02191nas a2200217   4500008004100000022001400041245011000055210006900165260008000234300001200314490000700326520133700333653002301670653002401693653003101717653002401748100001701772700003701789700001901826856012801845       2014                        eng d  a1367-543500aIn situ pH management for microbial culture in shake flasks and its application to increase plasmid yield0 aIn situ pH management for microbial culture in shake flasks and   aTIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANYbSPRINGER HEIDELBERGcAPR  a647-6550 v413 a<p>Shake flasks are widely used to culture microorganisms, but they do not allow for pH control without additional infrastructure. In the presence of a carbon source like glucose, culture pH typically decreases due to overflow metabolism and can limit the growth of microorganisms in shake flasks. In this study, we demonstrate the use of magnesium hydroxide-loaded pH managing hydrogels (m-pHmH) for in situ base release to counter the decrease in culture pH in shake flasks using Escherichia coli as a model organism, in both complex and mineral salts medium. Base release from m-pHmH is shown to increase with decreasing pH (22-fold increase in release rate from pH 8 to 5), thus providing feedback from culture pH. The addition of m-pHmH resulted in better pH maintenance and higher biomass yields of E. coli K12 in media containing glucose as a carbon source. The use of m-pHmH with additional buffer resulted in pH being maintained above 6.9 while pH decreases below 5 without m-pHmH. We demonstrate one application of such in situ pH management to increase the volumetric plasmid yield from E. coli in shake flask culture. In situ glucose release through a hydrogel to mimic fed-batch culture along with the addition of m-pHmH resulted in a 395 % increase in volumetric plasmid yield to 38 mu g/ml in shake flask culture.</p>10aIn situ pH control10aMagnesium hydroxide10apH-responsive base release10aShake flask culture1 aSanil, Reenu1 aMaralingannavar, Vishwanathgouda1 aGadgil, Mugdha  uhttps://library.ncl.res.in/content/situ-ph-management-microbial-culture-shake-flasks-and-its-application-increase-plasmid-0