Biotechnological Properties Research Articles

Functional Expression and Characterization of the Highly Promiscuous Lanthipeptide Synthetase SyncM, Enabling the Production of Lanthipeptides with a Broad Range of Ring Topologies.

Lanthipeptides are ribosomally synthesized and post-translationally modified peptides characterized by the presence of lanthionine rings that provide stability and functionality. Genome mining techniques have shown their huge diversity and potential for the discovery of novel active molecules. However, in many cases, they are not easily produced under laboratory conditions. The heterologous expression of these molecules using well-characterized lanthipeptide biosynthetic enzymes is rising as an alternative system for the design and production of new lanthipeptides with biotechnological or clinical properties. Nevertheless, the substrate-enzyme specificity limits the complete modification of the desired peptides and hence, their full stability and/or biological activity. New low substrate-selective biosynthetic enzymes are therefore necessary for the heterologous production of new-to-nature peptides. Here, we have identified, cloned, and heterologously expressed in Lactococcus lactis the most promiscuous lanthipeptide synthetase described to date, i.e., SyncM from the marine cyanobacteria Synechococcus MITS9509. We have characterized the functionality of SyncM by the successful expression of 15 out of 18 different SyncA substrates, subsequently determining the dehydration and cyclization processes in six representatives of them. This characterization highlights the very relaxed substrate specificity of SyncM toward its precursors and the ability to catalyze the formation of exceptionally large rings in a variety of topologies. Our results suggest that SyncM could be an attractive enzyme to design and produce a wide variety of new-to-nature lanthipeptides with a broad range of ring topologies.

Marine Organisms as a Rich Source of Biologically Active Peptides

Oceanic environments are one of the largest sources of bioactive molecules, due to the high degree of biodiversity and the innumerable ecological relationships established between macro and microorganisms found in the different ecosystems of these complex environments. Marine organisms are being studied increasingly because they are considered important producers of biologically active peptides. Peptides extracted from marine sources have different functions and structures, when compared to peptides isolated from terrestrial sources, considering the different adaptive pressures undergone by these organisms throughout the evolutionary process. Most bioactive compounds isolated from marine environments are obtained from symbiont microorganisms. Of these microorganisms, bacteria are an important source of bioactive peptides, isolated by metagenomic studies from complex gene networks expressed under marine conditions. Several peptides have been shown to have biotechnological properties such as antimicrobial, antitumor, antihypertensive, anticoagulant, anti-fouling, and antioxidant activity and can be used in the pharmaceutical and food industries. This review article aims to provide an overview of peptides of biotechnological importance, isolated from different phyla of marine organisms, examining the relationship between structure and function of some of these peptides, as well as the ways of extracting, purifying and prospecting new peptides by traditional methods of isolation or sequence analysis in databases. It also intends to list the peptides that are already being produced and used by the industry, in its various branches, and their current state in the market and in clinical tests.

New technology for preparing acidophilic steread with improved biotechnological properties

The studies of the effect of barley flour on the processes occurring during the production of acidophilic sourdough have been carried out. It was found that the introduction of barley flour in the preparation of saccharified brew for the breeding cycle of the starter leads to an improvement in its lifting force and acceleration of acid accumulation. The best result was observed when barley flour was introduced in an amount of 5% - 10% of the flour mass in the dough. Improvement of the biotechnological parameters of the starter culture with the introduction of 5% - 10% of barley flour is accompanied by a reduction in the period of its ripening by 60-120 minutes. A new technology for the preparation of acidophilic starter culture using barley flour has been developed, which enriches the amino acid and vitamin composition of the nutrient substrate and intensifies the process of preparing the starter culture, improving its biotechnological properties.

