Whole genome sequence data of Lactobacillus fermentum HFD1, the producer of antibacterial peptides.

Here we report the whole genome sequence of Lactobacillus fermentum HFD1 strain, the producer of antibacterial peptides. The genome consists of one circular chromosome with 2101878 bp in length and GC-content of 51.8%, and includes linear DNA with 5386 bp in length with 100% identity to bacteriophage phiX174. The analysis of the genome has revealed 2049 genes encoding for proteins including 867 proteins without known function and 70 genes encoding for RNAs (10 rRNAs, 59 tRNAs and 1 tmRNA). Putative genes responsible for the biosynthesis of 4 antimicrobial peptides were identified. The NCBI Bioproject has been deposited at NCBI under the accession number PRJNA615901 (https://www.ncbi.nlm.nih.gov/bioproject/PRJNA615901/) and consist of full annotated genome and raw sequence data.

Efficient fructose production from plant extracts by immobilized inulinases from Kluyveromyces marxianus and Helianthus tuberosus.

The enzymatic hydrolysis of poly- and oligosaccharides from plants seems like an advantageous approach for sugars production. Two inulinases producing fructose from plant oligosaccharides were isolated from yeast Kluyveromyces marxianus and plant Helianthus tuberosus. Both enzymes were immobilized on polymeric carriers by using the static adsorption approach. We could save 80.4% of the initial catalytic activity of plant inulinase immobilized on KU-2 cation-exchange resin and 75.5% of yeast enzyme activity adsorbed on AV-17-2P anion-exchange resin. After immobilization, the Km values increased 1.5 and 6 times for enzymes from K. marxianus and H. tuberosus, respectively. The optimal temperatures for catalysis of both enzymes were increased from 48-50 °C up to 70 °C. The activities of both immobilized enzymes remained unchanged after the 10 cycles of 20-min hydrolysis reaction at 70 °C model batch reactor. Sorbents, native and immobilized enzymes did not exhibit any mutagenic or cytotoxic activity.

[Recombinant small heat shock protein from Acholeplasma laidlawii increases the Escherichia coli viability in thermal stress by selective protein rescue].

In both prokaryotes and eukaryotes, the survival at temperatures considerably exceeding the optimum is supported by intense synthesis of the so-called heat shock proteins (HSPs), which act to overcome the adverse effects of heat stress. Among mycoplasmas (class Mollicutes), which have significantly reduced genomes, only some members of the Acholeplasmataceae family possess small HSPs of the α-crystallin type. Overproduction of a recombinant HSP IbpA (Hsp20) from the free-living mycoplasma Acholeplasma laidlawii was shown to increase the resistance of Escherichia coli to short-term heat shock. It has been long assumed that IbpA prevents protein aggregation and precipitation thereby increasing viability of E. coli cells. Several potential target proteins interacting with IbpA under heat stress were identified, including biosynthetic enzymes, enzymes of energy metabolism, and components of the protein synthesis machinery. Statistical analysis of physicochemical properties indicated that IbpA interaction partners significantly differ in molecular weight, charge, and isoelectric point from other members of the E. coli proteome. Upon shortterm exposure to increased temperature, IbpA was found to preferentially interact with high-molecular weight proteins having a pI of about 5.1, significantly lower than the typical values of E. coli proteins.

Thio Derivatives of 2(5H)-Furanone as Inhibitors against Bacillus subtilis Biofilms.

Gram-positive bacteria cause a wide spectrum of infectious diseases, including nosocomial infections. While in the biofilm, bacteria exhibit increased resistance to antibiotics and the human immune system, causing difficulties in treatment. Thus, the development of biofilm formation inhibitors is a great challenge in pharmacology. The gram-positive bacterium Bacillus subtilis is widely used as a model organism for studying biofilm formation. Here, we report on the effect of new synthesized 2(5H)-furanones on the biofilm formation by B.subtilis cells. Among 57 compounds tested, sulfur-containing derivatives of 2(5H)-furanone (F12, F15, and F94) repressed biofilm formation at a concentration of 10 µg/ml. Derivatives F12 and F94 were found to inhibit the biosynthesis of GFP from the promoter of the eps operon encoding genes of the biofilm exopolysaccharide synthesis (EPS). Using the differential fluorescence staining of alive/dead cells, we demonstrated an increased bacterial sensitivity to antibiotics (kanamycin and chloramphenicol) in the presence of F12, F15, and F94, with F12 being the most efficient one. The derivative F15 was capable of disrupting an already formed biofilm and thereby increasing the efficiency of antibiotics.