Aquaculture, a rapidly growing sector of agriculture globally, faces various challenges that impe... more Aquaculture, a rapidly growing sector of agriculture globally, faces various challenges that impede its production growth. Among these challenges, fish diseases caused by a diverse range of infectious organisms pose a significant concern, leading to substantial economic losses for farmers (Francis-Floyd, 2005; Alfred et al., 2020; Assefa and Abunna, 2018). Bacterial infections pose a significant threat to both wild and aquaculture-reared fish. In the aquatic environment, bacteria are commonly present as part of the normal flora, and they typically do not cause disease unless fish are exposed to unfavorable environmental conditions and inadequate husbandry techniques (Tendencia and Lavilla-Pitogo, 2004). Pseudomoniasis, also known as Pseudomonas septicemia or Pseudomonas infection, is a bacterial disease caused by various species within the genus Pseudomonas.
In the present study, production of rhamnolipid biosurfactant by Pseudomonas aeruginosa OG1 was s... more In the present study, production of rhamnolipid biosurfactant by Pseudomonas aeruginosa OG1 was statistically optimized by response surface methodology. Box-Behnken design was applied to determine the optimal concentrations of 52, 9.2, and 4.5 g/L for carbon source (waste frying oil), nitrogen source (chicken feather peptone), and KH 2 PO 4 , respectively, in production medium. Under the optimized cultivation conditions, rhamnolipid production reached up to 13.31 g/L (with an emulsification activity of 80%), which is approximately twofold higher than the yield obtained from preliminary cultivations. Hence, rhamnolipid production, noteworthy in the literature, was achieved with the use of statistical optimization on inexpensive waste materials for the first time in the present study. Keywords Rhamnolipid Á Pseudomonas aeruginosa Á Waste frying oil Á Chicken feather peptone Á Response surface methodology Á Box-Behnken design Electronic supplementary material The online version of this article (
Yüzüncü yıl üniversitesi fen bilimleri enstitüsü dergisi, Mar 15, 2023
Nanoparticles (NPs) are tiny materials ranging in size from 1 to 100 nm and have unique magnetic,... more Nanoparticles (NPs) are tiny materials ranging in size from 1 to 100 nm and have unique magnetic, electrical, and optical characteristics differing from bulk materials. They have a broad spectrum of applications in different industries. Several physical and chemical techniques have been applied to produce metal NPs. Alternatively, green synthesis offers an environmentally friendly and simple means for NP preparation. In the present study, silver NPs were produced by the Pseudomonas aeruginosa OG1 strain. Characterization of NPs was performed by TEM, SEM, and XRD. These NPs were used against pathogenic Proteus mirabilis, which shows high-level urease activity and forms clear biofilms. Silver NPs obtained in the present study were applied to inhibit the growth, urease production, and biofilm formation of P. mirabilis. Growth inhibition zones of 9 mm and 11 mm and, 60 % and 85% antibiofilm effects were obtained by 100 µg mL-1 and 200 µg mL-1 NPs, respectively. The urease activity of P. mirabilis was completely inhibited in both concentrations. These results show that AgNPs can be used as effective antimicrobial, antibiofilm, and antiurease agents in the fight against pathogens.
Pseudomonas aeruginosa is a Gram-negative, opportunistic bacterium and is one of the most biotech... more Pseudomonas aeruginosa is a Gram-negative, opportunistic bacterium and is one of the most biotechnologically important microorganisms. P. aeruginosa secretes an extracellular secondary metabolite known as pyocyanin, which is highly functional. In this study, the effects of toluene on pyocyanin production in the presence of different carbon sources in submerged culture of P. aeruginosa OG1 were investigated. It was determined that the addition of toluene to all carbon sources increased the production of pyocyanin. Maximum pyocyanin production was achieved when glycerol was used as the sole carbon source. With the addition of toluene, pyocyanin production generally increased, but bacterial biomass decreased. In addition, when glucose was used as the carbon source, the final pH decreased more than the other carbon sources. This study revealed that the addition of toluene to the fermentation medium significantly increased the production of pyocyanin in the presence of different carbon sources. These findings support that the solvent assisted fermentation strategy can be used in microbial fermentations to increase the production of industrially important biotechnological products such as pigments.
