Browsing by Author "Oskay M."
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Item Antibacterial activity of some actinomycetes isolated from farming soils of Turkey(Academic Journals, 2004) Oskay M.; Tamer A.U.; Azeri C.A total of 50 different actinomycete strains were recovered from farming soil samples collected from Manisa Province and its surrounding. These were then assessed for their antibacterial activity against four phytopathogenic and six pathogenic bacteria. Results indicated that 34% of all isolates are active against, at least, one of the test organisms; Agrobacterium tumefaciens, Erwinia amylovora, Pseudomonas viridiflova, Clavibacter michiganensis subsp. michiganensis, Bacillus subtilis ATTC 6633, Klebsiella pneumoniae ATTC 10031, Enterococcus feacalis ATCC 10541, Staphylococcus aureus ATCC 6538, Esherichia coli ATCC 29998 and Sarcina lutea ATCC 9341. According to antibacterial activity and spectrum broadness, seven of the isolates were selected and characterized by conventional methods. The unusual antibiotic profile of these isolates underlined their potential as a source of novel antibiotics. © 2004 Academic Journals.Item Antimicrobial screening of some Turkish medicinal plants(2007) Oskay M.; Sari D.Ethanol extracts of 19 Turkish medicinal plants, used in the traditional system of medicine, were investigated for their antimicrobial activity against 14 pathogenic bacterial species and a yeast, Candida albicans, using the agar well diffusion method. Anticandidal activity was detected in 10 plant extracts. Extracts of Eucalyptus camuldulensis (leaves), Rosmarinus officinalis (leaves), Ecballium elaterium (leaves, fruits; 2:1, v/v), Liquidambar orientalis (leaves), Cornus sanguinea (leaves, flowers, stems; 2:1:1, v/v/v), Vitis vinifera (leaves, raw fruits, young branches; 2:1:1, v/v/v), Inula viscosa (leaves), Hypericum perforatum (leaves, flowers, stems; 2:1:1, v/v/v), and Punica granatum (leaves, flowers; (2:1, v/v) showed broad-spectrum antimicrobial activity with inhibition zones ranging from 4 to 34 mm. The most resistant organisms were Escherichia coli, Candida albicans, Pseudomonas fluorescens, Bacillus subtilis ATCC 6683, and Enterobacter faecalis ATCC 29212, and the most susceptible species were Proteus vulgaris ATCC 6997, Salmonella typhimurium CCM 5445, Staphylococcus epidermidis ATCC 12228, and Serratia marcescens CCM 583, respectively. The minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined for the seven highly active plants that showed antimicrobial activity against methicillin-resistant Staphylococcus aureus ATCC 95047 (MRSA), E. coli, and C. albicans. The MICs of active extracts ranged from 8 to 14.2 mg/mL while the MBCs were 14.2 to 24.4 mg/mL. © 2007 Informa Healthcare.Item A comparative study of antimicrobial activity using well and disk diffusion method on Asphodelus aestivus (Liliaceae); [Asphodelus aestivus (Liliaceae)'un antimikrobiyal etkisinin çukur ve disk diffüzyon yöntemiyle karşilaştirmali olarak belirlenmesi](2007) Oskay M.; Aktaş K.; Sari D.; Azeri C.Plant parts were powdered, extracted in a Soxhlet extractor with n-butanol and ethanol (60-80°C) for 12 h, filtered using Whatman filter paper no:4 and the filtrate was then evaporated at 70°C. For determination of antimicrobial activity, different concentrations of crude extract tested against bacteria and yeasts by both well and disk diffusion method. Results showed that the Asphodelus aestivus extract (Flower, fruits and whole plant) exhibited antimicrobial activity ranging from 2 to 15 mm. Extract obtained with ethanol was showed more inhibision. According to same concentrations of crude extract used with well diffusion method results were a bit higher than disc diffusion results. Minimal inhibitory concentration (MIC) determined on susceptible microorganisms by macrobroth dilution method, and MIC values were shown from 36 to 90 mg/mL. Also some commercial antibiotics were used to determine sensitivity of the test microorganisms and comparison.Item Activity of some plant extracts against multi-drug resistant human pathogens(Brieflands, 2009) Oskay M.; Oskay D.; Kalyoncu F.Plants used for traditional medicine contain a wide range of substances which can be used to treat various infectious diseases. Hence, antibacterial activities of ethanolic extracts of 19 plant species were studied against multi-drug resistant clinical isolates using agar well diffusion method. Extracts of Liquidambar orientalis, Vitis vinifera, Rosmarinus