Toxicological Characteristics of Bacterial Nanocellulose in an In Vivo Experiment-Part 1: The Systemic Effects.

Bacterial nanocellulose (BNC) is being considered as a potential replacement for microcrystalline cellulose as a food additive and a source of dietary fiber due to its unique properties. However, studies on the risks of consuming BNC in food are limited, and it is not yet approved for use in food in the US, EU, and Russia. AIM: This study aims to perform a toxicological and hygienic assessment of the safety of BNC in a subacute 8-week administration in rats. METHODS: BNC was administered to male Wistar rats in doses of 0, 1.0, 10.0, and 100 mg/kg body weight for 8 weeks. Various parameters such as anxiety levels, cognitive function, organ masses, blood serum and liver biochemistry, oxidative stress markers, vitamin levels, antioxidant gene expression, and liver and kidney histology were evaluated. RESULTS: Low and medium doses of BNC increased anxiety levels and liver glutathione, while high doses led to elevated LDL cholesterol, creatinine, and uric acid levels. Liver tissue showed signs of degeneration at high doses. BNC did not significantly affect vitamin levels. CONCLUSION: The adverse effects of BNC are either not dose-dependent or fall within normal physiological ranges. Any effects on rats are likely due to micronutrient deficiencies or impacts on intestinal microbiota.

Assessment of antibiotic resistance genes in soils polluted by chemical and technogenic ways with poly-aromatic hydrocarbons and heavy metals.

Anthropogenic activities are leaving lots of chemical footprints on the soil. It alters the physiochemical characteristics of the soil thereby modifying the natural soil microbiome. The prevalence of antimicrobial-resistance microbes in polluted soil has gained attention due to its obvious public health risks. This study focused on assessing the prevalence and distribution of antibiotic-resistance genes in polluted soil ecosystems impacted by industrial enterprises in southern Russia. Metagenomic analysis was conducted on soil samples collected from polluted sites using various approaches, and the prevalence of antibiotic-resistance genes was investigated. The results revealed that efflux-encoding pump sequences were the most widely represented group of genes, while genes whose products replaced antibiotic targets were less represented. The level of soil contamination increased, and there was an increase in the total number of antibiotic-resistance genes in proteobacteria, but a decrease in actinobacteria. The study proposed an optimal mechanism for processing metagenomic data in polluted soil ecosystems, which involves mapping raw reads by the KMA method, followed by a detailed study of specific genes. The study's conclusions provide valuable insights into the prevalence and distribution of antibiotic-resistance genes in polluted soils and have been illustrated in heat maps.

The Complete Genome of a Novel Typical Species Thiocapsa bogorovii and Analysis of Its Central Metabolic Pathways.

The purple sulfur bacterium Thiocapsa roseopersicina BBS is interesting from both fundamental and practical points of view. It possesses a thermostable HydSL hydrogenase, which is involved in the reaction of reversible hydrogen activation and a unique reaction of sulfur reduction to hydrogen sulfide. It is a very promising enzyme for enzymatic hydrogenase electrodes. There are speculations that HydSL hydrogenase of purple bacteria is closely related to sulfur metabolism, but confirmation is required. For that, the full genome sequence is necessary. Here, we sequenced and assembled the complete genome of this bacterium. The analysis of the obtained whole genome, through an integrative approach that comprised estimating the Average Nucleotide Identity (ANI) and digital DNA-DNA hybridization (DDH) parameters, allowed for validation of the systematic position of T. roseopersicina as T. bogorovii BBS. For the first time, we have assembled the whole genome of this typical strain of a new bacterial species and carried out its functional description against another purple sulfur bacterium: Allochromatium vinosum DSM 180T. We refined the automatic annotation of the whole genome of the bacteria T. bogorovii BBS and localized the genomic positions of several studied genes, including those involved in sulfur metabolism and genes encoding the enzymes required for the TCA and glyoxylate cycles and other central metabolic pathways. Eleven additional genes coding proteins involved in pigment biosynthesis was found.

Draft genome sequence of perfluorinated acids C7-C9 degrading bacterium Pseudomonas mosselii 5(3), isolated from soil contaminated with pesticides.

