Screening and statistical optimization of media ingredients for production of microbial transglutaminase

Abstract

Transglutaminase is a calcium dependent enzyme that catalyses acyl transfer reactions between primary amino groups and protein bound glutamine residues. Eighteen bacteria and twenty eight actinomycetes were screened for the presence of transglutaminase. Among the microbial cultures screened Streptomyces sp. D1, showed maximum transglutaminase activity. In this study characterisation of transglutaminase. In this study characterisation of transglutaminase and its usefulness to cross link milk proteins was studied, using enzyme treated milk for preparation of paneer (Indian cottage cheese). Optimum temperature and pH for enzyme was found to be at 50 °C and 6.0, respectively. Optimisation of media ingredients for maximising the transglutaminase activity using Streptomyces sp. D1 was carried out by central composite design. Response surface methodology was employed to standardise the optimum media composition for maximum enzyme activity. Three factors such as carbon source, nitrogen source and pH were tested for the maximum enzyme activity as response. The optimised medium with sugarcane molasses as carbon source 6.0 per cent (w/v), peptone as nitrogen source 1.75 per cent (w/v) were found to be optimal at initial pH 6.5 and incubation temperature 30.0 °C with agitation at 100 rpm for 72 h. The enzyme activity of transglutaminase obtained from the optimised medium was found to be 4.1 (AU/ml). Low cost substrate such as sugarcane molasses in the form of a renewable substrate is proposed to be suitable for scale-up production of enzyme and for industrial applications. The ethanol fractionated enzyme treated milk produced increased amount of paneer with more water content and decreased cooking loss in comparison to the untreated control.

Biphasic Drug Release from Rolled-Up Gelatin Capsules with a Cylindrical Cavity

“…Swelling of capsules was explored at pH = 2, approximately corresponding to stomach level, at pH = 4.5, and at pH = 7.4 (Figure 2a). In the most acidic medium (pH = 2), transglutaminase is deactivated [21] and did not perform the crosslinking of the roll's layers to each other. As a consequence, the capsules unrolled after about 4 h with a gain in mass equal to approximately 550%.…”