titer hyaluronic acid production in recombinant Lactococcus lactis

Abstract Hyaluronic acid (HA) is a natural biopolymer and has long been attracting the attention of biotechnology industry due to its various biological functions. HA production with natural producer Streptococcus equi subsp. zooepidemicus has not been preferred because it has many drawbacks due to its pathogenicity. Therefore, in the present study, Streptococcal hyaluronan synthase gene (hasA) was introduced and expressed in Lactococcus lactis, through the auto inducible NICE system and the effect of nisin amount on the production of HA was examined. Newly constructed plasmid was transformed into L. lactis CES15, produced 6.09 g/l HA in static flask culture after three hours of induction period with initial 7.5 ng/ml nisin concentration within total six hours of incubation. The highest HA titer value ever was reported for recombinant HA-producing L. lactis by examining the effect of initial nisin concentration. We have shown that initial nisin concentration, which used to initiate the auto-inducing mechanism of NICE system and consequently hyaluronan synthase expression, has a direct and significant effect on the produced HA amount. Recently constructed recombinant L. lactis CES15 strain provide significant advantages for industrial HA production than those in literature in terms of production time, energy demand, carbon usage, and safety status.

Applying on Bacillus cereus of Low-Pressure and Low-Temperature Plasma Jet in a Postdischarge Chamber

A low-temperature flowing postdischarge plasma reactor is first presented. The reactor is a postdischarge chamber coupled to a plasma jet system. The low-pressure flowing postdischarge (jet) in the postdischarge chamber can be generated using direct current (dc) or alternative current (ac) power supplies. A low-pressure plasma jet of Neon using a 25-kHz 25-kV ac voltage and low-pressure plasma jet of ambient air using a 5-kV dc voltage produced in the postdischarge chamber are given. By using sample holders in the postdischarge chamber, early or late flowing postdischarge (jet) can be exposed to the sample surface. In this paper, the low-temperature and low-pressure dc air plasma jet generated using the plasma jet system coupled to a postdischarge chamber is first exposed on to Bacillus cereus, as a model bacterium. The inactivation effect on Bacillus cereus of the low-temperature and low-pressure dc air plasma jet at several exposure times was observed. With treatment of 30 min of exposure times, a value below the decimal value of the used bacterium was obtained of 15 min of exposure times.

Talaromyces aculeatus from acidic environment as a new fungal biosorbent for removal of some reactive textile dyes

Biosorption potential of Talaromayces aculeatus AMDC-14 (KF588645) as low-cost biosorbent for different dyes (Reactive Blue 13, Reactive Blue 72, Reactive Yellow 85 and Reactive Orange 13) removal from aqueous medium was studied. Experiments were performed to determine effect of initial solution pH (1-7), biosorbent dose (0.1-2.5 g L -1 ), time (15-1440 min), dye concentration (10-200 ppm) and temperature (25-40 °C) onto Talaromayces aculeatus biosorption . Biosorption equilibrium data were described very well for Reactive Blue 13, Reactive Blue 72, Reactive Yellow 85 and Reactive Orange 13 by Langmuir isotherm model than Freundlich isotherm model with maximum biosorption capacities which are 32.10, 71.30, 20.67 and 31.30 mg g -1 , respectively. Biosorption of investigated dyes fitted to kinetic model of pseudo-second-order for all dyes. Gibbs free energies (ΔG°) of biosorption processes were calculated and the results indicated that all selected dyes biosorption onto Talaromayces aculeatus AMDC-14 were spontaneous in this study. And also biosorption processes had endothermic enthalpy values except Reactive Blue 72.

Optimization of a biosurfactant production from bacteria isolated from soil and characterization of the surfactant / Topraktan izole edilen bakterilerden biyosurfaktan üretiminin optimizasyonu ve surfaktanın karakterizasyonu

Abstract Objective: Biosurfactants are surface-active substances produced by microorganisms. The growth of microorganism supports biosurfactant production on hydrocarbon polluted environments. In this study, the capacity of biosurfactant production of Georgenia daeguensis (accession number, KP798810) isolated from hydrocarbon- contaminated soil was studied. Methods: The components of biosurfactant production medium were investigated through Plackett-Burman methodology. By using Placket-Burman based on statistical screening, six of the eleven factors of production medium were found to be critically effective on the biosurfactant production. Results: The significant factors were KCl, ZnSO4.7H2O, CaCl2.2H2O, KH2PO4, MgSO4.7H2O and glucose. Among of these, KCl had the highest effect contribution with 55.22%. After the optimization by such design, critical micelle concentration value was reached to 2.2 g L-1. When antibacterial activity of biosurfactant was screened, it showed antibacterial effect against to Klebsiella pneumoniae. Besides, the biosurfactant was characterized by FT-IR, critic micelle concentration and zeta analysis. Conclusion: This study reported that Georgenia daeguensis is able to produce effective biosurfactant exhibiting antibacterial activity against K. pneumoniae. Özet Amaç: Biyosurfaktanlar, mikroorganizmalar tarafından üretilen yüzey aktif bileşiklerdir. Hidrokarbonla kirlenmiş çevrelerde mikroorganizmanın gelişmesi biyosurfaktan üretimini destekler. Bu calışmada hidrokarbonca kirlenmiş topraktan izole edilen Georgenia daeguensis (giriş numarası, KP798810)’nin biyosurfaktan üretme kapasitesi calışılmıştır. Metod: Biyosurfaktan üretim ortamının bileşenleri Plackett- Burman metodolojisi kullanılarak değerlendirilmiştir. Istatistiksel taramaya bağlı Plackett-Burmankullanılarak, üretim ortamının 11 faktorden 6’sının biyosurfaktan üretiminde önemli ölcüde etkili olduğunu ortaya çıkarılmıştır. Bulgular: Önemli faktörler; KCl, ZnSO4.7H2O, CaCl2.2H2O, KH2PO4, MgSO4.7H2O ve glukoz olarak belirlenmiştir. Bunlarına arasından KCl, %55,2 ile en yüksek katkıya sahip olmuştur. Bu şekilde gerçekleştirilen optimizasyon sonrası, kritik misel konsantrasyonu 2,2 g L-1’ye ulaşmıştır. Biyosurfaktanın antibakteriyel aktivitesi değerlendirildiğinde Klebsiella pneumoniae’ye karşı antibakteriyel etkiye sahip olduğu gösterilmiştir. Bunun yanısıra, biyosurfaktan FTIR, kritik misel konsantrasyonu ve zeta analizi açısından da karakterize edilmiştir. Sonuç: Bu çalışma Georgenia daeguensis’in, K. pneumoniae’ye karşı antibakteriyel etki sergileyen etkili bir şekilde biyosurfaktan üretebildiğini bildirmektedir.