Bioprocess design parameters for beta-lactamase production by Bacillus species

Çelik, Eda
In this study, the effects of bioprocess design parameters on β-lactamase production were systematically investigated using wild type Bacillus species. For this purpose, the research programme was carried out in mainly four parts. Initially, potential β-lactamase producers were screened and Bacillus licheniformis ATCC 25972, a constitutive β-lactamase producer, was selected. Next, the effects of bioprocess medium components, i.e., carbon sources (glucose, fructose, sucrose, citric acid and glycerol), inorganic nitrogen sources ((NH4)2HPO4 and NH4Cl) and organic nitrogen sources (yeast extract, peptone and casamino acids), were investigated in agitation and heating rate controlled laboratory scale bioreactors. Thereafter, by using the designed medium, the effects of bioprocess operation parameters, i.e., pH and temperature, on β- lactamase activity were investigated in order to achieve a higher β-lactamase production. Among the investigated bioprocess conditions, the highest β- lactamase activity was obtained as 275 U cm-3, in the medium with 10.0 kg m-3 glucose, 1.2 kg m-3 (NH4)2HPO4, 8.0 kg m-3 yeast extract and the salt solution, at pH0=6.0, T=32°C, N=200 min-1, which was 7.9 fold higher than the activity obtained in the reference medium. Finally, using the optimum bioprocess parameters obtained in laboratory scale experiments, the fermentation and oxygen transfer characteristics of the bioprocess were investigated in 3.0 dm3 pilot scale bioreactor, having temperature, pH, foam and stirring rate controls, at Q0/V=0.5 vvm and N=500 min-1 oxygen transfer conditions. The variations in β- lactamase activity, cell, glucose, amino acid and organic acid concentrations with the cultivation time; the oxygen uptake rate and the liquid phase mass transfer coefficient values were determined. Throughout the bioprocess, overall oxygen transfer coefficient (KLa) varied between


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Gunes, Hande; Boy, Erdem; Ata, Ozge; Zerze, Gul H.; Çalık, Pınar; Ozdamar, Tuncer H. (2016-03-01)
BACKGROUND: The effects of designed methanol and co-substrate feeding strategies on fed-batch recombinant human growth hormone (rhGH) production by Pichia pastoris hGH-Mut(+) were investigated.
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Most risk analysis studies in invasion biology have focused on the invasiveness of non-native species, even though some native species also can pose a high risk to the environment and human well-being. This is especially true under current global change, which may cause dominant native species to expand their range of distribution and have substantial effects on the ecosystem. In this study, the risk of invasiveness of five non-native and five native plant species in Turkey was evaluated using a standard ri...
Bioproduction, structure elucidation and in vitro antiproliferative effect of eumelanin pigment from Streptomyces parvus BSB49
Bayram, Sinan; Dengiz, Çağatay; GERÇEK, Yusuf Can; ÇETİN, İdil; TOPÇUL, Mehmet Rıfkı (Springer Science and Business Media LLC, 2020-01-01)
In this study, the structure of the purified extracellular eumelanin pigment isolated from Streptomyces spp. was elucidated by detailed analysis via two different spectroscopic techniques (FT-IR and NMR). In vitro antiproliferative effects of eumelanin were evaluated on HeLa cell line. These experiments were carried out with the evaluation of the parameters including cell viability, cell index, and mitotic index. With the cell viability and cell index, IC50 concentration of eumelanin was determined as 10 μM...
An extracellular - Pepstatin insensitive acid protease produced by Thermoplasma volcanium
Kocabıyık, Semra (Elsevier BV, 2007-01-01)
In this study, some parameters for the production and caseinolytic activity of an extracellular thermostable acid protease from a thermoacidophilic archaeon Thermoplasma volcanium were determined. The highest level of growth and enzyme production were detected at pH 3.0 over an incubation period of 192 h at 60 degrees C. The pH optimum for the acid protease activity was 3.0 and the enzyme was fairly stable over a broad pH range (pH 3.0-8.0). The temperature for maximum activity of the enzyme was 55 degrees ...
The Effects of Chloramphenicol on Some Biochemical Parameters in Mice
Ege, Hismiogullari Sahver; Tunay, Kontas; Adil, Hismiogullari Adnan; Dinc, Essiz; Gokhan, Eraslan (2008-12-01)
The aim of the study was to investigate the effects of some dose regimens of chloramphenicol on some biochemical parameters in mice for acute and subacute periods. Chloramphenicol was given to the experimental groups at the doses of 100 mg kg(-1) bw (group 2) and 200 mg kg(-1) bw (group 3) in drinking water for 7 days. Blood samples were taken from all animals on day 0, 1, 7 and 14 of the study. The hepatotoxic effect of cloramphenicol occurred in groups 2 and 3 with increasing doses of cloramphenicol. Hepa...
Citation Formats
E. Çelik, “Bioprocess design parameters for beta-lactamase production by Bacillus species,” M.S. - Master of Science, Middle East Technical University, 2003.