The Pseudomonas mosselii 5(3) strain is a potential degrader of persistent perfluorinated pollutants, particularly C7-C9 perfluorinated acids. The genome of the strain has been fully sequenced. It consists of a chromosome with a length of 5,676,241 base pairs and a G-C content of 64.38%.

Whole-Genome Sequencing and Biotechnological Potential Assessment of Two Bacterial Strains Isolated from Poultry Farms in Belgorod, Russia.

Bacteria, designated as A1.1 and A1.2, were isolated from poultry waste based on the ability to form ammonia on LB nutrient medium. Whole genome sequencing identified the studied strains as Peribacillus frigoritolerans VKM B-3700D (A1.1) and Bacillus subtilis VKM B-3701D (A1.2) with genome sizes of 5462638 and 4158287 bp, respectively. In the genome of B. subtilis VKM B-3701D, gene clusters of secondary metabolites of bacillin, subtilisin, bacilisin, surfactin, bacilliacin, fengycin, sactipeptide, and ratipeptide (spore killing factor) with potential antimicrobial activity were identified. Clusters of coronimine and peninodin production genes were found in P. frigoritolerans VKM B-3700D. Information on coronimine in bacteria is extremely limited. The study of the individual properties of the strains showed that the cultures are capable of biosynthesis of a number of enzymes, including amylases. The B. subtilis VKM V-3701D inhibited the growth of bacterial test cultures and reduced the growth rate of the mold fungus Aspergillus unguis VKM F-1754 by 70% relative to the control. The antimicrobial activity of P. frigoritolerans VKM V-3700D was insignificant. At the same time, a mixture of cultures P. frigoritolerans VKM B-3700D/B. subtilis VKM B-3701D reduced the growth rate of A. unguis VKM F-1754 by 24.5%. It has been shown that strain A1.1 is able to use nitrogen compounds for assimilation processes. It can be assumed that P. frigoritolerans VKM V-3700D belongs to the group of nitrifying or denitrifying microorganisms, which may be important in developing methods for reducing nitrogen load and eutrophication.

Genome Analysis and Physiology of Pseudomonas sp. Strain OVF7 Degrading Naphthalene and n-Dodecane.

The complete genome of the naphthalene- and n-alkane-degrading strain Pseudomonas sp. strain OVF7 was collected and analyzed. Clusters of genes encoding enzymes for the degradation of naphthalene and n-alkanes are localized on the chromosome. Based on the Average Nucleotide Identity and digital DNA-DNA Hybridization compared with type strains of the group of fluorescent pseudomonads, the bacterium studied probably belongs to a new species. Using light, fluorescent, and scanning electron microscopy, the ability of the studied bacterium to form biofilms of different architectures when cultured in liquid mineral medium with different carbon sources, including naphthalene and n-dodecane, was demonstrated. When grown on a mixture of naphthalene and n-dodecane, the strain first consumed naphthalene and then n-dodecane. Cultivation of the strain on n-dodecane was characterized by a long adaptation phase, in contrast to cultivation on naphthalene and a mixture of naphthalene and n-dodecane.

Whole Genome Analysis and Assessment of the Metabolic Potential of Gordonia rubripertincta Strain 112, a Degrader of Aromatic and Aliphatic Compounds.

The application of Gordonia strains in biotechnologies of environmental purification as degraders of pollutants of different chemical structures is an interesting research topic. The strain Gordonia rubripertincta 112 (IEGM112) is capable of utilizing diesel fuel, alkanes, and aromatic compounds. The aim of this work was to study the potential of G. rubripertincta 112 as a degrader of aromatic and aliphatic compounds and analyze its complete genome in comparison with other known G. rubripertincta strains. The genome had a total length of 5.28 Mb and contained 4861 genes in total, of which 4799 were coding sequences (CDS). The genome contained 62 RNA genes in total, of which 50 were tRNAs, three were ncRNAs, and nine were rRNAs. The strain bears plasmid elements with a total length of 189,570 nucleotides (plasmid p1517). The strain can utilize 10.79 ± 1.17% of hexadecane and 16.14 ± 0.16% of decane over 3 days of cultivation. In the genome of the strain, we have found metabolic pathways of alkane (cytochrome P450 hydroxylases) and catechol (ortho- and meta-pathways) degradation. These results will help us to further approach the fundamental study of the processes occurring in the strain cells and to enrich our knowledge of the catabolic capabilities of G. rubripertincta.

