The Influence of Temperature and Nitrogen Source on Cellulolytic Potential of Microbiota Isolated from Natural Environment.

Bacteria from the genus Bacillus are a rich source of commercial enzymes, including amylases, proteases, cellulases, glucose isomerase, and pullulanase. Cellulases account for 15% of the global market of industrial enzymes; thus, new microorganisms producing cellulases in a higher concentration and new ingredients, which can enhance the level of enzyme synthesis, are still needed. Many of cellulose-degrading microorganisms have been isolated so far and characterized in various regions of the world. In this study, we were looking for the bacteria isolated from the natural environment with the high cellulolytic potential, which could be used as components of a biopreparation to accelerate decomposition of postharvest leftovers in agriculture. The 214 bacterial strains were isolated from environmental samples rich in cellulose and their ability to synthesize cellulases were examined using the diffusion method. Six strains, which have the highest diameter of clearing zone both for biomass and supernatant, were selected for identification. Optimization of biosynthesis of the cellulose-degrading enzymes indicated that optimal temperature of this process fluctuated in the range of 21-42°C (depending on the strain and carbon source). The highest cellulolytic activity was observed for the isolates designed as 4/7 (identified as Bacillus subtilis) and 4/18 (identified as Bacillus licheniformis) in a temperature of 32°C. With the use of a desirability function methodology, the optimal medium composition to achieve a simple, cost-efficient process of cellulases production was developed for both strains. These experiments show that microorganisms isolated from natural environmental samples have unique properties and potential for commercial applications (e.g. for biopreparations production).Bacteria from the genus Bacillus are a rich source of commercial enzymes, including amylases, proteases, cellulases, glucose isomerase, and pullulanase. Cellulases account for 15% of the global market of industrial enzymes; thus, new microorganisms producing cellulases in a higher concentration and new ingredients, which can enhance the level of enzyme synthesis, are still needed. Many of cellulose-degrading microorganisms have been isolated so far and characterized in various regions of the world. In this study, we were looking for the bacteria isolated from the natural environment with the high cellulolytic potential, which could be used as components of a biopreparation to accelerate decomposition of postharvest leftovers in agriculture. The 214 bacterial strains were isolated from environmental samples rich in cellulose and their ability to synthesize cellulases were examined using the diffusion method. Six strains, which have the highest diameter of clearing zone both for biomass and supernatant, were selected for identification. Optimization of biosynthesis of the cellulose-degrading enzymes indicated that optimal temperature of this process fluctuated in the range of 21­42°C (depending on the strain and carbon source). The highest cellulolytic activity was observed for the isolates designed as 4/7 (identified as Bacillus subtilis) and 4/18 (identified as Bacillus licheniformis) in a temperature of 32°C. With the use of a desirability function methodology, the optimal medium composition to achieve a simple, cost-efficient process of cellulases production was developed for both strains. These experiments show that microorganisms isolated from natural environmental samples have unique properties and potential for commercial applications (e.g. for biopreparations production).

Inhibition of autophagy by 3-methyladenine potentiates sulforaphane-induced cell death of BE(2)-C human neuroblastoma cells.

Sulforaphane (SFN) is an isothiocyanate present in cruciferous vegetables, which has been shown to exert an anti-cancer effect when tested in vitro and in vivo. The anti-cancer effects of SFN encompass induction of cytoprotective autophagy; therefore, the present study aimed to determine whether the chemopreventive activity of SFN may be potentiated by inhibition of autophagy. The present study provided detailed insight into the susceptibility of human neuroblastoma cells to treatment with synthetic SFN, in combination with an inhibitor of autophagy, 3-methyladenine (3-MA). The present study confirmed the suppression of the viability of the human neuroblastoma cell line BE(2)-C by SFN and reported the inhibition of DNA synthesis, as determined by a decrease in tritiated thymidine incorporation. Furthermore, the results verified the effectiveness of SFN in inducing apoptosis in the BE(2)-C cell line as demonstrated by caspase activation, increased protein expression levels of B-cell lymphoma 2-associated X protein and loss of mitochondrial membrane potential. Combined treatment of the cells with SFN with 3-MA proved to be effective in decreasing cell viability, through a mechanism that may proceed via the early induction of autophagy by SFN, followed by induction of apoptosis, as well as inhibition of autophagy by 3-MA.

[Mechanisms of urinary tract sterility maintenance]. / Mechanizmy utrzymania sterylnosci ukladu moczowego.

Physiologically, urine and the urinary tract are maintained sterile because of physical and chemical properties of urine and the innate immune system's action. The urinary tract is constantly exposed to the invasion of microorganisms from the exterior environment, also because of the anatomical placement of the urethra, in the vicinity of the rectum. Particularly vulnerable to urinary tract infections (UTI) are women (an additional risk factor is pregnancy), but also the elderly and children. The main pathogens causing UTI are bacteria; in 70-95% of cases it is the bacterium Escherichia coli. Infections caused by viruses and fungi are less common and are associated with decreased immunity, pharmacotherapy, or some diseases. Bacteria have evolved a number of factors that facilitate the colonization of the urinary tract: the cover and cell membrane antigens O and K1, lipopolysaccharide (LPS), fimbriae, pile and cilia. On the other hand, the human organism has evolved mechanisms to hinder colonization of the urinary tract: mechanisms arising from the anatomical structure of the urinary tract, the physicochemical properties of the urine and the activity of the innate immune system, also known as non-specific, which isolates and destroys pathogens using immunological processes, and the mechanisms for release of antimicrobial substances such as Tamm-Horsfall protein, mucopolysaccharides, immunoglobulins IgA and IgG, lactoferrin, lipocalin, neutrophils, cytokines and antimicrobial peptides. This review aims to analyze the state of knowledge on the mechanisms to maintain the sterility of the urinary tract used by the human organism and bacterial virulence factors to facilitate the colonization of the urinary tract.