System analysis of resource interaction processes in the biotechnological system

The paper provides mathematical modeling of processes occurring in the biotechnological system, using the example of the interaction of functional microorganisms with contaminating microflora, which is currently a promising scientific direction. The analysis showed that there are no existing studies on this issue, as well as systematic and integrated approaches to solving this problem that allow describing the processes under consideration. Therefore, it is necessary to analyze and build a system model that reflects the full range of interactions between useful and extraneous populations of microorganisms in the production of bakery products. System analysis and mathematical modeling of microbiological processes is a complex task. It is necessary to take into account a lot of factors, such as the simultaneous flow of several non-stationary processes; a lot of state parameters, including the analysis of relationships between them; changes in real-time technological parameters, in particular the main resource, taking into account various properties of microbial populations that affect the behavior of microbiological systems (mortality, birth rate, the existence of extraneous microflora, etc.), and other factors that directly affect the quality of the finished product. These factors characterize the complexity of forming a mathematical model that allows you to take into account all the main features of the production of bakery products. The existing mathematical apparatus and the system analysis of this kind of production carried out before considered the behavior of the population of beneficial microorganisms, but did not contain an analysis of the effect of contaminating microflora on it. The problem can be reduced to a system of differential equations describing the microbiological process as a whole. To describe the General model needed to describe an unknown function, including constraints on the parameters. In addition, you must set the initial and boundary conditions and determine the coefficients of the model. The paper offers a system model for analyzing the effect of plant additives on biotechnological properties and test quality indicators. The presented system model allows you to continue the study of the issues raised in the work, by further studying its components.

Kocuria spp. in Foods: Biotechnological Uses and Risks for Food Safety

Background and objective: Bacteria of the Genus Kocuria are found in several environments and their isolation from foods has recently increased due to more precise identification protocols using molecular and instrumental techniques. This review describes biotechnological properties and food-linked aspects of these bacteria, which are closely associated with clinical cases. Results and conclusion: Kocuria spp. are capable of production of various enzymes, being potentially used in environmental treatment processes and clinics and production of antimicrobial substances. Furthermore, these bacteria show desirable enzymatic activities in foods such as production of catalases and proteases. Beneficial interactions with other microorganisms have been reported on increased production of enzymes and volatile compounds in foods. However, there are concerns about the bacteria, including their biofilm production, which generates technological and safety problems. The bacterial resistance to antimicrobials is another concern since isolates of this genus are often resistant or multi-resistant to antimicrobials, which increases the risk of gene transfer to pathogens of foods.

Potential Probiotic Strains of Saccharomyces and Non-Saccharomyces: Functional and Biotechnological Characteristics.

Due to the evident demand for probiotic microorganisms, a growing number of scientific studies have involved the preliminary selection of new strains, but deeper studies for knowing specific functional and biotechnological properties are needed. In the present work, twenty yeasts (Saccharomyces and non-Saccharomyces) with potential probiotic characteristics, selected in previous works, were evaluated. The following assays were realized: adhesion to Caco-2/TC7 cells, prebiotic metabolisms, assimilation of cholesterol, enzymatic and antioxidant activity, and antifungal resistance. In addition, the effect of ultrasonic treatment was evaluated for attenuating the cultures before their possible incorporation into a food or supplement. In all of the cases, the unique commercial probiotic yeast (S. boulardii CNM I-745) was used as positive control. Results show different capabilities depending on the property studied. In general, no Saccharomyces yeasts were better in the adhesion to Caco cells, prebiotic metabolism, and presented higher variability of enzymatic activities. The ones related to cholesterol assimilation and antioxidant capability did not show a marked trend, and with respect to the attenuation process, the Saccharomyces yeasts were more resistant. For selecting the potential probiotic yeasts with better balance among all characteristics, a principal component analysis (PCA) was carried out. The most promising yeasts for use as health-promoting probiotics are Hanseniaspora osmophila 1056 and 1094, Lachancea thermotolerans 1039, and S. cerevisiae 3 and 146.

Proteolytic Lactococcus lactis and Lipolytic Enterococcus durans of Dairy Origin as Meat Functional Starter Cultures.

