The design allowed comparison of production between (1) CCF selleck compound with hydrophobic surface (PMMA-CCF), (2) CCF with hydrophilic glass surface (GS-CCF), and (3) standard unbaffled Erlenmeyer flask (EF). Melanin production in the PMMA-CCF was higher by at most 33.5% and growth of S. colwelliana by at most 309.2% compared to the other vessels. Melanin synthesis was positively correlated with reactor surface area and hydrophobicity, suspended cell growth, and biofilm formation. Antibiotic production in the EF was higher by at most 83.3%, but growth of P. rubra was higher in the PMMA-CCF by at most
54.5% compared to the other vessels. A hydrophilic vessel surface, abundant air supply, but low shear stress enhanced antibiotic production. The CCF together with the EF allowed identification of the crucial parameters (vessel surface characteristics, growth, biofilm formation, and aeration) influencing productivity, knowledge of which in the initial stages of process development will facilitate informed decisions at the later phases.”
“Oxidative stress is an unavoidable peril that aerobic organisms have to Staurosporine inhibitor confront. Thus, it is not surprising that intricate strategies are deployed in an effort to fend the dangers associated with
living in an O(2) environment. In the classical models of anti-oxidative defense mechanisms, a variety of stratagems including the reactive oxygen species (ROS) scavenging systems, the NADPH-generating enzymes and the DNA repair machineries are highlighted. However, it is becoming increasingly clear that metabolism may be intimately involved in anti-oxidative defence. Recent data show that metabolic reprogramming plays a pivotal role in the survival of organisms exposed to oxidative stress. Here, we describe how Pseudomonas fluorescens, the metabolically-versatile soil microbe, manipulates its metabolic networks in
an effort to counter oxidative stress. An intricate selleckchem link between metabolism and anti-oxidative defense is presented. P. fluorescens reconfigures its metabolic processes in an effort to satisfy its need for NADPH during oxidative insult. Seemingly, disparate metabolic modules appear to partner together to concomitantly fine-tune the levels of the anti-oxidant NADPH and the pro-oxidant NADH. Central to this shift in the metabolic production of the pyridine nucleotides is the increase in NAD kinase with the concomitant decrease in NADP phosphatase. The tricarboxylic acid cycle is tweaked in an effort to limit the formation of NADH. This metabolic redox-balancing act appears to afford a potent tool against oxidative challenge and may be a more widespread ROS-combating tactic than hitherto recognized.