Beneficial Effects of Spore-Forming Bacillus Probiotic Bacteria Isolated From Poultry Microbiota on Broilers' Health, Growth Performance, and Immune System.

Probiotics are known for their beneficial effects on poultry health and wellbeing. One promising strategy for discovering Bacillus probiotics is selecting strains from the microbiota of healthy chickens and subsequent screening for potential biological activity. In this study, we focused on three probiotic strains isolated from the gastrointestinal tract of chickens bred in different housing types. In addition to the previously reported poultry probiotic Bacillus subtilis KATMIRA1933, three strains with antimutagenic and antioxidant properties Bacillus subtilis KB16, Bacillus subtilis KB41, and Bacillus amyloliquefaciens KB54, were investigated. Their potential effects on broiler health, growth performance, and the immune system were evaluated in vivo. Two hundred newly hatched Cobb500 broiler chickens were randomly divided into five groups (n = 40). Four groups received a standard diet supplemented with the studied bacilli for 42 days, and one group with no supplements was used as a control. Our data showed that all probiotics except Bacillus subtilis KATMIRA1933 colonized the intestines. Treatment with Bacillus subtilis KB54 showed a significant improvement in growth performance compared to other treated groups. When Bacillus subtilis KB41 and Bacillus amyloliquefaciens KB54 were applied, the most significant immune modulation was noticed through the promotion of IL-6 and IL-10. We concluded that Bacillus subtilis KB54 supplementation had the largest positive impact on broilers' health and growth performance.

Quorum-Sensing Inhibition by Gram-Positive Bacteria.

The modern paradigm assumes that interspecies communication of microorganisms occurs through precise regulatory mechanisms. In particular, antagonism between bacteria or bacteria and fungi can be achieved by direct destruction of the targeted cells through the regulated production of antimicrobial metabolites or by controlling their adaptive mechanisms, such as the formation of biofilms. The quorum-quenching phenomenon provides such a countermeasure strategy. This review discusses quorum-sensing suppression by Gram-positive microorganisms, the underlying mechanisms of this process, and its molecular intermediates. The main focus will be on Gram-positive bacteria that have practical applications, such as starter cultures for food fermentation, probiotics, and other microorganisms of biotechnological importance. The possible evolutionary role of quorum-quenching mechanisms during the development of interspecies interactions of bacteria is also considered. In addition, the review provides possible practical applications for these mechanisms, such as the control of pathogens, improving the efficiency of probiotics, and plant protection.

Antimutagenic Activity as a Criterion of Potential Probiotic Properties.

The antimutagenic activity of probiotic strains has been reported over several decades of studying the effects of probiotics. However, this activity is rarely considered an important criterion when choosing strains to produce probiotic preparations and functional food. Meanwhile, the association of antimutagenic activity with the prevention of oncological diseases, as well as with a decrease in the spread of resistant forms in the microbiota, indicates its importance for the selection of probiotics. Besides, an antimutagenic activity can be associated with probiotics' broader systemic effects, such as geroprotective activity. The main mechanisms of such effects are considered to be the binding of mutagens, the transformation of mutagens, and inhibition of the transformation of promutagens into antimutagens. Besides, we should consider the possibility of interaction of the microbiota with regulatory processes in eukaryotic cells, in particular, through the effect on mitochondria. This work aims to systematize data on the antimutagenic activity of probiotics and emphasize antimutagenic activity as a significant criterion for the selection of probiotic strains.

A Review of the Effects and Production of Spore-Forming Probiotics for Poultry.

One of the main problems in the poultry industry is the search for a viable replacement for antibiotic growth promoters. This issue requires a "one health" approach because the uncontrolled use of antibiotics in poultry can lead to the development of antimicrobial resistance, which is a concern not only in animals, but for humans as well. One of the promising ways to overcome this challenge is found in probiotics due to their wide range of features and mechanisms of action for health promotion. Moreover, spore-forming probiotics are suitable for use in the poultry industry because of their unique ability, encapsulation, granting them protection from the harshest conditions and resulting in improved availability for hosts' organisms. This review summarizes the information on gastrointestinal tract microbiota of poultry and their interaction with commensal and probiotic spore-forming bacteria. One of the most important topics of this review is the absence of uniformity in spore-forming probiotic trials in poultry. In our opinion, this problem can be solved by the creation of standards and checklists for these kinds of trials such as those used for pre-clinical and clinical trials in human medicine. Last but not least, this review covers problems and challenges related to spore-forming probiotic manufacturing.

