Banca de DEFESA: JONATHAS DIEGO LIMA SANTOS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : JONATHAS DIEGO LIMA SANTOS
DATA : 15/12/2017
HORA: 13:00
LOCAL: Sala Carl Peter von Dietrich - Departamento de Bioquímica
TÍTULO:

PROTEOMIC ANALYSIS OF CHROMOBACTERIUM VIOLACEUM SUBMITTED TO SIMULATED MICROGRAVITY

PALAVRAS-CHAVES:

Bacteria, microgravity, proteome and interaction network

PÁGINAS: 150
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
RESUMO:

 

Chromobcterium violaceum (C.violaceum) is a Gram-negative bacteria, which has been found at tropical and subtropical regions. Some proteomic studies performed with this bacterium have demonstrated its ability to adapt to environmental challenges such as high iron concentration and oxidative stress exposure. However, no study was made with this specie submitted to simulated microgravity (SMG). SMG refers to conditions in which the gravity is artificially reduced to less than 1xg. Life on Earth has evolved at 1xg and study SMG is important to understand the overall changes that organisms might face in space travels. Therefore, the aim of this study was to characterize the response of C. violaceum, as free-living model organism, cultured at MGS, using proteomics techniques in order to understand how this bacterium response to this stress. The SMG was achieved by rotating the vessel around the horizontal axis perpendicular to the gravitational vector in Rotating Cell Culture Systems (RCCS4). SMG was conducted at a speed of 40 rpm for a period of 12 hours to obtain the growth curve every 2 hours. Total protein extraction was made in two times: 5 and 12 hours, corresponding to early (MG5) and late (MG12) exponential phase, respectively. After trypsinization, samples were analyzed with Q-TOF mass spectrometer. In our results, we detected 155 proteins during MG5, from which 18 proteins were upregulated, 19 down-regulated and 17 proteins were exclusive when compared to GN5. In MG12 were identified 173 proteins, from which 17 were upregulated, 22 down-regulated and 28 exclusive when compared to control. When comparing the amount of proteins identified in both early (5 hours) and late (12 hours) exponential phase, we detected 212 proteins during MG5 and 192 during MG12 from which 144 of them are common to both phases. We also observed a decrease of C. violaceum growth at MGS when compared to bacterial cultures submitted to normal gravity. Proteins correlated with transcriptional processes and release of energy through aerobic pathways were down-regulated, while proteins involved with the inhibition of transcription, anaerobic pathway and cell survival had their expression increased, indicating a decrease in metabolism and proliferation of C. violaceum. MGS can cause alterations in respiratory metabolism, decreasing of transcription and translation rates and, consequently, C. violaceum proliferation. These data can be understood as a strategy for maintenance and survival at reduced gravity environment.

MEMBROS DA BANCA:
Externo à Instituição - DANIEL CHAVES DE LIMA - IFRN
Interno - 1149356 - ELIZEU ANTUNES DOS SANTOS
Externo ao Programa - 2267860 - GUSTAVO ANTONIO DE SOUZA
Externo à Instituição - MAGNOLIA DE ARAUJO CAMPOS PFENNING - UFCG
Presidente - 1199127 - SILVIA REGINA BATISTUZZO DE MEDEIROS