Selcuk Hazir - Academia.edu (original) (raw)

Papers by Selcuk Hazir

Viral diseases like yellow fever, dengue, zika have an alarming impact on public health affecting... more Viral diseases like yellow fever, dengue, zika have an alarming impact on public health affecting millions of people around the globe. These diseases can be transmitted by Aedes albopictus – a species originally endemic to South Asia but now widely distributed in several countries outside Asia. Xenorhabdus and Photorhabdus spp., are enteric Gram-negative bacterial symbionts of insect-preying nematodes and are known to produce an array of natural products (NP) with various activities including larvicidal activity. This study demonstrated that supernatants of different Xenorhabdus and Photorhabdus bacteria effectively deterred Ae. albopictus mosquito oviposition in a concentration dependent manner. Xenorhabdus cabanillasii displayed deterrent effects at 50-5% concentrations with oviposition activity index values ranging between -0.87 and -0.35, whereas the index values for X. nematophila were between -0.82 and -0.52 at concentrations of 50-10%. The other bacteria (X. szentirmaii, X. d...

Turkish Journal of Zoology, Jan 22, 2002

... Populations of Bumblebees (Apidae: Hymenoptera) in Ankara Province A. Murat AYTEKN, Nefle ÇA... more ... Populations of Bumblebees (Apidae: Hymenoptera) in Ankara Province A. Murat AYTEKN, Nefle ÇA⁄ATAY, Selçuk HAZIR Hacettepe University Faculty of Science Department of Biology, 06532 Beytepe, Ankara - TURKEY Received: 20.02.2001 ...

Journal of Nematology, 2020

In Fiji, little or no attention has been given to entomopathogenic nematodes (EPNs) in biocontrol... more In Fiji, little or no attention has been given to entomopathogenic nematodes (EPNs) in biocontrol programs due to the lack of awareness about their occurrence and distribution in Fiji. A survey of EPNs was conducted for the first time in Fiji Islands in 2012 and 2013, throughout the eight provinces in Viti Levu to determine the occurrence and distribution across different habitat in Viti Levu. The soil samples from various habitats were collected and assayed for the presence of EPN using Galleria mellonella as baits. EPNs were recovered from five out of seven provinces with 35 positive sites (7.3%) out of 478 sites sampled. The only EPN genera encountered was Heterorhabditis. Steinernema was not isolated from any of the samples. Characterization of isolates was done by using morphometric and molecular examinations and isolates were identified as Heterorhabditis indica. H. indica isolates were primarily recovered from leeward side of the Viti Levu Island along the coastline and riversides, being more prevalent in lighter soil with pH > 6. Further, this study found significant association between habitat type, soil type, soil pH, average annual rainfall and EPN occurrence. This is the first record of naturally occurring EPNs in Fiji. The found nematodes will serve as the basis for efficacy screening with the ultimate aim of delivering effective, more sustainable and environmentally safe control for agricultural pests in Fiji.

Acta horticulturae, Sep 1, 2018

Capnodis tenebrionis L. is an important pest of stone fruit trees. The larval stage of the pest c... more Capnodis tenebrionis L. is an important pest of stone fruit trees. The larval stage of the pest causes serious damage to apricot saplings and trees in Malatya regions of Turkey. Chemical control of C. tenebrionis larvae is not practical and effective in these orchards. Therefore, it is necessary to improve biological control methods against this pest. In this study, the effects of the entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae and the entomopathogenic nematode Steinernema carpocapsae against the larval stage of C. tenebrionis were evaluated under semi-field conditions. Saplings of apricot 'Hacihalioglu' grafted on wild apricot rootstock were planted into pots and kept in greenhouse (semi-controlled environment). Sapling pots were inoculated with 50 first-instar C. tenebrionis larvae. Three different concentrations of B. bassiana and M. anisopliae (10 4 , 10 5 and 10 6 spores cm-2) and S. carpocapsae (25, 50 and 100 infective juveniles cm-2) were applied to the pots. All tested entomopathogens decreased the extent of C. tenebrionis larval penetration. B. bassiana at 10 6 spores cm-2 was the most effective application, exhibiting no larval penetration.

Frontiers in Microbiology, Mar 8, 2022

Springer eBooks, 2015

Entomopathogenic nematodes (EPNs) play several roles in the soil ecosystem. While EPNs are genera... more Entomopathogenic nematodes (EPNs) play several roles in the soil ecosystem. While EPNs are generally thought of in the context of reducing the density of pest populations when they are applied, they are also natural components of soil food webs and exert considerable influence on the population dynamics of many players in the system in addition to the intended targets of biological control efforts (Hodson, Siegel, & Lewis, 2012). They are lethal parasites of insects, but not all of the species they infect are the targets for which they are applied. They are also prey and hosts to a variety of other soil organisms. Here, we attempt explain the fate of EPNs after they are applied to soil in the context of the complicated interactions among members of soil food webs.

