The notable increase in chicken waste resulting from the rapid expansion of the chicken industry represents a major concern and danger to public health and the environment. Therefore, this varied waste stream in the chicken industry, including bedding materials, dung, feathers, and mortalities, requires efficient management techniques. Improper chicken waste disposal can lead to nutrient leakage and water and soil contamination, which can cause eutrophication and aid in spreading harmful bacteria such as Escherichia coli and Salmonella. Moreover, untreated waste exacerbates climate change by increasing greenhouse gas emissions. Thus, in response to these challenges, this review analyses many treatment techniques that might convert this complicated waste stream into a useful resource to support environmental sustainability in the chicken industry and enhance soil health. Furthermore, this study evaluates gasification, pyrolysis, anaerobic digestion, and composting as viable methods to reduce pollution from chicken waste while producing useful byproducts. Anaerobic digestion uses bacteria to produce biogas, a sustainable energy source; pyrolysis produces biochar and bio-oil; composting converts waste into fertilizer; gasification produces syngas for fertilizer production. However, choosing the most efficient treatment approach necessitates thoroughly assessing waste properties, intended end products, and economic factors. This review aims to expand the understanding of these treatment procedures and their related advantages to assist in developing sustainable and effective strategies for dealing with chicken waste. These strategies, which prioritize value development, environmental preservation, and public health, have the potential to pave the way for a more responsible and sustainable future for the chicken industry.
Bacillus bacteria are often used in the production of biopreparations. Moreover, these bacteria can be used in agriculture as probiotics or starters for manufacturing fodder preserved by fermentation (silage). The ability of Bacillus bacteria to produce many biologically active molecules and metabolites with antimicrobial activity means that these bacteria can stimulate plant growth and restore the balance of the microbiome in the digestive system of certain animals.
Using molecular biological analysis, bioinformatic annotation, and metabolic profiling of whole genome sequences, we analyzed two promising candidates for creating biopreparations, i.e., two Bacillus strains, namely B. mucilaginosus 159 and B. subtilis 111. We compared the genomes of these two strains and characterized both their microbiomic and metabolomic features.
We demonstrated that both strains lacked elements contributing to the formation of toxic and virulent properties; however, both exhibited potential in the biosynthesis of B vitamins and siderophores. Additionally, these strains could synthesize many antimicrobial substances of different natures and spectrums of action. B. mucilaginosus 159 could synthesize macrolactin H (an antibiotic from the polyketide group), mersacidin (a class II lanthipeptide), and bacilysin. Meanwhile, B. subtilis 111 could synthesize andalusicin (a class III lanthipeptide), bacilysin, macrolactin H, difficidin, bacillaene (a polyene antibiotic), fengycin (a lipopeptide with antifungal activity), and surfactin (another lipopeptide). Further, a unique pathway of intracellular synthesis of the osmoprotectant glycine betaine was identified in B. subtilis 111, with the participation of betaine aldehyde dehydrogenase (BetB); this is not widely represented in bacteria of the genus Bacillus. These compounds can increase osmotic stability, which may be key for manufacturing biological starters for silage preparation.
These two Bacillus strains are safe for use as probiotic microorganisms or starters in producing preserved fodder. However, B. subtilis 111 may be preferable due to a wider spectrum of synthesized antimicrobial substances and vitamins. Our findings exemplify using genomic technologies to describe the microbiomic and metabolomic characteristics of significant bacterial groups such as Bacillus species.
This study evaluates the possibility of using the experimental preparation “Naturost-M” based on the Bacillus megaterium B-4801 strain in crop production in conditions representative of Russia’s non-Chernozem zone. The research objectives included whole genome sequencing of the B-4801 strain to determine its biotechnological potential and to study the effect of the preparation on the growth and grain productivity of several cereal crops.
Whole genome sequencing of the B. megaterium B-4801 strain was performed at the Biotroph molecular genetic laboratory using the MiSeq platform (Illumina, Inc.). We conducted studies using cereal crops (barley, oats, and wheat) during the 2019–2022 growing seasons at the Vologda Research Center of the Russian Academy of Sciences experimental field. The preparation “Naturost-M” was applied twice: soaking seeds and spraying the phyllosphere of plants in the tillering phase. The raw and dry weights of experimental and control plants were measured in the tillering and earing phases during the growing season. We evaluated grain productivity at the end of the growing season.
