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1.
K. Sasikala Ch.V. Ramana P. Raghuveer Rao M. Subrahmanyam 《FEMS microbiology letters》1990,72(1-2):23-28
Abstract Photoproduction of hydrogen, nitrogenase activity (acetylene reduction) and hydrogenase activity (methylene blue dye reduction) were studied in free and alginate immobilized whole cells of a purple non-sulfur photosynthetic bacterium Rhodobacter sphaeroides O.U. 001. Four-fold increase in hydrogen production, two-fold increase in nitrogenase activity and 1.2-fold increase in the hydrogenase activity were observed in immobilized cells compared to free cells. Effect of various inhibitors (CO and C2 H2 ) and electron donor (H2 ) on the above three functions by free and immobilized cells has also been studied. 相似文献
2.
3.
Ramana M. Gosukonda Ananta Porobodessai Essie Blay Channapatna S. Prakash Curt M. Peterson 《In vitro cellular & developmental biology. Plant》1995,31(2):65-71
Adventitious shoots of sweetpotato (Ipomoea batatas L. Lam.) were produced in vitro using a two-stage culture method. Petiole explants were incubated on Murashige and Skoog
(MS) medium supplemented with 2,4-dichlorophenoxy acetic acid (0.2 mg·liter−1) for 3 d, and transferred to MS medium with thidiazuron (0 to 0.4 mg·liter−1). Shoot regeneration was observed in most explants (78.2%) of genotype PI 318846-3 within 28 days when cultured on thidiazuron
at 0.2 mg·liter−1. Histological studies of cultured petiole explants showed meristematic activity within cells of vascular bundles and throughout
the ground tissue. Explants isolated from apical leaves exhibited higher shoot regeneration frequency than those isolated
from the basal portion of the shoot. Leaf lamina explants exhibited lower frequency of regeneration than petiole explants.
In contrast to thidiazuron, the use of zeatin riboside, and kinetin resulted in a lower frequency of shoot regeneration although
more sweetpotato genotypes could be regenerated using either of these two cytokinins. The sweetpotato plants regenerated using
thidiazuron grew vigorously and rooted easily when transferred to the greenhouse. 相似文献
4.
5.
Rabindranath Ray Chinmay K. Panda Bimal K. Chakraborty Sheela Mukherji Kanakendu Chaudhury Jayashree Roychoudhury 《Molecular and cellular biochemistry》1994,131(1):67-73
Partial hepatectomy (P.H.) induces a partially synchronized growth response of liver under normal regulation of growth. In this phase changes in cellular morphology, radial distribution pattern of cells and other biological as well as major biochemical changes are well documented [24]. Here, we have shown that the cellular content of UsnRNAs altered during this proliferative phase as well. The level of spliceosomal UsnRNAs (U1, U2, U4–U6) gradually decreased by 30–50% upto 48 hrs of P.H. followed by gradual increase to reach the normal level within one month of P.H. The U3 snRNA level on the other hand, was nearly equal to that in normal liver at 48 hrs of P.H. but in 24 and 72 hrs of P.H. its level was high (4 fold) in contrast to that in other UsnRNAs. Thus, it is clear from our data that the level of all the six UsnRNAs decreased during 48 hrs of P.H. compared to that after first 24 hrs. This has been correlated in the kinetics of UsnRNAs' synthesis (in terms of labelling) in isolated hepatocytes, where the rate of labelling of all the six UsnRNAs increased 20–30% in 24 hrs regenerating hepatocytes (R.H.) followed by sharp decrease by 30–50% within next 24 hrs, compared to that in the normal hepatocytes. But from 72 hrs onwards in R.H. the rate of labelling of all the six UsnRNAs again increased by 30–50% (compared to that in normal hepatocytes) followed by decrease of their labelling-rate to reach the normal level in R.H. within one month of P.H. Thus, it may be concluded that the changes in UsnRNAs' level during the proliferative phase of liver regeneration may be either due to the alteration in the rate of synthesis (in terms of labelling) or along with it differential turn over rate; this phenomenon may have some consequences with the regenerative process of liver.This paper was published in Molecular and Cellular Biochemistry131:67–73, 1994. Kluwer Academic Publishers regret the publication of the only partly corrected version. 相似文献
6.
