Studies on the extraction and characterization of thermostable a-amylase from pericarp of Borassus indica

Thermostable a-amylase was extracted and characterized from the fruits (pericarp) of Borassus indica. Analysis on the influence of various physico-chemical parameters on the extracted enzyme revealed a Vmax of 0.793 and a Km of 0.022. The optimum temperature was found to be 370C at pH 4.5. The stability studies on enzyme activity envisaged that the enzyme is stable up to 800C and retained its activity over a wide range of pH (4.0 – 8.5). Significant enhancement in the enzyme activity was observed in the presence of metal ions like Manganese and Strontium and an insignificant decrement in the presence of Sodium ions.African Journal of Biotechnology Vol. 4 (3), pp. 289-291, 200

Polychaete community structure of Vasishta Godavari estuary, east coast of India

The community structure of polychaete fauna from the Vasishta Godavari estuary was analyzed in this study. The data presented in this paper were collected during 1976 - 78 and published in 1983, and now re-analysed using PRIMER 6.1, CANOCO 4.5. The polychaetes were collected from a 16 km stretch of the lower Vasishta Godavari estuary (16o18’N lat., 81o42’E long.) during flood, summer and recovery seasons at 6 permanent stations. Altogether 216 sediment samples were analysed and 73 polychaete taxa were identified. Polychaete diversity was higher (Shannon-Wiener H’: 1.94±0.28) in samples from recovery season relative to summer season (H’: 1.54±0.44) and flood season (H’: 1.44±0.024). Using multivariate statistical techniques two polychaete associations could be recognised from the Vasishta Godavari estuary, namely Heteromastus similis, Nephthys oligobranchia and Indonereis gopalai assemblage Group 1 (samples from recovery and summer season) and Group 2 (samples from flood season). Group 2 did not reveal any particular species from flood season samples. Canonical correspondence analysis (CCA) showed that sand, salinity, clay and temperature have influenced the polychaete distribution. This study therefore provides key information on the biodiversity of polychaete communities of the Vasishta Godavari estuary

Influence of Exogenous Glycinebetaine on Hot Pepper under Water Stress

A study was conducted to evaluate the effect of exogenous application of glycinebetaine (GB) on physiological response in hot-pepper (Capsicum annuum L. vs. Arka Lohit and Pusa Jwala) under water stress. Glycinebetaine was applied to seeds as well as plants through foliar applications. Water stress affected considerably the morphophysiological parameters in both the cultivars. However, in glycinebetaine (GB) treated plants, plant height, leaf area (LA), flower and fruit number and total dry matter (TDM) were greater compared to the untreated stress plants (T4) under water stress. Glycinebetaine application enhanced the photosynthesis (PN) in water deficit experiencing plants, mostly due to a greater stomatal conductance (gs) and carboxylation efficiency of CO2 assimilation. In both the cultivars after 12 day of stress, the PN decreased from 10.1 to 1.0-1.3 μ mol m-2 s-1 in untreated stressed plants (T4), while in the treated stressed plants PNhad reduced to 2.0 - 3.0 μ mol m-2 s-1 (T1 - T3). The application of GB increased the WUE in both the cultivars. The better WUE in treated plants of hot-pepper under stress was attributed to the improved PN. The higher per plant yield in the GB applied plants under stress in both the cultivars associated with higher PNrate, gs and WUE in treated plants. Though there was an increase in PN rate, WUE and plant yield in the treated plants (T1 - T3), the better results were found in the plants (T2) where seeds were treated and foliar application was given at the time of imposing stress

Diversity and Distribution of Pteridophytic flora of Punyagiri hill, Vizianagaram District, Andhra Pradesh, India

The present paper deals with the diversity and distribution of Pteridophytic flora in Punyagiri hill.  It is located 180 06’ 70",180 06’ 68",latitudes and 830 06’ 72",830 06’ 40" longitudes , 55 km away from Visakhapatnam. Quadrate method was adopted to calculate the IVI. Sampling was carried out with 0.5x0.5m2 quadrate; fifteen quadrate samples were taken in three seasons. A total no of 13 species belonging to 10 genera and 9 families were recorded. Maximum relative density was reported for Selaginella involvense (10.6) and Pteris vittata (8.4). Minimum relative density and relative frequency were reported in the species Nephrolepis cordifolia(5.5) and Pteris pellucida (6.3). The maximum IVI was reported in Selaginella involvens (30.2) fallowed by Pteris vittata (26.2), Adiantum lunulatum(25.4), Pleopeltis pallida (24.5) and minimum in Nephrolepis cordifolia (18.6). It is concluded that the population of Pteridophytes in this region is heterogeneous

Numerical analysis of C.I engine to control emissions using exhaust gas recirculation and advanced start of injection