Whole genome sequencing of the B. megaterium B-4801 strain revealed the main components of antimicrobial compound biosynthesis pathways, including a cluster of genes responsible for synthesizing enzymes for forming aliphatic unsaturated carboxylic acids containing 3–18 carbon atoms. Our research identified genetic loci encoding the synthesis of bacteriocins such as canosamine and polyketide ansamycin bacteriocins. The genome of the studied strain included clusters responsible for the biosynthesis of secondary metabolites such as siderophores and lantipeptides, as well as a whole range of genes responsible for various adaptation mechanisms of the strain to environmental conditions. Treatment of cereal crops with the experimental preparation “Naturost-M” contributed to an increase in growth parameters: raw weight was increased to 67% compared to the control, dry weight was up to 79% (depending on the year of study, phase of ontogenesis and culture), which occurred against the background of an increase in the content of photosynthetic pigments. Grain productivity grew in barley by 7–46%, oats by 12–31%, and wheat by 5–11% under conditions of small-plot experiments when using the preparation.
The B. megaterium B-4801 strain has a certain biotechnological potential for crop production practice; experimental preparation created on its basis showed a stimulating effect on the growth and productivity of grain crops in conditions representative of Russia’s non-Chernozem zone.
The oral cavity is a complex ecosystem that harbors a diverse microbial community. Viral infections can significantly disrupt this delicate balance, leading to various oral health issues. This review delves into the intricate relationship between viruses and oral health, exploring the impact of both RNA and DNA viruses. We discuss the mechanisms through which these viruses influence the oral microbiome, modulate immune responses, and contribute to various oral diseases, including periodontal disease, oral candidiasis, and oral cancer. Additionally, we highlight the potential of saliva as a valuable diagnostic tool for viral infections and oral health assessment. By understanding the viral–oral health nexus, we can develop effective strategies for prevention, early diagnosis, and targeted interventions to improve oral health outcomes.
The tolerance and productivity of soybeans under the current climate change conditions can be increased by providing these crops with the necessary macro- and microelements. This can be achieved using effective Bradyrhizobium strains for seed inoculation and adding chelated trace elements.
Soybean Bradyrhizobium japonicum symbioses were cultivated by adding chelates of trace elements, such as iron (Fe), germanium (Ge), and molybdenum (Mo), to the culture medium, after which microbiological and biochemical analyses were performed.
The addition of chelated forms of Fe or Ge to the Bradyrhizobium culture medium promoted a change in the pro-oxidant-antioxidant balance in soybean nodules under different water supply conditions. This is due to the production of hydrogen peroxide in the nodules (an increase of 12.9%), as well as a twofold increase in the ascorbate peroxidase activity and a decrease in the levels of superoxide dismutase (by 40%) and catalase (by 50%) under water stress. Stimulation of nodulation and nitrogen fixation in soybeans (by 40.1 and 73.0%) and an increase in grain productivity (by 47.5 and 58%) were observed when using Bradyrhizobium inoculant containing Fe or Ge chelates. The inoculation of soybeans with Bradyrhizobium modified using Mo chelate causes similar changes in antioxidant processes as Fe or Ge chelates, but the soybean symbiotic capacity decreases under water stress.
Chelated forms of Fe or Ge as additional components in the Bradyrhizobium culture medium are effective in regulating the antioxidant status of soybeans under drought conditions and can simultaneously contribute to increased nitrogen fixation and grain productivity. These findings are important in expanding the current technologies used to grow this legume in risky farming areas caused by climate change.
