Fructose phosphorylation by Zymomonas mobilis glucokinase

Zymomonas mobilis ATCC 53431, a fructokinase negative mutant is unable to utilize fructose as a sole carbon source for growth. At high fructose concentrations, however, fructose was converted to ethanol. The fructose uptake displayed MICHAELIS‐MENTEN kinetics with an apparent Km of 185 mM fructose. Purified glucokinase from ATCC 53431 and the wild strain ATCC 29191 both exhibited fructose phosphorylating activity at high fructose concentrations with an apparent Km value of 222 mM fructose. Glucokinase substrate specificity was found not be absolute, as previously reported

Sward evaluation of eleven 'Stylosanthes seabrana' accessions and S. scabra cv. Seca at five subtropical sites

Sown pasture development in the light-textured soils of the seasonally dry tropics and subtropics is based mainly on Stylosanthes species. S. scabra cv. Seca, the cultivar most widely sown, has poor long-term persistence and yield in lower-rainfall subtropical environments experiencing frosts and drought, particularly on clay soils. This study has identified accessions of "Stylosanthes seabrana" which perform well on clay soils in the subtropics, greatly extending the contribution that Stylosanthes species can make to beef production in northern Australia. Although there was abnormally low rainfall during the first 2 years of the experiment, the stylos established and survived in all environments. Most "Stylosanthes seabrana" accessions were consistently superior to Seca in seedling and perennial plant density and yield at most sites, particularly in the third year of the experiment. Seca performed poorly in all attributes in all years with the lowest rank over all years indicating its lack of adaptation. The accessions 92838B and 110361 were selected and released as cultivars Primar and Unica, respectively, in 1996. Primar appears better adapted to the more southerly subtropical sites with early frosts and a short growing season. Unica appears superior to Primar in central Queensland which normally has a longer summer growing season

Small-sward testing of Stylosanthes in Northern Australia: Preliminary considerations

An experiment is described in which 27 accessions of Stylosanthes, comprising some seven species, were grown for 3 years in small swards at eight different sites covering a wide range of environments. The accessions used were selected on the basis of previous studies, so as to represent a wide range of species and species forms. Numerical data was used to delineate those species, or species forms, likely to be of agronomic value in the various areas. The implications of the methods used and the results obtained are discussed in relation to plant introduction and plant evaluation techniques