Iğdır Üniversitesi Fen Bilimleri Enstitüsü Dergisi, Sep 1, 2021
ÖZET: Aeromonas caviae LipT51'den ekstrasellüler termo-alkali lipaz üretimi, tepki yüzey metodu (... more ÖZET: Aeromonas caviae LipT51'den ekstrasellüler termo-alkali lipaz üretimi, tepki yüzey metodu (response surface methodology: RSM) ile istatistiksel olarak optimize edilmiştir. İlk olarak, en yüksek lipaz üretimi için farklı karbon (zeytinyağı, tributirin, ayçiçek yağı, atık kızartma yağı, gliserol, Tween 80, Tween 20, palmiye yağı ve Triton X100) ve azot (pepton, maya özütü, tripton, peynir altı suyu, üre, NaNO2, NH4NO3) kaynaklarını taramak üzere tek seferde bir faktör yöntemi uygulandı. Ardından, karbon kaynağı olarak seçilen atık kızartma yağı, azot kaynağı olarak seçilen tripton ve başlangıç pH'sı için optimum değerler Box-Behnken tasarımı (BBD) kullanılarak RSM ile belirlenmiştir. Lipaz üretimi için BBD'nin ikinci dereceden modeli istatistiksel olarak anlamlı ve güvenilir bulundu (p <0.0001, R 2 = 0.9881). Maksimum lipaz üretimi (1.6 U mL-1) için doğrulanmış optimum koşullar, % 1.13 atık kızartma yağı, % 1.5 tripton ve pH 7.9 olarak belirlenmiştir. İlk kez bu çalışmada, bir A. caviae suşundan lipaz üretiminin optimizasyonu, ucuz atık malzeme kullanılarak optimize edilmiş kültür koşulları altında gerçekleştirildi. Deterjan aktivitesi ile değerli olduğu bilinen lipaz enziminin üretim verimliliği, optimize edilmeyen koşullara göre 2.7 kat arttı.
INTERNATIONAL CONFERENCE ON ADVANCES IN NATURAL AND APPLIED SCIENCES: ICANAS 2016, 2016
Recently, advanced oxidation processes have gained significant interest for bacterial inactivatio... more Recently, advanced oxidation processes have gained significant interest for bacterial inactivation. In the present study, the efficacy of sonolysis, photocatalysis and sonophotocatalysis was evaluated for disinfection of Escherichia coli O157:H7 strain. Sonophotocatalysis proved to be the most effective disinfection methods by generating greater amount of •OH radical.
Preparative Biochemistry & Biotechnology, Nov 11, 2022
This study aimed to determine the ability of bacteria to produce the chitinase enzyme, purify and... more This study aimed to determine the ability of bacteria to produce the chitinase enzyme, purify and characterize the enzyme from the isolate with the best activity, and determine the use of this puri ed enzyme as a biocontrol agent. The chitinolytic bacterium was identi ed as Stenotrophomonas maltophilia. The chitinase enzyme was puri ed 1.4 times at a 30% ammonium sulfate concentration with a yield of 40.7%. Following partial puri cation, the enzyme was puri ed by ion-exchange chromatography using HiPrep Q XL 16/10 column and HiPrep ™ 26/10 desalting column with 25.34% and 18.12% yields, respectively. The molecular weight of the puri ed enzyme was calculated as 52 kDa by SDS-PAGE. The optimum temperature of the enzyme was determined to be 50°C, and the optimum pH was 7.0. While Fe 2+ most induced the activity, it was most inhibited by Zn 2+ at a 5 mM concentration. K m and V max values of the enzyme for colloidal chitin were calculated as 1.6419 mg/ml and 16.129 U/mg, respectively. The puri ed chitinase was used as a biocontrol agent against the fungus Fusarium oxysporum and potato beetle Leptinotarsa decemlineata. The enzyme was shown to be effective in reducing the growth of fungus and causing disruption of the chitin structure of potato beetle.
Recently, the rapid increase in antibiotic-resistant pathogens has caused serious health problems... more Recently, the rapid increase in antibiotic-resistant pathogens has caused serious health problems. Researchers are searching for alternative antimicrobial substances to control or prevent infections caused by pathogens. Different strategies are used to develop effective antibacterial agents, and in this respect, nanoparticles are undoubtedly promising materials. Nanoparticles act by bypassing drug resistance mechanisms in bacteria and inhibiting biofilm formation or other important processes related to their virulence potential. Nanoparticles can penetrate the cell wall and membrane of bacteria and act by disrupting important molecular mechanisms. In combination with appropriate antibiotics, NPs may show synergy and help prevent the developing global bacterial resistance crisis. Furthermore, due to characteristics such as enhanced biocompatibility and biodegradability, polymer-based nanoparticles enable the development of a wide range of medical products. Antibacterial applications of nanoparticles range from antimicrobial synthetic textiles to biomedical and surgical devices when nanoparticles are embedded/loaded/coated into different materials. In this review, the antibacterial mechanisms of nanoparticles and their potential for use in the medical field are discussed.
