Ahmet Çabuk

Airborne Fungi and Actinomycetes Concentrations in the Air of Eskisehir City (Turkey)

The present study investigated the isolation and identification of airborne fungi from three different urban stations located in Eskisehir (Turkey). Air samples were taken by exposing a Petri dish with Rose-Bengal streptomycin agar medium for 15 min and after incubation the number of growing colonies was counted. The sampling procedure for fungi was performed 35 times at the research stations weekly between March and November 2001. A total of 2518 fungal and 465 actinomycetes colonies were counted on 420 Petri plates over a nine-month period. In total, some 20 mould species belonging to 12 genera were isolated. Alternaria alternata, Cladosporium cladosporioides and Scopulariopsis brevicaulis were the most abundant species in the study area (13.66, 5.80 and 5.50% of the total, respectively). Relationships between fungal spore numbers, aerosol air pollutants (that is the particulate matter in the air) and sulphur dioxide together with the meteorological conditions were examined using statistical analysis. Number of fungi and actinomycetes were tested by multivariate analysis (MANOVA) according to the areas and months. Fungal numbers were nonsignificant according to the areas and months (p > 0.05), but the number of actinomycetes recorded was significant (p < 0.01).

Decolorization of a textile dye, reactive red 198 (rr198), by Aspergillus parasiticus fungal biosorbent

The decolorization potential of textile dye Reactive Red 198 (RR198) by Aspergillus parasiticus fungal biosorbent has been investigated as a function of initial pH, contact time, biosorbent and initial dye concentration in a batch system. Maximum dye biosorption capacity 1.03x10-4 mol g-1 was observed at pH 2.0 and 2.0 g L-1 of biosorbent concentration. Biosorption equilibrium was attained within 50 min. The equilibrium data followed Langmuir, Freundlich and Dubinin-Radushkevich isotherm models at 20, 30, 40 and 50oC. Anincrease in the biosorption capacity of A. parasiticus with temperature showed that the decolorization process is endothermic. Results indicated that Aspergillus parasiticus was an effective candidate for textile dye RR198 removal from aqueous solutions.

New fungal biomasses for cyanide biodegradation

Cyanide, a hazardous substance, is released into the environment as a result of natural processes of various industrial activities which is a toxic pollutant according to Environmental Protection Agency. In nature, some microorganisms are responsible for the degradation of cyanide, but there is only limited information about the degradation characteristics of Basidiomycetes for cyanide. The aim of the present study is to determine cyanide degradation characteristics in some Basidiomycetes strains including Polyporus arcularius (T 438), Schizophyllum commune (T 701), Clavariadelphus truncatus (T 192), Pleurotus eryngii (M 102), Ganoderma applanatum (M 105), Trametes versicolor (D 22), Cerrena unicolor (D 30), Schizophyllum commune (D 35) and Ganoderma lucidum (D 33). The cyanide degradation activities of P. arcularius S. commune and G. lucidum were found to be more than that of the other fungi examined. The parameters including incubation time, amount of biomass, initial cyanide concentration, temperature, pH and agitation rate were optimized for the selected three potential fungal strains. The maximum cyanide degradation was obtained after 48 h of incubation at 30°C by P. arcularius (T 438). The optimum pH and agitation rate were measured as 10.5 and 150 rev/min, respectively. The amount of biomass was found as 3.0 g for the maximum cyanide biodegradation with an initial cyanide concentration of 100mg/L. In this study, agar was chosen entrapment agent for the immobilization of effective biomass. We suggested that P. arcularius (T 438) could be effective in the treatment of contaminated sites with cyanide due to capability of degrading cyanide.

Biosorption Potential of the Macrofungus Ganoderma carnosum for Removal of Lead(II) Ions from Aqueous Solutions

This paper reports the utilization of a macro-fungus Ganoderma carnosum as a biosorbent material for the removal of lead(II) ions from aqueous solutions. The biosorption potential of G. carnosum was investigated by batch experiments. The influences of physico-chemical parameters like pH, biosorbent dosage, contact time and initial metal ion concentration were evaluated. The biosorption equilibrium was attained in 10 minutes. Equilibrium biosorption data were analyzed by the Freundlich, Langmuir and Dubinin–Radushkevich (D–R) isotherm models. Maximum biosorption capacity of biosorbent was found to be 22.79 mg g− 1 (1.10 × 10− 4 mol g− 1) at the pH value of 5.0. The biosorbent was regenerated using 10 mM HCl solution, with up to 96% recovery, and reused four times in biosorption-desorption cycles successively. Biosorption efficiency of G. carnosum was also examined in a real effluent. The mechanism of the biosorption was investigated with FTIR, SEM and EDAX analysis and the findings suggested that the biosorption process involved in ion exchange as dominant mechanism as well as complexation. The ion exchange mechanism was also confirmed by the mean free energy value obtained from D–R isotherm model.

