Development of eco-friendly bioplastic like PHB by distillery effluent microorganisms

During screening for poly-β-hydroxybutyrate (PHB) producing bacteria from distillery effluent sample, six out of 30 isolates comprising of three strains of Alcaligenes sp., two strains of Bacillus sp., and one strain of Pseudomonas sp. were found to accumulate varying levels of intracellular PHB. Amongst the various isolates, Alcaligenes sp. RZS4 was found as the potent PHB-producing organism, accumulating higher amounts of PHB. PHB productivity was further enhanced in the presence of oxygen, nitrogen-limiting conditions, and cloning of PHB synthesizing genes of Alcaligenes sp. RZS 4 into Escherichia coli. A twofold increase in PHB yield was obtained from recombinant E. coli vis-à-vis Alcaligenes sp.; the recombinant E. coli accumulated more PHB in NDMM, produced good amount of PHB in a single-stage cultivation process under both nutrient-rich and nutrient-deficient conditions. Extraction of PHB with acetone–alcohol (1:1) was found as suitable method for optimum extraction of PHB as this mixture selectively extracted PHB without affecting the non-PHB cell mass. PHB extract from recombinant E. coli showed the presence of C–H, =O stretching, =C–H deformation, =C–H, =CH, and =C–O functional groups characteristic of PHB.     

Structural change and sustainable development

In this paper, we show that the commonly observed decline in primary (natural resource using) sector output and employment shares, often termed structural change, can be explained as an endogenous response to the presence of nature's constraint. Structural change takes place even if consumer preferences are homothetic, and technological progress does not discriminate against the primary sector. Under certain conditions, structural change allows an open economy to grow with natural resource sustainability. Sustained and environmentally sustainable economic growth is possible even if the natural resource is exploited under open access. Well-defined property rights are neither necessary, nor sufficient for sustainable growth. We show that there is no unique relationship between natural resource endowment and the rate of economic growth over the long run. Resource-rich economies may grow faster or slower than resource-poor ones.     

Changing patterns of organochlorine pesticide residues in raw bovine milk from Haryana, India

Bovine milk samples were collected and analyzed during 1992 and 1998 from rural areas of 14 different districts of Haryana state for the presence of HCH and DDT residues. The study revealed that the mean residues of ΣHCH in raw bovine milk have declined by 67.5% while mean levels of ΣDDT have decreased by 92.8% during six years gap. The obtained results reveal that during 1992 p,p'-DDT was the main component followed by p,p'-DDD, α-HCH and β-HCH while in 1998, p,p'-DDE and β-HCH followed by p,p'-DDT were relatively more as compared to other isomers and metabolites of these pesticides.     

Zooplankton and its grazing as indicators of trophic status in Dutch lakes

The existing data on the species composition of zooplankton and grazing intensities of crustacean plankton are discussed in the light of trophic status, particularly in the Dutch lakes of varying trophy. Several species of rotifers in northern Europe and North America are considered to indicate eutrophic environments. However, unanimity is less regarding crustacean zooplankton, since several species are encountered in lakes varying widely in trophic degree. The zooplankton to seston (33 μm) biomass ratio may provide information about the ecological transfer efficiency and trophic status. In the Dutch lakes the ratio decreases sharply with increase in food concentration during eutrophication, namely from ca 0.4 in oligotrophic lakes to about 0.05 in the hypertrophic ones. The zooplankton community grazing is high and variable in lakes of low trophy but low and relatively constant in lakes of high trophy. The fluctuations in the filtering rates of Daphnia sp. (e.g. D. magna) may provide information both on trophic degree as well as dissolved substances in lake waters. The dominance of small cladocerans in lakes may be due to quality of food and trophic level, besides fish predation. The recurrent clear-water phase in lakes would indicate oligo-mesotrophic situations in which the zooplankton plays an important role in the phytoplankton wax and wane.     

Fungal-modification of Natural Fibers: A Novel Method of Treating Natural Fibers for Composite Reinforcement

Growing interest in green products has provided fresh impetus to the research in the field of renewable materials. Plant fibers are not only renewable but also light in weight and low in cost. Polymer composites manufactured using them find applications in diverse fields such as automobiles, housing, and furniture. However, their hydrophilic nature and inadequate adhesion with matrix limits their use in high performance applications. In this study, a novel method for improving adhesion characteristics of natural fibers has been developed. This method is carried out by treating hemp fibers with a fungus: Ophiostoma ulmi, obtained from elm tree infected with Dutch elm disease. Treated fibers showed improved acid–base characteristics and resistance to moisture. Improved acid–base interactions between fiber and resin are expected to improve the interfacial adhesion, whereas improved moisture resistance would benefit the durability of the composites. Finally, composites were prepared using untreated/treated fibers and unsaturated polyester resin. Composites with treated fibers showed slightly better mechanical properties, which is most probably due to improved interfacial adhesion.     

Chlorpyrifos degradation by the cyanobacterium <Emphasis Type="Italic">Synechocystis</Emphasis> sp. strain PUPCCC 64

Background, aim, and scope  

Indiscriminate use of insecticides leads to environmental problems and poses a great threat to beneficial microorganisms. The aim of the present work was to study chlorpyrifos degradation by a rice field cyanobacterium Synechocystis sp. strain PUPCCC 64 so that the organism is able to reduce insecticide pollution in situ.     

Autoantibodies and autoimmune disorders in SARS-CoV-2 infection: pathogenicity and immune regulation

Environmental Science and Pollution Research - Coronavirus disease 2019 (COVID-19) is an infectious disease associated with the respiratory system caused by the SARS-CoV-2 virus. The aim of this...     

Changes in cardiac rhythm and calcium levels in guinea pigs treated chronically with fenitrothion

Fenitrothion, an acetylcholinesterase inhibitor, causes bradycardia following long‐term exposure. To analyse the mechanism underlying these cardiac changes, ginea pigs were exposed to fenitrothion 5 and 10 mg/kg for 30 consecutive days. Electrocardiogram (ECG) showed increase in PR and RR intervals. These changes were more prominent in the animals receiving 10 mg/kg fenitrothion which occasionally showed extrasystoles. In isolated atria preparation heart rate was decreased at higher dose. Amplitude of cardiac rhythm decreased with respect to increased ACh concentration. Hypocalcemia was recorded in fenitrothion‐treated animals. The residual content of fenitrothion was increased in both groups of animals following a pattern: brain> spleen> heart> liver> kidney.     

Nutraceuticals and mitochondrial oxidative stress: bridging the gap in the management of bronchial asthma

Environmental Science and Pollution Research - Asthma is a chronic inflammatory disease primarily characterized by inflammation and reversible bronchoconstriction. It is currently one of the...