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101.
Kuvalekar Aniket Pawar Pankaj Khare Ankita Gandhe Kanchanganga Harsulkar Abhay 《Plant Cell, Tissue and Organ Culture》2008,94(1):101-104
Ravenelia esculenta Naras. and Thirum. is a rust, pathogenic to Acacia eburnea Willd. The infection leads to hypertrophy changing the morphology with bizarre shapes of plant organs. Healthy and infected
tissues were subjected to extraction of IAA and indole derivatives and were estimated by spectrophotometric methods. The hypertrophy
produced was presumed to be due to increase in the indole-3-acetic acid (IAA) content in the infected tissue, however, the
amount of IAA in infected tissues decreased with the progression of disease. Concomitantly, the infected tissue showed the
presence of a novel, slow migrating, indole derivative on TLC. Cultured shoot tips of Withania somnifera were dosed with the methanolic extract of the infected hypertrophied tissue (MEHT) (0.25, 0.5, 0.75, 1.00 and 1.25 mg/l).
The stimulation in shoot growth along with profuse rooting was observed in a dose dependent manner with maximum at 1.00 and
1.25 mg/l concentration. 相似文献
102.
Epicotyl, petiole, and cotyledon explants derived from 14-d-old seedlings of Albizia odoratissima were cultured on Murashige and Skoog (MS) basal medium supplemented with different concentrations of either 6-benzylaminopurine
(BAP) solely or in combination with 0.5 μM naphthalene-3-acetic acid (NAA). The percentage of shoot regeneration and the number
of shoots regenerated varied significantly depending on the type of explants used, the concentration of plant growth regulators,
and the orientation of explants on the culture medium. The best response in terms of the percentage of shoot regeneration
was obtained from epicotyls cultured horizontally on MS medium supplemented with 5 μM BAP, whereas the highest number of shoots
per responding explant was recorded on medium containing 2.5 μM BAP and 0.5 μM NAA. Successful rooting was achieved by placing
the microshoots onto MS medium containing 25 μM indole-3-butyric acid (IBA) for 24 h first, then transferring to the same
medium without IBA. Of the various substrates tested, vermiculite was the best for plant acclimatization, as 75% of the plants
survived and became established. 相似文献
103.
Spatio-temporal tumour model for analysis and mechanism of action of intracellular drug accumulation
We have developed a one-dimensional tumour simulator to describe the biodistribution of chemotherapeutic drugs to a tumoral
lesion and the tumour cell’s response to therapy. A three-compartment model is used for drug dynamics within the tumour. The
first compartment represents the extracellular space in which cells move, the second corresponds to the intracellular fluid
space (including cell membrane) which is in direct equilibrium with the extracellular space, and the third is a non-exchangeable
compartment that represents sequestered drug which is trapped in the nucleus to damage the cellular DNA, directly triggering
cell death. Analytical and numerical techniques (Finite Element Method) are used to describe the tumour’s response to therapy
and the effect of parameter variation on the drug concentration profiles in the three compartments. 相似文献
104.
Chao Tai Diego S. Voltan Deepak R. Keshwani George E. Meyer Pankaj S. Kuhar 《Bioprocess and biosystems engineering》2016,39(6):937-944
A fuzzy logic feedback control system was developed for process monitoring and feeding control in fed-batch enzymatic hydrolysis of a lignocellulosic biomass, dilute acid-pretreated corn stover. Digested glucose from hydrolysis reaction was assigned as input while doser feeding time and speed of pretreated biomass were responses from fuzzy logic control system. Membership functions for these three variables and rule-base were created based on batch hydrolysis data. The system response was first tested in LabVIEW environment then the performance was evaluated through real-time hydrolysis reaction. The feeding operations were determined timely by fuzzy logic control system and efficient responses were shown to plateau phases during hydrolysis. Feeding of proper amount of cellulose and maintaining solids content was well balanced. Fuzzy logic proved to be a robust and effective online feeding control tool for fed-batch enzymatic hydrolysis. 相似文献
105.
Diversity of halophilic microorganisms: Environments,phylogeny, physiology,and applications 总被引:13,自引:0,他引:13
Oren A 《Journal of industrial microbiology & biotechnology》2002,28(1):56-63
The phylogenetic diversity of microorganisms living at high salt concentrations is surprising. Halophiles are found in each
of the three domains: Archaea, Bacteria, and Eucarya. The metabolic diversity of halophiles is great as well: they include
oxygenic and anoxygenic phototrophs, aerobic heterotrophs, fermenters, denitrifiers, sulfate reducers, and methanogens. The
diversity of metabolic types encountered decreases with salinity. The upper salinity limit at which each dissimilatory process
takes place is correlated with the amount of energy generated and the energetic cost of osmotic adaptation. Our understanding
of the biodiversity in salt-saturated environments has increased greatly in recent years. Using a combination of culture techniques,
molecular biological methods, and chemotaxonomic studies, we have obtained information on the nature of the halophilic Archaea
as well as the halophilic Bacteria that inhabit saltern crystallizer ponds. Several halophilic microorganisms are being exploited
in biotechnology. In some cases, such as the production of ectoine, the product is directly related to the halophilic behavior
of the producing microorganism. In other cases, such as the extraction of β-carotene from Dunaliella or the potential use of Haloferax species for the production of poly-β-hydroxyalkanoate or extracellular polysaccharides, similar products can be obtained
from non-halophiles, but halophilic microorganisms may present advantages over the use of non-halophilic counterparts. Journal of Industrial Microbiology & Biotechnology (2002) 28, 56–63 DOI: 10.1038/sj/jim/7000176
Received 20 May 2001/ Accepted in revised form 20 June 2001 相似文献
106.
