Replacement of protein extraction from chitin of the crustacean's carapace by biotechnology

Chitin is a Biopolymer with more than 5000 N- acetyl glucosamine monomer. Its extraction occurs by conventional chemical methods and overall four steps; removal of proteins using alkaline compounds, removal of fat, minerals eliminating and dye remove. Using alkaline materials in the removal of protein, cause changes in the structure of space, De-polymerization, quality decrease and a large number of chemical materials and environmental pollution. This study was done to replace proteolytic enzyme of Bacillus subtilis bacterium instead of sodium hydroxide, a substance that is damaging for the nature. The results showed that the mentioned bacterium is able to digest 90±5 % of protein compounds by photolytic enzymes. Quality of the gained chitin was investigated by using of an infrared spectrometer to analysis the element structure. Also by x-rays radiography and via determination the viscosity, molecular weight, crystallinity percent, color, and molecular structure. The gained chitin have had a profile introduction containing of 49.6 % carbon, 8.2 % nitrogen, 7.5 % hydrogen and 34.5 % oxygen. Their physical characteristics were showed as 4.9×106 Dalton average molecular weight, 74.5 % crystallinity, 32 °poise viscosity oriented at 20 °C, and white color. The chemical structure of each unit of chitin was obtained as C7H12NO4. The results show that replacement of a biological method rather than chemical methods to achieve this production with the right conditions could help to achieve the better quality products and may cause eliminating the use of environmentally harmful chemical environmental pollution such as heavy sodium hydroxide.