SUMMARYResearch backgroundAs fermentation is an integral feature of both, dry sausage and cheese production, this has led to the evaluation of bacterial cultures Lactococcus lactis ssp. cremoris (LL8307) and Enterococcus durans (ED0207) originally isolated from artisanal Croatian hard type cheese to diversify the range of flavours of dry fermented sausages and to increase their microbiological safety. Both strains were chosen for their high or medium acidifying, proteolytic and/or lipolytic activity and bioprotective potential after step-by-step selection of wild isolates. Therefore, this study aims to evaluate the survival rate of selected starter cultures in wild boar meat sausages during the ripening period of 40 days at a local small-scale facility under artisanal conditions as well as their influence on sausage quality parameters.Experimental approachSafety, biotechnological and probiotic properties of twenty-three enterococcal and lactococcal isolates of dairy origin were studied. Based on the results, two best candidates were selected and added to the meat batter during the artisanal wild boar meat sausage preparation where their survival rate, effect on physicochemical, microbiological and sensorial properties and histamine content were evaluated.Results and conclusionsAs revealed by repetitive element-polymerase chain reaction (rep-PCR), native starter cultures survived up to 15 days of ripening and were either absent from (LL8307) or reduced by 80% (ED0207) in final products. The application of native starter cultures rapidly decreased pH (p<0.05), leading to the significantly lower load of E. coli, coliforms and Enterobacteriaceae in ready-to-eat sausages prepared by the addition of starter cultures (3.04-3.94 log CFU/g) than in the control (3.88-5.00 log CFU/g). Analysis of hedonic test data revealed that some of the sensory traits (odour, flavour, juiciness) of treatments with starter cultures were highly liked by the higher percentage of consumers. The results suggest that these starter cultures would represent a valuable tool to improve the homogeneity of artisanal manufacture and hygienic quality of fermented sausages and can be safely used for food application.Novelty and ccientific contributionThis is the first study to explore in depth the biotechnological potential of bacterial cultures isolated from artisanal Croatian cheese as functional starter cultures for high-quality game meat sausage production.

Biotechnological aspects of ensuring the dairy food safety

One of the urgent issues of modern food industry is the biological safety. In this regard, especially important for ensuring the safety of functional dairy food for healthy nutrition are new methods developed for the primary sanitation of raw milk, prior to technological processing, in order to reduce the bacteriological contamination and extend the shelf life of the food produced. This is of particular importance for improving the biotechnological properties of milk used in cheese making. The purpose of the work was to develop alternatives to innovative technologies for the heat treatment of raw milk by mild heating that ensures a controlled decrease in its bacterial contamination with a targeted effect on especially dangerous and heat-resistant spore-forming bacteria. Based on biotechnological principles, the theoretical foundations of the bacterial sanitation of dairy raw material prior to technological processing have been studied and developed; the parameters of mild heat treatment that provides a decrease in bacterial contamination by six orders of magnitude, with spores being converted into vegetative forms and subsequently destructed, experimentally and analytically substantiated; the suitability of cheese and other technological properties of raw materials has been increased; the shelf life has been prolonged; and innovative technologies for the production of biologically safe dairy products have been developed. There has been developed a procedure for the heat treatment of low-grade cow’s milk - raw material - for further reservation or use in technological processes in order to improve its microbiological and technological properties and increase the product shelf life. Studies have been performed to inactivate spore-forming bacteria in milk, which has halved their incubation time.

Culturable fungi from dredged and marine sediments from six ports studied in the framework of the SEDITERRA Project

Mycological characterisation of marine and dredged sediments consists of the isolation of vital and culturable fungal strains as well as their identification and analysis, in order to increase knowledge of sediment mycobiota and isolated species that can be employed in biotechnological processes. Our study undertook the mycological characterisation of sediments from six different port environments: marine bottom sediments from the ports of Genoa (Liguria, Italy) and Centuri (Corsica, France), dredged sediments (sediments removed from the sea bottom) from landfill sites (contaminated land sites where dredged sediments are deposited) of the ports of Leghorn (Tuscany, Italy) and Cagliari (Sardinia, Italy), bottom muds from the brackish environment of the navigable Navicelli Canal of Pisa (Tuscany, Italy) and dredged marine sediments from a temporary storage site in the port of Toulon (Var, France). At each site, 30 kg of sediment was sampled for physical, chemical and mycological analyses. They were analysed in terms of grain size composition, organic and inorganic content, metal concentration and hydrocarbon and polychlorinated biphenyl concentration. Fungi were then isolated from sediments by a modified dilution plate technique from 1:10 up to 1:100. Fungal identification was carried out using a morphological and molecular polyphasic approach. Forty-six fungal species belonging to 20 genera were isolated. The highest biodiversity was found in Leghorn (14 species), Genoa (11) and Cagliari (11) sediments, while very low numbers of species were isolated from the ports of Centuri (3) and Toulon (4). Similarly, the number of colony-forming units (CFUs), calculated on the dry weight of the sediments, followed this order: Genoa (3,765 CFUs*g-1) > Leghorn (1,370 CFUs*g-1) > Pisa (1,190 CFUs*g-1) > Cagliari (410 CFUs*g-1) > Toulon (380 CFUs*g-1) > Centuri (220 CFUs*g-1). The most represented genera were Penicillium, Aspergillus and Trichoderma. Some halotolerant species known for their biotechnological properties were isolated: Emericellopsis maritima, Cladosporium halotolerans and Aspergillus micronesiensis. A potential marine pathogenic fungus was found: Aspergillus sydowii. This work increased knowledge of fungi from marine and dredged sediments in six Mediterranean ports in the framework of the SEDITERRA Project.

