78 research outputs found
Purification, characterization, and cloning of a bifunctional molybdoenzyme with hydratase and alcohol dehydrogenase activity
A bifunctional hydratase/alcohol dehydrogenase was isolated from the cyclohexanol degrading bacterium Alicycliphilus denitrificans DSMZ 14773. The enzyme catalyzes the addition of water to α,β-unsaturated carbonyl compounds and the subsequent alcohol oxidation. The purified enzyme showed three subunits in SDS gel, and the gene sequence revealed that this enzyme belongs to the molybdopterin binding oxidoreductase family containing molybdopterins, FAD, and iron-sulfur clusters
Monitoring of microbial hydrocarbon remediation in the soil
Bioremediation of hydrocarbon pollutants is advantageous owing to the cost-effectiveness of the technology and the ubiquity of hydrocarbon-degrading microorganisms in the soil. Soil microbial diversity is affected by hydrocarbon perturbation, thus selective enrichment of hydrocarbon utilizers occurs. Hydrocarbons interact with the soil matrix and soil microorganisms determining the fate of the contaminants relative to their chemical nature and microbial degradative capabilities, respectively. Provided the polluted soil has requisite values for environmental factors that influence microbial activities and there are no inhibitors of microbial metabolism, there is a good chance that there will be a viable and active population of hydrocarbon-utilizing microorganisms in the soil. Microbial methods for monitoring bioremediation of hydrocarbons include chemical, biochemical and microbiological molecular indices that measure rates of microbial activities to show that in the end the target goal of pollutant reduction to a safe and permissible level has been achieved. Enumeration and characterization of hydrocarbon degraders, use of micro titer plate-based most probable number technique, community level physiological profiling, phospholipid fatty acid analysis, 16S rRNA- and other nucleic acid-based molecular fingerprinting techniques, metagenomics, microarray analysis, respirometry and gas chromatography are some of the methods employed in bio-monitoring of hydrocarbon remediation as presented in this review
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Success in rat control in Kuwait
The preliminary rat survey prior to the actual attack phase of Rat Control Programme in Kuwait revealed an infestation rate with the Norway rat, Rattus norvegicus, in buildings ranging between 32.7%.and 70.7%. The comparatively high infestation was observed in 92.5% of Kuwait buildings. Moreover, the infestation reached 99% in certain districts of the country. This high infestation was associated with an increase in rat-borne diseases particularly murine typhus, salmonellosis rat-bite fever, and certain parasitic diseases. A programme for rodent control in Kuwait was initiated through a political decision by the cabinet which gave the full responsibility of rodent control to the Ministry of Public Health coordinating with other authorities involved in the problem in addition to an independent budget to fulfill all the programme requirements. Financing, administration, guidance, public health information, field work, and research studies were all monitored by the High Committee in addition to Supervising and Following up Committee. The first phase of the programme began in the late months of 1979. It included geographical reconnaisance, survey of rodents and their ectoparasites, establishment of the general plan, and a skeletal organization for the programme. The second phase was the attack phase. It highlighted biological and epidemiological studies, bioassays of pesticides, and training of personnel, which was followed by the actual chemical attack of the incriminated rodents and their ectoparasites for three consecutive years. In addition, sanitation and health education were involved. The third phase, i.e., the maintenance phase, began in August 1982. It is still running to maintain the drastic drop of the Norway rat infestation and to control the house mouse. Kuwait's control programme, based on a scientific basis and with a well-organized administration, has successfully realized 99.7% reduction in the infestation rate, with a 99.6% density of infestation of Norway rats remaining at the end of the attack phase. However, the control of the house mouse produced a reduction of only 71.4% in the infestation rate, and 20% in the density of infestation, possibly indicating intraspecific competition between the two species or less-effective control measures against the mice
Effects of Fermented Madre De Agua Leaf Meal (Trichanthera gigantea) on Growth Performance of Heritage Free-Range Chicken (Gallus domesticus Linn.)
The study was conducted to evaluate the performance of six (6) week-old heritage chicken (Black Australorp) fed with Madre de agua leaf meals of the compound diets. A single-factor experiment was used for 75-head starter chicks with three (3) dietary treatments and five (5) replications. The feeding trial was run for 84 days through feed mixtures containing 16.105% and 3,105; Crude Protein and ME, Kcal/kg, respectively. Trichantheragigantea leaf meal was produced through 3-day sun drying and 10 min of oven-drying until the 10-14% moisture content was achieved. The dried leaves were hammer-milled through a 2-mm sieve. The experimental feeds were subjected to laboratory analysis. The results of the study observed a marked improvement in the growth performance of the experimental birds as measured by the parameters used. Significant differences among treatment means were observed from the average gain weight, average feed consumption (3,698g – 4,538g), and final weight gain (774.82–977.39 g). The feed conversion ratio (4.65 – 4.77), and feed cost per kg of meat produced (PhP126.60 – 37.72) were not significantly affected by the experimental diets (P>0.05). The improved growth performance of the experimental chicken indicated that the madre de agualeaf meals-treated dietcan be a viable feed option for free-range chicken. It is recommended to further explore the viability of the said experimental feed mixture to other chicken breeds and poultry species using various feed formulations with madre de agua leaf meals as protein feed ingredients
Spatial variation in leaf nutrient traits of dominant desert riparian plant species in an arid inland river basin of China
Understanding how patterns of leaf nutrient traits respond to groundwater depth is crucial for modeling the nutrient cycling of desert riparian ecosystems and forecasting the responses of ecosystems to global changes. In this study, we measured leaf nutrients along a transect across a groundwater depth gradient in the downstream Heihe River to explore the response of leaf nutrient traits to groundwater depth and soil properties. We found that leaf nutrient traits of dominant species showed different responses to groundwater depth gradient. Leaf C, leaf N, leaf P, and leaf K decreased significantly with groundwater depth, whereas patterns of leaf C/N and leaf N/P followed quadratic relationships with groundwater depth. Meanwhile, leaf C/P did not vary significantly along the groundwater depth gradient. Variations in leaf nutrient traits were associated with soil properties (e.g., soil bulk density, soil pH). Groundwater depth and soil pH jointly regulated the variation of leaf nutrient traits; however, groundwater depth explained the variation of leaf nutrient traits better than did soil pH. At the local scale in the typical desert riparian ecosystem, the dominant species was characterized by low leaf C, leaf N, and leaf P, but high leaf N/P and leaf C/P, indicating that desert riparian plants might be more limited by P than N in the growing season. Our observations will help to reveal specific adaptation patterns in relation to the groundwater depth gradient for dominant desert riparian species, provide insights into adaptive trends of leaf nutrient traits, and add information relevant to understanding the adaptive strategies of desert riparian forest vegetation to moisture gradients
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