Bulletin of Environmental Studies

1-9

Authors: Muhammad Arslan*, Michael A. Kaminski, Amjad B. Khalil

The benthic foraminifera are among the major carbonate producers in modern Arabian Gulf waters and are found living in all marine habitats. They have been recognized as proxies to assess paleoenvironmental changes, however, their biological behavior in modern environments needs to be further studied. The current study attempts to explain the biology of benthic foraminifera in terms of their living behaviors (locomotion, survival, response to external stimuli, and reproductive strategy), from different regions of the western side of the Arabian Gulf. Accordingly, two major groups of benthic foraminifera, namely rotaliids and miliolids, are examined under laboratory conditions. Results illustrate that the rotaliids are more resistant to environmental changes than miliolids, as their granular reticulopodial network is stronger than among the miliolids, with high cytoplasmic streaming. The pseudopodia extend out from both primary and secondary apertures, and aid the organism in locomotion by attaching to the wall of hard substrate. As a result, they drag their whole bodies toward the direction of motion. In rotaliids, the movement rate is high and is attributed to the extension of pseudopodia through all apertures, compared with miliolids in which pseudopodia extend out from the primary aperture only. The innate behavior of both groups was observed as a function of external stimulus, i.e., light, nutrients, and availability of substrate. Lastly, the observation on the average life span indicates that the rotaliids are able to survive longer than miliolids. It is suggested that further studies on living behaviors should be conducted for different species towards better understanding of foraminiferal responses.

18-28

Authors: Hamna Saleem

Petroleum hydrocarbons are harmful to living organisms when they are exposed in natural environment. Once they come in contact, it is not an easy to remove them because many of their constituents are persistent in nature. To achieve this target, different approaches have been exploited by using plants, bacteria, and plant-bacteria together. Among them, combined use of plants and bacteria has gained tremendous attention as bacteria possess set of catabolic genes which produce catabolic enzymes to decontaminate hydrocarbons. In return, plant ooze out root exudates containing nutrients and necessary metabolites which facilitate the microbial colonization in plant rhizosphere. This results into high gene abundance and gene expression in the rhizosphere and, thus, leads to enhanced degradation. Moreover, high proportions of beneficial bacteria helps plant to gain more biomass due to their plant growth promoting activities and production of phytohromones. This review focuses functioning and mechanisms of catabolic genes responsible for degradation of straight chain and aromatic hydrocarbons with their potential of degradation in bioremediation. With the understanding of expression mechanisms, rate of degradation can be enhanced by adjusting environmental factors and acclimatizing plant associated bacteria in plant rhizosphere.

36-38

Authors: Muhammad Riaz, Tahir Mahmood, Muhammad Arslan

This current report intends to highlight the importance of considering background assumptions required for the analysis of real datasets in different disciplines. We will provide comparative discussion of parametric methods (that depends on distributional assumptions (like normality)) relative to non-parametric methods (that are free from many distributional assumptions). We have chosen a real dataset from environmental sciences (one of the application areas). The findings may be extended to the other disciplines following the same spirit.