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61.
Summary A novel cultivation method using a microporous membrane (membrane-surface liquid culture) was developed, in which moulds are grown on the membrane surface with its opposite side being in contact with a liquid medium. The amount of neutral protease from Aspergillus oryzae produced was more than 10 times higher than that produced by the conventional liquid culture. 相似文献
62.
Ayaaki Ishizaki Tomoko Ueda Kenji Tanaka Peter F. Stanbury 《Biotechnology letters》1993,15(5):489-494
Summary The relative contributions of lactate inhibition and the generation of sterile (undividing) cells to the low xylose utilisation rate of Lactococcus lactis IO-1 was investigated. The lactate inhibition constant of xylose grown cells was shown to be 9.3 times more than that of glucose grown cells. However, the sterile cell production rate and LDH inactivation rate of the xylose cultures were at least 10 times less than the glucose cultures. Thus, it is suggested that the slower substrate consumption rate in xylose medium is caused mainly by the large inhibition constant for the end product. 相似文献
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Kawarabayasi Yutaka; Tanaka Ayako; Ohara Osamu; Arakawa Taku; Oka Masanori; Kato Hisako; Morita Miyo; Fujisawa Hisao 《DNA research》1994,1(6):289-296
To sequence a DNA segment inserted into a cosmid vector underthe directed sequencing strategy, we established a simple andrapid method for generating nested deletions which uses thein vitro packaging system of bacteriophage T3 DNA. The principleis based on the previous finding that this system can translocateany linear double-stranded DNA up to 40 kb into the phage capsidin a time-dependent manner and the encapsulated DNA becomesDNase-resistant. For this purpose, we constructed a cosmid vectorthat carries two different antibiotic selection markers at bothsides of the multiple cloning site, and after insertion of aDNA segment, the clone was linearized by -terminase at the cossite. After the packaging reaction in vitro followed by DNasetreatment, the encapsulated DNA was introduced into Escherichiacoli cells to give clones with unidirectional deletions by differentialantibiotic selection. Restriction and sequence analyses of deletionclones demonstrated that an ordered set of clones with nesteddeletions, ranging from less than 1 kb to 25 kb, was createdfrom either the end of the DNA segment. Thus, nested deletionclones that cover the entire region of a 40-kb cosmid insertcan be obtained by a single packaging reaction, and its restrictionmap can be simultaneously obtained. 相似文献
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To study the roles of m5C in the differentiation of rice calli derived from protoplasts (protoclones), the m5C level of the total DNA was analyzed using the32P post-labeling method. The level of m5C in regenerable and nonregenerable protoclones was similar, as was in calli and leaves of plants regenerated from the same
protoclones. Treatment with 0.5 mM 5-azacytidine caused significant reduction of the level of m5C and of the regeneration frequency of callus. Significantly increased m5C levels were observed during prolonged culture. 相似文献
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