Under the lower temperature condition of 1￣2℃, the structure of protoplasm slightly damaged and the quantity of exudate reduced. The electric conductivity of treated seedlings was less from 0.12×10-4 to 0. 22×10-4sm-1 than control.
Streptomyces 702 can obviously result in condensing of the plasma in the mycelium cell and strongly inhibit sclerotium and spore germination,a complete inhibition takes place when the dosage is at the level of 15.11 mg/L and 10.64 mg/L.
When the plants were kept under the low temperature of 0-2℃, the plasma structure damage of the plants of the treatments was less serious than that of the plants of the control. Because of less amount of substances leaking out from the plasma, the electrical conductivity of the treatments was 0. 12 × 10(-4)s/m lower than that of the control.
By using the tylosin producing Streptomyces fradiae strain 028-3 as a starter,a mutant H188 with a yield of 2 times higher was obtained after three rounds of NTG mutation. After further treatments by means of protoplant regeneration and protoplast mutation,two new mutants, A117 and D85, were obtained and their yields were 6. 5 and 5. 5 times higher than that of H188,respetively.
The main work presented in this study is as follows:Riboflavin-producing strain B.subtilis 24, a recA4 mutant, was transformed with a DNA fragment containing whole recA gene by an approach of protoplast transformation with DNA fragments, then the ability of homologous recombination in B.subtilis 24 was recovered.
These evidences suggested that both Hg2+-sensitive aquaporins and ion channels existing in the protoplasm and vacuole membranes could regulate root water uptake, transport, and integral plant water balance.
DCWFs exhibited an integrity of their protoplasm and were metabolically active.
The results of energy-dispersive X-ray microanalysis indicated that Eu3+ and La3+ can be absorbed into plant cells and bind to the membranes of protoplasm, chloroplast, mitochondrion, cytoplast, and karyon.
A detailed description of their fine structure is presented here which tends to support the ascribed function of microtubules in maintaining the structural integrity of the protoplasm.
The alga reduced acetylene to ethylene and incorporated 15N2 into cell protoplasm when incubated in a low oxygen atmosphere.
Recombinant tissue-type plasmogen activator (rt-PA) was produced in Escherichia coli cells in order to obtain an unglycosylated rt-PA (BM 06.021) with increased thrombolytic potency due to altered pharmacokinetic properties.