Purification and characterization of a new endoglucanase from Aspergillus aculeatus

Endoglucanase has been isolated from Aspergillus aculeatus. The purified enzyme showed a single band and had a molecular weight of 45,000 Da as indicated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, with a specific activity of 1.4 units/mg. The purified enzyme was identified as endoglucanase, showing a high specific activity toward CM-cellulose and low specific activity toward Avicel. The activity of the isolated enzyme was optimum at a pH of 5.0 and temperature of 40 degrees C, respectively. The isoelectric point of the enzyme was 4.3. T(m) was found to be 57 degrees C. The treatment of the endoglucanase with diethylpyrocarbonate resulted in the modification of the histidine residues present in the enzyme, with a concomitant loss of 70% of the original enzymatic activity. However, carbodiimide completely inactivated the endoglucanase. The results show that the enzyme is able to sustain 50% of its activity even when heated at 90 degrees C for a period of 5 h. Endoglucanase can be used in the controlled hydrolysis of cellulose and other cellulose-rich foods. It can be used in the development of targeted functional foods from agrimaterials for value addition in the food chain.     

Anthropogenic disturbances and status of forest and wildlife in the dry deciduous forests of Chhattisgarh state in India

The advent of modern forces and the changes in socioeconomic patterns of forest dwellers have increased the pressures on the forests. In order to mitigate such pressures and also to protect the forests and wildlife the model of protected areas networks has shifted and enhanced such pressures in the unprotected natural forests due to several reasons. Being a low profile category of protected status and continuous human settlements, the present study highlights the case of dry deciduous forests of Sarguja district of Chhattisgarh state of India. The major objectives of this study were to quantify the status of forests and wildlife and also to determine the extent of anthropogenic disturbances faced by the dry deciduous forests of central India. Transect and silent drive count methods were used for sampling wildlife and quadrat method was used for sampling vegetation. Besides, the local uses of various forest produces were also studied in view of understanding the people dependency on forests. The forest vegetation, in the study area, was pre-dominated by Shorea robusta, which had Madhuca indica, Diospyrus melanoxylon and Buchnania lanzan as the major companion species. The forest had either the high girth class mature tree species or the saplings. The low vegetation cover and density were due to the high anthropogenic pressures mainly in the form of heavy livestock grazing and collection of ethnobotanically important species. The study though reveals that the area is not rich in wildlife and the forest is fragmented, the area still supports some important species, which include many rare and endangered plants and animals. The findings of this study have been discussed in view of the management and conservation of the forest and wildlife in the dry deciduous forests.     

Financial feasibility of increasing carbon sequestration in harvested wood products in Mississippi

Longer forest rotation ages can potentially increase accumulation of carbon in harvested wood products due to a larger proportion of sawlogs that can be used for manufacturing durable wood products such as lumber and plywood. This study quantified amounts of carbon accumulated in wood products harvested from loblolly pine (Pinus taeda L.) stands grown in Mississippi by extending rotation ages traditionally used to manage these stands for timber. The financial viability of this approach was examined based on carbon payments received by landowners for sequestering carbon in standing trees and harvested wood products. Results indicated a potential to increase carbon accumulated in wood products by 16.11 metric tons (t) of carbon dioxide equivalent (CO₂e) per hectare (ha) for a rotation increase of 5 years and 67.07 tCO₂e/ha for a rotation increase of 65 years. Carbon prices of $50/tCO₂e and $110/tCO₂e would be required to provide a sufficient incentive to forest landowners to extend rotations by 5 and 10 years, respectively. With 2.8 million ha of loblolly pine stands in Mississippi, this translates to a possible increase in wood products carbon of 45 million tCO₂e and 80 million tCO₂e for harvest ages increased by 5 and 10 years, respectively. Higher carbon prices lengthened rotation ages modestly due to low present values of carbon accumulated with long rotations.     

Effects of long-term growth hormone-releasing factor treatment on growth, feed conversion efficiency and dry matter intake in growing female buffaloes (Bubalus bubalis)

Effects of long-term growth hormone-releasing factor (GRF) on growth performance, feed conversion efficiency (FCE) and dry matter intake (DMI) were studied in growing buffaloes. Twelve female Murrah buffaloes of 6-8 months of age were divided into two groups of six each on the basis of their body weights so that the average body weights of the groups did not differ (p > 0.05). Animals of each group were administered intravenously with either sterile distilled water (control group) or equal volume of GRF solution containing 10 mug GRF (1-44)-NH2/100 kg body weight (treatment group) at fortnight interval from week 6 (5-week pre-treatment period) for 36 weeks (weeks 6-42 treatment period). Thereafter a 10-week post-treatment period was added. All the animals were weighed consecutively 2 days in a week and the average body weight of the two observations in the week was thus considered for further calculation. Dry matter intake was recorded daily. Average daily gain, FCE and DMI/100 kg body weight were also calculated. Plasma progesterone was estimated in the samples collected twice a week at 3-4-day intervals to assess whether either group had begun ovarian cycles. It was found that ADG and FCE were higher (p < 0.01) in GRF-treated animals during treatment and even 10-week post-treatment period. Interestingly, total DMI was not different (p > 0.05) between the groups during treatment period but found to be lower in GRF treated animals during post-treatment period. The DMI/100 kg body weight was lower (p < 0.01) in GRF-treated animals during treatment and even after cessation of treatment for 10 weeks. The GRF administration for long-term increased (p < 0.05) plasma progesterone. Plasma progesterone concentrations suggest that no animal from either group reached puberty till the end of the experiment. In conclusion, repeated GRF administration for longer term decreased (p < 0.01) DMI/100 kg body weight and increased (p < 0.01) FCE and enabled the animals to grow faster.     