Lipopeptides production by a newly Halomonas venusta strain: Characterization and biotechnological properties

A halotolerant marine strain PHKT of Halomonas venusta was isolated from contaminated seawater as an efficient biosurfactant producer candidate, on low-value substrate (glycerol). The produced biosurfactants (Bios-PHKT) were characterized as lipopeptides molecules, belonging to surfactin and pumilacidin families, by using Thin Layer Chromatography (TLC), Fourier Transform Infrared Spectroscopy (FT-IR) and Tandem Mass Spectrometry (MALDI-TOF/MS-MS). Bios-PHKT has a critical micelle concentration (CMC) of 125 mg/L, and showed a high steadiness against a wide spectrum of salinity (0–120 g/L NaCl), temperature (4–121 °C) and pH (2–12), supporting its powerful tensioactive properties under various environmental conditions. Likewise, the cytotoxic test revealed that the biosurfactant Bios-PHKT, at concentrations lower than 125 µg/mL, was not cytotoxic for human HEK-293 cells since the cell survival is over than 80%. Furthermore, Bios-PHKT lipopeptides showed excellent anti-adhesive and anti-biofilm activities, being able to avoid and disrupt the biofilm formation by certain pathogenic microorganisms. In addition, the biosurfactant Bios-PHKT showed a remarkable anti-proliferative activity towards tumor B16 melanoma cell line. Besides, Bios-PHKT exhibited an excellent in vitro and in vivo wound healing process. In light of these promising findings, Bios-PHKT could be successfully used in different biotechnological applications.

Optimization of nutrient medium composition to increase biomass of propionic acid bacteria and acidophilic bacteria

Numerous studies have shown that it is very important that the microorganisms included in the composition be in a strong symbiotic relationship when selecting vents for fermented dairy products. Therefore, it is the primary task to identify the relationship between microorganisms in the preparation of the starter. Strains that retain biochemical activity for a long time, depending not only on external factors (composition of nutrient medium, temperature, etc.), but also on the ratio between biochemical active and inactive cells in populations of microorganisms, which determines the viability of the culture, its practical value, are considered valuable. Microorganisms of the genus Lactobacillus are widespread in nature and are members of human microflora. They have high biological and functional activity, which determines their practical use as probiotics and in food production. Propionic acid bacteria are considered as promising probiotics, the positive impact of which on human health is generally recognized. The scientific results show the expediency of using strains of propionic acid bacteria in the production of functional dairy bio-products for the purpose of enrichment with probiotics cells and their useful exometabolites. As a result of the co-cultivation of propionic acid bacteria and acidophilic bacterium, a stable microbial association with high probiotic and biotechnological properties (inoculum) has been developed. A scheme for preparing an inoculum for producing a bacterial concentrate using pure cultures of propionic acid bacteria and an acidophilic bacterium has been developed. This article presents the results of studies on the selection of nutrient medium in order to increase the yield of biomass and the accumulation of certain metabolic products by microorganisms.