Characterization and Genomic Analysis of the Naphthalene-Degrading Delftia tsuruhatensis ULwDis3 Isolated from Seawater.

Strains of the genus Delftia are poorly studied microorganisms. In this work, the complete genome of the naphthalene-degrading Delftia tsuruhatensis strain ULwDis3 isolated from seawater of the Gulf of Finland of the Baltic Sea was assembled. For the first time, genes encoding naphthalene cleavage pathways via salicylate and gentisate were identified in a strain of the genus Delftia. The genes are part of one operon (nag genes). Three open reading frames (ORFs) were found in the genome of D. tsuruhatensis strain ULwDis3 that encode gentisate 1.2-dioxygenase. One of the ORFs is part of the nag operon. The physiological and biochemical characteristics of the strain ULwDis3 when cultured in mineral medium with naphthalene as the sole source of carbon and energy were also studied. It was found that after 22 h of growth, the strain stopped consuming naphthalene, and at the same time, naphthalene 1.2-dioxygenase and salicylate 5-hydroxylase activities were not detected. Later, a decrease in the number of living cells and the death of the culture were observed. Gentisate 1.2-dioxygenase activity was detected from the time of gentisate formation until culture death.

Complete Genome Sequence of Gordonia polyisoprenivorans 135, a Promising Degrader of Aromatic Compounds.

Gordonia polyisoprenivorans 135 is a promising degrader of aromatic hydrocarbons. It can utilize phenanthrene, anthracene, benzoate, chlorobenzoates, and phenol. The genome of strain 135 was completely sequenced; it consists of a single 5,988,360-bp circular chromosome (GC content of 67.01%).

Effect of chicken manure on soil microbial community diversity in poultry keeping areas.

The poultry industry is generating a significant amount of waste from chicken droppings that are abundant in microbes as well as macro- and micronutrients suitable for manure. It has the potential to improve the microbial activity and nutrient dynamics in the soil, ultimately improving soil fertility. The present study aimed to investigate the effect of chicken droppings manure (CDM) on the diversity of the soil microbiome in the free walking chicken's area located in Stefanidar, Rostov Region, Russia. The data obtained were compared with 16 s rRNA from control samples located not far from the chicken's free-walking area, but not in direct contact with the droppings. Effect of CDM on the physicochemical characteristics of the soil and changes in its microbial diversity were assessed by employing the metagenomic approaches and 16 s rRNA-based taxonomic assessment. The alpha and beta diversity indices revealed that the application of the CDM significantly improved the soil microbial diversity. The 16S taxonomical analysis confirmed Proteobacteria, Actinobacteria, Bacteroidetes, Firmicutes, and Planctomycetes as abundant bacterial phylum. It also revealed the increase in the total number of the individual operational taxonomic unit (OTU) species, a qualitative indicator of the rich microbial community. The alpha diversity confirmed that the significant species richness of the soil is associated with the CDM treatment. The increased OTUs represent the qualitative indicator of a community that has been studied up to the depth of 5-20 cm of the CDM treatment range. These findings suggested that CDM-mediated microbial richness are believed to confer the cycling of carbon, nitrogen, and sulfur, along with key soil enzymes such as dehydrogenases and catalase carbohydrate-active enzymes. Hence, the application of CDM could improve soil fertility by nutrient cycling caused by changes in soil microbial dynamics, and it could also be a cost-effective sustainable means of improving soil health.

Methods of Identifying Gordonia Strains in Clinical Samples.

Gordonia spp. are members of the family Gordoniacea in the suborder Corynebacteriales; their habitat, in most cases, is soil. Many representatives of this genus are human or veterinary pathogens. The main cause of the lack of a standardized approach to dealing with infections caused by Gordonia is their erroneous identification and little information regarding their susceptibility to antimicrobial drugs. This review presents the most common methods for identifying Gordonia strains, including modern approaches for identifying a species. The main prospects and future directions of this field of knowledge are briefly presented.

Complete Genome Analysis of Rhodococcus opacus S8 Capable of Degrading Alkanes and Producing Biosurfactant Reveals Its Genetic Adaptation for Crude Oil Decomposition.

