Shelf life studies on Biotech produced alkaline protease from Bacillus subtilis NRRL B- 3749 (BIOTECH 1679)

Date

11-2006

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Teresita M. Espino

Abstract

RUBIN, RONA VANESSA A. College of Arts and Sciences, University of the Philippines Los Banos, November 2006. Shelf Life Studies on BIOTECH Produced Alkaline Protease from Bacillus subtilis NRRL B- 3749 (BIOTECH 1679).

Adviser: DR. TERESITA M. ESPINO, Ph.D.

Different compounds such as glycerol, sodium benzoate and potassium sorbate were used as preservatives in the shelf life studies of liquid alkaline protease. Results of the study showed that glycerol was the most effective preservative while sodium benzoate and potassium sorbate resulted in the loss of alkaline protease activity even up to 2 days storage at room temperature (RT).

The effect of different concentrations of glycerol (5%, 10% and 15% levels) on the activity of liquid alkaline protease showed that the 15% glycerol level was the most effective in preserving the activity of alkaline protease after 4 weeks of storage at RT which had 63.64% remaining volumetric activity. However, the recorded remaining volumetric activities after 2 weeks of storage at 5% and 10% levels of glycerol were 92.37% and 80.97% respectively, which were much higher than that at 15% (70.91%). The 5% glycerol level was used in the subsequent studies for economic consideration.

The effect of temperatures, RT (-32 °C) and 4°C on the activity of liquid alkaline protease showed that the remaining volumetric activity of the sample stored at 4°C with 5% glycerol was the highest (39.80%) after 6 weeks of storage, although the enzyme sample stored at 4°C without glycerol recorded 37.07% remaining activity. Both enzyme samples stored at RT without and with 5% glycerol had almost the same values of 24.25% and 24.31% remaining alkaline protease activities respectively.

Storage of the dried or powdered alkaline protease at 4°C showed that the remaining specific activities at storage times from 2 to 8 weeks were higher than those stored at RT. This indicated that temperature is inversely proportional to enzyme activity. As the temperature and storage time increased, the activity of the enzyme decreased.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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