A Study on the Prevalence of Indoor Mycoflora in Air Conditioned Buses.

Aim: To study the presence of indoor mycoflora in A/c Buses to know the commuters risk of exposure to fungal spores. Place and Duration: Chennai Mofussil Bus Terminus (CMBT), Koyambedu, Chennai, India. Study was conducted from November 2011 to April 2012. Methodology: Airborne fungi from 50 A/c buses were studied using Reuter Centrifugal Sampler (Biotest, Germany), fungi from the surfaces of air vents through swab sample and bus seats by rubbing sterile petridishes on the seats. Sabourauds Dextrose Agar (SDA) was used for the isolation of fungi from different buses. The collected data were statistically analyzed. Results: A total of 38 species classified in 21 genera were recorded. Among which, Zygomycetes was represented by 4 species, Ascomycetes and Coelomycetes by single species each and the remaining belongs to Hyphomycetes. The genus, Aspergillus was represented by maximum number of species (11 species) followed by Penicillium (5 species). A total average of 713 CFU/m3 of air was recorded within the buses. Aspergillus niger was the first dominant fungi in the order of dominance followed by Chrysonilia sitophila, Alternaria alternata and Aspergillus flavus in that order. From the surface of bus seats, Aspergillus niger, A. flavus, Rhizopus stolonifer and A. japonicus were recorded as dominant. However, different mycofloral composition was recorded from air vents. Cladosporium chlorocephalum and Curvularia lunata dominated the surface of air vents. Conclusion: The study demonstrates the presence of potential fungal species which pose exposure risk to the immune compromised commuters.

Studies on Phytochemistry of 100 Plants in Chennai, India.

Aims: Knowledge on the plant phytochemistry provides a fundamental use of plants as a reservoir of chemical agents. Hence, the study on the presence of Phytochemicals in the aqueous extract of 100 different plant species belonging to 44 families collected from Chennai, India was detected. Place and Duration: Plants distributed in the Chennai district of Tamil Nadu state in India were studied. The study was conducted during the period of November 2012 to January 2013. Methods: Leaves of around 100 plant species belonging to different habit like trees, shrubs, herbs and creepers or climbers from Chennai and its surround districts of India were collected. The aqueous extract of air dried, pulverized leaf samples of collected plants were examined for the presence of Tannins, Phlobatannins, Saponins, Flavonoids, Terpenoids, Cardiac glycosides and Steroids using the standard techniques proposed by Evans (1996). The presence of individual secondary metabolites was calculated in percentage and their prevalence in different plant habit was studied. Results: Around 29%, 20%, 23%, 48%, 22%, 30% and 44% of plants showed the presence of Tannins, Phlobatannins, Saponins, Flavonoids, Terpenoids, Cardiac glycosides and Steroids in that order. Further, the presence of secondary metabolites according to the plant habit like, tree, shrub, herb and creeper or climber was detected. Conclusion: It was evident that the presence of Tannin, Phlobatannin, Flavonoids and Cardiac glycosides are found prevalent in trees, Steroids in herbs and Terpenoids in shrubs. However, further study on this aspect is recommended.

Enhanced production of mosquitocidal cyclic lipopeptide from Bacillus subtilis subsp. subtilis.

Background & objectives: A cyclic lipopeptide, surfactin produced by a strain of Bacillus subtilis subsp. subtilis (VCRC B471) was found to exhibit activity against both the larval and pupal stages of mosquitoes. The present study was aimed at increasing the production of the mosquitocidal metabolite by modifying the conventional medium. Methods: Enhancement of mosquitocidal metabolite production was attempted by replacing the existing micronutrients of the conventional NYSM and supplementing the medium with additional amounts of glucose. The LC50 value of culture supernatant (CS) against the larval and pupal stages of Anopheles stephensi was determined. Crude mosquitocidal metabolite (CMM) was separated from the CS, identified by MALDI-TOF analysis and its LC50 dosage requirement for the pupal stage of the above mosquito species determined. Results: The medium containing a new composition of micronutrients and glucose up to 1 per cent resulted in increased metabolite production. The LC50 value of the CS obtained in the improved medium against larvae and pupae of An. stephensi was 5.57 and 0.71 μl/ml, respectively. The yield of CMM was doubled in the improved medium. MALDI-TOF analysis revealed that the CMM was surfactin. Interpretation & conclusions: The new improved medium enhanced the production of mosquitocidal metabolite as the dosage required for inciting 50 per cent mortality among the pupal stages of mosquitoes was only half of that required when the metabolite was produced in the conventional medium. The mosquitocidal metabolite was identified as surfactin, a cyclic lipopeptide and biosurfactant.