Effect of natural preservatives on the growth of histamine producing bacteria

Present study deals with the hampering of the growth of histamine producing bacteria (HPB), by using NaCl and spices which are easily available and cheaper cost wise. For this experiment, four strains of HPB viz. Vibrio parahaemolyticus, Bacillus cereus, Pseudomonas aeruginosa and Proteus mirabilis were tested against 1 to 10% concentrations of NaCl and 1 to 5% concentrations of natural preservatives (turmeric, ginger and garlic) in a basal medium. HPB showed different growth rates at different concentrations of NaCl and natural preservatives. V. parahaemolyticus, B. cereus and Ps. aeruginosa showed no growth at 10% concentration. When the HPB growth was tested with garlic, turmeric and ginger extracts, growth of all the bacteria was inhibited by garlic and turmeric extracts at 5% concentration. In ginger, V. parahaemolyticus, B. cereus and P. mirabilis were totally inhibited at 5% concentration. But Ps. aeruginosa showed very less growth at this concentration.     

Invasive alien species as drivers in socio-ecological systems: local adaptations towards use of Lantana in Southern India

Lantana camara. L (hereafter Lantana) was first introduced by the British into India in 1807 as an ornamental plant. Since then the species has spread across the length and breadth of the country. Attempts to control Lantana in India have not been successful. In this study, we analysed the use of Lantana by local communities in southern India and identified the possible causes and consequences of its use through the use of a household survey of the socio-economic profile of the user and nonuser households and an analysis of the ecological history of the communities. Communities have been using Lantana for over 25–30 years and apparently such use was not prompted by external agencies. The characteristics of user and nonuser households were similar, except that Lantana users were more literate and had a greater number of occupations per household than nonusers. Per capita income was similar between user and nonuser groups. For nonuser groups, their main income sources were from trading (44 %), wage labour (32 %) and forest resources (23 %). In contrast, the Lantana user groups substituted their loss of income from forest resources (7 %) by income from Lantana (46 %). The ecological history revealed that Lantana was adopted as a resource at a time when it was increasing in the landscape and traditional bamboo resources were in decline because of overuse by commercial enterprises and mast flowering. This change in ecological resource availability prompted a major shift in livelihoods for some in the area.     

Computational analysis of turbulence enhancement in a compression ignition engine with modified inlet design

Environmental Science and Pollution Research - This study aims to enhance the turbulence of direct injection (DI) diesel engine by modifying the inlet manifold design with an inclined nozzle-like...     

A survey of parabens in aquatic environments in Hanoi,Vietnam and its implications for human exposure and ecological risk

Environmental Science and Pollution Research - Seven parabens including methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), iso-propylparaben (iPrP), butylparaben (BuP), benzylparaben...     

A review on the conversion of cassava wastes into value-added products towards a sustainable environment

The solid and liquid wastes generated from cassava-based industries are organic and acidic in nature, which leads to various global concerns—primarily global warming and biodiversity loss. But the conversion of these wastes into value-added products associated with environmental pollution control contributes to sustainable development. Generally, the thermochemical process such as pyrolysis and gasification and biochemical processes such as anaerobic digestion have been applied for the conversion of cassava waste into value-added products. This review addresses the valorization of cassava wastes, which fulfill almost all needs of the hour, such as energy (biofuel), wastewater treatment (adsorbents), bioplastics, starch nanoparticles, organic acid production, and antimicrobial agents. The major aim of this paper is to analyze and provide the disclosure of the efficiency of cassava-based industrial waste as a source to minimize the problem associated with conventional fossil fuels and through which mitigate the impact of global warming and climate change. Furthermore, recent research and achievements in the valorization of cassava waste have been highlighted.

