Yazar "Ulutas, Mehmet Sefa" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • [ X ]
    Öğe
    Isolation of a thermophilic Anoxybacillus flavithermus sp nov and production of thermostable ?-amylase under solid-state fermentation (SSF)
    (Bmc, 2012) Ozdemir, Sadin; Matpan, Fatma; Okumus, Veysi; Dundar, Abdurrahman; Ulutas, Mehmet Sefa; Kumru, Mert
    A new bacteria was isolated from hot-spring water of Gazligol, Afyonkarahisar in Turkey. Based on morphological and biochemical tests and 16S rRNA gene sequence analysis, the isolate belonged to the Anoxybacillus flavithermus species which has 99% similarity with the bacterium DNA. The production of alpha-amylase by thermophilic Anoxybacillus flavithermus was investigated under solid-state fermentation by using some agricultural waste as substrates. Solid substrates such as rice husk, banana husk, millet, water melon husk, lentil bran, wheat bran and maize oil cake were studied for enzyme production. Of these, rice husk was proved as the best substrate for alpha-amylase production (1,271 U/mg). The maximum alpha-amylase production was observed as 1,803 U/mg at 72 h, 1,000 mu m particle size, 70% initial moisture content (w/v), and 40% inoculum level (v/w). Among the various nitrogen sources tested, 1% peptone (3,170 U/mg) was found to be the best nitrogen source for alpha-amylase production. As additional carbon sources, 1% starch (2,364 U/mg) enhanced alpha-amylase production. The optimum temperature for the activity of alpha-amylase was found to be 70A degrees C. The enzyme was optimally active at pH 6.0 and stable in the pH range of 6.0-8.0.
  • [ X ]
    Öğe
    Purification and characterization of thermostable a-amylase produced from Bacillus licheniformis So-B3 and its potential in hydrolyzing raw starch
    (Pergamon-Elsevier Science Ltd, 2021) Fincan, Sema Aguloglu; Ozdemir, Sadin; Karakaya, Adem; Enez, Baris; Mustafov, Sibel Demiroglu; Ulutas, Mehmet Sefa; Sen, Fatih
    Aims: This work was achieved to obtain the optimum culture conditions of the thermostable alpha-amylase produced by thermophilic Bacillus licheniformis SO-B3. Furthermore, the alpha-amylase was purified and then characterized, and also its kinetic parameters were determined. Materials and methods: A new thermotolerant bacteria called Bacillus licheniformis SO-B3 employed in this work was isolated from a sample of thermal spring mud in Sirnak (Meyremderesi). Several parameters such as the impact of temperature, time, and pH on enzyme production were examined. Thin-Layer Chromatography (TLC) was employed to analyze the end-products of soluble starch hydrolysis, and the utilization of purified alpha-amylase in the clarification of unripe apple juices was studied. Key findings: The highest enzyme production conditions were determined as 35 degrees C, 36th hour, and pH 7.0. Thermostable alpha-amylase was purified by 70% ammonium sulfate precipitation, DEAE-cellulose ion-exchange chromatography, and dialysis, with a 51-purification fold and 30% yield recovery. The K-m and V-max values for this enzyme were 0.004 mM and 3.07 mu mol min(-1) at 70 degrees C, respectively. The alpha-amylase's molecular weight was found as 74 kDa. In addition, alpha-amylase showed a good degradation rate for raw starch. Significance: It was hypothesized that Bacillus licheniformis SO-B3 could be used as an alpha-amylase source. These findings displayed that purified enzyme could be utilized in fruit juice industries for clarification of apple juice and raw starch hydrolyzing.