The seasonal dynamics of epilithic algae in a third order pristine forest stream were analyzed over a period of 2 years. Stream water was slightly acidic and nutrient poor. Encrusting, filamentous flocs, and filaments were found. Algal standing crop was high (mean concentration of Chl a 16–43 mg m–2) in spring. Filamentous algae contributed most to standing crop. Diatoms made up over 85% by number of the epilithon. Blue-greens were abundant upstream, and chlorophytes downstream. This shift was ascribed to greater light availability downstream. The community was more diverse during spring. Water current was the most important variable regulating epilithon structure. Total phosphorus (TP), orthophosphate (O-PO
inf4
su3–
), silica (Si4+), nitrate (NO
inf3
su–
) and conductance correlated negatively with flow rate. Green algae showed a positive correlation to phosphorus during low and stable flow. During rapid runoff, diatoms were the most resistant forms. Seasonal change in the epilithic community was mainly regulated by fluctuations in flow rate. 相似文献
7.
Ch. Sasikala Ch. V. Ramana G. S. Prasad 《World journal of microbiology & biotechnology》1994,10(2):221-223
Production of H2 from glucose by an anoxygenic phototrophic bacterium (Rhodobacter sphaeroides), a cyanobacterium (Synechococcus cedrorum) and a heterotrophic bacterium (Pseudomonas fluorescens) was tested individually and in mixed cultures of various combinations in light. H2 production was maximal with a mixed culture of R. sphaeroides and P. fluorescens, which could be further enhanced by immobilization of the bacteria in alginate gel. Inhibition of H2 photoproduction was observed in a mixture of S. cedrorum and P. fluorescens and a co-culture of all the three organisms.Ch. Sasikala and Ch. V. Ramana are and G. S. Prasad was with the Microbial Biotechnology Laboratory, Department of Botany, Osmania University, Hyderabad-500 007, India. G. S. Prasad is now with the Microbial Type Culture Collection Centre (MTCC), IMTECH, Chandigar, India. 相似文献
8.
Pallavi R.M.V. Ramana D. Sashidhar R.B. 《World journal of microbiology & biotechnology》1997,13(6):713-714
Most agricultural commodities are susceptible to Aspergillus sp. infestation and aflatoxin elaboration. A simple test-tube screening procedure using fresh coconut milk agar medium (CMAM), for identifying toxigenic strains of Aspergillus sp., based on u.v. fluorescence (365 nm) and visual detection has been proposed and evaluated. 相似文献
9.
Narendra Jawali Jayashree Krishna Sainis Prafullachandra Vishnu Sane 《Phytochemistry》1978,17(9):1527-1530
Nitrate reductase from Amaranthus viridis is similar to nitrate reductase from other plant sources. NH2OH inhibits nitrate reduction from NADH by the nitrate reductase complex, but it does not inhibit either the NADH-dehydrogenase activity or nitrate reduction from reduced flavin mononucleotides. The inhibition observed was non-competitive with nitrate when the enzyme was pre-incubated with NH2OH and NADH, and competitive with nitrate without pre-incubation. The Ki values for NH2OH were 5 μM and 30 μM with or without pre-incubation respectively. 相似文献
10.
Measurements made in fresh water wetland have shown that temperature, pH, dissolved oxygen and bicarbonate alkalinity in the hyacinth infested area were lower, but dissolved free carbon dioxide concentration was excitingly greater than in the open water area. This extreme hypoxic and hypercarbic condition of hyacinth covered areas was caused by the thick coverage of Eichhornia crassipes which was crucial for the composition of the characteristic flora and fauna. 相似文献