Fermented Duckweed as a Potential Feed Additive with Poultry Beneficial Bacilli Probiotics.

In this study, the duckweed varieties Lemna minor, Spirodela polyrhiza, and a commercially processed duckweed food supplement were investigated as potential substrates for the propagation of two probiotic Bacillus strains, B. subtilis KATMIRA1933 and B. amyloliquefaciens B-1895. Both L. minor and S. polyrhiza were found to be suitable substrates for the propagation of both bacilli, with 8.47-9.48 Log CFU/g and 10.17-11.31 Log CFU/g after 24 and 48 h growth on the substrates, respectively. The commercial duckweed product was a less favorable substrate, with growth reaching a maximum of 7.89-8.91 CFU/g after 24 h with no further growth after 48 h. Growth and adherence of the bacilli to the three products were confirmed via electron microscopy. These strains have demonstrated health-promoting benefits for poultry and thereby have the potential to enhance duckweed as an animal feed through the process of fermentation. Duckweed has been shown to be a promising alternative resource for protein and has the opportunity to become a valuable resource in multiple industries as a potential means to increase sustainability, food security, and reduce environmental impact.

Probiotic Bacilli Inhibit Salmonella Biofilm Formation Without Killing Planktonic Cells.

Salmonellosis is a foodborne infection caused by Salmonella. Domestic poultry species are one of the main reservoirs of Salmonella, which causes the foodborne infection salmonellosis, and are responsible for many cases of animal-to-human transmission. Keeping backyard chickens is now a growing trend, increasing the frequency of direct contact with the flock and, by consequence, the incidence of Salmonella infections. Bacillus subtilis KATMIRA1933 and Bacillus amyloliquefaciens B-1895 are probiotic bacilli that produce the bacteriocins subtilosin A and subtilin, respectively. The antimicrobial activity of the two strains was determined against the reference strain Micrococcus luteus ATCC 10420. The cell-free supernatant of B. subtilis KATMIRA1933 inhibited biofilm formation by Salmonella enterica subsp. enterica serovar Hadar, Salmonella enterica subsp. enterica serovar Enteritidis phage type 4, and Salmonella enterica subsp. enterica serovar Thompson by 51.1, 48.3, and 56.9%, respectively. The cell-free supernatant of B. amyloliquefaciens B-1895 inhibited the biofilm formation of these Salmonella strains by 30.4, 28.6, and 35.5%, respectively. These findings suggest that the bacillus strains may have the potential to be used as probiotics and antibiotic alternatives for the control of Salmonella in poultry. The number of planktonic cells was unaffected by treatment with the cell-free supernatant. A co-culture of the Salmonella strains with either bacilli showed no signs of growth inhibition, suggesting that it might have been quorum sensing that is affected by the two Bacillus strains.

Mechanisms of Candida Resistance to Antimycotics and Promising Ways to Overcome It: The Role of Probiotics.

Pathogenic Candida and infections caused by those species are now considered as a serious threat to public health. The treatment of candidiasis is significantly complicated by the increasing resistance of pathogenic strains to current treatments and the stagnant development of new antimycotic drugs. Many species, such as Candida auris, have a wide range of resistance mechanisms. Among the currently used synthetic and semi-synthetic antifungal drugs, the most effective are azoles, echinocandins, polyenes, nucleotide analogs, and their combinations. However, the use of probiotic microorganisms and/or the compounds they produce is quite promising, although underestimated by modern pharmacology, to control the spread of pathogenic Candida species.

Comprehensive study of nitrofuroxanoquinolines. New perspective donors of NO molecules.

The goal of present work is the study of NO releasing mechanisms in nitrofuroxanoquinoline (NFQ) derivatives. Mechanisms of their structural non-rigidity and pathways of NO donation - spontaneous or under the action of sulfanyl radicals or photoirradiation - were considered in details, both experimentally and quantum chemically. Furoxan-containing systems of the discussed type are not capable of spontaneous or photoinduced decomposition under mild conditions, and sulfanyl (radical) induced processes are the most preferable. It was shown that appropriate modification of NFQ through [3 + 2] cycloaddition and subsequent aromatization is a powerful tool to design new prospective donors of NO molecule. Two newly obtained NFQ derivatives were proven to have unusually high NO activity in full accordance with the theoretical model. We hope that these examples will encourage community to seek for new NO active molecules among cycloadducts and modified furoxanes.

SOS Response Inhibitory Properties by Potential Probiotic Formulations of Bacillus amyloliquefaciens B-1895 and Bacillus subtilis KATMIRA1933 Obtained by Solid-State Fermentation.