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.

Diversity of acidophilic prokaryotes at two acid mine drainage sites in Turkey

The biodiversity of acidophilic prokaryotes in two acidic (pH 2.8–3.05) mine drainage (AMD) sites (Balya and Çan) in Turkey was examined using a combined cultivation-based and cultivation-independent approach. The latter included analyzing microbial diversity using fluorescent in situ hybridization (FISH), terminal restriction enzyme fragment length polymorphism (`T-RFLP), and quantitative PCR (qPCR). Numbers of cultivatable heterotrophic acidophilic bacteria were over an order of magnitude greater than those of chemolithotrophic acidophiles in both AMD ponds examined. Isolates identified as strains of Acidithiobacillus ferrivorans, Acidiphilium organovorum, and Ferrimicrobium acidiphilum were isolated from the Balya AMD pond, and others identified as strains of Leptospirillum ferriphilum, Acidicapsa ligni, and Acidiphilium rubrum from Çan AMD. Other isolates were too distantly related (from analysis of their 16S rRNA genes) to be identified at the species level. Archaeal diversity in the two ponds appeared to be far more limited. T-RFLP and qPCR confirmed the presence of Ferroplasma-like prokaryotes, but no archaea were isolated from the two sites. qPCR generated semiquantitative data for genera of some of the iron-oxidizing acidophiles isolated and/or detected, suggesting the order of abundance was Leptospirillum > Ferroplasma > Acidithiobacillus (Balya AMD) and Ferroplasma > Leptospirillum > Acidithiobacillus (Çan AMD).

Removal of Reactive Dyes using Magnetically Separable Trametes versicolor Cells as a New Composite Biosorbent

Magnetically modified Trametes versicolor cells were used for biosorption of Reactive Blue 13 (RB13), Reactive Yellow 85 (RY85) and Reactive Violet 1 (RV1). Percent biosorption values and maximum adsorption capacities of 98.30% and 135.35 mg g−1 for RB13, 96.02% and 125 mg g−1 for RY85, and 98.56% and 227.27 mg g−1 for RV1 were observed under optimal conditions. The biosorption of all dyes was exothermic in nature. The biosorbent was characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy, and magnetic force microscopy. The Langmuir model was found to be most suitable for describing the biosorption of all dyestuffs. The experimental data fitted very well the pseudo second order kinetic model.

Production of an alkaline protease using Bacillus pumilus D3 without inactivation by SDS, its characterization and purification

Abstract In this study, protease-producing capacity of Bacillus pumilus D3, isolated from hydrocarbon contaminated soil, was evaluated and optimized. Optimum growing conditions for B. pumilus D3 in terms of protease production were determined as 1% optimum inoculum size, 35 °C temperature, 11 pH and 48 h incubation time, respectively. Stability studies indicated that the mentioned protease was stable within the pH range of 7–10.5 and between 30 °C and 40 °C temperatures. Surprisingly, the activity of the enzyme increased in the presence of SDS with concentration up to 5 mM. The protease was concentrated 1.6-fold with ammonium sulfate precipitation and dialysis. At least six protein bands were obtained from dialysate by electrophoresis. Four clear protein bands with caseinolytic activity were detected by zymography. Dialysate was further purified by anion-exchange chromatography and the caseinolytic active fraction showed a single band between 29 and 36 kDa of reducing conditions.

Dechlorination of chlorinated compounds by Trametes versicolor ATCC 200801 crude laccase and quantitative structure-activity relationship of toxicity

Chlorinated compounds constitute an important class of xenobiotics. Crude laccase was produced using Trametes versicolor ATCC (200801) in potato dextrose broth, with wheat bran as an inducing medium, and its ability to dechlorinate eight compounds was determined. The compounds were 2-chlorophenol, 4-chlorophenol, 2,4-dichlorophenol, 2,6-dichlorophenol, 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, heptachlor and pentachlorophenol. A range of parameters for the dechlorination of some compounds was tested, including incubation period, pH, initial substrate concentration, temperature, and enzyme quantity. The oxygen consumption was determined during each dechlorination process, under pre-determined optimum conditions. The changes in chemical structure of the compounds were also determined, by using FTIR analysis, following dechlorination of test chlorophenolics. Strong interactions were found to lead to the reactivity of hydroxyl groups in some cases and chlorine atoms were released from the benzene ring. The changes in compound toxicity were monitored before and after enzymatic treatment, using Microtox. Quantitative structure-activity relationships for the toxicity of the chlorinated compounds were developed. Consequently, the toxic activity of the test compounds was controlled by electrophilic index and electronic properties.

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.