Screening of Xylanase and Glucose Isomerase Producing Bacteria Isolated from Hot Springs in Turkey

Abstract

The aim of this study was screening of xylanase and glucose isomerase producing thermophilic bacteria isolated from some hot springs located in Aegean Region of Turkey. Total sixty eight thermophilic isolates (Anoxybacillus, Brevibacillus, Geobacillus, Aneurinibacillus, Thermus, Paenibacillus and Proteobacter) were collected previously from these fields and identified based on 16S rDNA gene sequences. Isolates were screened by plate assay for determining the xylanase and glucose isomerase production abilities seperately in order to find new strains for industrial processes. After an incubation period of two days for xylanase and 5-6 days for glucose isomerase at 50-60 °C, positive isolates were determined. Enzyme producing isolates were confirmed by spectrophotometric measurements with crude enzyme extracts, birchwood xylan and glucose were used as substrates. Most of the isolates (fifty nine) were positive for xylan degradation while only sixteen of them were positive for glucose isomerase activity. Fourteen of the isolates showed both xylanase and glucose isomerase activity. None of the isolates belong to the genera Paenibacillus, Aneurinibacillus, and Proteobacter were glucose isomerase positive, although the glucose isomerase activity of Geobacillus isolates were notably high. Both xylanase and glucose isomerase activities were observed at 50-60 °C which is suitable for biotechnological applications.

Al-5Ti-0,2B ve Al-5Ti-1B Tane İncelticilerin AA 1050 Alüminyum Alaşımının Mekanik Özellikleri Üzerine Etkileri

“…Katılaşma işlemi sırasında kullanılan tane incelticiler ince ve eş eksenli tanelerin oluşumunu sağlayarak, mekanik özelliklerin iyileşmesinde yardımcı olurlar. Ayrıca tane inceltici kullanılmış alüminyum malzemelerde beslenme kabiliyetlerinin yüksek olması ile porozitesiz ve homojen bir yapının oluşması alüminyum malzemeler için avantaj sağlamaktadır [2], [3].…”

“…Titanyum partikülleri yeni çekirdeklenme bölgeleri sağlarken, bor ince ve eş eksenli taneciklerin oluşumunu destekler. Borun alüminyum malzeme üzerindeki bu tane inceltici etkisi nedeniyle günümüzde en çok tercih edilen tane inceltici (Al-Ti-B) olmasını sağlamıştır [2], [3].…”