Abstract:The Northeastern part of India sprawls over an area of 262 379km 2 in the Eastern Himalayan range. This constitutes a biodiversity hotspot with high levels of biodiversity and endemism; unfortunately, is also a poorly known area, especially on its microbial diversity. In this study, we assessed cultivable soil bacterial diversity and distribution from lowlands to highlands (34 to 3 990m.a.s.l.). Soil physico-chemical parameters and forest types across the different altitudes were characterized and correlated with bacterial distribution and diversity. Microbes from the soil samples were grown in Nutrient, Muller Hinton and Luria-Bertani agar plates and were initially characterized using biochemical methods. Parameters like dehydrogenase and urease activities, temperature, moisture content, pH, carbon content, bulk density of the sampled soil were measured for each site. Representative isolates were also subjected to 16S rDNA sequence analysis. A total of 155 cultivable bacterial isolates were characterized which were analyzed for richness, evenness and diversity indices. The tropical and sub-tropical forests supported higher bacterial diversity compared to temperate pine, temperate conifer, and sub-alpine rhododendron forests. The 16S rRNA phylogenetic analysis revealed that Firmicutes was the most common group followed by Proteobacteria and Bacteroidetes. Species belonging to the genera Bacillus and Pseudomonas were the most abundant. Bacterial CFU showed positive but insignificant correlation with soil parameters like pH (r=0.208), soil temperature (r=0.303), ambient temperature (r=0.443), soil carbon content (r=0.525), soil bulk density (r=0.268), soil urease (r=0.549) and soil dehydrogenase (r=0.492). Altitude (r=-0.561) and soil moisture content (r=-0.051) showed negative correlation. Altitudinal gradient along with the vegetation and soil physico-chemical parameters were found to influence bacterial diversity and distribution. This study points out that this is a biome with a vast reservoir of bacteria which decrease with increasing altitudes, and highlights the microbiological importance of the poorly studied Eastern Himalayan range, justifying efforts to explore the prevalence of novel species in the biome. Rev. Biol. Trop. 61 (1): 467-490. Epub 2013 March 01.
Background. In the present study, quality and quantity of indoor dust mites was evaluated at the residence of 150 atopic allergic patients from four different districts of South Assam. Methods. Suspected patients with case history of allergic disease were selected for indoor survey. Dust samples (500 mg) were collected from the selected patient's house and were analyzed using standard methods. Results. About 60% of the selected patients were found suffering from respiratory disorders and rest 40% from skin allergy. The dominant mites recorded from indoor dust samples were Dermatophagoides followed by Blomia, Acarus, and Cheyletus while Caloglyphus was recorded in least number. The distribution of mites on the basis of housing pattern indicates that RCC type of buildings supports maximum dust mite's population followed by Assam type (semi-RCC) buildings, and the lowest count was observed in wooden houses. Environmental factors like temperature, rainfall, and relative humidity are found to determine the indoor mite's population. Severity of allergic attack in some of the typical cases was found to be proportional to the allergen load of mites in the dust samples. Conclusions. The economic status, housing pattern, and local environmental factors determine the diversity and abundance of dust mites in indoor environment.
Non-timber forest products are important component of subsistence and livelihood of tribal communities living in and near forests. This is of particular significance in the state of Arunachal Pradesh having more than 80% of geographical area under forest cover and predominantly inhabited by tribal people. Purpose of this study was to document the status and utilization pattern and to assess the economic value of NTFPs of the state. Present study was carried out in eight districts of Arunachal Pradesh viz., Changlang, East Kameng, Lower Subansiri, Tawang, Tirap, Upper Siang, West Kameng and West Siang covering 34 villages and 350 households. Altogether, 135 plant based and 36 animal based non-timber forest products were recorded. Among plant based NTFPs, 54 species were collected for leaves, 30 for stem and 22 for fruits. Most of the animal based NTFPs (93%) were collected/hunted for food. Average 20∼40 kg of NTFPs was collected annually per household. Maximum plant based NTFP collection was recorded from West Siang followed by West Kameng and Tawang. Similarly, highest collection of animal based NTFPs was recorded from West Siang followed by Tirap and Lower Subansiri. NTFP contributed more than 50% of annual income of the people of East Kameng, Tirap, Lower Subansiri and Upper Siang districts. An illiterate and unemployed person with minimum agricultural land was more dependent on forests for his livelihood than a literate jobholder. The study concludes that a large section of people of Arunachal Pradesh are dependent on NTFPs for their livelihood however due to its unscientific harvesting, the availability of NTFPs is receding with time. There is an urgent need to promote cultivation and scientific harvesting of NTFPs in order to conserve the plant and animal diversity of this global biodiversity hotspot and for ensuring livelihood security of the people living in this area.
In this study an attempt was made to evaluate the qualitative and quantitative fungal burden (load) in five different working environments of South Assam (India) and the possible risks of indoor fungi to employees and stored products. Fungal concentrations in different working environments were studied using a Burkard personal petriplate sampler. The survey was done in five different working environments for one year. A total of 76 fungal types were recorded in the indoor air of South Assam during the survey period. The maximum fungal concentration (5,437.6 ± 145.3 CFUm -3 air) was recorded in the indoor air of medical wards, followed by the paper-processing industry (3,871.7 ± 93.4 CFU m -3 air). However the lowest concentration was observed in the indoor air of a bakery (1,796.8 ± 54.4 CFU m -3 air). The most dominant fungal genera were Aspergillus (34.2%) followed by Penicillium (17.8%), Geotrichum (7.0%) and the most dominant fungal species were Aspergillus fumigatus (2,650.4 CFU m -3 air) followed by Aspergillus flavus (1,388.2 CFU m -3 air), Geotrichum candidum (1,280.3 CFU m -3 air), Aspergillus niger (783.3 CFU m -3 air), and Penicillium aurantiovirens (774.0 CFU m -3 air). The fungal species viz., Aspergillus fumigatus, Penicillium aurantiovirens, Aspergillus flavus, Aspergillus niger, Geotrichum candidum, and Penicillium thomii, which were recorded well above threshold levels, may lead to adverse health hazards to indoor workers. Setting occupational exposure limits for indoor fungal spores as reference values is obligatory for prevention and control of adverse effects of indoor fungal exposure.
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