Metagenomic identification, purification and characterisation of the Bifidobacterium adolescentis BgaC \u03b2-galactosidase

Members of the human gut microbiota use glycoside hydrolase (GH) enzymes, such as β-galactosidases, to forage on host mucin glycans and dietary fibres. A human faecal metagenomic fosmid library was constructed and functionally screened to identify novel β-galactosidases. Out of the 16,000 clones screened, 30 β-galactosidase-positive clones were identified. The β-galactosidase gene found in the majority of the clones was BAD_1582 from Bifidobacterium adolescentis, subsequently named bgaC. This gene was cloned with a hexahistidine tag, expressed in Escherichia coli and His-tagged-BgaC was purified using Ni2+-NTA affinity chromatography and size filtration. The enzyme had optimal activity at pH 7.0 and 37 °C, with a wide range of pH (4–10) and temperature (0–40 °C) stability. It required a divalent metal ion co-factor; maximum activity was detected with Mg2+, while Cu2+ and Mn2+ were inhibitory. Kinetic parameters were determined using ortho-nitrophenyl-β-d-galactopyranoside (ONPG) and lactose substrates. BgaC had a Vmax of 107 μmol/min/mg and a Km of 2.5 mM for ONPG and a Vmax of 22 μmol/min/mg and a Km of 3.7 mM for lactose. It exhibited low product inhibition by galactose with a Ki of 116 mM and high tolerance for glucose (66% activity retained in presence of 700 mM glucose). In addition, BgaC possessed transglycosylation activity to produce galactooligosaccharides (GOS) from lactose, as determined by TLC and HPLC analysis. The enzymatic characteristics of B. adolescentis BgaC make it an ideal candidate for dairy industry applications and prebiotic manufacture.Key points• Bifidobacterium adolescentis BgaC β-galactosidase was selected from human faecal metagenome.• BgaC possesses sought-after properties for biotechnology, e.g. low product inhibition.• BgaC has transglycosylation activity producing prebiotic oligosaccharides.Graphical

Comparison of cell wall polysaccharides in Schizophyllum commune after changing phenotype by mutation

The Agaricomycetes fungi produce various compounds with pharmaceutical, medicinal, cosmetic, environmental and biotechnological properties. In addition, some polysaccharides extracted from the fungal cell wall have antitumor and immunomodulatory actions. The aim of this study was to use genetic modification to transform Schizophyllum commune and identify if the phenotype observed (different from the wild type) resulted in changes of the cell wall polysaccharides. The plasmid pUCHYG-GPDGLS, which contains the Pleurotus ostreatus glucan synthase gene, was used in S. commune transformations. Polysaccharides from cell wall of wild (ScW) and mutants were compared in this study. Polysaccharides from the biomass and culture broth were extracted with hot water. One of the mutants (ScT4) was selected for further studies and, after hydrolysis/acetylation, the GLC analysis showed galactose as the major component in polysaccharide fraction from the mutant and glucose as the major monomer in the wild type. Differences were also found in the elution profiles from HPSEC and NMR analyses. From the monosaccharide composition it was proposed that mannogalactans are components of S. commune cell wall for both, wild and mutant, but in different proportions. To our knowledge, this is the first time that mannogalactans are isolated from S. commune liquid culture.

From the vineyard to the cellar: new insights of Starmerella bacillaris (synonym Candida zemplinina) technological properties and genomic perspective.

A large diversity of yeasts can be involved in alcoholic fermentation; however, Starmerella bacillaris strains have gained great attention due to their relevant and particular characteristics. S. bacillaris is commonly known as an osmotolerant, acidogenic, psychrotolerant, and fructophilic yeast. Most strains of this species are high producers of glycerol and show low ethanol production rates, being highlighted as promising alternatives to the manufacture of low-alcohol beverages. The increased production of high alcohols, such as benzyl alcohol that has antifungal and antibacterial properties, highlights S. bacillaris potential as a biocontrol agent. After harvest, antifungal yeasts become part of the must microbiota and may also improve the fermentation process. Moreover, during the fermentation, S. bacillaris releases important molecules with biotechnological properties, such as mannoproteins and glutathione. Considering the potential biotechnological properties of S. bacillaris strains, this review presents an overview of recent trends concerning the application of S. bacillaris in fermented beverages. KEY POINTS: •S. bacillaris as an alternative to the production of low-alcohol beverages. •S. bacillaris strains present biocontrol potential. •Molecules released by S. bacillaris may be of great biotechnological interest.

