Lactic acid bacterial extract as a biogenic mineral growth modifier

• Published in: Journal of crystal growth 2009-04, Vol.311 (9), p.2664-2672
• Main Authors: Borah, Ballav M., Singh, Atul K., Ramesh, Aiyagari, Das, Gopal
• Format: Article
• Language: English
• Subjects: A1. Biocrystallization; A1. Crystal morphology; A2. Growth from solutions; B1. Barium compounds; B1. Calcium compounds; B1. Nanomaterials; Bacteria; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; General studies of phase transitions; Lactobacillus acidophilus; Lactobacillus plantarum; Materials science; Methods of crystal growth; physics of crystal growth; Nucleation; Pediococcus acidilactici; Physics; Solid-solid transitions; Specific phase transitions; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2009.02.015

The formation of minerals and mechanisms by which bacteria could control their formation in natural habitats is now of current interest for material scientists to have an insight of the mechanism of in vivo mineralization, as well as to seek industrial and technological applications. Crystalline uniform structures of calcium and barium minerals formed micron-sized building blocks when synthesized in the presence of an organic matrix consisting of secreted protein extracts from three different lactic acid bacteria (LAB) viz.: Lactobacillus plantarum MTCC 1325, Lactobacillus acidophilus NRRL B4495 and Pediococcus acidilactici CFR K7. LABs are not known to form organic matrix in biological materialization processes. The influence of these bacterial extracts on the crystallization behavior was investigated in details to test the basic coordination behavior of the acidic protein. In this report, varied architecture of the mineral crystals obtained in presence of high molecular weight protein extracts of three different LAB strains has been discussed. The role of native form of high molecular weight bacterial protein extracts in the generation of nucleation centers for crystal growth was clearly established. A model for the formation of organic matrix–cation complex and the subsequent events leading to crystal growth is proposed.