Lipase producer bacterium isolated from Erzurum was identified as Aeromonas caviae LipT51 (GenBan... more Lipase producer bacterium isolated from Erzurum was identified as Aeromonas caviae LipT51 (GenBank ID: MN818567.1) by 16S rDNA sequencing and conventional methods. Extracellular lipase was purified by ammonium sulphate precipitation, centrifugal filtration, and anion-exchange chromatography resulting in 6.1-fold purification with 28% final yield. Molecular weight was 31.6 kDa on SDS-PAGE. Lipase was stable over a broad range of pH (6-11) and temperature (25-70 °C), and showed optimum activity at pH 9 and 60 °C. Km and Vmax for pNPP hydrolysis were 0.88 mM and 34.2 U/mg protein, respectively. Ba2+, Ca2+, Co2+, Cu2+, Fe3+, and Mg2+ increased activity, while Mn2+, Mo2+, Ni2+, Zn2+, and other additives partially decreased. Activity and stability increased with laundry detergent and slightly decreased with handwash and dishwashing detergents. Alkaline and thermostable lipase from newly isolated A. caviae has been shown for the first time to be remarkably compatible with laundry detergent and improve washing performance by enhanced oil-stain removal.
Biocatalysis and agricultural biotechnology, Nov 1, 2019
Pseudomonas aeruginosa is capable of producing a wide range of industrially important biotechnolo... more Pseudomonas aeruginosa is capable of producing a wide range of industrially important biotechnological products like pigment, biosurfactants, enzymes, etc. Pyocyanin is a pigment produced by P. aeruginosa and widely used in many industries such as food, agriculture, pharmaceuticals and cosmetics. In order to increase the production of pyocyanin, in this study, the effects of previously untested oxygen vectors on P. aeruginosa OG1 pyocyanin production were studied. The oxygen vectors (n-hexadecane, n-dodecane and n-hexane) were compared in terms of pyocyanin production. All of the oxygen vectors were found to exhibit a stimulatory effect on pyocyanin production and the best result (11.96 mg/L) was obtained with n-hexane. In the next step, pyocyanin production in the presence of n-hexane, was optimized by response surface methodology. In addition to the n-hexane concentration, the optimum size of inoculum and the time of n-hexane addition to the fermentation liquid were investigated. Experimental design and the results were analysed by using Box-Behnken design of Response Surface Methodology (RSM). Accordingly, the optimum size of inoculum was found to be 2.07%, n-hexane concentration was 3.48% and the addition time was 33.93 h and at these optimum values, the amount of pyocyanin increased 2-fold (21.2 mg/L). According to these results, n-hexane addition as an oxygen carrier could be a useful technique in industrial production of pyocyanin.
The antibiotic resistance of pathogenic microorganisms has become a worldwide concern to public h... more The antibiotic resistance of pathogenic microorganisms has become a worldwide concern to public health. To overcome the current resistance problem, new antimicrobial agents are extremely needed. The aim of the present study was to evaluate the antibacterial activity of Satureja hortensis essential oils against seven clinical pathogens. Chemical compositions of hydro distillated essential oils from S. hortensis were analyzed by GS-MS. The antibacterial activity was investigated against Corynebacterium diphtheria, Salmonella typhimurium, Serratia plymuthica Yersinia enterocolitica, Y. frederiksenii, Y. pseudotuberculosis and Vibrio cholerae by the use of disc diffusion method and broth micro dilution method. The minimum inhibitory concentration (MIC) values of essential oils were found as low as 7.81 µg/mL. Notably, essential oils of S. hortensis exhibited remarkable antimicrobial activities against the tested clinical pathogens. The results indicate that these essential oils can be used in treatment of dif...
