Endophytic Bacillus sp. Isolated from the Interior of Balloon Flower Root

A bacterial strain, designated CY22, was isolated from the interior of balloon flower (Platycodon grandiflorum) root in the Republic of Korea. The isolate coproduced an iturin-like antifungal compound and a surfactin-like potent biosurfactant. Analysis of the 16S-rDNA of strain CY22 showed that the isolate was a member of Bacillus. High similarities were observed between strain CY22 and Bacillus sp. TKSP 24, and between strain CY22 and B. subtilis 168. Phylogenetic analysis based on 16S-rDNA sequences showed that strain CY22 was closely related to Bacillus sp. The main whole-cell fatty acids were anteiso-C_15:0 (37%), C_17:0 (5.1%), and iso-C_15:0 (27.7%). DNA G + C content was 54 mol%. Based on phylogenetic inference, phenotypic and chemotaxonomic characteristics, this endophytic strain Bacillus sp. CY22 was assigned to the genus Bacillus.     

Restriction on Conjugational Transfer of pLS20 in Bacillus subtilis 168

Conjugational transfer of pLS20 in Bacillus subtilis Marburg 168 is restricted by the BsuM restriction-modification system. Restriction efficiency was measured using pLS20 derivatives possessing various numbers of XhoI sites, which are known to be recognized by BsuM. An increase in XhoI sites clearly reduced the conjugational efficiency of pLS20 as compared with that of pUB110 plasmid lacking XhoI.     

Transfer and expression of the cryIVB and cryIVD genes of Bacillus thuringiensis subsp. israelensis in Bacillus sphaericus 2297

Abstract The genes encoding the CryIVB and CryIVD crystal polypeptides of B. thuringiensis subsp. israelensis were cloned indepently on a stable shuttle vector, and transfered into B. sphaericus 2297. Recombinant cells expressed the B. thuringiensis toxins during sporulation and were shown to be toxic to Aedes aegypti fourth instar larvae, whereas the parental strain was not.     

Stress integrated tests and cytological analyses reveal Brassica villosa subsp. drepanensis seed quality decrease upon long-term storage

Under stress integrated germination test (SIGT), seeds undergo osmo-saline stresses, which enable to detect differences in vigour of long-term stored seeds with high germination percentage (G%). The quality of Brassica villosa subsp. drepanensis seeds stored in a genebank (at ? 20°C for 16 years) was compared with seeds at harvest by standard germination tests (GT), SIGT and cytogenetic analysis. No differences were detected in G% and mean germination time under GT. Conversely, SIGT performed with NaCl ? 0.9 MPa osmotic potential did not influence G% at harvest but reduced that of stored seeds, SIGT at ? 1.4 MPa reduced G% of both. Cytogenetic analysis showed reduction of mitotic index, appearance of chromosomal aberrations and smaller nucleoli in stored seeds compared with harvest seeds germinated in water. SIGT at ? 0.9 MPa had no effect on mitotic index, but increased chromosome aberrations and nucleoli number. SIGT at ? 1.4 MPa inhibited G% of harvest and stored seeds, reduced mitoses in harvest and completely prevented it in stored seeds. The results indicate that GT does not faithfully reflect the quality of stored seeds, with misinterpretation of their vigour, whereas SIGT and cytogenetical parameters are sensitive, reliable and inexpensive methods for early prediction of genetic erosion in germplasm banks.     

Effect of nonionic detergents on the activity of a thermostable lipase from Bacillus stearothermophilus MC7

The influence of nonionic surfactants on the activity of a novel thermostable lipase from Bacillus stearothermophilus MC7 was investigated with a view to its potential for synthesis of structured lipids. A large number of modifiers within a broad concentration range were applied. The activity of the enzyme was measured at a relatively high reaction temperature. Highest degree of activation was observed when PEG₆₀₀₀ was applied (up to 2.3-fold increase). Modification essentially changed the performance of the lyophilised preparations—they keep up to 80% of the activity of the native enzyme in the presence of a detergent against 30% in its absence. The effect of sorbitan esters (spans) and polyoxyethylene derivatives of sorbitan esters (tweens) on lipase MC7 was estimated, their HLB value varying within the interval 2.1–16.7. Tweens were strong inhibitors at higher concentrations. For all spans, excepting span 60, an increase of enzyme activity with concentration was observed. All studied additives slow down the process of thermal denaturation. Lipase preparations preserve more than 60% of their activity after 30-min incubation at 75 °C in the presence of tween 60 or PEG₄₀₀₀.