A New Bacterial Strain Alcaligenes aquatilis MAG 1 Associated with the Mediterranean Sea Lithophaga (Bivalvia) Precipitating in Nutrient Free Medium Shell-Like Calcium Carbonate Polymorphs

Mehanni, Magda M. and Abd El-Aziz, Shaban H. Abd (2019) A New Bacterial Strain Alcaligenes aquatilis MAG 1 Associated with the Mediterranean Sea Lithophaga (Bivalvia) Precipitating in Nutrient Free Medium Shell-Like Calcium Carbonate Polymorphs. Egyptian Academic Journal of Biological Sciences, G. Microbiology, 11 (1). pp. 111-124. ISSN 2090-0880

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Abstract

Mediterranean Sea Lithophaga bivalve associated bacteria and their capability in calcium carbonate polymorphs formation have been investigated in the present study. Isolated bacteria were a single strain of Gram-negative, rod-shaped, and flagellated motile cells. Phylogenetic analysis based on 16S rDNA sequences consigned the isolated bacterium to Alcaligenes aquatilis species as a distinct strain assigned as Alcaligenes aquatilis strain MAG 1. Phenotypic and biochemical characteristics of the strain recorded no acids produced from different carbohydrates under aerobic conditions except for D-mannose, amygdalin, glucose, L-rhamnose, L- arabinose and D- melibiose. Isolates showed negative results for nitrate reduction, urea degradation, sulphate reduction (H2S production) and tryptophan deaminase (TDA). Alcaligenes aquatilis strain MAG 1 precipitated in nutrient-free medium different polymorphs of anhydrous CaCO3, initially, as a mixture of aragonite and calcite, and well-organized rhombohedral calcite crystals dominated by the fourth day. Conclusively, calcium carbonate biomineralization away from any added nutrients by this new strain magnifies its role as nucleation sites and retracts the effect of bacterial metabolic pathways. Besides, various CaCO3 crystal polymorphs formed by the isolated strain advocate a potential complementary role in Lithophaga shell assembly.

Item Type: Article
Subjects: Archive Paper Guardians > Biological Science
Depositing User: Unnamed user with email support@archive.paperguardians.com
Date Deposited: 17 Jul 2023 06:14
Last Modified: 03 Nov 2023 04:43
URI: http://archives.articleproms.com/id/eprint/1453

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