Research

Rearing of Spiders in the Laboratory for Pesticide Testing

The harmful effect of insecticide on spider community is of major concern since these invertebrates act as a biological buffer of controlling pest populations in the ecosystem. Among the chemical family of insecticides, synthetic pyrethroids are known to have stronger effect on the abundance, survival, reproduction and foraging of spiders. Despite that, the ecotoxicology of arachnids have received little attention. They are not even included as a test organism in the Environmental Risk Assessment (ERA) of plant protection products. One possible reason might be the lack of an efficient rearing technique. Besides, different guild of spiders may react to insecticides in a different way. Consequently, selecting a surrogate organism, which represent the whole community and can be easily maintained in the laboratory is crucial. Therefore, this study was designed to develop (1) a rearing technique, which is time and labor efficient and (2) an acute toxicity test to evaluate the adverse effect of insecticide. Out of all families, Lycosidae showed higher survival probability, higher reproduction and lowest mortality of spiderlings in the laboratory. In contrast, Linyphiidae displayed lowest fitness and highest mortality of both mother and spiderlings. Hence, species from Lycosidae family can be considered as a successful test organism for ecotoxicology study. However, more extensive research is needed to identify which species would be an ideal surrogate species. Then, to observe the effect of synthetic pyrethroid (Lambda-Cyhalothrin), a 24-hour mortality test was conducted on spiderlings hatched from field- captured spiders, P. agrestis and D. graecus. Both of these species were collected from agricultural field. The result illustrates that P. agrestis was more sensitive to Lambda-cyhalothrin than D. graecus, although more information is required in this prospect.

Publication:

Duque, T., Chowdhury, S., Scherf, G., Schäfer, R. B., Entling, M. H. (2021). Chemical sensitivity of spiders: effects of morphology, phylogeny and habitat. In Proceedings of the 2021 Virtual Meeting of the American Arachnological Society. [Poster]

Soil Salinity of Hazaribagh Tanning Industrial Area, Bangladesh

Soil supports all types of structures such as buildings, roads, bridges, dams, etc. However, the salinity of soil is a critical problem and responsible for extensible damage to the public and private infrastructures. This study was conducted to provide the necessary information to builders so that they are aware of the physico-chemical properties of the soil and its impact on building materials.

Publication:

Mottalib, M. A, Sultana, A., Rahman, M. M., Zilani, G., Chowdhury, S. & Hoque, S. (2017). Investigation onto Soil Salinity of Hazaribagh Tanning Industrial Area, Dhaka, Bangladesh. IOSR-JESTFT, 11(8), 44 - 49. [Peer-reviewed Journal Article]

Antibacterial activity of soil-bound oxytetracycline

I completed my Master's thesis at University of Dhaka, under the supervision of Dr. Sirajul Hoque. I investigated whether soil bound antibiotics have harmful effect on soil-derived bacteria or not. I used three different textured soils, incubated them with five bacterial cultures and then enumerated the number of colony forming units. Incubation was done for 24 hours. The results showed that adsorption behavior of oxytetracycline in the three soils were mainly influenced by soil organic matter content, cation exchange capacity (CEC) and pH but the adsorbed antibiotic doesn’t have any significant effect on the growth of bacterial cultures.

Publication:

Chowdhury, S., Chakma, P. & Hoque, S. (2017). Antibacterial activity of soil-bound oxytetracycline. In Proceedings of the Symposium on Environmental Chemistry for Securing Water Quality, Dhaka, Bangladesh. [Poster]

Degradation of malathion by phosphate solubilizing bacteria

Microbial bioremediation has emerged as an efficient technique to clean up polluted environments. In this study the efficiency of phosphate solubilizing bacteria isolated from agricultural fields were investigated to metabolize malathion, an organophosphate pesticide commonly used in Bangladesh. We identified four bacterial strains, which showed the capability of malathion degradation under different temperature regime.

Publication:

Chakma, P., Chowdhury, S. & Hoque, S. (2017). Transformation of malathion by phosphate solubilizing bacteria. In Proceedings of the Symposium on Environmental Chemistry for Securing Water Quality, Dhaka, Bangladesh. [Poster]

Microalgae: An Alternative Source of Renewable Energy

For my Bachelor's project at University of Dhaka, I did a literature review on bio-fuel. The main goal of this paper was to analyze the necessity of bio-fuel production for ensuring a safe environment as well as sound economy for Bangladesh. The prospect of bio-fuel production in this country is analyzed very deeply.