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1.
Summary The glucose isomerase activity ofStreptomyces haeochromogenes strains 1 and 2 varies considerably with the assay conditions (pH, glucose concentration,etc.). Nine other species of streptomyces were tested under conditions optimal forS.phaeochromogenes 2. The highest enzyme activity was found inS.nigrificans 3014. 相似文献
2.
Summary The fermentation of D-xylose byPachysolen tannophilus Y2460,Pichia stipitis Y7124,Kluyveromyces marxianus Y2415 andCandida shehatae Y12878 was investigated in aerobic, anaerobic and microaerophilic batch cultures. The aeration rate greatly influenced the fermentations; growth, rate of ethanol production and oxidation of ethanol are affected. Of the strains tested,Pichia stipitis appears superior; under anaerobic conditions it converts D-xylose (20 g/l) to ethanol with a yield of 0.40 g/l and it exhibits the highest ethanol specific productivity (3.5 g of ethanol per g dry cell per day) under microaerophilic conditions. 相似文献
3.
Michihiko Kobayashi Toru Nagasawa Noriyuki Yanaka Hideaki Yamada 《Biotechnology letters》1989,11(1):27-30
Summary The reaction conditions for the enzymatic production ofp-aminobenzoic acid were optimized, using a nitrilase in cells ofRhodococcus
rhodochrous J1. The highest accumulation, 110 gp-aminobenzoic acid/liter of reaction mixture, was attained fromp-aminobenzonitrile, with a conversion yield of 100%. 相似文献
4.
Issay Narumi Kazumi Sawakami Shinya Nakamoto Noriyuki Nakayama Tadashi Yanagisawa Nobutaka Takahashi Hiroshi Kihara 《Biotechnology Techniques》1992,6(1):83-86
Summary Optimal conditions for the plasmid transformation of a newly isolatedBacillus
stearothermophilus K1041 by electroporation were investigated. The optimal conditions allowed a transformation efficiency of 5.8×105 transformants per μg plasmid pUB110. 相似文献
5.
Summary For the protein upgrading of sugar-beet pulp in solid state fermentation byTrichoderma
reesei andFusarium
oxysporum, serveral conditions were studied to prepare an economical preculture for large scale process. The best performance was shown by a preculture obtained in 24 h from 1.5 % molasses solution at pH 4.5–5.0 with 1.0 % milled beet pulp. 相似文献
6.
Summary A phenol tolerant thermophile,Bacillus
stearothermophilus BR219, catabolizes phenol via a plasmid encoded catecholmeta pathway. Direct and selective inhibition of catechol 2,3-dioxygenase encoded in this pathway by tetracycline results in accumulation of the specialty chemical catechol. Optimal conditions for catechol production are presented. 相似文献
7.
Influence of the inoculum size ofLactobacillus
plantarum on the competition withEnterobacter
cloacae
Summary The size of the inoculum ofLactobacillus
plantarum or its natural density, appears to be of predominant importance in the exclusion ofEnterobacter
cloacae in mixed fermentations, such as ensilage. In a liquid medium, simulating adverse silage conditions, an initial density ofL.
plantarum at least twice that ofE.
cloacae was found necessary in order to obtain a succesful silage. 相似文献
8.
Bacillus
brevis 47 was grown in shake flasks under varying conditions of agitation, culture volume, inoculum size, medium supplementation, and initial pH. It was found to have a high demand for oxygen, and, under appropriate conditions, could produce up to 9 g/l of two extracellular wall proteins in 24 h. 相似文献
9.
Summary The reducing sugars, glucose, and ethanol produced during growth of the anaerobes Clostridium thermocellum and Acetivibrio cellulolyticus on cellulose were assayed. Zymomonas mobilis was grown under similar conditions and could ferment glucose to ethanol. The ethanol production by the cellulolytic bacteria alone and in co-culture with Zymomonas is described. Approximately 27% of a 1% cellulose substrate could be converted to ethanol by this co-culture. 相似文献
10.
Stem and petiole explants, obtained from mature trees, ofAlbizzia lebbeck,Cassia fistula andC.siamea callused and differentiated shoot-buds and later shoots on B5 medium supplemented with either 0.5 mg/l IAA + 1 mg/l BAP or BM + 2 mg/l NAA + 0.5 mg/l BAP. The stem explants were more responsive than the petiole explants. InA.lebbeck, the IAA substituted medium favoured differentiation from both types of explants. However, inC.fistula, the type of explants rather than the medium composition had an overriding influence on shoot differentiation since those from petiole hardly responded in either medium. It has been possible to obtain plantlets from bothA.lebbeck andC.fistula under conditions conducive to rooting. Plantlets ofA.lebbeck have also been successfully transferred to the field. 相似文献
11.
Cultured protoplasts from cell suspensions of Pelargonium aridum, P.x hortorum and P. peltatum divided and formed callus. On agar-solidified regenerative medium, such protoplast-derived calli (p-calli) underwent plant regeneration at frequencies approaching 100% for P. aridum and 10% for P.x hortorum. Under similar conditions shoot primordia arose in 5% of P. peltatum p-calli, but these never developed into normal shoots. However, following a liquid-shake culture regime, whole plants were induced in 20% of P. peltatum p-calli. This approach also improved regeneration of P.x hortorum to 60%.Abbreviations NAA
napthaleneacetic acid
- 6-BAP
6-benzylaminopurine 相似文献
12.