Surfactants are surface active agents that reduce the surface tension between immiscible phases. ... more Surfactants are surface active agents that reduce the surface tension between immiscible phases. They are amphiphilic molecules which can be produced by chemical and biological methods. Compared with chemical surfactants with the same functionality, biosurfactants have advantages such as being able to operate under extreme temperature, pH and salinity conditions, being non-toxic or very low toxic and biodegradable. In addition, since they are of biological origin, they can be produced from renewable substrates and structurally modified by genetic engineering and biochemical methods, and they can reach different markets with innovative formulations. Recently, interest in biological surfactants has increased considerably. With their unique physicochemical properties and various biological activities, they have application areas in detergent, cosmetics, medicine, food, bioremediation and agriculture sectors. However, despite the huge market demand, the production of biosurfactants is not as competitive as their synthetic counterparts. In order to improve biosurfactant production, different parameters should be considered. In this review, the types of biosurfactants and the factors affecting microbial biosurfactant production are discussed.
β-carotene is a commercially important natural pigment and has been widely applied in the medicin... more β-carotene is a commercially important natural pigment and has been widely applied in the medicine, pharmaceutical, food, feed and cosmetic industries. The current study aimed to investigate the usability of molasses for β-carotene production by Arthrobacter agilis A17 (KP318146) and to optimize the production process. Box-Behnken Design of Response Surface Methodology was used to determine the optimum levels and the interactions of three independent variables namely molasses, yeast extract and KH2PO4 at three different levels. β-carotene yield in optimized medium containing 70 g/l molasses, 25 g/l yeast extract and 0.96 g/l KH2PO4, reached up to 100 mg/l, which is approximately 2.5-fold higher than the yield, obtained from control cultivation. A remarkable β-carotene production on inexpensive carbon source was achieved with the use of statistical optimization.
Abstract Biosurfactants are surface-active amphiphilic compounds produced mostly on microbial cel... more Abstract Biosurfactants are surface-active amphiphilic compounds produced mostly on microbial cell surfaces or excreted extracellularly. Because of their ability to reduce surface and interface tension, biosurfactants have been used as emulsifiers, wetting agents, dispersing agents, detergents, and foaming agents and therefore have received more attention recently. The main concerns in using biosurfactants as an alternative to synthetic counterparts are high production costs and low yields. Many application areas, such as bioremediation and oil recovery, require large quantities of biosurfactants. Accordingly, the production process must be efficient and economical. Improving the production process relies on many strategies such as the use of inexpensive raw materials, optimization of cultivation conditions, and screening for overexpressing strains. Yet, the most important point is to scale-up the production by using bioreactors. Efficient scale-up from laboratory to industrial production requires compliance with some parameters. The most prominent parameters for efficient microbial growth and biosurfactant production are the choice of high-yielding microorganisms, adequate inoculum size, cheap carbon and nitrogen sources, and appropriate C/N ratio in the medium. Sufficient aeration and agitation, favorable temperature and pH controls, use of antifoaming agents are other crucial factors affecting the overall yield of biosurfactant production in bioreactors.
Chitin, a linear polymer of β-1,4-N-acetylglucosamine units, is one of the most abundant biopolym... more Chitin, a linear polymer of β-1,4-N-acetylglucosamine units, is one of the most abundant biopolymers widely distributed in the marine and terrestrial environments. It is found as a structural component of insects, crustaceans and the cell walls of fungi. Chitinases, the enzymes degrading chitin by cleaving the β-(1-4) bond, have gained increased attention due to their wide range of biotechnological applications, especially for biocontrol of harmful insects and phytopathogenic fungi in agriculture. In the present study, 200 bacterial isolates from Western Anatolia Region of Turkey were screened for chitinolytic activity on agar media amended with colloidal chitin. Based on the chitin hydrolysis zone, 13 isolates were selected for further study. Bacterial isolates with the highest chitinase activity were identified as Acinetobacter calcoaceticus, Arthrobacter oxydans, Bacillus cereus, Bacillus megaterium, Brevibacillus reuszeri, Kocuria erythromyxa, Kocuria rosea, Novosphingobium capsulatum, Rhodococcus bratislaviensis, Rhodococcus fascians and Staphylococcus cohnii by MIS and BIOLOG systems. The next aims of the study are to compare the productivity of these bacteria quantitatively, to purify the enzyme from the most potent producer and to apply the pure enzyme for the fight against the phytopathogenic fungi and harmful insects.