Cobucci-Ponzano B Conte F Rossi M Moracci M 《Extremophiles : life under extreme conditions》2008,12(1):61-68
Glycoside hydrolases form hyperthermophilic archaea are interesting model systems for the study of catalysis at high temperatures
and, at the moment, their detailed enzymological characterization is the only approach to define their role in vivo. Family
29 of glycoside hydrolases classification groups α-l-fucosidases involved in a variety of biological events in Bacteria and Eukarya. In Archaea the first α-l-fucosidase was identified in Sulfolobus solfataricus as interrupted gene expressed by programmed −1 frameshifting. In this review, we describe the identification of the catalytic
residues of the archaeal enzyme, by means of the chemical rescue strategy. The intrinsic stability of the hyperthermophilic
enzyme allowed the use of this method, which resulted of general applicability for β and α glycoside hydrolases. In addition,
the presence in the active site of the archaeal enzyme of a triad of catalytic residues is a rather uncommon feature among
the glycoside hydrolases and suggested that in family 29 slightly different catalytic machineries coexist. 相似文献
107.
Eman M. Alissa Suhad M. Bahjri Waqar H. Ahmed Nabeel Al-Ama Gordon A. A. Ferns 《Biological trace element research》2009,131(3):215-228
Chromium deficiency is associated with impaired glucose tolerance (IGT) and dyslipidemia. Hence, the objective of the current
study was to investigate chromium status among Saudi men with and without established cardiovascular disease (CVD) and its
relationship to glucose tolerance, lipid profile and other established CVD risk factors. We measured serum and urine chromium
concentrations, fasted lipid profile, plasma glucose, and serum lipid peroxide in 130 Saudi men with an established history
of myocardial infarction and 130 age-matched controls without established CVD. Patients with established CVD had higher serum
triglycerides (p < 0.05) and plasma glucose (p < 0.0001) and lower serum and urinary chromium concentrations (p < 0.0001) than controls. Serum chromium was inversely correlated with plasma glucose among cases and controls (r = −0.189, p < 0.05 and r = −0.354, p < 0.00001, respectively). Plasma glucose (OR 1.127, CI 1.0–1.269, p < 0.05), serum chromium (OR 0.99, CI 0.985–0.995, p < 0.0001), and urinary chromium (OR 0.988, CI 0.981–0.995, p < 0.001) were independently associated with the presence of established coronary disease applying this model. While chromium
metabolism appears to be altered in individuals with CVD, it is unclear whether chromium supplementation would be effective
in CVD prevention among patients with IGT. This would need to be tested in long-term outcome trials. 相似文献
108.
Chloroplasts are believed to be descendants of ancestral cyanobacteria that had peptidoglycan layer between the outer and the inner membranes. Historically, the glaucophyte Cyanophora paradoxa and the rhizopod Paulinella chromatophora were believed to harbor symbiotic cyanobacteria having peptidoglycan, which were conventionally named “cyanelles”. In addition, the complete set of genes involved in the synthesis of peptidoglycan has been found in the moss Physcomitrella patens and some plants and algae. The presence of peptidoglycan-like structures was demonstrated by a new metabolic labeling technique in P. patens. However, many green algae and all known red algae lack peptidoglycan-related genes. That is the reason why we questioned the origin of peptidoglycan-synthesizing enzymes in the chloroplasts of the green algae and plants. We performed phylogenetic analysis of ten enzymes involved in the synthesis of peptidoglycan exploiting the Gclust homolog clusters and additional genomic data. As expected, all the identified genes encoded in the chromatophore genome of P. chromatophora were closely related to cyanobacterial homologs. In the green algae and plants, only two genes, murA and mraY, were found to be closely related to cyanobacterial homologs. The origins of all other genes were diverse. Unfortunately, the origins of C. paradoxa genes were not clearly determined because of incompleteness of published genomic data. We discuss on the probable evolutionary scenarios to explain the mostly non-cyanobacterial origins of the biosynthetic enzymes of chloroplast peptidoglycan: A plausible one includes extensive multiple horizontal gene transfers during the early evolution of Viridiplantae. 相似文献
109.
Priya Padmanabhan Mukund R. Shukla J. Alan Sullivan Praveen K. Saxena 《Plant Cell, Tissue and Organ Culture》2017,128(1):145-160
C4 plants can efficiently accumulate CO2 in leaves and thus reduce wasteful oxygen fixation by the RuBisCO enzyme. Three C4 enzymes, namely carbonic anhydrase (CA), phosphoenol pyruvate (PEPC) and pyruvate orthophosphate dikinase (PPDK), were over expressed in Oryza sativa L. ssp. indica var. Khitish under the control of green tissue specific promoters PD54o, PEPC and PPDK, respectively. Integration of these genes was confirmed by Southern hybridization. The relative expression of PEPC, CA and PPDK were, respectively, 6.75, 6.57 and 3.6-fold higher in transgenic plants compared to wild type plants (control). Photosynthetic efficiency of the transgenic plants increased significantly along with a 12?% increase in grain yield compared to wild type plants. Compared to control plants, transgenic plants also showed phenotypic changes such as increased leaf blade size, root biomass, and plant height and anatomical changes such as greater leaf vein number, bundle sheath cells, and bulliform cells. Our findings indicate that the combined over expression of these three enzymes is an efficient strategy for incorporating beneficial physiological and anatomical features that will enable subsequent yield enhancement in C3 rice plants. 相似文献
110.