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排序方式: 共有711条查询结果,搜索用时 234 毫秒
1.
F F Dias M K Shaikh Y B Bhatt D C Modi V R Subramanyam 《The Journal of applied bacteriology》1986,60(4):271-275
Mutants of Bacillus amyloliquefaciens resistant to at least 10 micrograms/ml of tunicamycin were isolated and shown to be pleiotropic. The mutants were more resistant to streptomycin, chloramphenicol, kanamycin and neomycin than was the parent strain but less resistant to penicillin G and tetracycline. They were more autolytic, presumably due to an altered cell wall. The mutants produced reduced levels of amylase, penicillinase and both metal and serine protease besides having an enhanced sporulation frequency and being more motile. 相似文献
2.
Kondeti Subramanyam K. V. Sailaja Koona Subramanyam D. Muralidhara Rao K. Lakshmidevi 《Plant Cell, Tissue and Organ Culture》2011,105(2):181-192
Plants, when exposed to abiotic or biotic stress, produce several pathogenesis-related proteins to counteract the effects
of stress. Osmotin is one of the important pathogenesis-related proteins induced during several stress conditions. We have
developed improved salt stress tolerant transgenic chilli pepper plants (Capsicum annum L. var. Aiswarya 2103) by ectopic expression of the Nicotiana tabaccum osmotin gene using Agrobacterium
tumefaciens EHA105 as a vector. Four-week-old chilli pepper leaves were used as an explant and A. tumefaciens EHA105 harboring pBINASCOSM plasmid that contains osmotin gene under the control of CaMV 35S promoter and npt II as a selectable marker was used in co-cultivation. Transgene integration and expression were analyzed using molecular,
immunochemical, and biochemical assays. PCR and Southern blot analysis confirmed that osmotin gene has been successfully integrated
into the genome of chilli pepper plants. The osmotin gene was stably segregated and expressed in T2 generation transgenic chilli pepper plants, and it was confirmed by Western blot analysis. Biochemical assays of these putative
transgenic plants revealed enhanced levels of chlorophyll, proline, glycinebetaine, APX, SOD, DHAR, MDHAR, GR, and relative
water content. Yield potential of the putative transgenic chilli pepper plants was evaluated under salinity stress conditions
in a green house. The putative transgenic chilli pepper plants overexpressing the osmotin gene were morphologically similar
to wild-type plants and produced 3.32 kg chilli pepper fruits per plant at 300 mM NaCl concentration. 相似文献
3.
4.
The free and N-acetyl glucosamine contents, serving as a measure of the amounts of chitosan and chitin respectively, were
determined in the chitinase hydrolysates of the cell wall of a wild strain ofNeurospora crassa. Chitinase, obtained from cultures ofSerratia marcescens, could hydrolyse the cell wall completely apart from being capable of hydrolysing preparations of chitin and chitosan. The
free and N-acetyl glucosamines, released by chitinase hydrolysis, were determined by a modified Morgan-Elson reaction carried
out in the presence and absence of acetic anhydride. The method is capable of estimating chitin and chitosan contents in as
little as 100 μg of cell wall material. 相似文献
5.
The cytogenetic effects of the antimetabolite, cytosine arabinoside (Ara-C) are evaluated using in vivo and in vitro test systems and applying multiple parameters. The in vivo assay was carried out on 8-10-week-old inbred Swiss albino male mice using bone marrow as the somatic test system and the cells of testis as the meiotic test system. In vitro human leukocyte cultures were also employed. In vivo experimental doses were computed on surface area basis within the therapeutic dose range and injected intraperitoneally and for in vitro they were calculated on blood volume basis. Evaluation of somatic chromosome mutations included conventional screening for chromosome aberrations, variations in mitotic index and sister-chromatid exchanges (SCEs) by in vivo and in vitro methods besides studies on meiotic test systems using conventional screening for chromosome and sperm-head abnormalities. The quantitative data were subjected to statistical analysis by applying appropriate tests to evaluate their significance. The results of in vivo and in vitro experiments reveal the chromosome mutational activity of the compound. This is further supported by data on SCEs from both systems. However, a comparison of both demonstrated a differential mutagenic response of the drug, more in vivo than in vitro. This is also true for SCEs. Even though the mechanisms involved in causing chromosome aberrations and SCEs are different, the data on both corroborate each other on induction of chromosome mutations. 相似文献
6.