Effects of Long-term Growth Hormone-releasing Factor Administration on Plasma Growth Hormone, Luteinizing Hormone and Progesterone Profiles in Growing Female Buffaloes (Bubalus bubalis)

To investigate the effects of long-term growth hormone-releasing factor (GRF) administration on plasma growth hormone (GH), LH and progesterone and body weight gain in growing buffalo calves, 12 female Murrah buffaloes within the age group of 6-8 months of age were divided into two groups (treatment and control groups) of six each in such a way so that average body weights between the groups did not differ (p > 0.05). Control buffaloes were not given any hormonal treatment and treatment group buffaloes were treated with synthetic bovine GRF [bGRF (1-44)-NH(2)] at the rate of 10 microg/100 kg body weight intravenously at an interval of 15 days from week 6 (5-week pre-treatment period) till 18 injections were completed (week 6-42 treatment period) and thereafter, effect of exogenous GRF were observed for 10-week post-treatment period. Jugular blood samples were drawn twice a week at 3-4-day intervals for plasma GH, LH and progesterone quantification. Body weight of all animals was recorded twice a week. During pre-treatment period, mean plasma GH, LH and progesterone did not differ (p > 0.05) between the groups. But during treatment as well as post-treatment period, mean plasma GH levels were found to be significantly (p < 0.01) higher in treatment than control group of buffaloes. Administration of GRF for longer term sustained a higher level of plasma GH even after cessation of treatment. GRF-treated buffaloes attained higher (p < 0.01) body weight than the controls. Repeated GRF administration for long-term significantly (p < 0.01) increased plasma LH and progesterone. In conclusion, repeated long-term exogenous GRF administration induces and even enhances GH release without any sign of refractoriness. GRF may, therefore, be used to induce daily GH release without loss of responsiveness over an extended period of time in young growing female buffaloes and it may assist these animals to grow faster.     

Morphological and Functional Aspects of Reptilian Ultimobranchial Gland

The intention of this review is to compare studies on the morphology and histology (light and electron microscopic) of ultimobranchial glands of various groups of reptiles. Moreover, experiments (including our investigations) on suppression or stimulation of the ultimobranchial gland are included. Adult reptiles possess one (on the left side) or two ultimo-branchial glands (UBG). The UBG lie just anterior to the heart. Light as well as electron microscopically, the gland has been shown to contain follicles and cell cords (cell aggregates). The follicular epithelium is lined by simple cuboidal or pseudo-stratified columnar cells. Ciliated and goblet cells may be present in the follicular epithelia in some groups. The lumen may contain a colloid-like substance with desquamated cells or debris. The UBG of reptiles seem to be an active secretory organ with influence on calcium regulation. Other functions of calcitonin have also been suggested in reptiles for example in neurotransmission, in volume regulation, phosphate balance and promotion of bone calcification (at least in juveniles).     

Effect of feeding Lagerstroemia speciosa and conventional fodder based rations on nutrient utilization,ruminal metabolites and body weight gain in mithun (Bos frontalis)

The aim of the present study was to evaluate the effect of feeding green fodder, rice straw and concentrate‐based total mixed rations (TMR) on dry matter (DM) intake (DMI), nutrient utilization, rumen fermentation patterns and body weight (BW) gain (BWG) in mithun (Bos frontalis) calves. In a randomized block design, male mithun calves (n = 18, 8–10 months of age, 121 ± 2 kg BW) were randomly divided into three experimental equal groups (six animals in each group) and fed isonitrogenous TMRs ad libitum for 120 days. The TMR₁ contained 30% Napier grass and 30% rice straw, TMR₂ contained 60% rice straw and TMR₃ contained 30% tree leaves (Lagerstroemia speciosa) and 30% rice straw (DM basis). All the TMRs contained 40% concentrate mixture (DM basis). The results indicated that the BWG, DMI and feed conversion efficiency were significantly (p < 0.01) increased with the inclusion of green fodder in TMRs. The apparent digestibility of DM, crude protein, ether extract, crude fibre and nitrogen free extract were also improved significantly (p < 0.01) with the inclusion of green fodder in TMRs. The higher concentration of total nitrogen and total volatile fatty acid in rumen liquor, but low ruminal pH were evident in animals fed green fodder supplemented TMRs. An increased (p < 0.01) molar proportion of acetic acid was evident in animals fed rice straw‐based TMR. In contrast, the molar proportion of propionic and butyric acids were significantly (p < 0.01) higher in animals fed green fodder supplemented TMRs. On the basis of higher DMI and higher daily BWG, it is concluded that Napier grass and L. speciosa tree leaves may be incorporated upto 30% (DM basis) in TMR of growing mithuns for feeding in complete confinement system.     

Persistence of Chlorpyrifos in Soils under Different Moisture Regimes

Chlorpyrifos is an organophosphorus insecticide used to control insect pests in soil. The fate of chlorpyrifos in soils under different moisture regimes is of interest because application directions specify soil-surface treatments for a number of agricultural and urban pests. Chlorpyrifos was degraded rapidly in all air-dry soils and slightly more slowly in soils at field capacity and/or under submerged conditions. Degradation rates were influenced by clay-catalysed hydrolysis under air-dry conditions and neutral or alkaline hydrolysis under submerged conditions. Degradation was faster in Bellary soil (chromic haplustert) and slower in Chettalli soil (ustic palehumult) under all three moisture regimes. The calculated half-lives ranged from 1·6 to 10·0, 5·2 to 22·0 and 8·7 to 25·1 days under air-dry, field capacity and submergence respectively at an application rate of 10 mg kg^-1. © 1997 SCI.