Screening Systems for Stable Markerless Genomic Deletions/Integrations in Streptomyces Species.

Bacteria of the genus Streptomyces are one of the most important producers of biologically active natural products. Recent robust genomic sequencing of Streptomyces strains has shown enormous genetic potential for new natural products. However, many biosynthetic gene clusters are silent. Therefore, efficient and stable genome modification methods are needed to induce their production or to manipulate them for the production of new compounds or biotechnologically improved strains. We have recently developed a simple and efficient markerless genome modification system for these bacteria based on the positive selection of double crossovers using the blue pigment indigoidine bpsA gene. This chapter is an attempt to provide methodological details of this strategy for stable markerless genomic engineering (deletions/insertions) to improve their biotechnological properties and to produce biologically active compounds.

Применение продуктов переработки винограда в рецептуре булочки к завтраку

The article considers the possibility of using grape seed flour in the recipe of a breakfast bun in the amount of 10 and 15% by weight of wheat flour and grape seed oil instead of margarine. The data of mixograms and Mixolab profilers are presented, which differ in the parameters of the rheological profile and indices. It is determined that the biotechnological properties of the semi-finished product allow you to reduce the duration of the technological process and choose the non-stick method for preparing the dough. It is noted that the experimental sample with a 10% content of grape seed flour in the recipe has a pleasant coffee color of the crumb, a pronounced, harmonious, pleasant aroma, the content of antioxidants increases, which allows us to recommend it for therapeutic and preventive nutrition.

The state of polymorphism of genes affecting the meat quality in micropopulations of meat simmentals

A comparative study of the biological characteristics of the heifers Bredy meat type of two populations located in Russia and Kazakhstan was carried out to determine the state of genes associated with the meat quality in the genotypeCAPN1, GDF5, TG5, BGL. In genotyping, we used the real-time PCR method using oligonucleotide primers (Gen Bank), for each primer individually in the corresponding sequences. Studies for improve breeding by innovative methods revealed the frequencies of genotypes and alleles for marker genes CAPN1, TG5, BGL and GDF5, which are related to meat quality indicators, a certain displacement in the genotypes of the compared populations of the Bredy meat type of Kazakhstan and Russia according to the CAPN1 gene (χ2 = 8.52) and the TG5 gene (χ2 = 4.73). The genotyping result of animals from LLC “Breeding plant Bredy” were analyzed from the point of view of attributing carriers of different genotypes to the offspring of bulls-producers Fakir, Kust and Chizhik, in order to determine the producer giving offspring with predictably high nutritional and biotechnological properties of beef. A comparison of the carriers of the identified genotypes of the studied genes by the characteristics used in the evaluation of young animals by their own productivity did not give significant results, however, showed trends by which scientific research can be directed. An assessment of the bulls-producers of the successors of the different line of meat simmentals on the quality of heifers – daughters showed that the largest comprehensive index was set for the bull-producer Bush 39046 – 102.7, which was recognized as an improver. The assignment of all, without exception, heifers of different groups, evaluated bulls-producers, to the highest class elite-record, indicates the value of all the studied genotypes.

Investigation of the biotechnological properties of Zygosaccharomyces kombuchaensis and Gluconacetobacter xylinus as promising microorganisms for the production of functional drinks

The issues of biological conversion of products of processing plant raw materials remain invariably relevant. The development of processing secondary resources allows to increase the efficiency of food production, solving environmental problems and to contribute to ensuring food security. The paper presents data on the results of studies of biotechnological properties of yeast cultures Zygosaccharomyces kombuchaensis sp. and bacteria Gluconoacetobacter xylinus (Brown 1886) Yamada et al 1998, constituting a symbiotic culture called SCOBY (symbiotic culture of bacreties and yeasts), adapted and cultivated in the Krasnodar Territory with the aim of their further use for biological conversion of fruit and berry raw materials and secondary raw materials for the production of functional drinks. The optimal values for the cultivation of the studied cultures were established: pH – 6.5, temperature – for Zygosaccharomyces kombuchaensis sp. minimum growth temperature t = +15-20 °С, maximum – t = +45-50 °С, for Gluconoacetobacter xylinus (Brown 1886) Yamada et al 1998 minimum growth temperature t = +10- 25 °С, maximum – t = +45-50 °C; the content of reducing substances is 10-15 %. The data obtained will be used to develop biotechnological processes for the production of functional drinks.

