Genetic and clonal diversity in Korean populations ofVitex rotundifolia (Verbenaceae)

Vitex rotundifolia L.f. is a woody perennial and has sexual and asexual modes of reproduction. Allozyme study was conducted on 550 plants in 13 Korean populations. The levels of genetic variability and divergence within and among populations, respectively, are considerably lower and higher than the mean values for woody plants with similar life history tralts. Mean percentage of polymorphic loci (P _P), mean number of alleles per locus (A _P), and mean genetic diversity (He _P) within populations ofV. rotundifolia were: 16.7%, 1.21, and 0.047. On average, about 79% of the total variation inV. rotundifolia was common to all populations (meanG _ST=0.208). In addition, significant differences in allele frequencies among populations were found in all polymorphic loci examined (P<0.001). On the other hand, levels of genotypic diversity within and among populations were moderate. About 44% (18/41) of multilocus genotypes were “local genotypes” (genotypes occurring in only one population), whereas only one “widespread genotype” (genotypes occurring in more than 75% of the populations) were detected. The mean number of multilocus genotypes per population (G) and mean genotypic diversity index (D _G) were 8.4 and 0.74, respectively. Most common multilocus genotypes found in populations were homozygous for five polymorphic loci. The abundance of ramets of these genets is responsible for the low levels of expected heterozygosity within populations. The results indicate that clonal reproduction may act as an enhancer of genetic drift by reducing effective size of local populations ofV. rotundifolia.     

Protoplast fusion between Lactobacillus casei and Lactobacillus acidophilus

Summary From the fusion between Lactobacillus casei and Lactobacillus acidophilus, 8 fusants were selected: Four were able to ferment maltose, lactose, galactose and mannose, but two had greater abilities of acid production than parents. Increased values of up to 7.6–8 % in -galactosidase activity were obtained from two when compared to that of L. acidophilus, whereas another 2 had activities of 800 and 548 nmol/mg protein/min comparable to that of L casei giving a value of 400 nmol/mg protein/min in phospho--galactosidase activity.     

Single-cell protein of Rhodotorula sp. Y-38 from ethanol, acetic acid and acetaldehyde

Summary Continuous cultivation of Rhodotorula sp. Y-38 was carried out on ethanol, acetic acid or acetaldehyde. At a feed concentration of 1.0 % (w/v) ethanol, the cell yield of 64 g/100 g ethanol and crude protein of 52 g/100 g biomass were obtained at D=0.5 h^-1. The respective value of the content of amino acids and nucleic acids was 42.6 and 9.4 g/100 g biomass. At 2.0 % (w/v) acetic acid, cell yield was found to be 50 g/100 g acetic acid at D=0.4 h^-1. The optimum dilution rate ranged between 0.3 and 0.4 h^-1. At 0.05 % (w/v) acetaldehyde, the maximum cell yield was obtained at D=0.14 h^-1.