Florida Entomologist, Mar 1, 2015

BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access t... more BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

Biological Control, Nov 1, 2018

Entomopathogenic nematodes (EPNs) have been commercially produced as biopesticides, but nematode ... more Entomopathogenic nematodes (EPNs) have been commercially produced as biopesticides, but nematode products still face significant barriers related to preservation and formulation. This study assessed the performance of seven different formulation substrates and two combinations involving vermiculite and gel, to preserve Steinernema feltiae at three temperatures: 15˚C, 25˚C and 35˚C. The first two experiments assessed the survival and mobility of S. feltiae infective juveniles (IJs) in mushroom compost (Hobin Wood Landscaping Products), peat (sphagnum peat moss), Potting mix (Metro Mix®), polyacrylamide gel, diatomaceous earth, vermiculite, and water (control). A third experiment assessed the survival of IJs in combinations of the two best substrates selected from the prior tests: vermiculite, polyacrylamide gel (1.33%), double polyacrylamide gel (2.66%), vermiculite + gel (1.33%), vermiculite + double gel (2.66%), and water (control). The greatest IJ fitness at 35°C and 25°C was observed in peat and vermiculite, respectively, and at 15°C the gel and water treatments were superior. In general, vermiculite and polyacrylamide gel were the two best substrates considering that they provided the best results at 25°C and 15°C. The polyacrylamide gel formulation held higher numbers of nematodes in the substrate compared with the solid substrates. The mixture of vermiculite + double polyacrylamide gel provided the best preservation at 35°C compared to the substrates tested separately. The combination of vermiculite with polyacrylamide gel preserves S. feltiae IJs with 4 viability higher than 80% for at least 30 days at 35˚C, 233 days at 25˚C, and 241 days at 15˚C.

Biological Control, May 1, 2013

ABSTRACT Using a Y-tube olfactometer, we assessed whether Sancassania polyphyllae (Acari: Acarida... more ABSTRACT Using a Y-tube olfactometer, we assessed whether Sancassania polyphyllae (Acari: Acaridae) female mites showed a differential preference when offered a choice between odors from various sources. The combinations of odor sources included the following: (1) no odor source (blank), (2) dissected larval tissues of uninfected Polyphylla fullo (Coleoptera: Scarabaeidae), (3) P. fullo killed by Steinernema glaseri (Rhabditida: Steinernematidae), (4) intact freeze-killed, uninfected P. fullo, (5) free-living infective juveniles (IJs) of S. glaseri, or (6) living uninfected P. fullo. When offered a choice between (1) blank and dissected tissues of uninfected P. fullo or (2) blank and P. fullo killed by S. glaseri or (3) blank and intact freeze-killed, uninfected P. fullo, S. polyphyllae showed a significant preference for the odor sources compared to the blank. S. polyphyllae showed no preference when offered a choice (1) between S. glaseri IJs and blank or (2) between living uninfected P. fullo and blank. When offered two different odor sources, S. polyphyllae showed a significant preference for volatiles from (1) dissected tissues of uninfected P. fullo, (2) P. fullo killed by S. glaseri, or (3) intact freeze-killed, uninfected P. fullo compared to S. glaseri IJs or living P. fullo. However, when the (1) dissected tissues of uninfected P. fullo versus P. fullo killed by S. glaseri, (2) intact freeze-killed, uninfected P. fullo versus P. fullo killed by S. glaseri, or (3) living uninfected P. fullo versus S. glaseri IJs were tested, there was no significant difference in mite distribution.

Biocontrol Science and Technology, Aug 1, 2009

... Orchard Applications. In Nematodes as Biocontrol Agents , Edited by: Grewal, PS, Ehlers, R.... more ... Orchard Applications. In Nematodes as Biocontrol Agents , Edited by: Grewal, PS, Ehlers, R.-U. and Shapiro-Ilan, DI 215229. ... Orchard Applications. In Nematodes as Biocontrol Agents , Edited by: Grewal, PS, Ehlers, R.-U. and Shapiro-Ilan, DI 215229. ...

Zeitschrift für Naturforschung C, Dec 1, 2001

The antibacterial activities of propolis samples have been examined in vitro, according to the pr... more The antibacterial activities of propolis samples have been examined in vitro, according to the principles accepted for the determination of a similar activity of antibiotics with the use of solid and liquid media. It has been found that propolis extracts showed antibacterial activ ity through a range of commonly encountered gram positive cocci (5. aureus, beta hem. Streptococus), but had weak activity against gram negative bacteria (E. coli, P. aeruginosa). GC/MS analysis showed that propolis samples contain a variety of chemical compounds in cluding aromatic compounds, fatty acid esters and sesquiterpenes.