officinalis, Punica granatum, Cornus sanguinea, Euphorbia peplus, Ecballium elaterium, Inula viscosa and Liquidambar orientalis showed broad-spectrum antibacterial activity with inhibition zones ranging from 8 to 26 mm. The most resistant organisms were Escherichia coli (E. coli) (Ampicillin-, amoxycillin- and sulfamethoxazole- resistant), Stenotrophomonas maltophilia (S. maltophilia) (Amoxycillin- and nalidixic acid-resistant) and Klebsiella pneumoniae (K. pneumoniae) (Ampicillin-, amoxycillin- and aztreonarn-resistant), and the most susceptible species were Staphylococcus aureus (S. aureus) (Penicillin G- and oxacillin-resistant), Streptococcus pyogenes (S. pyogenes) (Penicillin G-, eiythromycin- and clindamycin-resistant) and Pseudomonas aeruginosa (P aeruginosa) (Sulfamethoxazole- and novobiocin-resistant), respectively. Minimum Inhibitory Concentrations (MIC) of crude extracts were determined for the seven highly active plants showing activity against methicillin resistant S. aureus (MRSA), E. coli, P aeruginosa, S. pneumoniae and the reference bacteria (E. coli ATCC 11229 and Kocuria rhizophila ATCC 9341 NA). MICs of active extracts ranged from 8 to 14.2 mg/mL against one or other test bacteria. Copyright © 2009 by School of Pharmacy Shaheed Beheshti University of Medical Sciences and Health Services.Item Antifungal and antibacterial compounds from Streptomyces strains(2009) Oskay M.Sixteen antibiotic-producing Streptomyces sp. isolated from the North Cyprus soils were evaluated for their ability to inhibit in vitro against six filamentous fungi including human and plant pathogens. One promising strain, designed as KEH23 with strong antifungal activity, was selected for further studies. This isolate was identified as Streptomyces sp. based on a great variety of morphological, cultural, physiological and biochemical characteristics. Its antifungal activity was confirmed in batch culture. In order to standardize the antibiotic production some cultural conditions like different incubation temperatures (20.0, 25.0, 30.0 and 37.0°C), carbon sources (glucose, glycerol, starch and sucrose), pH (6.0, 7.0, 7.5, 8.0 and 9.0) and incubation time in hours (24, 48, 72, 96 and 120) were determined. During fermentation, growth, pH and antibiotic production were monitored at 12 h intervals. Penicillium sp. was most sensitive to the produced compound(s) followed by Candida albicans, Cladosporium oxysporum and Alternaria alternata with an inhibition zone 28.0, 20.0, 16.0 and 15.0 mm, respectively. In addition, antibacterial activity of this strain was determined against human pathogenic bacteria such as Staphylococcus aureus, Klebsiella pneumoniae, Kocuria rhizophila, Escherichia coli, Salmonella typhimurium and methicillin-resistant Staphylococcus aureus (MRSA). The present results indicate that isolate KEH23 is a potential antibiotic producer agent for the biocontrol of plant and human pathogens. © 2009 Academic Journals.Item Comparison of Streptomyces diversity between agricultural and non-agricultural soils by using various culture media(2009) Oskay M.Streptomycetes play a key role in the sustainability of agriculture and indicates the level of health of soil, especially when considering the richness of them that are involved in biological control of soil borne diseases. 20 different soil samples were taken from agricultural (7) and non-agricultural places (13) and populations of Streptomycetes were quantified in order to select the general culture media that had better reflect the changes of these bacteria. The most efficient medium for the isolation of Streptomyces was starch casein agar by the addition of nystatin. Pretreatment of soil samples with CaCO3 (1%) increased the streptomycetes occurring on the isolation plates. To establish a correlation with soil physico-chemical parameters, such as pH, salt, N, P, K, Na, Fe, Zn and Cu were also determined, most of the correlations being significantly positive on the quantification of Streptomyces diversity. Streptomycete counts ranged from a high of 6.7 × 106 to a low of 2.3 × 106 cfu/g dry soil of non-agricultural soils. Streptomycetes constituted 4.8 to 45.8% of the total culturable bacterial community. Higher streptomycete densities were greatest in non-agricultural soils with an average of 14.0% compared to agricultural soils with average of 10.1%. These results suggest that these bacteria may be represent an unexplored resource for pharmaceutical drug discovery but also may provide additional