High-Cell-Density Cultivation of <I>Pseudomonas putida</I> IPT 046 and Medium-Chain-Length Polyhydroxyalkanoate Production From Sugarcane Carbohydrates

Abstract

We studied high-density cultures of Pseudomonas putida IPT 046 for the production of medium-chain-length polyhydroxyalkanoates (PHAMCL) using an equimolar mixture of glucose and fructose as carbon sources. Kinetics studies of P. putida growth resulted in a maximum specific growth rate of 0.65 h(-1). Limitation and inhibition owing to NH4+ ions were observed, respectively, at 400 and 3500 mg of NH4+/L. The minimum concentration of dissolved oxygen in the broth must be 15% of saturation. Fed-batch strategies for high-cell-density cultivation were proposed. Pulse feed followed by constant feed produced a cell concentration of 32 g/L in 18 h of fermentation and low PHAMCL content. Constant feed produced a cell concentration of 35 g/L, obtained in 27 h of fermentation, with up to 15% PHAMCL. Exponential feed produced a cell concentration of 30 g/L in 20 h of fermentation and low PHAMCL content. Using the last strategy, 21% PHAMCL was produced during a period of 34 h of fed-batch operation, with a final cell concentration of 40 g/L and NH4+ limitation. Using phosphate limitation, 50 g/L cell concentration, 63% PHAMCL and a productivity of 0.8 g/(L x h) were obtained in 42 h of fed-batch operation. The PHAMCL yield factors from consumed carbohydrate for N-limited and P-limited experiments were, respectively, 0.15 and 0.19 g/g.

High cell density strategy for poly(3-hydroxybutyrate) production by Cupriavidus necator

“…The design of the high cell density culture must take into account mainly oxygen transfer and the limiting substrate flow to the mass culture medium. Because of economical reasons, pure oxygen for aeration purposes must be avoided during PHA production (Diniz et al, 2004). Taking into account the analysis performed by Diniz et al (2004), Figure 1( ), a fact that can contribute to the reduction of the production costs due to the low oxygen requirement.…”

“…In order to simplify the control of the culture, a linear growth can be established during the growth phase (Diniz et al, 2004) until a desired biomass concentration is reached. The exponential growth phase for high cell density cultures presents higher specific growth rates (µ Xr ), high biomass concentration (Xr), and, consequently, a higher specific oxygen uptake rate (Q O2 ) that can result in undesirable limitations of oxygen.…”

Production of medium-chain-length polyhydroxyalkanoate by Pseudomonas oleovorans grown in sugary cassava extract supplemented with andiroba oil

“…Bacteria of the genus Pseudomonas, which belongs to ribosomal RNA homology group I, are able to synthesize PHA using a variety of carbon sources, including glucose, fructose and sucrose (Diniz et al, 2004;Santhanam & Sasidharan, 2010;Davis et al, 2013), n-octane and octanoate (Smet et al, 1983;Durner et al, 2000), and fatty acids (Du & Yu, 2002;Allen et al, 2010), among others.…”

Estudo do metabolismo de ácidos graxos em Pseudomonas putida visando a modulação da composição monomérica de elastômero biodegradável.

“…P.putida.................................................................................. (LAGEVEEN et al, 1988), álcoois (HAYWOOD et al, 1989;HUISMAN et al, 1989) ácidos graxos (BARBUZZI et al, 2004;DE WAARD et al, 1993;BRANDL et al, 1988;HAZER et al, 1998;), óleos vegetais (EGGINK et al, 1995;SOLAIMAN et al, 2006;WENNAN et al, 1998) e carboidratos (GOMEZ, 2000;DINIZ et al, 2004;SANCHEZ et al, 2003).…”