Purification and partial characterization of lipases from Rhizopus delemar

Date

4-1993

Degree

Bachelor of Science in Agricultural Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Teresita M. Espino

Abstract

SANTOS, MA. CARMENCITA TOMAS, College of Agriculture - College of Arts and Sciences, University of the Philippines at Los Banos, April, 1993. Purification and Partial Characterization of Lipases from Rhizopus delemar

ADVISER: TERESITA M. ESPINO. Ph. D.

Purification of lipases obtained by liquid culture fermentation using Starch Soybean Meal medium (SBM) with Rhizopus delemar was done. The supernatant, labelled as Phase I, and the precipitate labelled as Phase II, collected after centrifugation of the culture broth were both used as crude enzyme extracts. Three fractions were obtained after purification steps which involved precipitation with 70 % ammonium sulfate, gel chromatography on Sephadex S - 25 (desalting of (NH4)2S04 precipitated fractions), ion-exchange chromatography on DEAE - Toyopearl of Phase I and gel chromatography on Sephadex G - 150 of Phase II. After a series of purification steps, the purification fold obtained for Phase I (P1F1.1) was 14 times than that of the culture filtrate, while for Phase II (P2F1.1), 21 times than that of the culture filtrate. The percent recoveries were 3.10 % for Phase I (P1F1.1) and 0.60 % for Phase II (P2F1.1).

The optimum temperature and pH for maximum lipase activity of Phase I (P1F1.1) was 35°C and pH 5.6, respectively with polyvinyl alcohol - coconut oil emulsion as substrate. The same optimum temperature and pH for maximum lipase activity were obtained for Phase II (P2F1.1).

Phase I (P1F1.1) was stable at temperature below 55°C with complete loss of lipolytic activity at 60°C. It was active at pH between 3 to 7. Phase II was stable at temperatures up to 50°C and with complete loss of lipolytic activity at 60°C and was active at pH 3 to 6.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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