AbstractAs major limitation of diesel engines is the high soot and nitrogen oxide emissions which cannot be reduced totally with only conventional catalytic converters today, varying fuel characteristics became a focus of interest to meet the pollution emission legislations as they require very few or no changes in existing engine model. The present work deals with, numerical analysis of combined effect of Advanced Start of Injection (SOI) and Exhaust Gas Re-circulation (EGR) on performance and emissions which were studied, by performing numerical analysis on a Caterpillar 3401 single cylinder C.I engine model at constant speed using diesel as fuel via three dimensional computational fluid dynamics (CFD) procedures and validated with experimental data. The SOI is advanced from 11° Crank angle bTDC to 14.5° Crank angle bTDC and EGR as a fraction is increased from 0% to 10%. The modified conditions of these parameters resulted in simultaneous reduction of NOx and Soot

Occurrence of black rot in Jatropha curcas L. plantations in India caused by Botryosphaeria dothidea

A new disease in Jatropha curcas L. plants was observed during the summer season in 2009 and 2010 in plantations in several Indian states, including Andhra Pradesh, Assam, Chhattisgarh and Madhya Pradesh. The outbreak of the disease coincided with the leafdropping (dormant) stage of the crop, which sets in with the increasing moisture stress. Affected J. curcas plants showed drying along with shrivelling, and discoloration of the stem with sticky reddish-brown exudation at the base of the plants. Black lesions (soft and rotting) on the stem under the bark and cambium layer were also observed. From the affected stem parts, fungal cultures were isolated and tested for their pathogenicity on pot-grown plants. The fungal isolates caused symptoms on J. curcas leaves and petioles (black spots, 1–3 mm in diameter). Then they spread to the stems causing shrivelling and gummosis of hard-wood stems, and finally led to the death of the infected plant. The causal fungus was identified as Botryosphaeria dothidea using microscopic observations of hyphae and spores, and internally transcribed spacers (ITS) sequencing technique. In addition, four other fungal isolates were also isolated from the affected tissues, which were identified as Macrophomina phaceolina, Phomosis longicolla, Fusarium oxysporum and Alternaria alternata using the ITS sequencing technique. The role of these fungal cultures, i.e. whether they grow as saprophytes on the affected dead tissues or have any role in causing the black rot disease, needs further study. Spraying J. curcas plants showing early symptoms of this disease with Bavistin (carbendazim 50% WP) at the rate of 2 g l–1 water controlled the spread of the symptoms and led to the recovery of plants with new leaf growth after the rains

Integrated Nutrient Management Sustainable for Land Use in Watersheds

Apart from water shortage, the productivity in rain-fed systems is also constrained by low soil fertility. The soils in the SAT regions generally have low organic matter and nutrient reserves. Extensive survey of the farmers’ &elds in the SAT regions of India revealed that the de&ciencies of sulfur, boron and zinc are very widespread and in most cases 80-100% farmers’ &elds were found critically de&cient in these nutrients. This paper underscores the need to integrate soil and water conserving practices with balanced nutrition of crops by adopting INM

Role of deforestation and hillslope position on soil quality attributes of loess-derived soils in Golestan province, Iran

Conversion of natural land resources into croplands, which is triggered by the rapid population growth, causes serious soil degradation. A loess hillslope located in eastern Golestan province of Iran was selected to study the role of deforestation and slope position on soil quality attributes. Surface (0–30 cm) and subsurface (30–60 cm) soil samples were taken from five slope positions (summit, SU, shoulder, SH, backslope, BS, footslope, FS and toeslope, TS) of forest (FO) and adjacent deforested cultivated land (DEF) in a factorial trial with completely randomized design. Ten pedons were also investigated and undisturbed soil samples were taken from different horizons for micromorphological studies. The texture of the original loess is silt loam. The soil textural class varies from silty clay loam in FO to silt loam in DEF, mainly due to the loss of finer particles as a result of soil erosion followed by deforestation and long-term cultivation. Mean weight diameter (MWD) of aggregates decreased following deforestation (0.88 mm compared to 1.49 mm in FO), as a result of considerable losses of organic carbon (OC) and breakdown of aggregates. Bulk density (BD) increased and soil infiltration rate decreased by about 50% in DEF. Reduction of annual organic matter input to soil as a result of deforestation and also rapid oxidation of organic matter in DEF were responsible for a significant decrease (>70%) in OC and total nitrogen (TN). Soil microbial respiration (SMR) also decreased significantly, following deforestation. Carbon, and N contents and population of fungi were significantly higher in all hillslope positions of the FO than the DEF. Changes in soil quality attributes were not significant in different slope positions of FO, which might be related to the stability of forest landscape. Effect of different slope positions on soil quality attributes was more pronounced in the DEF. The SH and BS were found as the most susceptible positions to erosion in DEF. Soils of the FO were mainly classified as Alfisols and Mollisols with evidences for clay illuviation compared to the weakly developed Inceptisols formed in the DEF. Micromorphological investigations revealed that the FO soils had strong granular and crumb microstructure with a high porosity indicating the presence of high amount of organic matter. The high microbial and faunal activity was confirmed through the presence of excremental pedofeatures in the topsoil of the FO. Lower organic matter and consequently microbial activity in the topsoil of the DEF have resulted in the massive microstructure with little porosit