Aquaculture, a rapidly growing sector of agriculture globally, faces various challenges that impe... more Aquaculture, a rapidly growing sector of agriculture globally, faces various challenges that impede its production growth. Among these challenges, fish diseases caused by a diverse range of infectious organisms pose a significant concern, leading to substantial economic losses for farmers (Francis-Floyd, 2005; Alfred et al., 2020; Assefa and Abunna, 2018). Bacterial infections pose a significant threat to both wild and aquaculture-reared fish. In the aquatic environment, bacteria are commonly present as part of the normal flora, and they typically do not cause disease unless fish are exposed to unfavorable environmental conditions and inadequate husbandry techniques (Tendencia and Lavilla-Pitogo, 2004). Pseudomoniasis, also known as Pseudomonas septicemia or Pseudomonas infection, is a bacterial disease caused by various species within the genus Pseudomonas.
In the present study, production of rhamnolipid biosurfactant by Pseudomonas aeruginosa OG1 was s... more In the present study, production of rhamnolipid biosurfactant by Pseudomonas aeruginosa OG1 was statistically optimized by response surface methodology. Box-Behnken design was applied to determine the optimal concentrations of 52, 9.2, and 4.5 g/L for carbon source (waste frying oil), nitrogen source (chicken feather peptone), and KH 2 PO 4 , respectively, in production medium. Under the optimized cultivation conditions, rhamnolipid production reached up to 13.31 g/L (with an emulsification activity of 80%), which is approximately twofold higher than the yield obtained from preliminary cultivations. Hence, rhamnolipid production, noteworthy in the literature, was achieved with the use of statistical optimization on inexpensive waste materials for the first time in the present study. Keywords Rhamnolipid Á Pseudomonas aeruginosa Á Waste frying oil Á Chicken feather peptone Á Response surface methodology Á Box-Behnken design Electronic supplementary material The online version of this article (
Yüzüncü yıl üniversitesi fen bilimleri enstitüsü dergisi, Mar 15, 2023
Nanoparticles (NPs) are tiny materials ranging in size from 1 to 100 nm and have unique magnetic,... more Nanoparticles (NPs) are tiny materials ranging in size from 1 to 100 nm and have unique magnetic, electrical, and optical characteristics differing from bulk materials. They have a broad spectrum of applications in different industries. Several physical and chemical techniques have been applied to produce metal NPs. Alternatively, green synthesis offers an environmentally friendly and simple means for NP preparation. In the present study, silver NPs were produced by the Pseudomonas aeruginosa OG1 strain. Characterization of NPs was performed by TEM, SEM, and XRD. These NPs were used against pathogenic Proteus mirabilis, which shows high-level urease activity and forms clear biofilms. Silver NPs obtained in the present study were applied to inhibit the growth, urease production, and biofilm formation of P. mirabilis. Growth inhibition zones of 9 mm and 11 mm and, 60 % and 85% antibiofilm effects were obtained by 100 µg mL-1 and 200 µg mL-1 NPs, respectively. The urease activity of P. mirabilis was completely inhibited in both concentrations. These results show that AgNPs can be used as effective antimicrobial, antibiofilm, and antiurease agents in the fight against pathogens.
Pseudomonas aeruginosa is a Gram-negative, opportunistic bacterium and is one of the most biotech... more Pseudomonas aeruginosa is a Gram-negative, opportunistic bacterium and is one of the most biotechnologically important microorganisms. P. aeruginosa secretes an extracellular secondary metabolite known as pyocyanin, which is highly functional. In this study, the effects of toluene on pyocyanin production in the presence of different carbon sources in submerged culture of P. aeruginosa OG1 were investigated. It was determined that the addition of toluene to all carbon sources increased the production of pyocyanin. Maximum pyocyanin production was achieved when glycerol was used as the sole carbon source. With the addition of toluene, pyocyanin production generally increased, but bacterial biomass decreased. In addition, when glucose was used as the carbon source, the final pH decreased more than the other carbon sources. This study revealed that the addition of toluene to the fermentation medium significantly increased the production of pyocyanin in the presence of different carbon sources. These findings support that the solvent assisted fermentation strategy can be used in microbial fermentations to increase the production of industrially important biotechnological products such as pigments.
