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Inhibitory Effect of Probiotics Lactobacillus Supernatants Against Streptococcus Mutans and Preventing Biofilm Formation
2021
Tuğba Demir | Hakan Demir
Probiotic microorganisms can release bioactive substances that can inhibit the growth and biofilm formation of pathogenic microorganisms such as Streptococcus mutans. Dental caries is a multi-factorial chronic infection disease, which starts with bacterial biofilm formation caused mainly by S. mutans. This study investigated the characteristics of Lactobacillus spp. strains as an oral probiotic. Twelve Lactobacillus spp. species obtained from fermented milk and dairy products were identified. Antimicrobial activity was determined with the Minimum Inhibition Concentration against S. mutans as an oral pathogen. Biofilm formation capabilities of the identified Lactobacillus strains in supernatant and culture media were determined. In addition, their ability to α-amylase tolerance and pH values (24h-48h) were determined. L.plantarum showed the highest antimicrobial activity compare other Lactobacillus strains. Also, L. plantarum inhibited biofilm formation.
Mostrar más [+] Menos [-]Evrişimsel Sinir Ağları Kullanılarak Yumurta Kabuğu Kusurlarının Tespiti
2021
Muammer Türkoğlu
Ticari yumurta çiftliği endüstrilerinde, kusurlu yumurtaların otomatik olarak ayrılması ekonomik ve sağlık açısından önemlidir. Günümüzde, kusurlu yumurtaların tespiti manuel olarak yapılmaktadır. Bu durum, zaman alıcı, yorucu ve karmaşık süreçler içermektedir. Tüm bu nedenlerden dolayı, yumurta yüzeyinde oluşabilecek kusurların otomatik olarak sınıflandırılması oldukça önemli bir konu haline gelmiştir. Bu amaç doğrultusunda, bu çalışmada, nesne tanıma ve sınıflandırma alanlarında yüksek performans sağlayan Evrişimsel Sinir Ağlarına (ESA) dayalı geliştirilen AlexNet, VGG16, VGG19, SqueezeNet, GoogleNet, Inceptionv3, ResNet18 ve Xception mimarileri kullanılarak yumurta kusurlarının sınıflandırılması gerçekleştirilmiştir. Bu mimarilerin performansını test etmek için kirli, kanlı, kırık ve sağlam yumurtaları içeren özgün bir veri seti inşa edilmiştir. Deneysel çalışmalar sonucunda, en yüksek doğruluk skoru VGG19 mimarisi ile %96,25 olarak elde edilmiştir. Bu sonuçlarda, ESA yöntemlerinin kusurlu yumurtaların sınıflandırılmasında yüksek başarı sağladığı gözlenmiştir.
Mostrar más [+] Menos [-]Cellular Bioenergetics in Spirulina platensis towards Growth and Phycocyanin Production Under Different Photon Flux Densities Using the Modified Zarrouk’s Medium
2021
Anyway Chofamba
From all the pigments found in Spirulina platensis, phycocyanin has been found to have a diverse application in various fields, and has a high market demand, calling for a need to increase production and easy isolation methods. In general, phycocyanin production in cells depends on the light conditions, among other factors during the cultivation period. The focus of this study was to look at the effect of different light intensities on phycocyanin production in Spirulina platensis. Other cellular biochemical parameters, including chlorophyll content and protein, were explored under the different treatments. An experimental design containing 4 different light intensities of 20, 150, 300 and 600 μmol photons m2/s was administered with 3 replicates. The results obtained from the study showed that high phycocyanin content was obtained from a low light intensity treatment. Chlorophyll results were a bit in contrary to the results obtained for phycocyanin, with high chlorophyll content obtained in high light intensity treatments. Protein and biomass accumulation also followed the same trend, where they were observed to be higher in high light intensities, with the maximum biomass achieved at 600 μmol photons m2/s and maximum protein content achieved at 300 μmol photons m2/s. Due to the commercial potential of phycocyanin to humans, its low cost downstream cultivation and processing of Spirulina platensis will be of economic advantage to the relevant stakeholders to fulfil the rampant demands and affordability of the blue phycocyanin pigment to both first and third World countries, hence the need of producing phycocyanin using the modified Zarouk’s media which has cheaper if not affordable ingredients.
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