disease control in agriculture. © 2009 Academic Journals.Item The effects of some environmental parameters on mycelial growth of six Morchella species(2009) Kalyoncu F.; Oskay M.; Kalyoncu M.A comparative evaluation was conducted to assess the effects of some environmental parameters such as pH, type of carbon source, salinity and temperature on the mycelial growth of six species of an ectomycorrhizal fungus, Morchella spp. (M. costata, M. elata, M. esculenta, M. hortensis, M.intermedia and M. rotunda) collected from different parts of Turkey. All carbon sources were found to be beneficial for mycelial growth. However, glucose, sucrose, maltose and fructose were better sources of carbon for some morels. Maximum mycelial growth in Petri dishes was achieved at 20 and 25°C after three weeks incubation for all Morchella species. Growth was reduced significantly below 15°C and above 30°C. Different pH and salinity (NaCI) levels markedly affected the mycelial growth of the fungi.Item Antimicrobial and antioxidant activities of mycelia of 10 wild mushroom species.(2010) Kalyoncu F.; Oskay M.; Saǧlam H.; Erdoǧan T.F.; Tamer A.U.Antimicrobial and antioxidant activities of mycelia obtained from 10 wild edible mushrooms-Armillaria mellea, Meripilus giganteus, Morchella costata, Morchella elata, Morchella esculenta var. vulgaris, Morchella hortensis, Morchella rotunda, Paxillus involutus, Pleurotus eryngii, and Pleurotus ostreatus-were investigated. For determination of antimicrobial activities of these mushrooms, ethanol extracts were examined with 11 test microorganisms by the agar well diffusion method. P. ostreatus and M. giganteus were the most active species against both bacteria and yeast. Antioxidant properties of ethanol extracts were studied by the 1,1-diphenyl-2-picrylhydrazyl free radical scavenging method. Among the mushroom extracts, M. elata showed the most potent radical scavenging activity. This research has shown that these 10 wild macrofungi have potential as natural antioxidants and antibiotics.Item Antioxidant activity of the mycelium of 21 wild mushroom species(2010) Kalyoncu F.; Oskay M.; Kayalar H.In this study, the antioxidant activity of mycelia from 21 wild mushrooms - Agaricus bresadolanus, Auricularia auriculajudae, Chroogomphus rutilus, Fomes fomentarius, Ganoderma lucidum, Gloeophyllum trabeum, Gymnopus dryophilus, Infundibulicybe geotropa, Inocybe flocculosa var. crocifolia, Inocybe catalaunica, Lentinula edodes, Lentinus sajor-caju, Lycoperdon excipuliforme, Macrolepiota excoriata, Morchella esculenta var. rigida, Morchella intermedia, Omphalotus olearius, Pleurotus djamor, Postia stiptica, Rhizopogon roseolus and Stropharia inuncta - were investigated. Antioxidant properties of ethanol, chloroform and water extracts of these 21 mycelia were studied by two methods: free radical scavenging (DPPH) and the scavenging activity of 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonic acid) radical cation (ABTS.+). Among the 21 mushroom extracts, Omphalotus olearius displayed the most potent antioxidant activity. The study has shown that these wild macrofungi have potential as natural antioxidants. © 2010 Mycological Society of China.Item Synthesis and antimicrobial activities of two novel amino sugars derived from chloraloses(2010) Yenil N.; Ay E.; Ay K.; Oskay M.; Maddaluno J.The synthesis of 5-amino-5-deoxy-1,2-O-(S)-trichloroethylidene-β-l-arabinofuranose and 6-amino-6-deoxy-1,2-O-(S)-trichloroethylidene-α-d-glucofuranose is described by a simple three- or four-step route. Antibacterial potency of the new compounds was determined using an inhibition zone diameter test. The results show that these compounds have a broad-spectrum activity against Gram-positive, Gram-negative bacteria and Candida albicans. © 2010 Elsevier Ltd. All rights reserved.Item Determination of some chemical parameters and antimicrobial activity of traditional food: Mesir paste(2010) Oskay M.; Karaildirim T.; Ay E.; Ay K.The antimicrobial activities and some chemical properties of the traditional Turkish food called mesir paste were studied. Results of chemical analysis for moisture and volatiles, water-insoluble components, refractive index, soluble solids content, raw fiber, invert sugar, total ash, 5-hydroxymethylfurfural, acidity, and pH were calculated as 17.06%, 2.55%, 1.491, 80.2%, 0.70%, 40.54%, 0.13%, 44 mg/kg, 0.9% anhydrous citric acid, and 3.6, respectively. Mesir paste was extracted individually by six solvents with different polarity, and