G. Ross Lawford

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High fermenter (volumetric) ethanol productivities (⩾80 g/lh−1) were attained in a simple single-stage continuous-stirred-tank-reactor (CSTR) employing a flocculent mutant of Zymomonas mobilis with a feed containing 100g/l glucose. Under these conditions a final ethanol concentration of 47.6 g/l was obtained, representing a maximum conversion efficiency of(More)
Candida utilis NRRLY -900 was grown in aerobic continuous culture in a minimal salts medium with sucrose (1% w/v) as the carbon source. increasing the concentration of zinc in the medium from 2.3 microM results in an increase in the apparent critical dilution rate from 0.3 to 0.47h-1, and in the maximum biomass productivity form 1.5g dry weight per litre(More)
The biosynthesis of a thermogelable, extracellular homo-beta-(1 leads to 3)-glucan called "curdlan," has been studied in batch and continuous cultures of Alcaligenes faecalis var. myxogenes. Curdlan production is associated with the poststationary phase of a nitrogen-depleted, aerobic batch culture. Exopolymer is not detected in single-stage, carbon-limited(More)
The steady-state levels of zinc in Candida utilis yeast grown in continuous culture under conditions of zinc limitations are <1nmol Zn2+/mg dry weight of cells. Unlike carbon-limited cells, zinc-depleted cells from a zinc-limited chemostat possess the capacity to accumulate and store zinc at levels far in excess of the steady-state level of 4 nmol/mg dry(More)
1. NADPH-ferricytochrome c oxidoreductase (EC was purified from the endoplasmic reticulum of rat liver cells. The methods, which involved digestion of membrane with Steapsin, a crude pancreatic extract containing diastase and trypsin, gel filtration and preparative electrophoresis on polyacrylamide, provided an enzyme with a high specific activity(More)
A two-stage continuous-stirred-tank-reactor (CSTR) system is used to achieve high final alcohol concentrations (>100 g/l) with Zymononas mobilis ATCC 29191. By employing continuous cell recycle on the second stage CSTR of a two-stage process a high overall volumetric productivity (18.13 g/l/h) is achieved together with >100 g/l effluent alcohol.
Growth of Zymomonas mobilis ATCC 29191 and CP4 in a continuous stirred tank fermentor resulted in the selection of stable flocculating variants. Factors responsible for enhancing the system pressures selective for the morphological variants were identified. By incorporating some modifications into the design of the fermentor, it was possible to achieve(More)
Leuconostoc mesenteroides NRRL B-512(F) was grown in continuous culture under conditions of energy-limited growth. The extracellular enzyme dextransucrase (sucrose: 1,6-alpha-D-glucan 6-alpha-glucosyltransferase EC, was not detected in glucose- or maltose-limited cultures. Under conditions of sucrose-limited growth, the enzyme activity of the(More)