NISCAIR ONLINE PERIODICALS REPOSITORY (NOPR)

Production of calcium gluconate by fermentation*

Mon, 28 Jun 1999 22:58:59 GMT

Title: Production of calcium gluconate by fermentation*

Authors: Tripathi, C K M; Rastogi, Smita; Bihari, Vinod; Basu, S K

Abstract: Calcium gluconate production by Aspergillus niger was investigated in shake flask, rolling shaker, air-lift reactor and stirred reactor. Growth pattern of the organism and fermentation conditions determined the yield of the product. High calcium gluconate production was achieved in air-lift reactor with pellet form of cell growth at moderate specific growth rate and biomass concentration. In another variation of air-lift reactor, when calcium carbonate was confined to a cellulose membrane, calcium gluconate production was maximum (149 g/L). At higher specific growth rate, obtained in shake flask, despite the formation of cell pellets, product formation was low. Physical separation of particulate calcium carbonate and growing cells favoured product formation. In stirred reactor pulpy mycelial growth was obtained and calcium gluconate production was poor.

Page(s): 731-733

In vitro studies on peroxidative changes leading to hemolysis of erythrocytes infested with malarial parasite Plasmodium vivax

Mon, 28 Jun 1999 22:58:59 GMT

Title: In vitro studies on peroxidative changes leading to hemolysis of erythrocytes infested with malarial parasite Plasmodium vivax

Authors: S, Meera; Rao, Ashalatha V; D’Souza, Vivian; Rao, Shrinivas B

Abstract: Blood erythrocytes of 25 confirmed malarial patients infested with P. vivax were analyzed for peroxidation and hemolysis and results compared with 10 uninfected normal control samples. Results indicated significant increase in peroxide formation measured as malondialdehyde, both in presence and absence of H₂O₂, in parasite infested erythrocytes. These changes induced hemolysis of infected erythrocytes which was increased manifold in presence of H₂O₂and could probably be the reason for extensive anemia reported in malaria.

Page(s): 729-730

Use of yeast respiratory adaptation test system to detect chemical mutagens/carcinogens in mammals

Mon, 28 Jun 1999 22:58:59 GMT

Title: Use of yeast respiratory adaptation test system to detect chemical mutagens/carcinogens in mammals

Authors: Pasupathy, K

Abstract: An approach to follow distribution of injected DNA-acting chemicals (mutagens/carcinogens) in mammal tissues has been described. This is based on the use of respiratory adaptation (mitochondrial biogenesis) process in Saccharomyces cererisiae during transition from anaerobic to aerobic state. By virtue of specific interaction of such chemicals with mitochondrial DNA associated with promitochondrial structures this process is extremely sensitive to DNA-acting chemicals. Solutions of berylium sulphate, aflatoxin G₁, aflatoxin B₁, and carbaryl (all known DNA-acting agents) were injected to rats at low concentrations and , after 24 hr, distribution of these chemicals or their metabolites was studied by determining the inhibitory action of appropriately diluted urine and tissue homogenates on respiratory adaptation in S.cerevisiae. Detectable amounts of the chemicals and their DNA-acting metabolites could be analyzed in urine, liver, lungs, kidney and spleen.

Page(s): 725-728

Latitudinal variation in eclosion rhythm among strains of Drosophila ananassae

Mon, 28 Jun 1999 22:58:59 GMT

Title: Latitudinal variation in eclosion rhythm among strains of Drosophila ananassae

Authors: Joshi, D S; Gore, A P

Abstract: Eclosion rhythm parameters of D. ananassae strains originating between 8°-34° N were highly variable and latitude dependent. In the field under naturally fluctuating light intensity, temperature and R.H., the amplitude of the rhythm was high and the eclosion gate was narrow; however, under the naturally fluctuating light intensity but at constant temperature and R.H .. the amplitude of the rhythm was lowered and the width of eclosion gate was widened. The eclosion rhythm entrained to lightdark (LD) cycles ranging from LD 6:18 to LD 18:6, the width of the eclosion gate was decreased and increased in the short and long photoperiods respectively. Among the strains, both the phase angle difference (ψ, the time from lights-off in a 24 hr LD cycle to the eclosion median) and the period of free-running rhythm (τ) in constant darkness varied by about 3 hr and the amplitude of the rhythmicity (Amp) by about 10%.Lower latitude was correlated with late ψ (r = -0.69), long τ (r = - 0.88) and high Amp value (r = -0.95).

Page(s): 718-724