Stephania Aragón Rojas

1- Aragón-Rojas S , Hernández-Álvarez A.J , Mainville I , Arcand Y , and Quintanilla-Carvajal M. X (2020).
Effect of the carrier material, drying technology and dissolution media on the viability of Lactobacillus
fermentum K73 during simulated gastrointestinal transit. Food Funct. 2020;11(3):2339-2348.
doi:10.1039/c9fo01091b.
2- Aragón-Rojas S, Quintanilla-Carvajal M.X., Hernández-Álvarez A.J., Champagne C.P., Fustier P. and
Arcand, Y. (2020). S/O/W emulsions prepared with whey proteins enhance the viability Lactobacillus
fermentum K73. Submitted in Food & Function.
3- Aragón-Rojas, S., Ruiz-Pardo, R. Y., Hernández-Álvarez, A. J., and Quintanilla-Carvajal, M. X. (2019).
Sublimation conditions as critical factors during freeze-dried probiotic powder production. Drying Technology:
An International Journal. https://doi.org/10.1080/07373937.2019.1570248
4- Aragón-Rojas, S., Quintanilla-Carvajal, M. X., Hernández-, H., Hernández-Álvarez, A. J., and Moreno, F.
L. (2019). Encapsulation of Lactobacillus fermentum K73 by Refractance Window drying. Scientific Reports,
1–15. https://doi.org/10.1038/s41598-019-42016-0
5- Aragón-Rojas, S., Ruiz-Pardo, R. Y., Hernández-Sánchez, H., and Quintanilla-Carvajal, M. X. (2018).
Optimization of the production and stress resistance of the probiotic Lactobacillus fermentum K73 in a
submerged bioreactor using a whey-based culture medium. CyTA - Journal of Food, 16(1), 1064–1070.
https://doi.org/10.1080/19476337.2018.1527785
6- Aragón-Rojas, S., Quintanilla-Carvajal, M. X., and Hernández-Sánchez, H. (2018). Multifunctional Role of
the Whey Culture Medium in the Spray-Drying Microencapsulation of Lactic Acid Bacteria. Food Technology
and Biotechnology, 56(3). https://doi.org/10.17113/ftb.56.03.18.5285
7- Aragón-Rojas, S., Quintanilla-Carvajal, M. X. (2016). Aprovechamiento del suero de leche como matriz
acarreadora de microorganismos probióticos: tolerancia a condiciones gastrointestinales. En Buera, M.P y
Román-Santagapita, P. (Ed.), “Aprovechamiento de subproductos y valorización de recursos autóctonos:
interrelación investigación, producción, desarrollo y sociedad” (p. 61-64). Buenos Aires: Red Temática
415RT0495 “LACFUN”.

PATENTS GRANTED BY THE SIC IN COLOMBIA
1. Culture medium with whey proteins and extract yeast
Date: August 16th, 2016.
Number: NC2016/0000830
Issuing entity: Superintendence of Industry and Commerce (SIC - Spanish acronym).
2. Encapsulation process for probiotics
Date: August 10th, 2017.
Number: NC2017/0008058
Issuing entity: Superintendence of Industry and Commerce (SIC - Spanish acronym)

As a master student under the guidance of Professor Maria Clementina Cueto at University of La Sabana; I primarily focused on the isolation, purification, and molecular identification of soil bacteria and lactic acid bacteria. With the soils bacteria I developed a mixture of Azotobacter sp., with Azospirillum spp., with properties for stimulating of growth plant and a phytopathogen agent. With the lactic acid bacteria I characterized as probiotics strains and I identified two mechanisms to low the cholesterol in in vitro conditions, adsorb the cholesterol on the cell membrane and the enzymatic activity of the bile salt hydrolase. With this study we contributed to the university strain bank and the study of the LAB with industrial application. So, with my experience in BSH molecular and enzymatic activity I can to contribute with the aim of the position. In my master research, I proposed a enzymatic mechanism to BSH in L. fermentum (only one with multiple substrate), because the enzyme is different than L. acidophilus or L. rhamnosus. The finding of potential probiotics with hypocholesterolemic activity led to an investigation to develop and specific Colombian probiotic product to decrease the serum cholesterol using the encapsulation process, my Ph. D thesis.

In my bachelor, I did the thesis "Identification and detection of Gram-positive and Gram-negative bacteria that cause neonatal sepsis through the polymerase chain reaction". I designed a bacterial DNA extraction protocol from neonatal blood (500 μL or less) because the conventional protocols use more than 1 mL and this amount of blood could cause anemia on the neonates. Then, I did the standardization of the polymerase chain reaction to identify Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae from clinic samples. The results were consistent with the microbiology identification of the strains and I could decrease the diagnostic time from 4 -5 days to 1 day. With this study the research group started to develop new protocols to identify the nosocomial diseases using different clinic samples.

1- Cueto C., Aragón S. (2012) Evaluación del potencial probiótico de bacterias ácido lácticas para reducir el
colesterol in vitro. Scientia Agropecuaria; 3:45-50.
2- Cueto, C., Acuña, Y., Aragón R, S.(2009). “Cuantificación de ácido láctico de bacterias aisladas del suero costeño”, VII Congreso Iberoamericano de Ingeniería de Alimentos, Colombia