Iğdır Üniversitesi Fen Bilimleri Enstitüsü Dergisi, Sep 1, 2021
ÖZET: Aeromonas caviae LipT51'den ekstrasellüler termo-alkali lipaz üretimi, tepki yüzey metodu (... more ÖZET: Aeromonas caviae LipT51'den ekstrasellüler termo-alkali lipaz üretimi, tepki yüzey metodu (response surface methodology: RSM) ile istatistiksel olarak optimize edilmiştir. İlk olarak, en yüksek lipaz üretimi için farklı karbon (zeytinyağı, tributirin, ayçiçek yağı, atık kızartma yağı, gliserol, Tween 80, Tween 20, palmiye yağı ve Triton X100) ve azot (pepton, maya özütü, tripton, peynir altı suyu, üre, NaNO2, NH4NO3) kaynaklarını taramak üzere tek seferde bir faktör yöntemi uygulandı. Ardından, karbon kaynağı olarak seçilen atık kızartma yağı, azot kaynağı olarak seçilen tripton ve başlangıç pH'sı için optimum değerler Box-Behnken tasarımı (BBD) kullanılarak RSM ile belirlenmiştir. Lipaz üretimi için BBD'nin ikinci dereceden modeli istatistiksel olarak anlamlı ve güvenilir bulundu (p <0.0001, R 2 = 0.9881). Maksimum lipaz üretimi (1.6 U mL-1) için doğrulanmış optimum koşullar, % 1.13 atık kızartma yağı, % 1.5 tripton ve pH 7.9 olarak belirlenmiştir. İlk kez bu çalışmada, bir A. caviae suşundan lipaz üretiminin optimizasyonu, ucuz atık malzeme kullanılarak optimize edilmiş kültür koşulları altında gerçekleştirildi. Deterjan aktivitesi ile değerli olduğu bilinen lipaz enziminin üretim verimliliği, optimize edilmeyen koşullara göre 2.7 kat arttı.
INTERNATIONAL CONFERENCE ON ADVANCES IN NATURAL AND APPLIED SCIENCES: ICANAS 2016, 2016
Recently, advanced oxidation processes have gained significant interest for bacterial inactivatio... more Recently, advanced oxidation processes have gained significant interest for bacterial inactivation. In the present study, the efficacy of sonolysis, photocatalysis and sonophotocatalysis was evaluated for disinfection of Escherichia coli O157:H7 strain. Sonophotocatalysis proved to be the most effective disinfection methods by generating greater amount of •OH radical.
Preparative Biochemistry & Biotechnology, Nov 11, 2022
This study aimed to determine the ability of bacteria to produce the chitinase enzyme, purify and... more This study aimed to determine the ability of bacteria to produce the chitinase enzyme, purify and characterize the enzyme from the isolate with the best activity, and determine the use of this puri ed enzyme as a biocontrol agent. The chitinolytic bacterium was identi ed as Stenotrophomonas maltophilia. The chitinase enzyme was puri ed 1.4 times at a 30% ammonium sulfate concentration with a yield of 40.7%. Following partial puri cation, the enzyme was puri ed by ion-exchange chromatography using HiPrep Q XL 16/10 column and HiPrep ™ 26/10 desalting column with 25.34% and 18.12% yields, respectively. The molecular weight of the puri ed enzyme was calculated as 52 kDa by SDS-PAGE. The optimum temperature of the enzyme was determined to be 50°C, and the optimum pH was 7.0. While Fe 2+ most induced the activity, it was most inhibited by Zn 2+ at a 5 mM concentration. K m and V max values of the enzyme for colloidal chitin were calculated as 1.6419 mg/ml and 16.129 U/mg, respectively. The puri ed chitinase was used as a biocontrol agent against the fungus Fusarium oxysporum and potato beetle Leptinotarsa decemlineata. The enzyme was shown to be effective in reducing the growth of fungus and causing disruption of the chitin structure of potato beetle.
Recently, the rapid increase in antibiotic-resistant pathogens has caused serious health problems... more Recently, the rapid increase in antibiotic-resistant pathogens has caused serious health problems. Researchers are searching for alternative antimicrobial substances to control or prevent infections caused by pathogens. Different strategies are used to develop effective antibacterial agents, and in this respect, nanoparticles are undoubtedly promising materials. Nanoparticles act by bypassing drug resistance mechanisms in bacteria and inhibiting biofilm formation or other important processes related to their virulence potential. Nanoparticles can penetrate the cell wall and membrane of bacteria and act by disrupting important molecular mechanisms. In combination with appropriate antibiotics, NPs may show synergy and help prevent the developing global bacterial resistance crisis. Furthermore, due to characteristics such as enhanced biocompatibility and biodegradability, polymer-based nanoparticles enable the development of a wide range of medical products. Antibacterial applications of nanoparticles range from antimicrobial synthetic textiles to biomedical and surgical devices when nanoparticles are embedded/loaded/coated into different materials. In this review, the antibacterial mechanisms of nanoparticles and their potential for use in the medical field are discussed.