Microorganisms capable of decomposing hydrophobic substrates in cold climates are of considerable interest both in terms of studying adaptive reactions to low temperatures and in terms of their application in biotechnologies for cleaning up oil spills in a crude-oil polluted soil. The aim of this work was to investigate the genome of Rhodococcus opacus S8 and explore behavior traits of this strain grown in the presence of hexadecane. The genome size of strain S8 is 8.78 Mb, of which the chromosome size is 7.75 Mb. The S8 strain contains 2 circular plasmids of 135 kb and 105 kb and a linear plasmid with a size of 788 kb. The analysis of the genome revealed the presence of genes responsible for the degradation of alkanes and synthesis of biosurfactants. The peculiarities of morphology of microbial cells when interacting with a hydrophobic substrate were revealed. An adaptive mechanism responsible in the absence of oxygen for maintaining the process of degradation of hexadecane is discussed. The data obtained show that the strain S8 has great potential to be used in biotechnologies.

Physiological and biochemical characterization and genome analysis of Rhodococcus qingshengii strain 7B capable of crude oil degradation and plant stimulation.

Rhodococci are typical soil inhabitants which take part in remediation of soil polluted with hydrocarbons. In this paper, we describe a new strain, Rhodococcus qingshengii 7B, which is capable of growth and hydrocarbon degradation at 45°C and in the presence of up to 10% NaCl in the medium. The genome of the 7B strain consists of a 6,278,280 bp chromosome and two plasmids. The circular plasmid is 103,992 bp in length. The linear plasmid is 416,450 bp in length. Genome analysis revealed the genes of degradation of various hydrocarbons, resistance to salt stress and plant growth promoting activity. This strain is promising for use in remediation of oil-contaminated soils, because it has a pronounced ability to utilize crude oil, oil sludge and individual hydrocarbons in a wide temperature range. Over 15 days of the experiment, the strain utilized 51% of crude oil at 28°C and 24% at 45 °Ð¡.

Draft Genome Sequence of Microbacterium sp. Strain KKR3/1, an Antimicrobial-Substance-Producing Strain Isolated from Banana Shrimp (Atyopsis moluccensis).

The strain KKR3/1 (VKM Ac-2910) was isolated from the microflora of the lower intestinal tract of the banana shrimp (Atyopsis moluccensis). The genome of the KKR3/1 strain consists of seven contigs, with a total length of 3,651,331 bp. The N50 value is 2,445,836 bp, and the GC content is 68.1%.

Complete Genome Sequence of Rhodococcus qingshengii VT6, a Promising Degrader of Persistent Pollutants and Putative Biosurfactant-Producing Strain.

The strain Rhodococcus qingshengii VT6 is a promising degrader of persistent pollutants and a putative biosurfactant producer. The genome of the strain was sequenced completely. It consists of a 6,457,868-bp chromosome and 4 plasmids (pLP1, 501,672 bp; pLP2, 188,969 bp; pCP1, 100,387 bp; and pCP2, 132,858 bp).

Capture of Essential Trace Elements and Phosphate Accumulation as a Basis for the Antimicrobial Activity of a New Ultramicrobacterium-Microbacterium lacticum Str. F2E.

Microbial interactions play an important role in natural habitat. The long-term coevolution of various species leads to the adaptation of certain types of microorganisms as well as to the formation of a wide variety of interactions such as competitive, antagonistic, pathogenic and parasitic relationships. The aim of this work is a comprehensive study of a new ultramicrobacterium Microbacterium lacticum str. F2E, isolated from perennial oil sludge, which is characterized by high antimicrobial activity and a unique ultrastructural organization of the cell envelope, which includes globular surface ultrastructures with a high negative charge. A previously undescribed mechanism for the antagonistic action of the F2E strain against the prey bacterium is proposed. This mechanism is based on the ability to preferentially capture essential microelements, in which charge interactions and the property of phosphate accumulation may play a significant role. The revealed type of intermicrobial interaction can probably be attributed to the non-contact type antagonistic action in the absence of any diffuse factor secreted by the antagonistic bacteria.

