CHEMICAL ENGINEERING TRANSACTIONS VOL. 79, 2020 A publication of The Italian Association of Chemical Engineering Online at www.cetjournal.it Guest Editors: Enrico Bardone, Antonio Marzocchella, Marco Bravi Copyright © 2020, AIDIC Servizi S.r.l. I SBN 978-88-95608-77-8; I SSN 2283-9216 Biomineralization of Calcium Carbonate by Bacillus Cereus for Self-Healing Biocement Pedro P. F. Brasileiro* a,b , Rita C. F. Soares da Silva b , Fernanda C. P. Rocha e Silva b , Yana B. Brandão b,c , Leonie A. Sarubbo b,d , Mohand Benachour a,b a Department of Chemical Engineering, Federal University of Pernambuco, Rua Arthur de Sá, S/N, Cidade Universitária, Zip Code: 50740-521, Recife, Pernambuco, Brazil b Advanced Institute of Technology and Innovation (IATI), Rua Joaquim de Brito, n. 216, Boa Vista, Zip Code: 500070-280, Recife, Pernambuco, Brazil c Academic Unit of Cabo de Santo Agostinho, Rodovia Armínio Guilherme, 2635, Garapu, Cabo de Santo Agostinho, Pernambuco, Brazil. d Centre of Science and Technology, Catholic University of Pernambuco, Rua do Príncipe, n. 526, Boa Vista, Zip Code: 50050-900, Recife, Pernambuco, Brazil. ppfbrasileiro@hotmail.com Concrete cracks can induce the disruption of dams, bridges, tunnels, and some structures that assist the human life. The agglomeration component of the concrete and the most applied compound, the Portland Cement, can be utilized in combination with calcium lactate and the Bacillus bacteria to produce the crystals of CaCO 3 (raw material of the cement production) through adsorption, biomineralization, and crystallization, reducing the risk of ruptures. Thus, a screening of the biotechnological potential of bacterium Bacillus cereus (UCP 1615) under a concentration of 10 7 cells/mL was carried out to evaluate the production of CaCO 3 crystals with 20 g of the Portland Cement II (PC-II), and 0,58, 1,00, and 1,42 g of calcium lactate. These Petri Dishes were incubated at 28°C and during 168 h. Besides, the crystals produced the B. cereus were analysed by an X-Ray Diffractometer (XRD) to estimate the relation (%) between the mainly and possible components. After 17 h, some crystals had already started to appear in the Petri Dishes of 1,00 and 1,42 g of calcium lactate, and after 168 h, the crystals were scraped of all Petri Dishes. The diffractometric analyse of the condition with the highest lactate condition, of 1,42 g, presented percentages of 82% SiO 2 (basic structure of cement) and 18% CaCO 3 . Therefore, the B. cereus strain shows a biotechnological potential to produce crystals of CaCO 3 and that this bacterium is able to be tested under different conditions of calcium lactate, microbial concentration, and water according to a factorial design. Keywords: Concrete cracks. Calcium Lactate. Crystals. XRD. 1. Introduction In the urban, building and industrial areas, effects of solar rays, winds, rainings, and any kind of weathering are able to wash out the concrete of structures as bridges and roads. The inside and outside cracks of this concrete will reduce the compressive, tensile, and flexural strength limits of the material, increasing the probability to cause any accident. Furthermore, the concrete composition is an essential factor to give a long shelf life for the concrete, requiring a suitable cement for the current application with the ideal proportions of water, and fine and coarse aggregates (Neville, 2016). For the production of cement, initially, there is the extraction of limestone (CaCO 3 ) from mines with the addition of iron ore and clay. This mixture will enter into a precalcifier (at about 1000 °C) to release CO 2 and CaO and after into a rotational furnace (at about 1500 ºC) to vitrify the clay, constituting a new mixture called clinker (Neville, 2016). These two processes represent the focus of the cement industry. Only this process represents approximately 5-7 % from all CO 2 production of the Earth, mainly because cement is the most utilized mixture of the world (Shanks et al., 2019). DOI: 10.3303/CET2079017 Paper Received: 1 August 2019; Revised: 6 November 2019; Accepted: 24 February 2020 Please cite this article as: Brasileiro P.P.F., De Cássia Freire Soares Da Silva R., Cristina Padilha Da Rocha E Silva F., Batista Brandao Y., Asfora Sarubbo L., Benachour M., 2020, Biomineralization of Calcium Carbonate by Bacillus Cereus for Self-healing Biocement , Chemical Engineering Transactions, 79, 97-102 DOI:10.3303/CET2079017 97