     

Metallic wastewater treatment by sulfate reduction using anaerobic rotating biological contactor reactor under high metal loading conditions

An-RBC reactor is highly suited to treat metallic wastewater. Metal removal is due to sulfide precipitation via sulfate reduction by SRB. Cu(II) removal was the best among the different heavy metals. Maximum metal removal is achieved at low metal loading condition. Metal removal matched well with the solubility product values of respective metal sulfide salts. This study was aimed at investigating the performance of anaerobic rotating biological contactor reactor treating synthetic wastewater containing a mixture of heavy metals under sulfate reducing condition. Statistically valid factorial design of experiments was carried out to understand the dynamics of metal removal using this bioreactor system. Copper removal was maximum (>98%), followed by other heavy metals at their respective low inlet concentrations. Metal loading rates less than 3.7 mg/L?h in case of Cu(II); less than 1.69 mg/L?h for Ni(II), Pb(II), Zn(II), Fe(III) and Cd(II) are favorable to the performance of the An-RBC reactor. Removal efficiency of the heavy metals from mixture depended on the metal species and their inlet loading concentrations. Analysis of metal precipitates formed in the sulfidogenic bioreactor by field emission scanning electron microscopy along with energy dispersive X-ray spectroscopy (FESEM-EDX) confirmed metal sulfide precipitation by SRB. All these results clearly revealed that the attached growth biofilm bioreactor is well suited for heavy metal removal from complex mixture.     

Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) and 2,3,7,8-TCDD equivalents (TEQs) in sediment from the Hyeongsan River, Korea

Sediment, pore water and water samples from the Hyeongsan River, Korea were analyzed for several classes of halogenated aromatic hydrocarbons (HAHs) and their dioxin-like activities were evaluated using the in vitro H4IIE-luc bioassay. Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) were detected in sediments from all six sampling locations with mean concentrations of 2.8 x 10(2) pg/g, 190 pg/g, and 61.4 ng/g, dw, respectively. Polycyclic aromatic hydrocarbons (PAHs) were predominated by 4-6 ring compounds with concentrations in the range of 5.30-7680 ng/g, dw. Chemical profiles of target analytes in sediment and water samples revealed that there was a gradient of concentrations along the river from upstream to downstream, which suggested that the primary source was a wastewater reservoir adjacent to a sewage treatment plant (STP). TEQs derived by summing the product of concentrations of individual congeners by their respective relative potencies (REPs or TEFs) ranged from 4.3 x 10(-1) to 1.1 x 10(3) pg/g, dw. Raw Soxhlet extracts from all six sampling locations induced significant dioxin-like responses in the H4IIE-luc bioassay. TCDD-EQs derived from H4IIE bioassay ranged from 7 x 10(-3) to 1.5 x 10(3) pg/g, dw, which were significantly correlated with TEQs (r2 = 0.994, p < 0.05). Among the three Florisil fractions tested, PCDD/Fs in fraction (F2) induced the greatest magnitude of response (range: 24-83%-TCDD-max.) in the H4IIE-luc assay. Comparison of the TEQ and TCDD-EQ suggested little non-additive interaction between fractions and AhR-active and inactive compounds. Concentrations of individual congeners as well as TEQs and TCDD-EQs suggest inputs from the industrial center waste stream in the Hyeongsan River.     

Chlorinated hydrocarbon contaminants in blood of black and turkey vultures from Savannah River Site,South Carolina,USA

Blood of adult and juvenile black and turkey vultures in the Savannah River Site of South Carolina, USA was analyzed for the presence of 2,3,7,8-chlorine substituted polychlorinated dibenzo-p-dioxins (2,3,7,8-PCDDs), dibenzofurans (2,3,7,8-PCDFs), -dioxin-like and -di-ortho polychlorinated biphenyls. Concentration ranges of 2,3,7,8-PCDD/DFs in blood of black and turkey vultures were 14.2-34.6 and 8.7-56.2 pg/ml wet wt., respectively. Dioxin-like PCBs were in the ranges of 815-4627 and 753-3611 pg/ml wet wt. respectively, in black and turkey vultures. Considerable concentrations of two congeners of di-ortho PCBs were noticed in the ranges of 1415-10325 and 663-7500 pg/ml respectively, in black and turkey vultures. Comparatively, greater toxic equivalency (TEQ) were observed in blood of turkey vultures with the ranges of 3.2-20, whereas black vulture contained 1.8-8.4 pgTEQ/ml wet wt. basis. The species-specific accumulation profiles of PCDD/DFs and dioxin-like PCBs may reflect the different feeding habits, ecology, metabolic capacity and migratory movements of these two scavenging species.