Volume 15, Issue 3, 2015 July-September

Volume 15, No 3 Pages:
2015 July-September Articles: 8

Screening of blue-green algae Lyngbya for its antimicrobial activities

This study aimed to assess the effect of extracts of Lyngbya strain, MZUCC066, prepared in different solvents (methanol-100%, ethanol:water-3:7 and dichloromethane:isopropanol-1:1) against six microorganisms that comprise three chlorophycean algae (Chlorella vulgaris, Scenedesmus quadricauda and Selenastrum capricornatum), one cyanobacterian alga (Anabaena variabilis), and two bacterial strains (Bacillus subtilis, ATCC11774 and Bacillus pumilus, ATCC14884). Among the algal test organisms, the highest inhibition was found in S. quadricauda (70%) by dichloromethane:isopropanol extract of Lyngbya followed by A. variabilis (41%) by the same extract. When tested on bacterial test organisms, the highest inhibition zone diameter of 15.67 mm was found in B. subtilis by dichloromethane:isopropanol extract and followed by 14 mm in B. pumilus by the same extract at 100 ┬Ál concentration. Minimum inhibitory concentrations of each extract on all the organisms were varied. The present study suggests that Lyngbya has specific bioactivities against different groups of microorganisms.

Seasonal variation in the diet of the frugivorous bat, Rousettus leschenaultia

Seasonal variation in the diet of the fugivorous bat, Rousettus leschenaulti of the Lengteng Wildlife Sanctuary was studied from January 2013 to December 2013. The diet of the frugivorous bats, R. leschenaulti was evaluated by four methods: analysis of the discarded plant parts like fruits, flowers, leaves, seeds and bolus; analysis of pollens attached to the body of bats; the field observation on feeding behaviour of bats, and the analysis of faecal matter to identify the undigested seeds. These bats consumed the fruits of 34 plant species, leaves of 6 plant species and, flowers, nectars, and pollens of 5 plant species. They consumed fruits exclusively from May to September, but during the remaining months, they supplemented their diet with other plant parts. Leaves, flowers, nectars and pollens were consumed during seven months, i.e., from January to April, and October to December, when the fruit resources were depleted or not available in sufficient quantity in the sanctuary.

Application of geo-spatial technologies for ground water quality mapping of Aizawl district, Mizoram, India

Water is one of the most important natural resources highly crucial for our day-to-day life. The main sources of water are surface water and ground water. Erratic and irregular availability of surface water leads to exploration and utilization of ground water for irrigation, industrial and domestic purposes. Therefore, the quality of ground water is equally important as its quantity. The present study utilizes geographical information system (GIS) technique to map the spatial variability of ground water quality. Ground water samples were collected from 188 point sources randomly distributed in Aizawl district, Mizoram. The major water quality parameters namely pH, electrical conductivity (EC), total dissolved solids, total hardness, iron, chloride, nitrate and fluoride have been estimated for all the sampling locations. The spatial variation maps of these ground water quality parameters were generated and utilize as thematic layers. These thematic layers were given ranks based on their relative importance. Different classes within each thematic layer were assigned weightages in numerical rating from 1 to 3 as attribute values in GIS environment. Summation of these attributes values and the corresponding rank values of the thematic layers were utilize to generate the final ground water quality map. This final map shows the different classes of ground water quality within the district which can be utilize to provide a guideline for the suitability of ground water uses.

Effects of induced abiotic stresses on growth and lipid accumulation of the green alga Stigeoclonium

The fresh water microalga, Stigeoclonium sp., was examined for its eligibility as a biodiesel feedstock. The lipid content and growth performances were studied under normal culture conditions and abiotic stress conditions of nutrient deficiency, hypersalinity and pH stress using Chu-10 medium. Total lipid content was found to be 12.58% dry weight under nutrient replete condition which was enhanced by about 14% dry weight under nitrogen deficiency and by about 6% dry weight under phosphorus deficiency. Growth performances observed under different pH and salinity regimes concluded the ability of the organism to survive in varying environmental conditions. The observations suggest the suitability of Stigeoclonium as a viable source of biodiesel production.

Effects of the absence of nitrogen and phosphorus on the growth rate and total chlorophyll content of a freshwater microalgae Scenedesmus sp.

The objective of this study was to determine the effect of nitrogen and phosphorus on the growth and total chlorophyll content of a freshwater microalgae Scenedesmus sp. Growth behavior under modified Chu-10 medium without nitrogen source showed strong inhibition with growth rate reduced to 72.84% after 96 hour of treatment. There was about 10.24% inhibition of growth when the algae were cultured in a modified Chu-10 medium without phosphorus source. The photosynthetic pigment such as total chlorophyll content decreased at the same extent after 96 hour of culture in modified Chu-10 medium without the nitrogen source but not decreases in the medium without phosphorus source and the inhibition was highest in the medium without the nitrogen source.

Molecular characterization of actinomycetes isolated from Tuichang river and their biosynthetic potential

Actinomycetes are antibiotic producing gram positive bacteria widely distributed in nature including fresh water habitat. The study of fresh water actinomycetes especially from river is still in infancy and has been less explored. In this study, 20 Streptomyces sp. were isolated from Tuichang river and were screened for their antimicrobial potential. Antibiotic sensitivity pattern of the isolates against standard antibiotics was also observed. Eight isolates (n=8; 40%) showed significant antibacterial activity against at least two tested bacterial pathogens, while six isolates (n=6; 30%) showed antifungal potential against at least two tested fungal phytopathogens. All the isolates showed resistance to penicillin G and ampicillin. Of all the isolates screened, BPSWAC23 and BPSWAC24 inhibited all the tested fungal and bacterial pathogens and showed resistance to 50% of the antibiotics. BPSWAC23 and BPSWAC24 were identified by using 16S rRNA gene sequencing and found to be Streptomyces sp. Streptomyces parvus respectively. Further, biosynthetic genes coding for polyketide synthase (PKS II) and nonribosomal peptide synthetase (NRPS) were also detected in these two isolates which indicates a good candidate for the discovery of novel antibiotics.

First report of the genus Neonoemacheilus Zhu & Guo (Cobitidae: Nemacheilidae) from rivers of Mizoram, northeastern India with a note on N. assamensis Menon

The study, for the first time, reports the occurrence of the genus Neonoemacheilus from rivers of Mizoram, namely Langkaih and Tlawng rivers,. The study provides descriptions of N. assamensis giving additional characters other than outlined in the original description, such as, number of unbranched dorsal and anal fin rays; intestine arrangement and numbers of vertebrae.

Impact of road construction on the socio-economic condition of the communities in the hilly terrain of Lunglei district, Mizoram, India

Roads are the major means of transportation and communication. They play significant role in the development of the community or society. Major import and export of goods, general transportation and communication services within a community or between communities take place mostly through roads. The efficiency of such function is hugely dependent on the condition and quality of the road. With this view, the Mizoram state government made an effort towards the construction of roads from Buangpui to Lunglei. This study is directed towards the impact of roads and road construction on the socio-economic status of a community directly within the project site. Pre-construction and post-construction conditions of the community were studied and analyzed through collection of various parameters. The study revealed that the construction of roads not only improves the livelihood of the community but also increases the number of educational institutions and health centers as well. More people are also engaged in certain jobs such as carpentry and handloom as they can now easily import and export their goods due to better road condition.