Optimisation of 2,3-butanediol production by Bacillus licheniformis NCIMB 8059 strain using response surface method

W pracy wykorzystano metodę płaszczyzny odpowiedzi w celu zoptymalizowania biosyntezy 2,3-butanodiolu przez szczep Bacillus licheniformis NCIMB 8059. Oceniono wpływ stężenia ekstraktu drożdżwego oraz jonów CH3COO", Fe2+i Mn2+ na końcową zawartość 2,3-butanodiolu w płynie pohodowlanym. Doświadczenie optymalizacyjne zaprojektowano w oparciu o plan D-optymalny obejmujący 25 wariantów hodowli. Zaobserwowano istotny (p < 0,05) wpływ stężenia ekstraktu drożdżowego oraz jonów CH3COO" i Mn2+na syntezę diolu. Na podstawie analizy statystycznej uzyskano optymalne wartości analizowanych zmiennych, wynoszące (g-dm3): ekstrakt drożdżowy - 4, CH3COONH4- 4, FeS04-7H20 - 0,1 oraz MnS04-H20 - 0,3, które odpowiadały końcowemu stężeniu 2,3-butanodiolu na poziomie 8,9 g-dm-3.Response surface method was used in this work in order to optimise the biosynthesis of 2,3-butanediol by strain Bacillus licheniformis NCIMB 8059. The effect of yeast extract and concentration of CH3COO", Fe2+and Mn2+ ions was evaluated on the final level of 2,3-butanediol in fermentation broth. The optimisation experiment was planned according to D-optimal design and consisted of 25 runs. Obtained results showed significant influence (p < 0,05) of the yeast extract, CH3COO" and Mn2+ concentration on the studied process. On the basis of statistic analysis, optimal values of analyzed variable were determined as follows (g-dm3): yeast extract - 4, CH3COONH4 - 4, FeS04-7 HzO - 0,1, MnS04-H20 - 0,3, that corresponded to 8,9 g-dm-3 final 2,3-butanediol concentration

Energy dispersion and relaxation in propynal using laser ir/visible double resonance

The dynamics of energy dispersion in propynal has been studied over the pressure range of 5 to 500 mtorr following excitation by a TEA CO/sub 2/ laser below the dissociation threshold. Wavelength resolved spectra, using the dye laser-induced fluorescence technique, are used to characterize the vibrational levels that are involved in the various energy transfer processes, while time-resolved spectra are used to determine the corresponding rates. The rate constants are extrapolated to zero pressure to obtain the regime of collisionless intramolecular relaxation time. Mechanisms of energy dispersion involving each of the probed vibrational levels (v = 0, ..nu../sub 6/(v = 1), ..nu../sub 9/(v = 1), and ..nu../sub 4/(v = 1)) are discussed