D C Modi Y B Bhatt M K Shaikh V R Subramanyam F F Dias 《The Journal of applied bacteriology》1986,61(4):315-318
Anilogel-E, a cross-linked starch, can be used with distinct advantages where native starch or soluble starch are conventionally used, e.g. in scoring for amylolytic organisms, as an ingredient of fermentation media, and in enhancing protoplast regeneration. It is particularly useful for the direct visualization of amylase producing micro-organisms on solid media, making prior replication of colonies unnecessary. 相似文献
7.
Cell Wall Composition of Neurospora crassa Under Conditions of Copper Toxicity 总被引:2,自引:0,他引:2 下载免费PDF全文
The mycelia of Neurospora crassa grown in the presence of high concentrations of copper were blue in color, but only on a medium containing inorganic nitrate and phosphate as the nitrogen and phosphate sources, respectively. The cell wall isolate of the blue mycelia contained large amounts (12%) of copper and higher amounts of chitosan, phosphate, and amino groups, with a 42% decrease in the chitin content. Although all the glucosamine of the cell wall of control cultures could be released within 6 h of hydrolysis with acid, that of the blue mycelium required prolonged hydrolysis for 24 h. On removal of copper, the cell wall of the blue mycelium could quantitatively bind again to copper as well as to zinc. Although zinc binding was fivefold greater, copper alone was preferentially bound from a mixture of the two metal ions. Supplementation of iron along with copper in the culture medium resulted in the disappearance of the blue color of the mycelium and restoration of normal growth and composition of the cell wall, probably by limiting the uptake of copper from the medium. The possibility of the cell wall being a specific site of lesion in copper toxicity in the mold is discussed. 相似文献
8.
Effects of Nerve Growth Factor on Glutathione Peroxidase and Catalase in PC 12 Cells 总被引:4,自引:1,他引:3
Deepa Sampath George R. Jackson Karin Werrbach-Perez J. Regino Perez-Polo 《Journal of neurochemistry》1994,62(6):2476-2479
Abstract: Nerve growth factor (NGF) is a member of the neuro- trophin family and is required for the survival and maintenance of peripheral sympathetic and sensory ganglia. In the CNS, NGF regulates cholinergic expression by basal forebrain cholinergic neurons. NGF also stimulates cellular resistance to oxidative stress in the PC12 cell line and protects PC12 cells from the toxic effects of reactive oxygen species. The hypothesis that NGF protection involves changes in antioxidant enzyme expression was tested by measuring its effects on catalase and glutathione per- oxidase (GSH Px) mRNA expression in PC12 cells. NGF increased catalase and GSH Px mRNA levels in PC 12 cells in a time- and dose-dependent manner. There was also a corresponding increase in the enzyme activities of catalase and GSH Px. Thus, NGF can provide cytoprotection to PC12 cells by inducing the free radical scavenging enzymes catalase and GSH Px. 相似文献
9.
Sushama Chaphalkar Rajdeep Dongre Deepa Joshi Sabita Dey 《Biotechnic & histochemistry》1993,68(3):166-168
A synthetic aromatic polymer has been used for preparing replicas of different microorganisms. This method of preparing highly concentrated (9.6 k) microbiological samples for scanning electron microscopy was compared with a standard method. The micrographs of the replicated samples are satisfactory. This method is rapid, cost effective and produces good results, especially in the case of spore-forming mycelial microorganisms. 相似文献
10.
New combinations for three species ofPolypleurum have been proposed. The Apinagia type of embryo sac is recorded for the first time in a species ofPolypleurum, P. filifolium. The Dicraea type of embryo sac found inP. dichotomum andP. munnarensis has been reinterpreted and renamed as the Polypleurum type. The embryo sac types met with in the family are discussed. The nucellar plasmodium organizes before the embryo sac attains maturity in all the three investigated species. 相似文献