Deniz bitkilerinden elde edilen çevre dostu sekonder metabolit kokteyllerinin antifouling performansları

Mikro ve makro deniz organizmalarının yapay bir yüzeye tutunmaları olayına biyofouling adı verilir. Biyofouling doğal bir olaydır ve herhangi bir substrat yüzeyinde meydana gelebilir. Fakat biyofouling gemiler için ciddi bir problemdir. Fouling organizmalar gemilerin yüzeyini kapladıkça, ağırlığın artmasına, hızın azalmasına, manevra kabiliyetinin sınırlanmasına, korozyona ve yüksek yakıt sarfiyatına neden olurlar. Biyofouling'i önlemek için, gemilerin karina kısımları antifouling boyalar adı verilen özel deniz boyaları ile boyanır. Tribütil kalay (TBT) tabanlı kendini temizleyen kopolimer (SPC) tip antifouling boyalar, fouling olayının önlenmesi için başarıyla kullanılmıştır; ancak bu boyaların yasaklanmasından sonra çevre dostu ve etkili bir antifouling boya ihtiyacı açığa çıkmıştır. Yukarıda sözü edilen ihtiyaçlar kapsamında, bu tezde hem laboratuar hem saha çalışmalarıyla deniz bitkilerinin sekonder metabolit kokteylleri vasıtasıyla yardımcı biyositlere alternatif bir çevre dostu biyositin geliştirilmesi hedeflenmiştir. Akut toksisite testlerinin sonuçlarına göre, test edilen diğer bileşiklerle karşılaştırıldığında zosterik asitin A. salina'ya karşı toksik olmadığı bulunmuştur. Fakat yardımcı biyositler (irgarol, diuron, bakır ve çinko prityon) ve Z. noltii ile C. nodosa ekstraktları 185 mikrog/mL'de A. salina'nın hayatta kalma yüzdesini yüzde 50'den daha fazla düşürmüştür. İki sezon boyunca gerçekleştirilen saha çalışmalarında, test panellerinin yüzeyleri genellikle diatomlardan oluşan mikro-film tabakasıyla kaplanmıştır. İkinci saha çalışmasında, boyasız ve astar ile kaplı test panellerinin üzerinde serpulidae, bryozoan ve boru kurtları gibi makro-fouling organizmalar gözlenmiştir. Zosterik asit içeren boya mikro-balçık tabakası ile kaplanmış olmasına rağmen 90 günlik test periyodu boyunca makro-fouling organizmalara karşı dayanıklılığını korumuştur. Sonuç olarak, zosterik asit çam reçinesi tabanlı kendini temizleyen antifouling boyalarda sadece tek başına değil aynı zamanda yardımcı biyosit olarak da kullanılabilir veya fouling organizmalardan daha uzun süreli koruma sağlamak üzere modifiye edilebilir. Attachment of micro and macro marine organisms onto an artificial surface is called as biofouling. Biofouling is a natural process and it can take place on any substrate surface. However, biofouling is a serious problem for the ships. As fouling organisms cover the hulls of the ships, they cause to increase of weight, reduction of speed, limitations in maneuverability, corrosion and high fuel consumption. In order to prevent biofouling, ship?s hulls are painted with special marine paints called as antifouling paints. Tributyltin (TBT) based self-polishing copolymer type antifouling paints were successfully used for prevention of fouling; but after their ban, a need for an eco-friendly and effective antifouling paint has been emerged. With respect to above mentioned needs, development of an eco-friendly biocide alternative to booster biocides was aimed based on secondary metabolite cocktails of marine plants both in laboratory and field tests in this thesis. According to results of acute toxicity tests, zosteric acid was not toxic to A. salina compared to other compounds tested. However, booster biocides (irgarol, diuron, copper and zinc pyrithione) and extracts of Zostera noltii and Cymodocea nodosa were decreased survival percentage of A. salina more than 50 percent at 185 mikrog/mL concentration. In the first field test, the surfaces of test panels were covered by micro-slime layer mostly composed of diatoms. In the second field test, macro-fouling organisms like serpulidae, bryozoans and tube worms were observed on paint free and primer coated test panels. Zosteric acid containing paint was covered by micro-slime layer but it was resistant against macro-fouling organisms for 90 days of test period. In conclusion, zosteric acid could be used in rosin based self-polishing antifouling paints not only solely but also as co-biocide or it could be modified to provide prolonged protection from fouling organisms