Lipase producer bacterium isolated from Erzurum was identified as Aeromonas caviae LipT51 (GenBan... more Lipase producer bacterium isolated from Erzurum was identified as Aeromonas caviae LipT51 (GenBank ID: MN818567.1) by 16S rDNA sequencing and conventional methods. Extracellular lipase was purified by ammonium sulphate precipitation, centrifugal filtration, and anion-exchange chromatography resulting in 6.1-fold purification with 28% final yield. Molecular weight was 31.6 kDa on SDS-PAGE. Lipase was stable over a broad range of pH (6-11) and temperature (25-70 °C), and showed optimum activity at pH 9 and 60 °C. Km and Vmax for pNPP hydrolysis were 0.88 mM and 34.2 U/mg protein, respectively. Ba2+, Ca2+, Co2+, Cu2+, Fe3+, and Mg2+ increased activity, while Mn2+, Mo2+, Ni2+, Zn2+, and other additives partially decreased. Activity and stability increased with laundry detergent and slightly decreased with handwash and dishwashing detergents. Alkaline and thermostable lipase from newly isolated A. caviae has been shown for the first time to be remarkably compatible with laundry detergent and improve washing performance by enhanced oil-stain removal.
Biocatalysis and agricultural biotechnology, Nov 1, 2019
Pseudomonas aeruginosa is capable of producing a wide range of industrially important biotechnolo... more Pseudomonas aeruginosa is capable of producing a wide range of industrially important biotechnological products like pigment, biosurfactants, enzymes, etc. Pyocyanin is a pigment produced by P. aeruginosa and widely used in many industries such as food, agriculture, pharmaceuticals and cosmetics. In order to increase the production of pyocyanin, in this study, the effects of previously untested oxygen vectors on P. aeruginosa OG1 pyocyanin production were studied. The oxygen vectors (n-hexadecane, n-dodecane and n-hexane) were compared in terms of pyocyanin production. All of the oxygen vectors were found to exhibit a stimulatory effect on pyocyanin production and the best result (11.96 mg/L) was obtained with n-hexane. In the next step, pyocyanin production in the presence of n-hexane, was optimized by response surface methodology. In addition to the n-hexane concentration, the optimum size of inoculum and the time of n-hexane addition to the fermentation liquid were investigated. Experimental design and the results were analysed by using Box-Behnken design of Response Surface Methodology (RSM). Accordingly, the optimum size of inoculum was found to be 2.07%, n-hexane concentration was 3.48% and the addition time was 33.93 h and at these optimum values, the amount of pyocyanin increased 2-fold (21.2 mg/L). According to these results, n-hexane addition as an oxygen carrier could be a useful technique in industrial production of pyocyanin.
The antibiotic resistance of pathogenic microorganisms has become a worldwide concern to public h... more The antibiotic resistance of pathogenic microorganisms has become a worldwide concern to public health. To overcome the current resistance problem, new antimicrobial agents are extremely needed. The aim of the present study was to evaluate the antibacterial activity of Satureja hortensis essential oils against seven clinical pathogens. Chemical compositions of hydro distillated essential oils from S. hortensis were analyzed by GS-MS. The antibacterial activity was investigated against Corynebacterium diphtheria, Salmonella typhimurium, Serratia plymuthica Yersinia enterocolitica, Y. frederiksenii, Y. pseudotuberculosis and Vibrio cholerae by the use of disc diffusion method and broth micro dilution method. The minimum inhibitory concentration (MIC) values of essential oils were found as low as 7.81 µg/mL. Notably, essential oils of S. hortensis exhibited remarkable antimicrobial activities against the tested clinical pathogens. The results indicate that these essential oils can be used in treatment of dif...
