Alginase enzyme production by Bacillus circulans

Area of Science:

• Microbiology
• Enzymology
• Biochemistry

Background:

• Alginate, a polysaccharide produced by mucoid Pseudomonas aeruginosa, is a carbon source for some microorganisms.
• Extracellular alginate-degrading enzymes (alginases) have been reported, but typically not from Gram-positive bacteria.

Purpose of the Study:

• To isolate and identify microorganisms capable of utilizing alginate as a sole carbon and energy source.
• To characterize the alginate-degrading enzyme produced by the isolated organism.

Main Methods:

• Screening of environmental samples (stream and soil) for alginate-utilizing bacteria.
• Isolation and pure culture of a promising microorganism.
• Characterization of the isolate using microscopy, Gram staining, spore production tests, DNA G+C content analysis, and biochemical tests.
• Detection and partial purification of alginate-degrading enzyme activity from the culture medium using gel filtration.
• Enzyme specificity and type determination.

Main Results:

• A pure culture of large, aerobic, spore-forming rods, identified as Bacillus circulans, was isolated.
• Bacillus circulans produced extracellular alginase activity in its culture medium.
• The alginase was partially purified, showing a molecular weight of approximately 40,000 daltons.
• The enzyme exhibited endomannuronidase specificity and appeared to be a lyase (eliminase).
• Several other Bacillus circulans strains also demonstrated inducible extracellular alginase activity.

Conclusions:

• Bacillus circulans can produce extracellular alginate lyase, a novel finding for this species and for Gram-positive bacteria.
• The isolated enzyme is a potential tool for alginate degradation and analysis.
• Further investigation into the inducible nature and broader distribution of alginase activity in Bacillus circulans is warranted.