The chestnut gall wasp, Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae) is one of the most important insect pests of chestnut. The aim of this study was to isolate and characterize bacteria from D. kuriphilus to obtain new microbial agents for both biological control and other biotechnological applications. D. kuriphilus larvae were collected from chestnut fields located in Bursa and Yalova provinces of Marmara Region of Turkey during May-July 2014. Four bacterial isolates were obtained from D. kuriphilus. According to their morphological, biochemical and molecular properties, these isolates were identified as Staphylococcus saprophyticus (Dk1), Paenibacillus sp. (Dk2), Pseudomonas flourescens (Dk3) and Paenibacillus sp. (Dk4). To the best of our knowledge, this is the first study on the bacterial flora of D. kuriphilus. In our study, the potential of these isolates as a biological control agent against different hazardous pests and other possible biotechnological applications of importance were discussed under the light of literature.

Broad host range of entomopathogenic fungi may have a commercial advantage for biological control industry. In addition, all entomopathogenic fungi rely on a combination of different enzymes to penetrate their hosts and these enzymes play an important role in the host range of fungal isolates. The aim of this study is to determine the potential of three Beauveria bassiana (Bals.) Vull. isolates in control of Tetranychus urticae Koch (Acari: Tetranychidae) and to determine their lipase, chitinase, and protease activities. For this purpose, B. bassiana (PaF04, PaF09 and PaF76) isolates, which was previously demonstrated to have entomopathogenic activity against Coleoptera, Lepidoptera, and Hymenoptera were chosen. T. urticae was used as the test organisms. Three different suspensions (1x10 6 , 1x10 7 and 1x10 8 conidia ml-1) were prepared in Tween 80. 2ml suspension of a single dose was sprayed onto down sides of bean leaf discs using hand sprayer. Mortality rates of T. urticae, in terms of LT50 values, were recorded daily for 5 days. Enzyme activities were investigated by petri plate assays and clear zones formed around the colonies indicated enzymatic activities. All tested fungal isolates were pathogenic to the T. urticae causing mortality between 64.2±5.6% and 100% on the 5 th day after the application. LT50 values varied between 3.16±0.2 and 3.72±0.5 days. Mortality caused by PaF04 isolate was found to be significantly different (p<0.05). In conclusion, PaF isolates of B. bassiana have been determined to have potential to suppress T. urticae, in addition to their potential in control of Coleoptera, Lepidoptera, and Hymenoptera. The present results showed that the isolates used, especially PaF04, have a broad host range.

This study was concerned with the screening of antimicrobial products from fungi collected from soil and evalution of their antibiofilm activity. The isolate having antimicrobial and antibiofilm compounds was characterized by the molecular methods and identified as Aspergillus sclerotiorum. A. sclerotiorum was grown in yeast peptone glucose (YPG) medium and extracellular medium was extraction by 1:1 ethyl acetate. Crude extraction characterized through thin layer chromatography (TLC) on silica gel 60 HF254 and was detected five bands. Agar diffusion and TLC overlay assays were done against Gram-positive (Staphylococcus aureus ATCC 25923, meticilin resistance S. aureus (MRSA) and Enterococcus faecalis ATCC 29212) and Gram-negative bacteria (Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853). The most dense band (Rf:0.42) showed the best inhibition zone on TLC overlay. The results showed that the most dense band can potential source for antimicrobial compound. After the most dense band in silica gel was scraped and dissolved ethyl acetate for minimum inhibitory concentration (MIC) determination and crystal violet assay against S. aureus and MRSA. These results indicate that fungi, A. sclerotiorum, isolated from soil was potential source for antimicrobial and antibiofilm compounds.

The fall webworm (Hyphantria cunea) is a polyphagous pest with numerous host plants. In the present study, the bacterial flora of H.cunea was investigated to identify new organisms that can be used as microbial control agent against the pest. Six bacteria were isolated and cultured from H. cunea. Some morphological, biochemical and other phenotypic characteristics (with API 20E, API 50 CH, API Staph and API Coryne kits) of bacterial isolates were determined. In addition, 16S rRNA gene region was sequenced. As a result of the studies conducted, bacterial isolates were identified as Lysinibacillus sphaericus (Abk1), Bacillus amyloliquefaciens (Abk2), Staphylococcus sciuri (Abk4), Kocuria palustris (Abk6), Arthrobacter arilaitensis (Abk7) and Microbacterium oxydans (Abk8). All bacterial isolates were tested for 12 days against third-fourth instar larvae of H. cunea. The highest insecticidal activity was obtained from L. sphaericus (Abk1) with 30% after application (p<0.05). These results indicate that L. sphaericus (Abk1) can be taken into account in the microbial pest control of H. cunea. In the future, further studies will be conducted by using pathogenicity enrichment strategies of L. sphaericus (Abk1) (ex. combining with other entomopathogens or insecticides) in order to increase the effectiveness on H. cunea. Özet