Surfactants are surface active agents that reduce the surface tension between immiscible phases. ... more Surfactants are surface active agents that reduce the surface tension between immiscible phases. They are amphiphilic molecules which can be produced by chemical and biological methods. Compared with chemical surfactants with the same functionality, biosurfactants have advantages such as being able to operate under extreme temperature, pH and salinity conditions, being non-toxic or very low toxic and biodegradable. In addition, since they are of biological origin, they can be produced from renewable substrates and structurally modified by genetic engineering and biochemical methods, and they can reach different markets with innovative formulations. Recently, interest in biological surfactants has increased considerably. With their unique physicochemical properties and various biological activities, they have application areas in detergent, cosmetics, medicine, food, bioremediation and agriculture sectors. However, despite the huge market demand, the production of biosurfactants is not as competitive as their synthetic counterparts. In order to improve biosurfactant production, different parameters should be considered. In this review, the types of biosurfactants and the factors affecting microbial biosurfactant production are discussed.
β-carotene is a commercially important natural pigment and has been widely applied in the medicin... more β-carotene is a commercially important natural pigment and has been widely applied in the medicine, pharmaceutical, food, feed and cosmetic industries. The current study aimed to investigate the usability of molasses for β-carotene production by Arthrobacter agilis A17 (KP318146) and to optimize the production process. Box-Behnken Design of Response Surface Methodology was used to determine the optimum levels and the interactions of three independent variables namely molasses, yeast extract and KH2PO4 at three different levels. β-carotene yield in optimized medium containing 70 g/l molasses, 25 g/l yeast extract and 0.96 g/l KH2PO4, reached up to 100 mg/l, which is approximately 2.5-fold higher than the yield, obtained from control cultivation. A remarkable β-carotene production on inexpensive carbon source was achieved with the use of statistical optimization.
Abstract Biosurfactants are surface-active amphiphilic compounds produced mostly on microbial cel... more Abstract Biosurfactants are surface-active amphiphilic compounds produced mostly on microbial cell surfaces or excreted extracellularly. Because of their ability to reduce surface and interface tension, biosurfactants have been used as emulsifiers, wetting agents, dispersing agents, detergents, and foaming agents and therefore have received more attention recently. The main concerns in using biosurfactants as an alternative to synthetic counterparts are high production costs and low yields. Many application areas, such as bioremediation and oil recovery, require large quantities of biosurfactants. Accordingly, the production process must be efficient and economical. Improving the production process relies on many strategies such as the use of inexpensive raw materials, optimization of cultivation conditions, and screening for overexpressing strains. Yet, the most important point is to scale-up the production by using bioreactors. Efficient scale-up from laboratory to industrial production requires compliance with some parameters. The most prominent parameters for efficient microbial growth and biosurfactant production are the choice of high-yielding microorganisms, adequate inoculum size, cheap carbon and nitrogen sources, and appropriate C/N ratio in the medium. Sufficient aeration and agitation, favorable temperature and pH controls, use of antifoaming agents are other crucial factors affecting the overall yield of biosurfactant production in bioreactors.
Chitin, a linear polymer of β-1,4-N-acetylglucosamine units, is one of the most abundant biopolym... more Chitin, a linear polymer of β-1,4-N-acetylglucosamine units, is one of the most abundant biopolymers widely distributed in the marine and terrestrial environments. It is found as a structural component of insects, crustaceans and the cell walls of fungi. Chitinases, the enzymes degrading chitin by cleaving the β-(1-4) bond, have gained increased attention due to their wide range of biotechnological applications, especially for biocontrol of harmful insects and phytopathogenic fungi in agriculture. In the present study, 200 bacterial isolates from Western Anatolia Region of Turkey were screened for chitinolytic activity on agar media amended with colloidal chitin. Based on the chitin hydrolysis zone, 13 isolates were selected for further study. Bacterial isolates with the highest chitinase activity were identified as Acinetobacter calcoaceticus, Arthrobacter oxydans, Bacillus cereus, Bacillus megaterium, Brevibacillus reuszeri, Kocuria erythromyxa, Kocuria rosea, Novosphingobium capsulatum, Rhodococcus bratislaviensis, Rhodococcus fascians and Staphylococcus cohnii by MIS and BIOLOG systems. The next aims of the study are to compare the productivity of these bacteria quantitatively, to purify the enzyme from the most potent producer and to apply the pure enzyme for the fight against the phytopathogenic fungi and harmful insects.
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Papers by Sumeyra Gurkok