antimicrobial activities of each extracts were determined against 12 microbial strains, mostly food-borne, including pathogens, by the agar well diffusion method. All extracts obtained showed antimicrobial activity ranging from 8 mm to 40 mm, and the butanolic extract displayed stronger antimicrobial activity against all tested microorganisms; Gram-positive strains were found to be more sensitive than Gram-negative strains. Antimicrobial potency of n-butanol extracts of mesir paste was determined in term of minimal inhibitory concentration and minimal bactericidal concentration for the sensitive microorganisms. In addition, some commercial antibiotics such as ampicillin, gentamicin, and nystatin were used as positive controls to determine the sensitivity of the strains. © 2010, Mary Ann Liebert, Inc. and Korean Society of Food Science and Nutrition.Item Antimicrobial activity of selected plant spices marketed in the West Anatolia(2010) Keskin D.; Oskay D.; Oskay M.Herbs and spices are sources of many bioactive compounds that can improve the taste of foods as well as influence digestion and metabolism processes. The present study was performed to evaluate the antimicrobial activity of ten Turkish medicinal plant spices, used in the traditional system of medicine, against 10 pathogenic bacterial species and yeast, C. albicans, using the agar well diffusion method. Anti-candidal activity was detected in 8 plants. Extracts of Alchemilla vulgaris, Laurus nobilis, Melissa officinalis, Silybum marianum, Camellia sinensis (5a), Camellia sinensis (5b), Rosmarinus officinalis, Hibiscus sp. and Foeniculum vulgare showed broad-spectrum antimicrobial activity with inhibition zones ranging from 4 to 32 mm, except Erica vulgaris. The most resistant microorganisms were Escherichia coli and Salmonella typhimurium. The most susceptible organisms were Kocuria rhizophila and Candida albicans. Minimum Inhibitory Concentrations (MIC) of crude extracts were determined for the three highly active plants showing activity against Staphylococcus aureus, Escherichia coli; Kocuria rhizophila, Bacillus cereus, Enterococcus faecalis and Candida albicans. MICs of active extracts ranged from 2.92 to 10≤mg/mL against one or other test bacteria. © 2010 Friends Science Publishers.Item Thermoactive cellulase-free xylanase production from alkaliphilic Bacillus strains using various agro-residues and their potential in biobleaching of kraft pulp(2010) Azeri C.; Tamer A.U.; Oskay M.The four bacterial strains were isolated on media containing xylan and screened for xylanase activity. The bacterial strains (Ag12, Ag13, Ag20 and Ag32) were characterized based on morphological, biochemical and physiological characters and identified as belonging to the genus Bacillus. The effects of different factors such as pH (7.0 - 10.0), temperature (25.0 - 50.0 °C) and inexpensive agro-residues (wheat straw, wheat bran and corncob) on xylanase production of strains were studied under shake flask conditions. Maximal enzyme activities were obtained by cultivation in birch-wood xylan, but high enzyme production was also obtained on wheat straw and corncob when cultivated at pH 8.5. Under optimized fermentation conditions, no cellulolytic activity were detected on the crude extracts. The effects of temperature (40.0 - 80.0 °C), pH (6.0 - 10.0) and salt concentration (1.0, 5.0 and 10.0%) on the xylanases activity were determined. The maximum activity was obtained temperature 60.0 °C and pH at 9.0. The enzyme was stable at 60.0 °C for more than 60 min, suggesting that the xylanases of Bacillus strains are thermoactive and being of interests for biobleaching processes. The effectiveness of crude xylanases from the strains Ag12, Ag20 and Ag32 on kraft pulp were carried out at pH 9.0 at 60.0 °C. Biobleaching studies of kraft pulp with xylanases and its subsequent treatment with 1.0% EDTA (30 min at 50.0 °C) and peroxide (80 min at 70.0 °C), showed that the enzymes reduced the kappa number by 27.4, 61.7 and 75.3% and enhanced the brightness by 1.0, 1.5 and 3.0% from xylanases produced by strains Ag12, Ag20 and Ag32, respectively. These results suggest that the application of this xylanases to the paper and pulp industry may be very promising. © 2010 Academic Journals.Item Isolation and screening for antimicrobial activities of culturable mesophilic streptomyces strains from north cyprus soils(2010) Oskay M.; Tamer A.U.; Karaboz I.A total of 249 different Streptomyces strains were isolated from