Antibacterial activity of the leaf essential oil of <Emphasis Type="Italic">Blumea mollis</Emphasis> (D. Don) Merr.

The antibacterial activity of the leaf essential oil of Blumea mollis was assayed against 14 clinically isolated bacterial strains on Muller–Hinton Agar medium and Muller–Hinton Agar medium with 5% sheep blood. The essential oil had promising antibacterial activity against all the bacterial strains tested. The highest mean zone of inhibition and lowest values of minimum inhibitory concentration were recorded against methicillin-resistant Staphylococcus aureus followed by beta hemolytic Streptococcus pyogenes. The Gram-positive bacteria were more sensitive than Gram-negative bacteria. Among the bacterial strains tested, Psudomonas aeruginosa was resistant to the essential oil. The results of the present study suggest that the essential oil of B. mollis is one of the new medicinal resources as an antibacterial agent against the bacterial strains tested.     

Chemical constituents and antibacterial activity of the leaf essential oil of <Emphasis Type="Italic">Feronia limonia</Emphasis>

Bioleaching of uranium was carried out with Turamdih ore sample procured from Uranium Corporation of India Limited, Jaduguda. The bacterial strain that was used in the leaching experiments was isolated from the Jaduguda mine water sample. Efficiency of bioleaching was studied by varying parameters like pulp density and initial ferrous concentration as source of energy. It is observed that the efficiency of bioleaching was 49% at 10% pulp density (w/v) and initial pH 2.0. Addition of external has no effect on efficiency of bioleaching showing domination of direct leaching mechanism over indirect.     

Screening of certain mangroves for photosynthetic carbon metabolic pathway

The mangroves Rhizophora lamarkii, Ceriops roxburghiana, Bruguiera gymnorrhiza, Aegiceras corniculatum, and Lumnitzera racemosa were screened for their carbon metabolic pathways by measuring net photosynthetic rate (P _N), ¹³C discrimination rate, leaf anatomy, titratable acidity, and activities of phosphoenolpyruvate carboxylase, NADH-malate dehydrogenase, alanine aminotransferase, aspartate aminotransferase, and pyruvate phosphate dikinase. The tested mangroves had a well developed succulence, opening of stomata during day time and closure in the night hours, and absence of diurnal fluctuation of organic acids in their leaves which excludes the possibility of these species being CAM plants. Moreover, the leaf anatomy had not exhibited Kranz syndrome. The high values of discrimination against ¹³C, low P _N, high CO₂ compensation concentration, and the activities of aminotransferases in the direction of alanine formation suggest that the species may follow C₃ mode of carbon metabolic pathway.     

Effect of seaweed extracts on the growth and biochemical constituents of Vigna sinensis

The effect of seaweed liquid fertilizers (SLF) of Sargassum wightii and Caulerpa chemnitzia on growth and biochemical constituents of Vigna sinensis was studied. The seeds soaked with aqueous extract of seaweeds performed better when compared to the water soaked controls. Hundred per cent germination was recorded both in aqueous extract soaked and water soaked treatments. The low concentration (20%) of aqueous extracts of S. wightii and C. chemnitzia promoted the seedling growth including the parameters of shoot length (15.87, 14.13 cm/seedling), root length (6.42, 5.38 cm/seedling), fresh weight (4.017, 4.012 g/seedling) and dry weight (0.878, 0.865 g/seedling), chlorophyll (1.599, 1.491 mg g-1 fr. wt.), carotenoids (0.899, 0.875 mg g-1 fr. wt.), protein content of shoot (3.956, 3.474 mg g-1 fr. wt.) and root (2.926, 2.890 mg g-1 fr. wt.), amino acid content of shoot (1.447, 1.429 mg g-1 fr. wt.) and root (0.698, 0.680 mg g-1 fr. wt.), reducing sugar content of shoot (6.426, 6.233 mg g-1 fr. wt.) and root (5.118, 5.103 mg g-1 fr. wt.), total sugar content of shoot (11.846, 11.350 mg g-1 fr. wt.) and root (10.368, 10.102 mg g-1 fr. wt.), alpha-amylase (1.927, 1.819 microg min-1 mg-1 protein) and beta-amylase (1.730, 1.617 microg min-1 mg-1 protein) activities in V. sinensis. Among the two seaweeds tested, S. wightii exhibited better responses.     