An in silico bioinformatics laboratory manual for bioscience departments: 'prediction of glycosylation sites in phosphoethanolamine transferases'

Genomics and proteomics projects have produced a huge amount of raw biological data including DNA and protein sequences. Although these data have been stored in data banks, their evaluation is strictly dependent on bioinformatics tools. These tools have been developed by multidisciplinary experts for fast and robust analysis of biological data. However, there is a gap in the development of educational materials in the bioinformatics area for undergraduate students in bioscience departments. A sample in silico laboratory manual on the prediction of N-glycosylation sites in phosphoethanolamine transferases is presented in this study. The method proposed in this study is simple to apply in laboratory courses and is dependent on the use of internet-based bioinformatics tools such as ProtParam, ClustalW2 and NetNGlyc. In conclusion, this application can stimulate the interest of undergraduate students in bioscience departments and may also contribute to the development of bioinformatics

A Letter to Editor: On the use of the term "self-polishing" for antifouling paints

This letter presents a confusion on the use of the term "self-polishing" which is widely used in the antifouling paint industry and in published literature. (C) 2013 Elsevier B.V. All rights reserved

Seasonal variations and distributions of dissolved free and total carbohydrates at the Izmir Bay, Aegean Sea

Seasonal variations and distributions of dissolved carbohydrate concentrations at the Izmir Bay were investigated with salinity, chlorophyll a (Chl a), and dissolved organic carbon (DOC) levels to understand their relationships. Samples were collected from surface, subsurface and bottom depths at seven stations. DOC concentrations ranged from 32.2 to 244.2 mu mol/L, and in general, DOC levels increased from winter to summer, then slightly decreased in autumn. Monosaccharide (MCHO), polysaccharide (PCHO) and total dissolved carbohydrate (TDCHO) levels were found between 0.7-8.3, 0.7-19.5, and 2.6-24.6 mu mol/L. DOC, MCHO, PCHO and TDCHO levels were found higher in middle-inner bays, under the influence of anthropogenic inputs, compared to outer bay. Seasonal changes of MCHO/DOC, PCHO/DOC and TDCHO/DOC ratios were statistically significant (p<0.05) and the ratios showed decrease trends from winter to summer-autumn seasons. Distributions of TDCHO/DOC ratios at wide ranges (2.5%-42.3%) indicated the presence of newly forming and degrading fractions of DOM. According to results of factor analysis, Chl a, MCHO and TDCHO were explained in the same factor groups. In conclusion, the results showed that dissolved carbohydrate levels in the Izmir Bay might be influenced by biological processes and terrestrial/anthropogenic inputs

Optical characterization of chromophoric dissolved organic matter at eutrophic and oligotrophic parts of a semi-enclosed bay (Izmir, Aegean Sea)

Optical characterization of chromophoric dissolved organic matter (CDOM) from Izmir Bay (Aegean Sea) waters was investigated. For sampling, surface and subsurface seawater from 7 stations were collected in summer 2015. Excitation-emission matrix (EEM) spectra of each sample were recorded on a fluorescence spectrophotometer. The results showed that dissolved organic carbon (DOC) concentrations and EEM peaks were increased from the outer bay to inner bay stations. EEM peaks indicated the presence of both humic-like and protein-like components which were higher at middle-inner bays than outer bay. Spearman's rank correlation coefficients for EEM peak intensities and DOC concentrations were highly positive (p<0.05). HIX found between 0.73-3.51, whereas BIX ranged from 0.31 to 0.96 in the bay. Humification degree of CDOM in the middle-inner bays were higher compared to outer bay stations. High HIX values in the middle-inner bays could be linked to the presence of Melez stream (heavily polluted), other streams, rain run-offs and maritime activities at Izmir Bay. High BIX values in the middle-inner bays indicated presence of freshly produced DOM from bacterial origin. Optical characterization of CDOM could be used for tracing fluorescent DOM components and determining different DOM sources (autochthonous or allochthonous) in further studies