This study aimed to determine the quality of drinking water supplied in different types of food stalls in Jashore Municipality, Bangladesh. A total of 35 water samples were collected from different tea stalls, street side fast food stalls, normal restaurants and well-furnished restaurants. The water quality was evaluated by determining the distinct physical, chemical and biological parameters. The results revealed that the water used in the food stalls and restaurants for drinking purpose was in desired quality in terms of turbidity, electrical conductivity, pH, total dissolved solids, nitrate (NO₃⁻), sulfate (SO₄²⁻), phosphate (PO₄³⁻), chloride (Cl⁻), sodium (Na) and potassium (K) concentrations. The values were within the permissible limit proposed by the Bangladesh Bureau of Statistics and the World Health Organization. Concentrations of calcium (Ca) and magnesium (Mg) found in several samples were higher than the World Health Organization standard. Iron (Fe) concentrations were higher than the permissible limit of the World Health Organization. Only 46% exceeded the permissible limit of Bangladesh Bureau Statistics. The threatening result was that the samples were contaminated by fecal coliform, indicating that the people of Jashore Municipality may have a greater chance of being affected by pathogenic bacteria. The drinking water provided in the street side fast food stalls was biologically contaminated. The findings demonstrate that the drinking water used in food stalls and restaurants of Jashore Municipality did not meet up the potable drinking water quality standards and therefore was detrimental to public health.

Aeromonas hydrophila, a ubiquitous inhabitant of aquatic environments, commonly expresses several cell-surface properties that may contribute to virulence. Since many aquatic microorganisms in hostile environments can withstand starvation conditions for long periods, we examined the effect of storage under nutrient poor conditions on the expression of cell-surface properties of this pathogen. Phenotypes studied were: (1) cell surface hydrophobicity and charge, and (2) the ability to bind connective-tissue proteins and lactoferrin. Our results suggest that the response of A. hydrophila to nutrient-poor conditions is regimen specific. Generally, A. hydrophila cells became more hydrophobic and significantly increased their ability to bind the iron-binding glycoprotein lactoferrin when the bacterium was stored under nutrient-poor conditions; however, under these conditions, the cells seemed to lose their ability to bind connective tissue proteins.

Vertical mixing and stratification are among the most important physical processes controlling nutrient dynamics, the dominant category of primary producers and consequently the dominant types of food web, and are therefore important for the assessment of the marine ecosystem's response to global climate change. This study showed consistent short-term cyclic successions of the plankton food web types, governed by the dynamics of water column stability changes, occurring in generally oligotrophic, phosphate deficient surface waters of the open middle Adriatic Sea. The biogeochemical nitrogen cycle appeared as a key driving force responsible for the food web structure changes. The ‘herbivorous food web’ dominated during the nitrate-rich mixed water column period (winter) and gradually changed to ‘multivorous food web’ where large phytoplankton still constitute a significant fraction of phytoplankton. This intermediate type of food web lasted for a short time and quickly changed to the typical ‘microbial food web’, which then dominated during the stratified water column period (summer) and was characterised by a large proportion of picoplankton size-fraction organisms in total plankton biomass and production. Furthermore, at the very end of summer, the high bacterial carbon flux through the ‘microbial loop’ was established. The succession of food web types affects the mechanisms of bacterial control in a way that ‘bottom up’ control dominated during the mixed water column period and ‘top-down’ control prevailed during the stratified period. Since the ongoing global warming is expected to change water column stability dynamics and thereby significantly affect the supply of nutrients in surface waters, this study helps to understand the possible direction of changes in the plankton food webs of the Adriatic Sea, and consequent changes in marine nitrogen and carbon biogeochemical cycles.

Herein, the synthesis of bovine serum albumin-Cu(II) hybrid nanoflowers (BSA-NFs) through the building blocks of bovine serum albumin (BSA) and copper(II) ions in phosphate buffered saline (PBS) and their use as adsorbent for cadmium and lead ions are reported. The BSA-NFs, for the first time, were efficiently utilized as novel adsorbent for solid phase extraction (SPE) of cadmium and lead ions in water, food, cigarette and hair samples. The method is based on the separation and pre-concentration of Cd(II) and Pb(II) by BSA-NFs prior to determination by slurry analysis via flame atomic absorption spectrometry (FAAS). The analytes were adsorbed on BSA-NFs under the vortex mixing and then the ion-loaded slurry was separated and directly introduced into the flame AAS nebulizer by using a hand-made micro sample introduction system to eliminate a number of drawbacks. The effects of analytical key parameters, such as pH, amount of BSA-NFs, vortexing time, sample volume, and matrix effect of foreign ions on adsorbing of Cd(II) and Pb(II) were systematically investigated and optimized. The limits of detection (LODs) for Cd(II) and Pb(II) were calculated as 0.37 μg L−1 and 8.8 μg L−1, respectively. The relative standard deviation percentages (RSDs) (N = 5) for Cd(II) and Pb(II) were 7.2%, and 5.0%, respectively. The accuracy of the developed procedure was validated by the analysis of certified reference materials (TMDA-53.3 Fortified Water, TMDA-70 Fortified Water, SPS-WW2 Waste Water, NCSDC-73349 Bush Branches and Leaves) and by addition/recovery analysis. The quantitative recoveries were obtained for the analysis of certified reference materials and addition/recovery tests. The method was successfully applied to the analysis of cadmium and lead in water, food, cigarette and hair samples.