Responses of Ceriops Roxburghiana to NaCl Stress

Responses of Ceriops roxburghiana Arn. leaves to the sodium chloride, applied at different concentrations (ranging from 100 to 600 mM), has been evaluated. Total amino acid content decreased with increasing NaCl concentration, while the protein content increased significantly up to 400 mM concentration and decreased thereafter. Total sugar content decreased at concentrations beyond 400 mM. Proline and glycine betaine were accumulated with increasing NaCl concentration. Protease and ATPase activities were increased whereas proline oxidase activity were decreased with increasing salinity. Peroxidase and malate dehydrogenase (NADH-MDH) activities did not significantly differ under various NaCl concentrations. This revised version was published online in July 2006 with corrections to the Cover Date.     

Chicory (Cichorium intybus) and wormwood (Artemisia absinthium) extracts exhibit strong larvicidal activity against mosquito vectors of malaria,dengue fever,and filariasis

Vector-borne diseases transmitted by mosquitoes cause globally important diseases such as malaria, dengue fever, and filariasis. The incidence of these diseases can be reduced through mosquito control programs but these control programs currently rely on synthetic insecticides that can impact the environment, and has selected widespread mosquito resistance. Environment friendly and biodegradable natural insecticides discovered in plants offer an alternative approach to mosquito control. Here, we investigated extracts from root or aerial parts of Chicory (Cichorium intybus) and wormwood (Artemisia absinthium) against the early 4th instar larvae of Anopheles stephensi (malaria vector), Aedes aegypti (dengue fever vector), and Culex quinquefasciatus (filariasis vector). The root and aerial parts extracts of A. absinthium and C. intybus at 200, 100, 50, 25 and 12.5?ppm caused significant mortality of the tested mosquito species. Root extracts exhibited higher larvicidal activity that aerial part extracts. The highest larvicidal activity was recorded in methanol extract of roots of C. intybus with LC50?=?66.16, 18.88 and LC¬90?=?197.56, 107.16?ppm for An. stephensi; LC50?=?78.51, 40.15 and LC90?=?277.31, 231.28?ppm for Ae. aegypti and LC50?=?103.99, 64.56 and LC¬90?=?314.04, 247.54?ppm for Cx. quinquefasciatus. These results reveal potent mosquito larvicidal activity against vectors of malaria, dengue fever, and filariasis is present in extracts of chicory and wormwood.     

Growth and Photosynthetic Characteristics of Ceriops Roxburghiana under NaCl Stress

The plant growth, net photosynthetic rate (PN), intercellular CO2 concentration (ci), and dry matter production of Ceriops roxburghiana Arn. were significantly increased with increasing salinity from 0 to 400 mM NaCl. At 600 mM NaCl, shoot and root lengths, and dry mass were significantly depressed with respect to control. Absence of diurnal fluctuation of concentrations of organic acids, and the low activity of phosphoenolpyruvate carboxylase and high activity of ribulose-1,5-bisphosphate carboxylase confirmed the operation of C3 pathway in Ceriops even at increasing salinity.     

Antibacterial activity of some salt marsh halophytes and mangrove plants against methicillin resistant Staphylococcus aureus

The antibacterial activity of aqueous and methanol extracts of leaves/shoots of five salt marsh halophytes and six mangroves was studied against methicillin resistant, clinical isolates of Staphylococcus aureus. There was a clear comparability between the salt marsh halophytes and mangroves in their antibacterial action. The mangrove plants possessed higher antibacterial potency than the salt marsh halophytes. The highest activity was recorded with the methanol extract of Excoecaria agallocha followed by the methanol extracts of Aegiceras corniculatum, Lumnitzera racemosa and Ceriops decandra. The minimum inhibitory concentration (MIC) values ranged from 0.125 to 4 mg/mL and 1 to 16 mg/mL for methanol and aqueous extracts, respectively. Further separation of active principle from the potent mangrove plant will be useful for the control of drug resistant strains of S. aureus.     

Antimicrobial activity of fatty acid methyl esters of some members of Chenopodiaceae

Fatty acid methyl ester (FAME) extracts of four halophytic plants, viz. Arthrocnemum indicum, Salicornia brachiata, Suaeda maritima and Suaeda monoica belonging to the family Chenopodiaceae, were prepared and their composition was analyzed by GC-MS. The FAME extracts were also screened for antibacterial and antifungal activities. The GC-MS analysis revealed the presence of more saturated fatty acids than unsaturated fatty acids. Among the fatty acids analyzed, the relative percentage of lauric acid was high in S. brachiata (61.85%). The FAME extract of S. brachiata showed the highest antibacterial and antifungal activities among the extracts tested. The other three extracts showed potent antibacterial and moderate anticandidal activities.