1887

Degradation of Biological Macromolecules by Bacillus species

  • Authors: Javier Gutierrez-Jimenez 1, Carlos Alberto Balcazar-Reyes 2, Juan de Dios Flores-Hernandez 3
  • VIEW AFFILIATIONS HIDE AFFILIATIONS
    Affiliations: 1: Lab. de Biologia Molecular Y Genetica, Facultad de Ciencias Biologicas, Universidad de Ciencias Y Artes de Chiapas, Tuxtla Gutierrez, Chiapas, 29000; 2: Lab. de Biologia Molecular y Genetica, Facultad de Ciencias Biologicas, Universidad de Ciencias y Artes de Chiapas, Tuxtla Gutierrez, Chiapas, 29000; 3: Lab. de Biologia Molecular y Genetica, Facultad de Ciencias Biologicas, Universidad de Ciencias y Artes de Chiapas, Tuxtla Gutierrez, Chiapas, 29000
  • Citation: Javier Gutierrez-Jimenez, Carlos Alberto Balcazar-Reyes, Juan de Dios Flores-Hernandez. 2009. Degradation of biological macromolecules by bacillus species.
  • Publication Date : February 2009
MyBook is a cheap paperback edition of the original book and will be sold at uniform, low price.
Add to My Favorites
You must be logged in to use this functionality

FIG. 1. Starch hydrolysis by Bacillus spp. A) A Bacillus spp. isolated from the environment, plated on starch agar, grown for 24 hours, and flooded with Gram's iodine solution. Iodine reacts with starch to produce a blue-black color. Starch degradation is visible as a clear zone surrounding the microbial growth where bacterial exoenzymes hydrolyzed the starch in the agar. B) Escherichia coli plated on starch agar, grown for 24 hours, and flooded with Gram's iodine. There is no clear zone surrounding the bacterial growth showing that E. colidid not hydrolyze the starch.   

FIG. 2. Casein hydrolysis by Bacillus species. A) A Bacillus spp. isolated from the environment, plated on casein agar, grown for 24 hours, and flooded with mercuric chloride solution. Casein degradation is visible as a clear zone surrounding the microbial growth where bacterial exoenzymes hydrolyzed the casein in the agar. B) Escherichia coli plated on casein agar, grown for 24 hours, and flooded with mercuric chloride solution. There is no clear zone surrounding the bacterial growth showing that E. colidid not hydrolyze the casein.  

FIG. 3. Gelatin degradation by Bacillusspecies.  A) A Bacillus spp. isolated from the environment, plated on gelatin agar, grown for 24 hours, and flooded with mercuric chloride solution. Gelatin degradation is visible as a clear zone surrounding the microbial growth where bacterial exoenzymes hydrolyzed the gelatin in the agar. B) Escherichia coli plated on gelatin agar, grown for 24 hours, and flooded with mercuric chloride solution. There is no clear zone surrounding the bacterial growth showing that E. colidid not hydrolyze the gelatin.  

Introduction

Polymeric molecules found in the environment such as cellulose, chitin, starch, protein, and nucleic acids are degraded by exoenzymes such as proteases, nucleases, and amylases synthesized by members of the genus Bacillus in order to obtain carbon sources for their metabolic processes. Bacterial membrane-spanning transporters admit biomolecules no larger than 600 to 700 daltons, and high molecular mass molecules must be degraded in order to pass through the bacterial membrane-spanning transporters. Starch is a homopolymer of glucose and is the most important reserve polysaccharide found in plants; casein is the principal protein fraction of milk and contains all essential amino acids; gelatin is a heterogeneous mixture of water-soluble proteins of high average relative molecular mass derived from collagen. Based on proteolytic, lipolytic, and saccharolytic activities of Bacillus species, these organisms have been used to ferment cereal or legume foods to obtain condiments such as Bikalga and dawadawa, used to flavor soups and stews in the African diet. Moreover, inclusion of amylases from Bacillus species in detergents affords advantages such as reduction or replacement of other components that may be harmful to the environment. The hydrolysis test with substrates such as starch, casein, and gelatin have been used mainly for screening of proteolytic and amylolytic activities in Bacillus species used in food microbiology settings, such as selection of Bacillus isolates for starter cultures for cereal or legume foods fermentations.

Methods

Starch-agar plates were prepared using 0.8% nutrient broth, 0.5% soluble starch, and 1.5% agar. After microbial growth, the plates were flooded with 5 ml of Gram´s iodine solution. Casein-agar plates consisted of 0.8% nutrient broth, 2.5%  skimmed milk, and 1.5% agar. After microbial growth, the plates were flooded with 5 ml of 12.5% mercuric chloride solution. Gelatin-agar plates consisted of 0.8% nutrient broth, 3% gelatin, and 0.75% agar. After microbial growth, the plates were flooded with 5 ml of 12.5% mercuric chloride solution.

References

1.  Amoa-Awua, W. K., N. N. Terlabie, and E. Sakyi-Dawson. 2006. Screening of 42 Bacillus isolates for ability to ferment soybeans into dawadawa. Int. J. Food Microbiol. 106 :343–347.

2.  Bravo-Rodríguez, V., E. Jurado-Alameda, J. F. Martínez-Gallegos, A. Reyes-Requena, and A. I. García-López. 2006. Enzymatic hydrolysis of soluble starch with an α-amylase from Bacillus licheniformis. Biotechnol. Prog. 22:718 722.

3.   Fossum, K., and J. R. Whitaker. 1974. Simple method for detecting amylase inhibitors in biologic materials. J. Nutr. 104:930 936.

4.   Harwood, C. R., and R. Cranenburgh. 2008. Bacillus protein secretion: an unfolding story. Trends Microbiol. 16:73 79.

5.   Ouba, L. I. I., C. Parkouda, B. Diawara, C. Scotti, and A. H. Varnam. 2007. Identification of Bacillus spp. from Bikalga, fermented seeds of Hibiscus sabdariffa: phenotypic and genotypic characterization. J. Appl. Microbiol. 104:122 131.

6.   Phromraksa, P., H. Nagano, T. Boonmars, and C. Kamboonruang. 2008. Identification of proteolytic bacteria from Thai traditional fermented foods and their allergenic reducing potentials. J. Food Sci. 73:M189 M195.

7.  Schaechter, M., J. L. Ingraham, and F. C. Neidhardt.   2006.  Microbe, p. 99 102. ASM Press, Washington, DC.

8.   Simonen, M., and I. Palva. 1993. Protein secretion in Bacillus species. Microbiol. Rev. 57:109 137.

9.   Whitaker, J. R., and R. E. Feeney. 1973. Enzyme inhibitors in foods, p. 276 298. In F. Strong (ed.), Toxicants occurring naturally in foods. Natl. Acad. Sci. USA, Washington, DC.

The ATP binding cassette system. © Gary Kaiser, author. Licensed for use, ASM MicrobeLibrary.

Related Resources

This is a required field
Please enter a valid email address
Please check the format of the address you have entered.
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error