Entomopathogenic nematode production in liquid fermentation still requires improvements to maximi... more Entomopathogenic nematode production in liquid fermentation still requires improvements to maximize efficiency, yield, and nematode quality. The objective of this study was to develop a more suitable liquid medium for mass production of S. feltiae by selecting lipid and nitrogen sources, and by assessing the impact of glucose. Seven sources of lipid (corn oil, palm oil, fish oil, peanut oil, sunflower oil, canola oil, and pork lard) and six of nitrogen (egg yolk, yeast extract, egg white, soy extract, beef extract, and fish collagen) were tested at a concentration of 4% (v/v) and 1.25% (w/v), respectively. Additionally, egg yolk and egg white selected in the previous experiment, were tested solely (both at 1.25% w/v) and combined (at 0.625% w/v each) in media with or without glucose (2.5% w/v), supplemented also with yeast extract (2.3% w/v), NaCl (0.5% w/v), peanut oil (4% v/v), and agar (0.2% w/v). For the lipid and nitrogen source experiments, pork lard and yeast extract provided the lowest yields. The combination of egg yolk + egg white increased nematode yield compared to these nitrogen sources tested individually. Also, the addition of 2.5% glucose increased nematode yields.

PubMed, Dec 1, 2015

Entomopathogenic nematode species differ in their optimum storage temperature; therefore, we cond... more Entomopathogenic nematode species differ in their optimum storage temperature; therefore, we conducted a study on the survival and infectivity of the recently described Steinernema innovationi from South Africa at five storage temperatures (5°C, 10°C, 15°C, 20°C, and 25°C) over 84 d using 20,000 infective juveniles (IJ) in 25 ml aqueous suspension containing 0.1% formalin. Our results showed that survival was highest and most stable at 15°C, ranging from 84% to 88% after 84 d. Infectivity of IJ against Galleria mellonella larvae was >90% for all temperatures except for 5°C at which survival decreased to 10% after 84 d. In addition, we stored 2.5 million IJ on a sponge formulation in 15 ml of 0.1% formalin solution for 84 d at the optimum 15°C followed by 2 wk storage at 25°C. Storage of the IJ on a sponge formulation for 14 d at 25°C post 15°C storage for 84 d did not have a detrimental effect on IJ survival (87%) or infectivity to G. mellonella (95%).

PubMed, Sep 1, 2005

Bursaphelenchus anatolius n. sp., a phoretic associate of Halictus bees from Ankara, Turkey, is d... more Bursaphelenchus anatolius n. sp., a phoretic associate of Halictus bees from Ankara, Turkey, is described and illustrated. Bursaphelenchus anatolius n. sp. is closest to B. kevini, which is phoretically associated with Halictus bees from the Pacific Northwest. Bursaphelenchus anatolius n. sp. and B. kevini appear to be sister taxa based upon several shared morphological features, similar life histories involving phoresy with soil-dwelling Halictus bees, and molecular analysis of the near-full-length small subunit rDNA, D2D3 expansion segments of the large subunit rDNA, and partial mitochondrial DNA COI. Bursaphelenchus anatolius n. sp. can be differentiated from all other species of Bursaphelenchus based upon spicule morphology. The paired spicules are uniquely shaped and ventrally recurved, and both B. anatolius n. sp. and B. kevini possess extending flaps that open when the spicules are protracted beyond the cloaca. Population growth of B. anatolius n. sp. was measured at 23 degrees C in the laboratory on cultures of the fungus Monilinia fructicola grown on lactic acid-treated, 5% glycerol-supplemented potato dextrose agar. Nematode population densities rapidly increased from 110 to about 110,000/9-cm-diam. dish within 21 days.

