A novel thermo-alkalitolerant endoglucanase production using cost-effective agricultural residues as substrates by a newly isolated Bacillus sp. NZ

Highly alkalitolerant and moderately thermotolerant Bacillus sp. NZ, isolated from degrading lignocellulose, produced a novel highly thermotolerant and alkalitolerant endoglucanase. Maximum activity of endoglucanase was observed in the medium with the initial pH=9 (920 U/L) after 72 h of fermentatio...

Full description

Saved in:
Bibliographic Details
Published in:Food technology and biotechnology 2009-10, Vol.47 (4), p.435-440
Main Authors: Nizamudeen, Sheikh, Bajaj, Bijender K
Format: Article
Language:English
Subjects:
alkalitolerant
Bacillus
Bacillus (Bacteria)
Bacillus sp. NZ
endoglucanase
Enzymes
Fermentation
Glucans
Physiological aspects
Production processes
thermo-alkalitolerant
thermotolerant
Triticum aestivum
wheat bran
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Highly alkalitolerant and moderately thermotolerant Bacillus sp. NZ, isolated from degrading lignocellulose, produced a novel highly thermotolerant and alkalitolerant endoglucanase. Maximum activity of endoglucanase was observed in the medium with the initial pH=9 (920 U/L) after 72 h of fermentation with shaking (250 rpm) at 45°C. Growth of the organism and enzyme production displayed a precise relationship, showing maxima after 72-96 h of fermentation; however, the organism formed maximum biomass at pH=8, but produced the highest enzyme titre at pH=9. Among the examined crude substrates, wheat bran gave maximum activity of endoglucanase (1960-2280 U/L), and was followed by wheat straw (1480-1760 U/L), filter paper (1360-1450 U/L) and sawdust (1160 U/L). Soybean meal served as a suitable nitrogen source for good production of endoglucanase. The enzyme showed activity over a broad pH range (5-10), with maximum at pH=9-10 (2240-2290 U/L). Endoglucanase was highly active (2210-2300 U/L) over a broad range of temperature (50-100°C), with maximum activity at 50°C (2290 U/L) and at 90°C (2300 U/L). Significantly high activity was observed even at 100°C (91.3 %). The enzyme was highly stable at temperatures from 60 to 90°C for a period of 30 min. Endoglucanase was purified 23-fold using ammonium sulphate precipitation. Substantial activity and stability of endoglucanase at elevated temperatures and at pH extremes indicate a potential for its successful application in industries. Key words: endoglucanase, Bacillus sp. NZ, thermo-alkalitolerant, alkalitolerant, thermotolerant, wheat bran
ISSN:1330-9862
1334-2606