different sites of the North Cyprus habitats for their antimicrobial potential. Out of these, 66 isolates exhibited inhibitory activity against at least one of the tested microorganisms. Approximately, 51% isolates produced antibacterial substances against Gram-positive bacteria, 6% against Gram-negative bacteria, and 23% against both Gramnegative and Gram-positive bacteria, whereas 18% of isolates showed antifungal activity. According to the spectrum of broadness, the two most active isolates were selected, and designed as KGG13 and KVK11. A great variety of morphological, physiological and biochemical features of selected strains were determined for their taxonomie position, and obtained data strongly suggested that these strains belong to the genus Streptomyces, confirmed by their antimicrobial activity in batch culture. In order to standardize the antibiotic production, some cultural conditions, such as the effect of different temperatures, nature of carbon sources, pH value, and time incubation in h, were determined. The highest antimicrobial activities were obtained when glucose and glycerol at 1% (w/v) was used as sole carbon source, at pHs 7.3 and 7.5 for the strains KGG13 and KVK11, respectively. © by PSP.Item Isolation and purification of two metabolites (KGG32-A & KGG32-B) from a soil bacterium, Streptomyces sp., KGG32(2011) Oskay M.This research is concerned with the isolation, purification and partial characterization of two metabolites from culture filtrate of Streptomyces sp. KGG32, by solvent extraction, silica gel chromatography, UV and FT-IR spectroscopic analyses. This strain is a highly stable antimicrobial metabolite producer against different microorganisms such as S. aureus, B. cereus, B. subtilis, Kocuria rhizophila, E. coli, Enterococcus faecalis and C. albicans under in-vitro growth conditions. In order to obtain crude extract, ten liters of the fermentation broth was extracted with different solvents and concentrated until dryness. The crude extract was subjected to silica gel column chromatography and the fractions showing the highest antimicrobial activity were pooled and determined by TLC for purity. Extraction of fermentation broth, various separation and purification steps led to isolation of two pure active compounds having a retention factor of 0.22 (methanol: water, 3:1, v/v) and 0.64 (ethanol: water, 3:1, v/v), respectively. MIC values of the isolated compounds were found between 5.209-25.0 μg/mL. © 2011 Friends Science Publishers.Item Effects of some environmental conditions on biomass and antimicrobial metabolite production by Streptomyces Sp., KGG32(2011) Oskay M.The purpose of the present study was concerned with the taxonomy and influences of some cultural conditions on growth and antimicrobial metabolite production of a strain of Streptomyces, designated KGG32, which is a highly stable antimicrobial metabolite producer against the Gram-positive and Gram-negative bacteria under in-vitro growth conditions. In order to optimize the culture conditions for the production of antimicrobial metabolite, such as the effect of different temperatures, nature of carbon and nitrogen sources, pH value and time incubation were determined. Effects of nutritional compounds on production of antimicrobial compounds showed that the highest antimicrobial activities were obtained when sucrose at 1.0% (w/v) level was used as sole carbon source, under aerobic conditions at temperature 30°C, pH at 7.5. Bacteriological peptone was identified as nitrogen source that significantly affected antibiotic production followed by meat extract. Phenotypic characters of the strain strongly suggested that this strain belongs to the genus Streptomyces. The strain was grey colored with rectiflexibiles spore chains, exhibited resistance to neomycin, vancomycin and penicillin. It had the ability to produce enzymes such as caseinase amylase and xylanase. The results showed that strain KGG32 was a potential soil microorganism with antimicrobial activity and may be used for biotechnological purposes. © 2011 Friends Science Publishers.Item Antimicrobial and cytotoxic activities of Tripleurospermum parviflorum (Willd.) Pobed; [Tripleurospermum parviflorum (Willd.) Pobed.'in antimikrobiyal ve sitotoksik aktiviteleri](2013) Erdoǧan T.F.; Gönenç T.M.; Oskay M.The antimicrobial and cytotoxic activities of n-hexane, methanol, ethanol, ethyl acetate and water extracts of Tripleurospermum parviflorum (Willd.) Pobed. were evaluated in this study. The