J E Hughes 《Biotechnology Techniques》1996,10(11):831-838
Summary The pIDDLE6 (for PCR-based, in-frame, directional DNA ligation and expression) system utilises novel ligation procedures to clone and overexpress almost any coding sequence. Inserts are cloned either by blunt ligation in the presence of PmeI or by ligation between dissimilar SfiI sites. A chimeric protein with both N- and C-terminal tags is produced, allowing purification by via starch-or nickel-affinity under native or denaturing conditions. The tags can be removed independently. The the vector and ligation procedures have been used successfully as described. 相似文献
13.
Summary A yeast strainMoniliella
pollinis produces an extracellular highly viscous gum-like polysaccharide of glucan type in a simple mineral medium. Optimum conditions for its production and properties are described. The viscosity decreased after lyophilization. 相似文献
14.
Eeva Levonen-Munoz Derek H. Bone Andrew J. Daugulis 《Applied microbiology and biotechnology》1983,18(2):120-123
Summary Seventee white-rot and brown-rot fungi were screened for their ability to fractionate the lignocellulose structure of oat straw through the preferential attack of lignin or cellulose. Fermentations were carried out under solid-state conditions with 25 g quantities of straw. The fermented straw was analyzed for weight loss, Klason lignin loss and cellulase digestion. All the fungi attacked both lignin and carbohydrate fractions causing 3–28% weight losses and 26–34 g/100 g enzymatic digestibility. Polyporus
tulipiferae, Phanerochaete
chrysosporium and Polyporus sp. were tested for the effects of various nitrogen, phosphate and carbon levels, incubation temperatures and incubation time. The three fungi had different responses to these factors. 相似文献
15.
Maria Cristina Baracat Maria Cristina Dantas Vanetti Eiza Fernandes de Araujo Daison Olzany Silva 《Biotechnology letters》1991,13(10):693-696
Summary Optimum growth conditions forA.
fumigatus strain 4 when citric pectin was the sole carbon source were at a temperature of 45°C, pH 4.0 and an incubation time from 36 to 42h. Under these conditions no cellulase activity was found. When orange pulp was the sole carbon source, optimum polygalacturonase activities were found when the fungus was cultured for 36 h at 45°C and a pH 3.0 to 4.5. 相似文献
16.
Mireille Chabaud Joan E. Passiatore Frank Cannon Vicky Buchanan-Wollaston 《Plant cell reports》1988,7(7):512-516
Kanamycin resistant plants of Medicago varia A2 were obtained by an optimized procedure for high frequency transformation using Agrobacterium tumefaciens infection of leaf and petiole tissue. Parameters which affected the frequency were explant type, the Agrobacterium strain used and the time allowed for cocultivation. Under optimum conditions, i.e., using the Agrobacterium strain A281 and a 4 day cocultivation period, the frequency of transformed leaflets obtained was greater than 70%. 相似文献
17.
Summary Optimal conditions for the transformation of Bacillus subtilis by electroporation were achieved. Frequencies of greater than 105 transformants/μg of plasmid DNA were obtained for a number of strains and plasmids. Increased transformation efficiency of mini-prep DNA from B. subtilis and Escherichia coli was obtained after microdialysis. 相似文献
18.
D. R. Modi A. K. Singh K. S. Rao D. Chakravarty H. N. singh 《Biotechnology letters》1991,13(11):793-798
Summary Machete resistant (Mat
r), basalin resistant (Bas
r), 3(3,4 dichlorophenyl)-1,1-dimethyl urea resistant (DCMU
r), atrazine resistant (Atr
r) and propanil resistant (Prp
r) phenotypes ofGloeocapsa sp. were cotransformed toNostoc
muscorum at high frequency. Spontaneously occurring mutants of the multiple herbicide resistant transformant containing L-methionine-DL-sulfoximine resistant (Msx
r), ethylene diamine resistant (Eda
r), or phosphinothricin resistant (Ppt
r) glutamine synthetase (GS) showed extracellular liberation of ammonia resulting from fixation of N2 under photosynthetic conditions. Results suggest a definite role of GS activity in regulation of extracellular ammonia. 相似文献
19.
Comparative evaluation of ethanol production by xylose-fermenting yeasts presented high xylose concentrations 总被引:5,自引:0,他引:5
Summary Three strains ofPichia
stipitis and three ofCandida
shehatae were compared withPachysolen
tannophilus in their abilities to ferment xylose at concentrations as high as 200 g/L when subjected to both aerobic and microaerophilic conditions. Evaluations based on accumulated ethanol concentrations, ethanol productivities, xylose consumption, and ethanol and xylitol yields were determined from batch culture time courses. Of the strains considered,P.stipitis NRRL Y-7124 seemed most promising since it was able to utilize all but 7 g/L of 150 g/L xylose supplied aerobically to produce 52 g/L ethanol at a yield of 0.39 g per gram xylose (76% of theoretical yield) and at a rate comparable to the fastest shown byC.shehatae NRRL Y-12878. For all strains tested, fermentation results from aerobic cultures were more favorable than those from microaerophilic cultures.The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned. 相似文献
20.
Lee R. Hagey Skaidrite K. Krisans 《Biochemical and biophysical research communications》1982,107(3):834-841
Under standard assay conditions peroxisomes were found to contain less than 5% of the liver's cholesterol degradation activity. The remainder of the activity was localized in the mitochondria. When CaCl2 was added to the standard assay mixture, peroxisomal cholesterol degradation activity increased to 34%. These results suggest that peroxisomes are capable of cholesterol catabolism, with the assay conditions used invitro determining the relative organelle contribution. 相似文献