Enzymatic Detergent From Aspergillus Niger'

Enzymatic detergent from Aspergillus niger'. A formulation containing amylase comparative study with commercial detergent formulations.

Abstract

There is a wide range of biotechnological applications for amylases. including the textile, pharmaceutical, food and laundry industries. Hydrolytic enzymes are l00%, biodegradable and enzymatic detergents can achieve effective cleaning with lukewarm water. Microorganisms and culture media were tested for amylase production and the best producer was Aspergillus niger L119 in submerged culture and its amylase demonstrated excellent activity at 50 55 ºC and pH 4.0, remaining stable at 53 ºC for up to 200 h. In order to to establish the potential uses of this enzyme in detergents, different formulations were tested using the A. niger amylase extract. Enzyme activity was compared with three commercial formulations The detergents are used in hospitals to clean surgical and endoscopy equipment. The presence of amylase in the formulation is because of its action within hospital drainage system, whether or not it has any function in cleaning the equipment.

1. Introduction

The majority of industrial enzymes being used currently belong to the hydrolase group, which utilizes several different natural substrates. Detergent industries are the primary consumers of enzymes, in terms of both volume and value. For years microorganisms have been the principal source of many different enzymes, which were identified after extensive research and currently find their main uses in industrial applications (Bon. 1995)'

Several industries employ microbial amylolytic enzymes and a growing industrial application for them is the enzymatic conversion of starch into a variety of sugar

solutions (Bon. 1995; Crueger and Crueger, 1984; CÌassen,1996). An expanding area in the application of enzymes is in improving the performance of enzymatic liquid detergents. Proteases are the first enzyme class used in the formulation of enzymatic detergent and amylases are the second type of enzyrnes employed. The term amylase encompasses a class of enzymes that occur in a wide variety of organisms, and refers to r-amylases, B-amylases and glucoamylases (Gas), which are capable of hydrolyzing starch and glycogen' The cÍ-amylases (1,4-ct-o-glucanohydrolase, EC 3'2'1'l) are enzymes that randomly caÍalyze the endoamylolytic cleávage of a-1,4-glucosidic chains in polysaccharides with three or more o-1,4-glucosidic starch chains or

extracts of similar substrates (amylase and V amylopectin).

They act by liberating maltose, oligosaccharides and

limit dextrins. The B-amylases (EC 3.2.1.2) are exoenzymes

that hydrolyze the nonreducing end of starch and

amylopectin chains and glycogen molecules, hydrolyzing

aiternate gh.rcosidic chains and consequentÌy resulting in

maltose. The GAs (EC 3.2.1'3) hydrolyze glucose units

from the nonreducing ends in amylase and amylopectin

in a step-by-step manner (Diaz etal., 2003). This is a

class of industrial enzymes that accounts for approximately

25%t of the world market (Fogarty and Keìly'

I 980: Ikram-Ul et a1., 2003).

Many species of microorganism have already been

identified as good amylase producers. Studies of amylases

from bacteria and fungi are well documented (Dey

etal.. 1991; Babu and Satyanarayana, 1995; Murado

eta1.. 1997: Sidhu et aI.. 199'1; Coronado et a1', 2000;

Yuguo et a1.. 2000; Jin et a1.. 2001 ; Stamford et a1.' 2001)'

Filamentous fungi are microorganisms that secrete large

amounts of protein in culture medium. Aspetgillus niger

has been described as secreting an cr-amylase (Ramasesh

et al., 1982) and GAs of a number of different molecular

weights (Saha and Zeikus. 1990) in submerged culture.

The use of amylases in detergent formulatìons is

problematic since the enzyme must offer stability and an

optimal level of activity in commercially utilized formulations,

in the presence of proteases. The present article

describes the production. purification and partial characterization

of an amylase produced by A. niger and

establishes a potential use for the enzyme in experimenta1

detergent formuiations.

2. Methods

2. I . Microorganisms and culturing conditíons

The microorganisms employed for this study were

Aspergillus niger Lll9, Aspergillus niger GMSA' Aspergiílus

awamori L107, Bacillus subtilis Lll9, Bacíllus

iubtÌtis ICBS, Bacittus thuringiensis Ll 19, Bacillus sphaericus

FF, Bacillus cereas GMSA and Bacíllus cereus FF

from the Culture Collection at the Uniuersidade Federal

clo Rio Grande do Sut Biotechnology Center' These

microorganisms are now deposited with Íhe Fundação

Anclré Tosello collection in Campinas, Brazil'

In order to select amylase-producing microorganÍsms,

bacteria and filamentous fungi were plated onto ISP9

medium (NH+ 0.264'6JK2HPO4 0'565"/'|KH2PO4

0.238'%/MgSO 4'7H2O 0'1'2,), containing l'% (w/v) starch

and2Y,(w/v) agar (pH 7.0) (Shirling and Gottlieb. 1966)'

After incubation at