antimicrobial activities of the extracts were reported against Escherichia coli ATCC 29998, Escherichia coli ATCC 25922, Escherichia coli ATCC 11230, Staphylococcus aureus ATCC 6538P, Staphylococcus aureus ATCC 29213, Enterobacter cloacae ATCC 13047, Enterococcus faecalis ATCC 29212, Pseudomonas aeroginosa ATCC 27853 as bacteria and Candida albicans ATCC 10239 as yeastlike fungi by disc diffusion method. Cytotoxic activity of the extracts was tested in vitro against Brine shrimp. All of the extracts showed a range of activity against the tested bacteria and brine shrimp.Item Synthesis and characterization of chloralose-derived thiosemicarbazones and semicarbazones and investigation of their antimicrobial properties(Taylor and Francis Inc., 2014) Yetgin C.E.; Oskay M.; Ay K.Thiosemicarbazones(7-10)/semicarbazones(11-14) were synthesized in good yields via the condensation of α-gluco-, β-gluco-, galacto-, manno- chloralose derived 1,4-furanodialdoses (1-4) with thiosemicarbazide(5)/ semicarbazide(6). The structures of all products were characterized by FTIR, NMR spectroscopic methods and elemental analysis. The compounds have been found to display moderate antimicrobial activity against Gram-positive, Gram-negative bacteria and antifungal activity against a Candida albicans. MIC values of the compounds range from 260 to 1510 g/mL. © 2014 Taylor & Francis Group, LLC.Item Synthesis, structure, electrochemical and antimicrobial properties of N,N′-bis(ferrocenylmethyl)imidazolinium salts(Elsevier S.A., 2014) Özbek H.A.; Aktaş P.S.; Daran J.-C.; Oskay M.; Demirhan F.; Çetinkaya B.The N,N′-bis(ferrocenylmethyl)imidazolinium chloride (3) and bromide (4) were prepared by reaction of N,N'-bis(ferrocenylmethyl)ethylenediamine (2) with NH4X (X = Cl, Br). The N,N′-bis(ferrocenylmethyl)imidazolinium tetrafluoroborate (6) was obtained in two steps from compound (2). The first step involves the synthesis of N,N′-bis(ferrocenylmethyl)imidazolidine (5) by condensation of (2) with aqueous formaldehyde. Compound (5) was successfully converted to the N,N′-bis(ferrocenylmethyl)imidazolinium tetrafluoroborate (6) by treatment with tritylium tetrafluoroborate. The new compounds were characterized by 1H and 13C NMR, IR and elemental analysis techniques which support the proposed structures. The X-ray crystal structure of the N,N′-bis(ferrocenylmethyl)imidazolidine (5) shows two ferrocenyl moieties bridged by an imidazolidine ring. The electrochemical properties were determined by cyclic voltammetry for all compounds. The compounds were screened for their in vitro antimicrobial activities against the Gram-positive, Gram-negative bacteria and antifungal activity against a Candida albicans. (3), (4), (6) show significant antimicrobial activity and theirs MIC values ranged from 169 to 520 μg/mL. © 2014 Elsevier B.V. All rights reserved.Item Screening of yeast strains for pectinolytic activity: Effects of different carbon and nitrogen sources in submerged fermentations(Science Publications, 2015) Oskay M.; Yalçin H.T.Twenty yeast strains were screened for pectinolytic activity, among the strains, only nine were positive for pectinase production. The best strain was Kluyveromyces marxianus NRRL-Y-1109 which gave high quantities of pectinase activity, by submerged fermentation. Different parameters such as incubation time, pH (3.5-7), temperature (20-45°C), nitrogen and carbon source, were optimized. The optimal incubation time, temperature and pH for pectinase production were found to be 48 h, 30°C and 6, respectively. Studies were conducted on the production of pectinase in submerged fermentation using agro-industrial residues such as wheat bran, grape waste, brewer's malt, beet molasses and corncob at a concentration of 1.5% (wt./vol.). Under optimized fermentation conditions, maximal enzyme were produced when citrus pectin (4.8 U/mL) was used as the carbon source, but high enzyme production was also obtained on wheat bran (2.2 U/mL) and grape waste (1.8 U/mL) in shaking conditions (120 rpm) for 48 h. Peptone and yeast extract used together as nitrogen source gave best enzyme production. The effects of temperature (30-70°C), pH (3.5-8) and salt concentration (1, 2, 5 and 10%) on the pectinase activity were determined. The optimum activity was obtained when temperature 45°C and pH at 5.5. The enzyme was stable at 45°C for more than 50 min, suggesting that it is relatively thermostable and being of interests for food processing. © 2015 Mustafa Oskay and Hüsniye Tansel Yalçin.