Recovery of chitin and chitosan from shrimp waste by chemical and microbial methods

Shrimp waste is the most important chitin source for commercial use. In this study chitin and chitosan were extracted from Penaeus semisulcatus waste collected from a shrimp processing landing center situated at Persian Gulf in south of Iran by chemical and microbial methods. Chitin and chitosan were extracted by alkali-acid treatment and the yields were 510 and 410mg/g, respectively. Demineralization is an important step in the chitin purification process from shrimp waste. Chemical extraction method included the use of NaOH solution and acetic acid. In microbial extraction, organic acids [lactic acid] produced by probiotic bacteria was used to demineralize microbial deproteinized shrimp shells. The study showed that the effectiveness of using lactic acid bacteria especially added Fe [NO[3][3] as extra nitrogen source for demineralization of shrimp shells than chemical method [1750 against 810mg/g]. Chitin and chitosan extracted from shrimp waste by chemical and microbial methods was crystalline powder, non-harmful and odorless, white and off-white, respectively. The moisture content was calculated as 63.8%. The amount of Ca, Fe, Cu and Mn present in the shells was 168, 35.58, 38.28 and 6.72mg/L, obtained by atomic absorption spectroscopy, respectively. The amount of calcium in the shells was 25 times higher than manganese. The results suggested Lactobacillus plantarum [PTTC 1058] is an attractive source of recovery for chitin and chitosan

Control of environmental health and removal of rats by alpha[2]-adrenergic antagonist and potassium channel blocker

In the present study, it is shown that in vivo oral administration of glibenclamide [1-10 mg/kg/day], an adenosine triphosphate -sensitive potassium channel blocker, and yohimbine [1-5 mg/kg/day], an alpha 2-adrenoceptor antagonist, potently reduced glycemia in male rats. Diazoxide [1-45 mg/kg/day], a potassium channel opener, and clonidine [0.05-0.5 mg/kg/day], an alpha 2- adrenoceptor agonist, antagonized the effects of glibenclamide and yohimbine respectively. Administration of glibenclamide and yohimbine separately decreased the serum glucose levels, so it was expected that coadministration of these two drugs significantly decreased this parameter in fasted animals. It is well known that glibenclamide blocks the potassium channels and it is likely that, yohimbine also blocks these channels, but according to our data, it seems that yohimbine acts via a different binding site to that of glibenclamide. In this research it is also observed that administration of yohimbine and glibenclamide causes death in rats, it seems that these drugs causes death in the experimental animals by lowering blood glucose level, which were the aim of this study and could be applied as a way to control the environmental health by abolishing rats

Treatment of dye containing colored index acid yellow 36 by electrocoagulation using iron electrodes

The removal of pollutants from effluents by electrocoagulation has become an attractive method in recent years. This paper deals with the batch removal of the reactive textile dye Colored Index [C. I.]. Acid yellow 36 from an aqueous medium by the electrocoagulation method using iron electrodes. The effects of electrolyte concentration, initial pH, current density, electrode area, interelectrode distance, dye concentration, and treatment time on the decolorization efficiency have been investigated. Iron hydroxypolymeric species formed during an earlier stage of the operation efficiently remove dye molecules by adsorption and precipitation, and in a subsequent stage, Fe[OH]3 flocs trap colloidal precipitates and make solid liquid separation easier during the flotation stage. These stages of electrocoagulation must be optimized to design an economically feasible electrocoagulation process. The increase of current density up to 127.8 A/m2 enhanced the color removal efficiency. Our results showed that the optimum electrolysis time was 6 min. The optimum pH was determined 8. It was also found that the color removal% [R.P.%] with increasing of dye concentration, decrease. The optimum amount of electrolyte [NaCl] was found to be 8 g/l when the dye concentration was 50 mg/l