The large plasmidome of Lactococcus lactis subsp. lactis bv. diacetylactis S50 confers its biotechnological properties

Plasmids are autonomous episomally replicating genetic elements, which carry backbone genes important for the replication and maintenance within their host, and accessory genes that might confer an advantage to their host under specific selective pressure in its ecological niche. The genome of dairy isolate L. lactis subsp. lactis bv. diacetylactis S50 was sequenced using the PacBio SMRT Cell Seq-RSII platform and revealed to possess one of the largest plasmidomes among L. lactis strains studied so far, harboring six plasmids: pS6 (5553 bp), pS7a (7308 bp), pS7b (7266 bp), pS19 (19,027 bp), pS74 (74,256 bp) and pS127 (127,002 bp) in total representing 8.9% of genome size (240,412 bp). Based on predicted plasmid replication proteins and origins it appears that all six plasmids replicate via the theta-type mechanism. The two the largest plasmids (pS74 and pS127), carry a number of genes known to be important for growth and survival in the dairy environment. These genes encode technological functions such as bacteriocin production, protein degradation, magnesium and cobalt/nickel transporters, selenium binding, exopolysaccharides (EPS) production, bacteriophage and stress resistance. Beside genes for replication, the small plasmids (pS6, pS7a, pS7a, and pS19) also carry genes important for mobilization and host survival such as type I restriction-modification (R-M) system, metal transporters, enzymes and transcriptional regulators. All plasmids in S50 strain are mobilizable, containing an oriT sequences, while pS127 is self-conjugative and allows for mobilization of the other plasmids. Small plasmids are prone to structural and segregational instability, while pS127 appeared to be segregationally stable thanks to the possession of two partition systems. The main characteristic of plasmid pS74 is EPS production, while plasmid pS127 is characterized by proteinase and multiple bacteriocins, tra locus, phage abortive systems and metal transporters. In addition to LcnA and LcnB, plasmid pS127 encodes several bacteriocin-pheromone molecules and a new bacteriocin named LcnS50, with narrow spectrum of action limited to lactococci, that has been successfully cloned and heterologously expressed.

Intensification of kvas biotechnology using non-traditional raw materials

In the production of beverages of incomplete alcoholic and lactic acid fermentation, it is important to use non-traditional raw materials that have advantages over well-known analogues. Of particular interest in the production of fermented beverages is the use of malt extract prepared from triticalic malt. Serum and products derived from it are biologically complete, have dietary and medicinal properties. To achieve this goal accomplished objectives: to assess the quality and applicability of triticale malt extract for kvass production; explore the possibility of using whey as a processing aid in the production of kvass on the basis of triticale malt extract; to choose a combination of microorganisms to obtain a mixed leaven with the best biotechnological properties; conduct a comparative analysis of the duration of fermentation samples of kvas wort. The most intensive decrease in the dry matter content was observed in the experimental sample of leavened wort prepared on the basis of malt triticalic extract with the use of whey and combined sourdough from dry baking yeast of the brand "SAF-Moment" of the species Saccharomyces cerevisiae and lactic acid bacteria L. lactis, L. cremoris, L. diacetylactis, Str. Thermophilus. The duration of fermentation of leavened wort in the test sample was 10 hours, which is 6–8 hours less than the traditional technology. As a result of this work, the possibility of using triticalic malt extract for the production of kvass was proved. According to the main physical and chemical parameters, triticale malt extract is not inferior to traditional raw materials. The possibility of using whey as a technological additive for fermentation of leavened wort based on triticalic malt extract is investigated. The composition of leavened wort and a combination of microorganisms were selected to produce a combined starter culture with the best biotechnological properties. A comparative analysis of the duration of fermentation of samples of leavened wort is carried out.