The ability of fermentates of two potential probiotic strains, Bacillus amyloliquefaciens B-1895 and Bacillus subtilis KATMIRA1933, to lower the SOS response in bacteria was evaluated using Escherichia coli-based Lux biosensors (pRecA-lux) and the tested bacilli fermentates obtained through solid-state fermentation. The SOS response was stimulated by the addition of ciprofloxacine. Preparations of both Bacillus fermentates demonstrated SOS-inhibitory activity (up to 54.21%). The strain КATMIRA1933 was characterized by higher SOS-inhibitory activity. The active components of the fermentates were stable against heating, proteinase, and RNase action.

Probiotic Intake Increases the Expression of Vitellogenin Genes in Laying Hens.

A promising approach for slowing down the rate of reproductive aging is the use of probiotic bacteria as a feed additive. In the current study was investigated the influence of the intake of a potential probiotic on the follicle content and expression of vitellogenin genes (vtg1, vtg2, vtg3) in aged hens. RNA was isolated from liver samples collected from 570-day-old laying hens and gene expression levels were measured using RT-PCR. Bacillus subtilis KATMIRA1933 supplementation had a positive effect on the number of formed follicles in hens and also triggered a significant increase in the relative expression levels of vtg1, vtg2, and vtg3. A Bacillus amyloliquefaciens B-1895 enriched diet or a combination of the two strains had a modest effect on both the number of follicles and the expression of vitellogenin genes. Additionally, the study demonstrates that vitellogenin mRNA expression levels can be considered as a biomarker in a convenient approach for analyzing the hen's egg-laying ability.

The Impact of Bacillus subtilis KATMIRA1933 Supplementation on Telomere Length and Mitochondrial DNA Damage of Laying Hens.

In the current study, we performed in vivo investigation of probiotic intake influence on nuclear and mitochondrial DNA damage of hens, using quantitative PCR techniques. The probiotic supplementation to the diet of Hisex Brown hens had no significant effect on the rate of telomere shortening. After prolonged probiotic intake (225 and 445 days), the 18-21% decrease in the mtDNA lesions was detected. Since avian mitochondrial DNA damage investigations are rare, the current study of the probiotic-enriched diet's impact on the damage of the hen mitochondrial DNA is novel and highly important. The decrease of mtDNA damage is a beneficial property, which could positively affect the reproductive aging of hens. The positive impact of probiotic supplementation on hens' performance traits such as hen-day egg production, egg weight and mass, and feed conversion ratio was observed.

Functions and emerging applications of bacteriocins.

Bacteriocins, defined as ribosomally synthesized antimicrobial peptides, have traditionally been used as food preservatives, either added or produced by starter cultures during fermentation. In-depth studies of a select few bacteriocins opened exiting new research fields and broadened the application of these antimicrobial peptides. The possibility of developing bacteriocins into next generation antibiotics, accompanied with the rapid development in genetics and nanotechnology, paves the way to even more fascinating applications such as novel carrier molecules (delivery systems) and the treatment of cancer. Also, some bacteriocins are found to regulate quorum sensing which suggests novel applications for this group of substances. While there is some interesting translational research on bacteriocins from Gram-negative bacteria, the majority of application-oriented studies are focused on bacteriocins from Gram-positive microorganisms, mostly lactic acid bacteria. The applications of bacteriocins are expanding from food to human health.

Bacillus Probiotic Supplementations Improve Laying Performance, Egg Quality, Hatching of Laying Hens, and Sperm Quality of Roosters.

The study aims at elucidating the effect of bacilli probiotic preparations on the physiology of laying hens and roosters. Probiotic formulations were prepared as soybean products fermented by Bacillus subtilis KATMIRA1933 and Bacillus amyloliquefaciens B-1895. In this study, groups of male and female chickens were used. These groups received a probiotic preparation based on either B. subtilis KATMIRA1933 or B. amyloliquefaciens B-1895, or of a mixture of strains, from the first day to the age of 39 weeks. These preparations positively affected egg production, quality of sperm production, and quality and hatchery of eggs. Considering the simplicity and cost effectiveness of the soy-based probiotic preparation, these formulations should be considered as advantageous in modern livestock production.

Draft Genome Sequence of Bacillus amyloliquefaciens B-1895.

In this report, we present a draft genome sequence of Bacillus amyloliquefaciens strain B-1895. Comparison with the genome of a reference strain demonstrated similar overall organization, as well as differences involving large gene clusters.