Heavy Metal Toxicity to a Freshwater Crab, Barytelphusa cunicularis (Westwood) from Aurangabad Region

Pesticides of heavy metal salts are common pollutants of freshwater ecosystems where they induce adverse effects on the aquatic biota. Barytelphusa cunicularis is a key-species in Marathwada region having good nutritional value. Crabs live in close association with the sediment where accumulation of heavy metals pesticides is reported. Acute toxicity tests were conducted against the pesticides copper sulphate and mercuric chloride. Median Lethal Concentration (LC50) values of Copper sulphate were found to be 282, 258, 238 and 215 ppm respectively for 24, 48, 72 and 96 h., while those for mercuric chloride were 1.04, 0.84, 0.63 and 0.45 ppm respectively. This crab was found more sensitive to mercuric chloride than copper sulphate

MEIOFAUNAL DENSITY & DIVERSITY OF TWO FRESHWATER RESERVOIRS, AMBADI AND SHIVNA TAKALI FROM KANNAD TALUKA, AURANGABAD DISTRICT (M.S.)

Meiofauna are the major mode of energy transfer between phytoplankton and end users like finfishes, shell fishes etc. This study reports the meiofaunal community in two freshwater reservoirs namely Ambadi and Shivna Takali from Kannad Taluka of Aurangabad district. A total 34 species of meiofauna recorded include 14 species of rotifers, 10 species of cladocerans, 06 species of copepods and 04 species of Ostracods. The study reveals the rotifers dominance followed by copepods, cladocerans and ostracods from Ambadi & Shivna Takali reservoirs. The average value of population density of meiofauna was maximum in the monsoon season (83 org/liter) and minimum in the winter season (68.175 org/liter) in the Ambadi reservoir. Where as in the Shivna Takali reservoir the value was maximum in the summer season (31.75 org/liter) and minimum in winter season (22.5 org/liter) was found. It can be said that the diversity and density of meiofaunal group and its seasonal variation show the nutrient levels were moderate, relatively high densities of zooplankton were found- in the order Rotifera>Cladocera>Copepoda>Ostracoda in Ambadi reservoir as compare to Shivna Takali reservoir

Imidazole-grafted nanogels for the fabrication of organic–inorganic protein hybrids

Here, a platform for the development of highly responsive organic–inorganic enzyme hybrids is provided. The approach entails a first step of protein engineering, in which individual enzymes are armored with a porous nanogel decorated with imidazole motifs. In a second step, by mimicking the biomineralization mechanism, the assembly of the imidazole nanogels with CuSO4 and phosphate salts is triggered. A full characterization of the new composites reveals the first reported example in which the assembly mechanism is triggered by the sum of Cu(II)–imidazole interaction and Cu3(PO4)2 inorganic salt formation. It is demonstrated that the organic component of the hybrids, namely the imidazole‐modified polyacrylamide hydrogel, provides a favorable spatial distribution for the enzyme. This results in enhanced conversion rates, robustness of the composite at low pH values, and a remarkable thermal stability at 65 °C, exhibiting 400% of the activity of the mineralized enzyme lacking the organic constituent. Importantly, unlike in previous works, the protocol applies to the use of a broad range of transition metal cations (including mono‐, di‐, and trivalent cations) to trigger the mineralization mechanism, which eventually broadens the chemical and structural diversity of organic–inorganic protein hybrids.This project had received funding from the Spanish Ministry of Economy and Competitiveness (MINECO) and the FEDER funds in the frame of “Plan Nacional – Retos para la Sociedad” call with the Grant Reference No. MAT2017‐88808‐R. This work was performed under the Maria de Maeztu Units of Excellence Programme – Grant No. MDM‐2016‐0618. A.B. thanks Diputación de Guipúzcoa for current funding in the frame of Gipuzkoa Fellows program. M.K. acknowledges financial support by the Spanish Ministry of Economy and Competitiveness (MINECO) within Grant Agreement No. MAT2016‐77393‐R, including FEDER funds.Peer reviewe