Optimization of bacterial sporulation using economic nutrient for self-healing concrete

Ryu, Youngung; Lee, Ki Eun; Tae, In; Park, Woojun

doi:10.1007/s12275-020-9580-y

Cited by 20 publications

(11 citation statements)

References 45 publications

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“…The results showed that spores with encapsulation still had the potential activity; when the suitable growth conditions were met, these dormant spores could still germinate and grow into vegetative cells. However, when the nutrients in the culture medium were consumed, the microbial vegetative cells again transformed into spores with potential activity, which showed that adding a certain amount of nutrients in concrete not only could increase the germination and growth of spores but also could improve the self-healing effect of concrete cracks. ,− However, the addition of nutrients could affect the mechanical properties of concrete to a certain extent . Therefore, adding a certain amount of nutrients in the preparation process of the microbial self-healing agent could be considered, which still needs to be further studied.…”

Section: Resultsmentioning

confidence: 99%

Effect and Mechanism of Encapsulation-Based Spores on Self-Healing Concrete at Different Curing Ages

Zheng

Zhang

et al. 2020

ACS Appl. Mater. Interfaces

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It has become an intelligent and environmental protection method to repair concrete cracks based on microbial-induced calcium carbonate precipitation (MICP). However, due to the high-alkali environment in concrete, even the microbial spores with strong alkali resistance find it difficult to survive for a long time, which affects the long-term self-healing effect of concrete cracks. In this paper, low-alkali sulfo-aluminate cement (SC) was used as a carrier to encapsulate spores, and the effects of the spore group and microbial group on the basic performances of concrete were studied. Then, the area repair ratio, water permeability, the repair ratio of anti-chloride ion penetration, and ultrasonic velocity were used to evaluate the self-healing efficiency of cracks, and the self-healing effects of two kinds of microbial self-healing agents on concrete cracks with different curing ages were further studied. Moreover, the growth, enzyme activity, and microbial morphologies of spores with and without encapsulation immersed in the simulated pore solution of cement-based materials at different times were studied to discuss the protective effect of the carrier on spores. Compared with the reference group, the results showed that the addition of two microbial self-healing agents would slightly affect the basic performances of concrete, but both were within the control range of concrete materials. For the early-age cracks, the two kinds of microbial self-healing agents could achieve a good self-healing effect, but for the later-age cracks, the concrete cracks of the microbial group could still be repaired well, while the self-healing effect of the spore group was greatly reduced. Moreover, the white precipitates generated at the crack mouth were all calcite CaCO3. In addition, the self-healing mechanism of different microbial self-healing agents on concrete cracks was discussed carefully. This study provides a new idea and method for the engineering application of microbial self-healing concrete.

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Section: Resultsmentioning

confidence: 99%

Effect and Mechanism of Encapsulation-Based Spores on Self-Healing Concrete at Different Curing Ages

Zheng

Zhang

et al. 2020

ACS Appl. Mater. Interfaces

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“…These properties may enable spores to better withstand the harsh conditions of concrete, including the heat of hydration that occurs inside curing concrete and the dry concrete matrix (Jang et al 2020). In addition, bacteria can be spray-dried for convenience in storage and transport, but vegetative cell will not be able to withstand the high-temperature during vaporization process (Hong et al 2019;Jang et al 2020;Jung et al 2020;Ryu et al 2020).…”

Section: Discussionmentioning

confidence: 99%

“…Purified spores were serially diluted in distilled water from 10 -1 to 10 -5 and 10 µL aliquots spotted onto each plate. Spores were purified using lysozyme and sodium dodecyl sulfate (Ryu et al 2020).…”

Section: Preparation Of Nutrient Solution For Ak13 Growth and Germinamentioning

confidence: 99%

Agricultural by-products and oyster shell as alternative nutrient sources for microbial sealing of early age cracks in mortar

et al. 2021

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Bio-concrete using bacterially produced calcium carbonate can repair microcracks but is still relatively expensive due to the addition of bacteria, nutrients, and calcium sources. Agricultural by-products and oyster shells were used to produce economical bio-concrete. Sesame meal was the optimal agricultural by-product for low-cost spore production of the alkaliphilic Bacillus miscanthi strain AK13. Transcriptomic dataset was utilized to compare the gene expressions of AK13 strain under neutral and alkaline conditions, which suggested that NaCl and riboflavin could be chosen as growth-promoting factors at alkaline pH. The optimal levels of sesame meal, NaCl, and riboflavin were induced with the central composite design to create an economical medium, in which AK13 strain formed more spores with less price than in commercial sporulation medium. Calcium nitrate obtained from nitric acid treatment of oyster shell powder increased the initial compressive strength of cement mortar. Non-ureolytic calcium carbonate precipitation by AK13 using oyster shell-derived calcium ions was verified by energy-dispersive X-ray spectroscopy and X-ray diffraction analysis. Stereomicroscope and field emission scanning electron microscopy confirmed that oyster shell-derived calcium ions, along with soybean meal-solution, increased the bacterial survival and calcium carbonate precipitation inside mortar cracks. These data suggest the possibility of commercializing bacterial self-healing concrete with economical substitutes for culture medium, growth nutrient, and calcium sources.

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“…Concrete represents an extremely harsh environment for bacteria due to its low nutrient availability [ 106 ]. Therefore, providing the main substrates that trigger targeted metabolic reactions and bacterial activity is crucial for an efficient self-healing effect in a concrete matrix.…”

Section: Influence Of Concrete Environment On Bacteria-based Self-hea...mentioning

confidence: 99%

Relationship between Bacterial Contribution and Self-Healing Effect of Cement-Based Materials

2022

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The civil research community has been attracted to self-healing bacterial-based concrete as a potential solution in the economy 4.0 era. This concept provides more sustainable material with a longer lifetime due to the reduction of crack appearance and the need for anthropogenic impact. Regardless of the achievements in this field, the gap in the understanding of the importance of the bacterial role in self-healing concrete remains. Therefore, understanding the bacterial life cycle in the self-healing effect of cement-based materials and selecting the most important relationship between bacterial contribution, self-healing effect, and material characteristics through the process of microbiologically (bacterially) induced carbonate precipitation is just the initial phase for potential applications in real environmental conditions. The concept of this study offers the possibility to recognize the importance of the bacterial life cycle in terms of application in extreme conditions of cement-based materials and maintaining bacterial roles during the self-healing effect.

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Optimization of bacterial sporulation using economic nutrient for self-healing concrete

Cited by 20 publications

References 45 publications

Effect and Mechanism of Encapsulation-Based Spores on Self-Healing Concrete at Different Curing Ages

Effect and Mechanism of Encapsulation-Based Spores on Self-Healing Concrete at Different Curing Ages

Agricultural by-products and oyster shell as alternative nutrient sources for microbial sealing of early age cracks in mortar

Relationship between Bacterial Contribution and Self-Healing Effect of Cement-Based Materials

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