The Effect of Cell Immobilization by Calcium Alginate on Bacterially Induced Calcium Carbonate Precipitation

Abstract

Abstract:Microbially induced mineral precipitation is recognized as a widespread phenomenon in nature. A diverse range of minerals including carbonate, sulphides, silicates, and phosphates can be produced through biomineralization. Calcium carbonate (CaCO3) is one of the most common substances used in various industries and is mostly extracted by mining. In recent years, production of CaCO3 by bacteria has drawn much attention because it is an environmentally-and healthfriendly pathway. Although CaCO3 can be produced by some genera of bacteria through autotrophic and heterotrophic pathways, the possibility of producing CaCO3 in different environmental conditions has remained a challenge to determine. In this study, calcium alginate was proposed as a protective carrier to increase the bacterial tolerance to extreme environmental conditions. The model showed that the highest concentration of CaCO3 is achieved when the bacterial cells are immobilized in the calcium alginate beads fabricated using 1.38% w/v Na-alginate and 0.13 M CaCl2.

Microencapsulation: Toward the Reduction of the Salinity Stress Effect on Wheat Plants Using NPK Rhizobacteria

“…This means that this method can be used as a capable tool for protection and enhancement of bacterial cells in a harsh environment without prompting the metabolic activity. This result is harmony with [63].…”

Biological Self-Healing of Cement Paste and Mortar by Non-Ureolytic Bacteria Encapsulated in Alginate Hydrogel Capsules

“…Previous studies on biological self-healing concrete that employed a carrier material for bacteria immobilization have largely reported proof of survival or indirectly measured bacterial [ 28 , 41 , 45 , 51 , 52 ]. Since the quantity of CaCO 3 formed through MICP is a direct function of the levels of bacterial activity [ 51 ], it is essential to determine if the encapsulation process affects the survival of the encapsulated bacteria.…”

“…There are three different forms of anhydrous polymorphs CaCO 3 that can be found in nature. In the order of thermodynamic stability, they are vaterite, aragonite, and calcite [ 52 ]. The different polymorphs can be easily identified by their distinctive shapes.…”

“…The enumeration of spores has been used to estimate spore survival when the spores were directly added to cementitious materials by crushing the samples to free the spores [ 7 , 35 ], which is not suitable for immobilized or encapsulated spores. Hence, providing qualitative proof of spore survival has become a popular direction in this field [ 28 , 41 , 45 , 51 , 52 ]. This also includes survival determination methods such as O 2 measurement and CaCO 3 precipitation as proof of bacterial survival [ 16 , 41 , 53 , 54 , 55 ].…”

Effects of different calcium sources on the mineralization and sand curing of CaCO3by carbonic anhydrase-producing bacteria

“…5A, D and G). While the bioprecipitation of CaCO 3 may result in different polymorphs, 40 it was visually conrmed that different shapes of crystals were precipitated. With the effect of the bacteria in the experimental groups, the crystal morphology was signicantly changed both in the CaCl 2 and Ca(CH 3 COO) 2 groups.…”