Comparative Genomic Analysis of the Hydrocarbon-Oxidizing Dibenzothiophene-Desulfurizing Gordonia Strains.

A number of actinobacteria of the genus Gordonia are able to use dibenzothiophene (DBT) and its derivatives as the only source of sulfur, which makes them promising agents for the process of oil biodesulfurization. Actinobacteria assimilate sulfur from condensed thiophenes without breaking the carbon-carbon bonds, using the 4S pathway encoded by the dszABC operon-like structure. The genome of the new dibenzothiophene-degrading hydrocarbon-oxidizing bacterial strain Gordonia amicalis 6-1 was completely sequenced and the genes potentially involved in the pathways of DBT desulfurization, oxidation of alkanes and aromatic compounds, as well as in the osmoprotectant metabolism in strain 6-1 and other members of the genus Gordonia, were analyzed. The genome of G. amicalis strain 6-1 consists of a 5,105,798-bp circular chromosome (67.3% GC content) and an 86,621-bp circular plasmid, pCP86 (65.4% GC content). This paper presents a comparative bioinformatic analysis of complete genomes of strain 6-1 and dibenzothiophene-degrading Gordonia strains 1D and 135 that do not have the dsz operon. The assumption is made about the participation in this process of the region containing the sfnB gene. Genomic analysis supported the results of phenomenological studies of Gordonia strains and the possibility of their application in the bioremediation of oil-contaminated environments and in the purification of oil equipment from oil and asphalt-resin-paraffin deposits.

Characterization and genomic analysis of Exiguobacterium alkaliphilum B-3531D, an efficient crude oil degrading strain.

The aim of the work was to carry out the physiological, biochemical and genetic characterization of the Exiguobacterium alkaliphilum B-3531D strain. This strain is promising for use in the field of environmental biotechnology, since it has a pronounced ability to utilize crude oil and individual hydrocarbons in a wide temperature range. The genome of the strain was sequenced and completely assembled, it consists of a 2,903,369 bp circular chromosome and two circular plasmids, namely, pE73 (73,590 bp) and pE52 (52,125 bp). When cultivated in a mineral medium containing 2% of crude oil, the strain utilized 50% within 30 days of the experiment. In simulated seawater with the same oil content, the loss of hydrocarbons was 45% over the same period. For the first time we observed in an E. alkaliphilum strain the ability to efficiently utilize crude oil, including with an increased content of sodium chloride in the cultivation medium.

Intracellular Sulfur Inclusions: Source of Energy or Heater?

There are various groups of bacteria which receive energy from oxidation of inorganic sulfur compounds. Some of them produce elemental sulfur as an intermediate product and deposit it outside their cells. The group "sulfur bacteria" was described by their ability to produce intracellular sulfur inclusions. Traditionally, calculations of the released energy considered effect of the bacterial sulfide oxidation but never considered energy of the S-polymerization from monoatomic S to 8 atoms ring which is also essential (262.9 kJ). Till present, no biochemical reactions are known which could use energy of this eight atoms ring formation process. Thus, it is proposed that the intracellular sulfur inclusions can provide a lasting heating content of the cells as an additional advantage for the sulfur bacteria.

Evaluation of red-colored carotenoids in yeasts by the biomass color.

Production of carotenoids with red yeasts is a promising area of industrial biotechnology. All spectrophotometrical ("classic") analyses of carotenoids are based on preliminary extraction of the water-insoluble carotenoids; thus, these analyses are precise but complicated and time consuming. This paper presents a simple method to evaluate the red-colored carotenoids in yeast biomass by its color, without extraction. The method is based on digital characteristics of the biomass whole coloring, and it has already been successfully applied in other areas of biology: to compare plant and animal objects. In contrast to spectrophotometry measuring the amount of light that can pass through a solution, the biomass photo is a reflected color of the insoluble compounds. Application of this method to microorganisms permitted to compare the yeast strains and the effects of substrates or culturing regimes for any change in the red-colored pigments. The proposed rapid method was compared with the classic analyses of the carotenoids and showed that evaluation of red-colored carotenoids by the whole coloring of biomass can be used to discover changes in the yeast carotenoid production. In whole, the paper contributes method which is new for pigmented microorganisms and has a potential application in biotechnology.