PubMed, Sep 1, 2015

Entomopathogenic nematodes (EPNs) can be highly effective biocontrol agents, but their efficacy c... more Entomopathogenic nematodes (EPNs) can be highly effective biocontrol agents, but their efficacy can be reduced due to exposure to environmental stress such as from ultraviolet (UV) radiation. Our objectives were to 1) compare UV tolerance among a broad array of EPN species, and 2) investigate the relationship between reduced nematode viability (after exposure to UV) and virulence. Nematodes exposed to a UV radiation (254 nm) for 10 or 20 min were assessed separately for viability (survival) and virulence to Galleria mellonella. We compared 9 different EPN species and 15 strains: Heterorhabditis bacteriophora (Baine, fl11, Oswego, and Vs strains), H. floridensis (332), H. georgiana (Kesha), H. indica (HOM1), H. megidis (UK211), Steinernema carpocapsae (All, Cxrd, DD136, and Sal strains), S. feltiae (SN), S. rarum (17C&E), and S. riobrave (355). In viability assessments, steinernematids, particularly strains of S. carpocapsae, generally exhibited superior UV tolerance compared with the heterorhabditids. However, some heterorhabditids tended to be more tolerant than others, e.g., H. megidis and H. bacteriophora (Baine) were most susceptible and H. bacteriophora (Vs) was the only heterorhabditid that did not exhibit a significant effect after 10 min of exposure. All heterorhabditids experienced reduced viability after 20 min exposure though several S. carpocapsae strains did not. In total, after 10 or 20 min exposure, the viability of seven nematode strains did not differ from their non-UV exposed controls. In virulence assays, steinernematids (particularly S. carpocapsae strains) also tended to exhibit higher UV tolerance. However, in contrast to the viability measurements, all nematodes experienced a reduction in virulence relative to their controls. Correlation analysis revealed that viability among nematode strains is not necessarily related to virulence. In conclusion, our results indicate that the impact of UV varies substantially among EPNs, and viability alone is not a sufficient measure for potential impact on biocontrol efficacy as other characters such as virulence may be severely affected even when viability remains high.

Journal of Invertebrate Pathology, Sep 1, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Nematology, 2008

An extensive biogeographical survey was conducted from 2004 through part of 2007 of nematodes ass... more An extensive biogeographical survey was conducted from 2004 through part of 2007 of nematodes associated with the edible fig, Ficus carica, in seven different regions of Turkey. Figs (syconia) were collected, dissected and harvested for nematodes from 308 apparently wild or naturalised F. carica trees along roadsides and trails. Nematode specimens were examined morphologically and molecular analyses of sequences of the D2/D3 expansion segments of the large subunit (LSU) rDNA and partial mitochondrial DNA COI (mtCOI) were done. Of the 308 fig trees, 150 (49%) were positive for what was morphologically confirmed to be Schistonchus caprifici. Figs on one tree in Kahramanmaras city, South East Turkey, were found to contain S. caprifici and dauer juveniles of what appears to be a diplogastrid nematode. Molecular analyses produced congruent trees for both sequenced loci supporting the hypothesis that S. caprifici from different locations in Turkey are part of a well supported clade with some inherent variability. No geographic patterns were observed for either locus suggesting that the sequences generated represent inherent intraspecific variation for S. caprifici and that human activities related to the culture of the edible fig have allowed for mixing of any previously allopatric lineages.

Beilstein Journal of Organic Chemistry, May 7, 2020

The global threat of multiresistant pathogens has to be answered by the development of novel anti... more The global threat of multiresistant pathogens has to be answered by the development of novel antibiotics. Established antibiotic applications are often based on so-called secondary or specialized metabolites (SMs), identified in large screening approaches. To continue this successful strategy, new sources for bioactive compounds are required, such as the bacterial genera Xenorhabdus or Photorhabdus. In these strains, fabclavines are widely distributed SMs with a broad-spectrum bioactivity. Fabclavines are hybrid SMs derived from nonribosomal peptide synthetases (NRPS), polyunsaturated fatty acid (PUFA), and polyketide synthases (PKS). Selected Xenorhabdus and Photorhabdus mutant strains were generated applying a chemically inducible promoter in front of the suggested fabclavine (fcl) biosynthesis gene cluster (BGC), followed by the analysis of the occurring fabclavines. Subsequently, known and unknown derivatives were identified and confirmed by MALDI-MS and MALDI-MS 2 experiments in combination with an optimized sample preparation. This led to a total number of 22 novel fabclavine derivatives in eight strains, increasing the overall number of fabclavines to 32. Together with the identification of fabclavines as major antibiotics in several entomopathogenic strains, our work lays the foundation for the rapid fabclavine identification and dereplication as the basis for future work of this widespread and bioactive SM class.

Zootaxa, Jun 23, 2014

A new entomopathogenic nematode, Steinernema tophus n. sp. is described from South Africa. Morpho... more A new entomopathogenic nematode, Steinernema tophus n. sp. is described from South Africa. Morphological, molecular (ribosomal gene sequence data) together with cross-hybridization studies were used for diagnostics and identification purposes. Both molecular and morphological data indicate the new species belongs to the 'glaseri-group' of Steinernema spp. Key morphological diagnostic traits for S. tophus n. sp. include the morphology of the spicules and gubernaculum. Morphometric traits of third-stage infective juveniles, including total body length (average 1,046µm), tail length (average 70µm), location of the excretory pore (average 92 µm), D% (average 63), E% (average 132) and H% (average 32) values are definitive. In addition to these morphological characters, analysis of rDNA (28S and ITS) gene sequences depict this Steinernema species as a distinct and unique entity.