Title: The newly identified proteins involved in the chromosome segregation in Mycobacteria- the functional analysis

Abstract:

Chromosome segregation in bacteria is an active process involving a number of proteins. In most of the bacteria, it depends on the presence of ParABS system.  ParB segregation protein binds to the parS sequence and forms segregation complexes. ParA segregation protein interacts with ParB complexes being responsible for their distribution
ParA homologs: C. cresentus MipZ, C. glutamicum PldP, MipZ exhibited nonspecific DNA binding activity similar to ParA-like proteins.
Characteristic Features of Mycobacteria: Rod shaped, Slow growing, Gram positive bacteria with high ( G + C ) content (61 - 71% ), Lipid rich cell wall, Resistant to many environmental factors: drying, high and low temperature, high and low pH
Unique chromosome organisation and segregation in Mycobacteria: Chromosome is positioned asymmetrically in M. smegmatis cells. oriC is in the off-centre position after oriC duplication, new pole segrosome migrates faster than old pole segrosome mycobacterial cell elongate asymmetrically – the old pole extends faster
ParA in M. smegmatis
ParA is responsible for the localisation of the ParB complexes in the cell
● parA deletion strain is characterized by slow growth ● parA deletion results in formation 30% of anucleate cells

Biography:

Rudra Suresh is a Medical biotechnology engineering graduate with a record of outstanding research skills, comprehensive knowledge of food standards regulations and operational dexterity in fast-paced laboratory environment. She is looking for a position in which I can make the best use of my scientific background and my creativity in order to develop innovative products, and solutions. She is interested in all aspects of the biotechnology industry from R&D to QC. She really would like to find a role in which she can constantly learn new skills and increase her knowledge.

Title: The impact of growth history on stress robustness of Listeria monocytogenes

Abstract:

Environmental factors like oxygen availability have an impact on the stress adaptive behavior and robustness of microorganisms. Adaptation to non-optimal environmental conditions induces molecular changes that help microorganisms developing survival strategies towards more severe stress conditions. Listeria monocytogenes as a food-borne pathogen is regularly exposed to such environmental stresses within its natural habitat, during food processing and throughout its infection cycle. The ability of Listeria to adapt to such changing environment enhances its ability for survival and growth in food and influences its pathogenic potential.

In this study, we will investigate the impact of oxygen availability on the growth and robustness induction towards lethal oxidative and acid stresses for three Listeria monocytogenes strains ScottA, EGDe and F2365. Aerobically grown cells showed higher growth rate and were more resistant to oxidative stress than anaerobically and microaerobically grown cells. While for the acid stress, anaerobically and microaerobically grown cells were more resistant than the cells that were cultured aerobically.

Catalase activity was measured in the exponential phase Listeria cells, cultured under the different atmospheric conditions i.e. aerobic, microaerobic and anaerobic. Induction of catalase activity was found to be correlated with robustness towards lethal oxidative stress with significant correlation only for F2365 strain. This correlation might be associated with intracellular accumulation of reactive oxygen species (ROS) and subsequent induction of catalase activity. Catalase scavenges the formed H2O2 upon oxidative stress treatment and helps the aerobically grown cells being more resistant towards further oxidative stress. Anaerobically grown cells showed lower level of catalase induction, and hence lower robustness, possibly due to the use of alternative respiration machinery than the aerobically grown cells that results in less ROS formation. That suggests the possibility of using catalase as a biomarker for predicting the robustness of L. monocytogenes towards lethal oxidative stress. However, an inverse correlation was found between catalase activity induction and robustness towards lethal acid stress.

Therefore, catalase activity could function as inverse-response biomarker in this condition.

The finding of our study might explain also why L. monocytogenes is a target organism in the minimally processed foods. Modified atmosphere packaging is widely used in ready-to-eat foods. The limited oxygen availability of this condition in particular vacuum packaging can have an impact on the robustness of Listeria to further acid stress treatment used in food industry.

Biography:

Islam Salih Sharkawy is a Surgeon - Dentist University of Chile. He did master of dental sciences in the University of Chile. He is Associate Clinical Professor in the School of Dentistry. He is a Author of book chapters and national and international scientific publications in the area of ​​cariology.

Title: Investigation of different agro-industrial wastes as bio-economical substrates to produce fungal laccase

Abstract:

Lignocellulosic biomass is made up of three main fractions: cellulose and hemicellulose and lignin. It is considered mainly as waste, but chiefly, as the most abundant renewable carbon source on the planet. Therefore, recently it has received a lot of attention as a potential source of bioenergy and bio-based chemicals. The objective of this study is to develop a valorization white biotechnology approach which allows both producing enzymes members of the lignocellulolytic degradation machinery, mainly laccases, and treating all the fractions of lignocellulosic biomass at a time. Hence, in this work five different lignocellulosic sources from Algeria were chosen according to their industrial exploitability properties, their abundance and their availability, which were alfa stems (Stipa tenacissima) (ALF), olive pomace (Olea europaea) (OLV), tomato residues (Solanum lycopersicum) (TMT), dry palm leaves (Phoenix dactylifera) (PLM) and pinecones (Pinus halepensis) (PIN). Among 12 laccase positive strains, only one fungal strain Trametes versicolor was able to produce laccase on these complex media by submerged fermentation. Indeed, variability in the enzyme secretion according to the type of the substrate used, has been perceived, thus, the most suitable wastes for producing laccase were TMT, OLV, and PLM. The results reveal that the optimum of the laccase activity was obtained on the TMT medium

55.6 U/L against 26,27U/L for OLV and 10.56U/L for PLM. The preliminary results of this research work, show that tomato waste can be optimized to be used as a potential biological resource to produce laccases that oxidize both phenolic and non-phenolic compounds bound to lignin as well as highly recalcitrant environmental pollutants, contributing at the same time to the biovalorisation of lignocellulosic biomass, which makes them very useful for their application to several biotechnological processes.

Biography:

S. CHAOUA is Surgeon in the Laboratory of Mycology, Biotechnology and Microbial Activity (LaMyBAM). Did her Phd in the Department of Applied Biology, University of Mentouri Brothers, Constantine- Algeria. She is a Professor of Applied Microbiology Lab, Interfaculty School of Bioengineers (EIB), 3CELABOR research center, Herve, Belgium.