Reaction kinetics of d-glucose fermentation by Saccharomyces cerevisiae

Data obtained on the conversion of d-glucose to alcohol using Saccharomyces cerevisiae in batch culture has been analysed kinetically. The effects of different kinetic parameters, e.g. rates of ethanol and biomass formation, rate of d-glucose utilization and variation of pH have been studied. Analysis of data was made on the basis of Michaelis-Menten, Leudeking-Piret and simple kinetics. Unsteady rate behaviour in the lag phase was observed and explained.     

Studies on the neurosecretory system and retrocerebral endocrine glands of Nezara viridula Linn. (Heteroptera: Pentatomidae)

The neurosecretory system and retrocerebral endocrine glands of Nezara viridula Linn. have been described on the basis of in situ preparations and histological sections employing the paraldehyde fuchsin (PF) and performic acid-victoria blue (PAVB) techniques. In the brain of N. viridula, there are two medial groups–each consisting of five neurosecretory cells which belong to A-type. The lateral neurosecretory cells are absent. The axons of the two groups of medial neurosecretory cells (MNC) compose the two bundles of neurosecretory pathways (NSP) that decussate in the anterodorsal part of the protocerebrum. The two pathways, after the cross-over, run deep into the protocerebrum and deutocerebrum and emerge as NCC-I from the tritocerebrum. The nervi corporis cardiaci-I (NCC-I) of each side which are heavily loaded with NSM terminate in the aorta wall. Thus, the neurosecretory material (NSM), elaborated in the medial neurosecretory cells of the brain, is stored in the aortic wall and nervi corporis cardiaci-I (NCC-I). The NCC-II are very short nerves that originate from the tritocerebrum and terminate in the corpora cardiaca (CC) of their side. Below the aorta, but dorsal to the oesophagus, lie two oval or spherical corpora cardiaca. A corpus allatum (CA) lies posterior to the corpora cardiaca (CC). The corpora cardiaca do not contain NSM; only the intrinsic secretion of their cells has been occasionally observed which stains orange or green with PF staining method. The corpus allatum sometimes exhibits PF positive granules of cerebral origin. A new connection between the corpus allatum and aorta has been recorded. The suboesophageal ganglion contains two neurosecretory cells of A-type which, in structure and staining behaviour, are similar to the medial neurosecretory cells of the brain. The course and termination of axons of suboesophageal ganglion neurosecretory cells, and the storage organ for the secretion of these cells have been reported. It is suggested that the aortic wall and NCC-I axons function as neurohaemal organ for cerebral and suboesophageal secretions.     

Effect of Polyamines on Photosynthesis of Source and Sink Organs in Rice (Oryza sativa L.)

The levels of total and individual polyamine and arginine decarboxylase,the key enzyme of its biosynthesis, varied not only betweensource (flag leaf) and sink (spikelet) organs but also in stagesof panicle development in rice. The polyamine(s) titers increasedby 1.2 and 3-fold (approx.) in source and sink organs, respectively,at the milky stage of panicle development. However, the activityof arginine decarboxylase did not follow the same patttern,decreasing gradually in the source organ. The effects of polyamineon the Hill reaction in isolated chloroplasts and in vivo ¹⁴CO₂fixation were inhibitory. The degree of inhibition in the variousdevelopmental stages depended on the concentration of the polyamines. (Received May 19, 1988; Accepted August 9, 1988)     

Characterization of endogenous fluorescence in nonsmall lung cancerous cells: A comparison with nonmalignant lung normal cells

Monitoring fluorescence properties of endogenous fluorophores such as nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) in normal and cancerous cells provide substantial information noninvasively on biochemical and biophysical aspects of metabolic dysfunction of cancerous cells. Time‐resolved spectral profiles and fluorescence lifetime images of NADH and FAD were obtained in human lung nonsmall carcinomas (H661 and A549) and normal lung cells (MRC‐5). Both fluorophores show the fast and slowly decaying emission components upon pulsed excitation, and fluorescence spectra of NADH and FAD show blue‐ and red‐shifts, respectively, during their decay. All identified lifetime components of NADH and FAD were found to be shorter in cancerous cells than in normal cells, no matter how they were measured under different extra‐cellular conditions (cells suspended in cuvette and cells attached on glass substrate), indicating that the changes in metabolism likely altered the subcellular milieu and potentially also affected the interaction of NADH and FAD with enzymes to which these cofactors were bound. The intensity ratio of NADH and FAD of cancerous cells was also shown to be larger than that of normal cells.     

In vitro clonal propagation of<Emphasis Type="Italic"> Clerodendrum serratum</Emphasis> (Linn.) Moon (barangi): a rare and threatened medicinal plant

An in vitro process for rapid clonal propagation of Clerodendrum serratum (Linn.) Moon, a rare and threatened medicinal shrub, has been developed. Nodal stem segments having axillary bud, taken from field-grown plant, showed bud-break within 15 days of culture on modified Murashige and Skoog (MS) (Physiol Plant 15:473–497, 1962) medium supplemented with 0.25 mg/l each of 6-benzylaminopurine and indole-3-acetic acid along with 15 mg/l adenine sulphate (AdS). Regenerated shoots could be further multiplied on the same agarified morphogenetic medium in presence of 0.5 mg/l 2-chloroethyltrimethyl ammonium chloride with increased concentration of AdS, i.e., 30 mg/l. A group of five shoots used as inoculum produced on an average 4.98 new shoots per original shoot after 4 weeks of subculture. Shoots excised from cultures of proliferating shoots were rooted in half-strength MS medium having 1 mg/l indole-3-propionic acid. In vitro rooted shoots—plantlets—grew luxuriantly under field conditions and came to flowering after 10 months of transplantation. The genetic fidelity of in vitro-raised field-grown plants and their mother plant was ascertained by random amplified polymorphic DNA markers. The protocol developed holds good for in vitro cloning of C. serratum.     

Novel and Efficient Protocol for DNA Coating-Based Identification of DNA-Protein Interaction by Antibody-Mediated Immunodetection

Background:Studying protein-protein and protein-DNA interactions are prerequisites for the identification of function and mechanistic role of various proteins in the cell. Protocols for analyzing DNA-based Protein-Protein and Protein-DNA interactions are complicated and need to be simplified for efficient tracking of binding capabilities of various proteins to specific DNA molecules. Here, we demonstrated a simple yet efficient protocol for the identification of DNA coating-based Protein-DNA interaction using antibodymediated immunodetection.Methods:Briefly, we have coated specific DNA in the microtiter plate followed by incubating with protein lysate. Specific protein-DNA and/or protein-protein bind with DNA interactions are identified using specific fluorophore-conjugated antibodies. Antibodies are used to detect a protein that is bound to the DNA.Results:Fluorescent-based detection identifies the specific interaction between Protein-DNA with respect to coated DNA fragments. The protocol uses indirect conjugated antibodies and hence the technique is sensitive for effective identification of Protein-DNA interactions.Conclusion:Based on the results we conclude that the demonstrated protocol is simple, efficient and sensitive for identification of Protein-DNA interactions.Key Words: DNA coating, Lamin A, Protein-DNA interaction.     

Protection of potato virus X infection by plant extracts

Extracts from the roots ofBoerhaavia diffusa L., stems ofCuscuta reflexa Roxb. or leaves ofEuphorbia hirta L. have shown a potential protective effect on the infection of potato virus X, in hypersensitive and systemic hosts. The inhibition by these extracts was systemic and sensitive to actinomycin D.