Recently, the importance of biocatalysis in bioenergy has been noted, with policymakers and regulatory authorities intervening at the technological level to establish more efficient, varied, and vast-scale exploitations of biocatalysis. These approaches leverage natural catalysts, primarily enzymes, to facilitate the breakdown of larger organic compounds into simpler molecules, which can be further biochemically transformed into biofuels, such as ethanol, biodiesel, and biogas, using improved versions of metabolic enzymes. Advances in enzyme engineering have significantly enhanced the stability, specificity, and activity of key enzymes involved in biofuel synthesis, such as cellulases, oxidoreductases, xylanases, glucose isomerases, butanol dehydrogenase, acetoacetate decarboxylase, ferredoxin oxidoreductases, etc. Further, synthetic biological approaches have allowed the construction of microbial cell factories with restructured integrated biocatalytic pathways, capable of converting the raw biomass directly into biofuels. Despite these advancements, challenges remain, such as the cost of enzymes, their robustness, and the scalability of their production and biotransformation processes. Ongoing research is focused on overcoming these hurdles through innovative biocatalyst design, metabolic engineering, in silico modeling, and optimization. However, changes in government policies and reduced regulatory frameworks are expected to leverage biofuel production and competitiveness with fossil fuels and gradually replace them completely. This review highlights the recent advances in the field of biocatalysis related to the production of biofuels. This review also discusses the current challenges, sustainability, promotional initiatives performed at the government level, and future directions in the field of biofuels.
Lignocellulosic materials, such as soybean hulls, possess a complex and recalcitrant structure that requires efficient pretreatment or enzymatic processing for effective conversion into valuable products. However, pretreatment processes often generate inhibitory byproducts (e.g., furfural, hydroxymethyl furfural (HMF), phenols, and lignin degradation products), which can impede enzymatic activity and increase overall production costs. This study explores soybean hulls, a byproduct of oil and meal production, as a potential high-carbohydrate biorefinery resource, assessing their chemical composition, fermentable sugar recovery, and bioethanol production potential.
Soybean hulls (5%, w/v dry basis) were subjected to enzymatic hydrolysis at 50 °C for 72 hours, utilizing a dual impeller mixing system at 250 rpm. An enzyme load of 45 mg enzyme protein per gram of solids was applied using a combination of commercial enzyme preparations, including Cellulase Blend and Multifect Pectinase. Conversion of cellulose, xylan, and arabinan into fermentable sugars was quantified. A moderate enzyme loading of 10 mg enzyme protein/g solids was also tested for comparison. Microbial fermentation was carried out using the xylose-fermenting Escherichia coli FBR5 strain to produce bioethanol.
Hydrolysis of untreated soybean hulls resulted in conversion yields of 94.4% for glucan, 72.6% for xylan, and 69.3% for arabinan into glucose, xylose, and arabinose, respectively. In comparison, control experiments without cellulolytic enzymes showed significantly lower conversion yields (14.2%, 20.1%, and 15.5% for glucose, xylose, and arabinose, respectively). A moderate enzyme loading of 10 mg enzyme protein per gram of solids achieved a cellulose conversion of 90.6%, which was nearly equivalent to the conversion obtained with 45 mg enzyme protein/g solids. Microbial fermentation with E. coli FBR5 resulted in 94% theoretical ethanol yield, with a production rate of 0.33 g/L/h and a productivity of 0.48 g ethanol/g sugar.
The study demonstrates that enzymatic hydrolysis of soybean hulls, which are rich in cellulose and hemicellulose, can be effectively conducted without the need for pretreatment. The moderate enzyme load used in this study provides a promising platform for efficient sugar release and bioethanol production, presenting a cost-effective and viable approach for utilizing soybean hulls in biorefinery applications.
Antibiotic resistance is a contemporary public health issue that poses significant environmental and public health concerns. The presence of antimicrobial-resistant (AMR) microbes has been reported across media irrespective of geography and landscape. This study aimed to analyze the antibiotic susceptibility of Bacillus subtilis obtained from the Indian Sector of the Southern Ocean (39°19′ S, 57°30′ E to 66°38′ S, 76°22′ E).
Bacillus subtilis was revived and cultured on Mannitol Yolk Polymyxin Agar. Antibiotic susceptibility was assessed via the agar well diffusion assay against 10 therapeutically significant antibiotics. Whole-genome sequencing was performed to identify the presence of AMR genes. A total of 12 AMR genes were identified via the Comprehensive Antibiotic Resistance Database (CARD). A comparative genomics approach was employed to investigate the global distribution of AMR genes from 2014 to 2024.
Antibiotic susceptibility testing indicated complete resistance to metronidazole, while the isolates remained susceptible to ampicillin, doxycycline, tetracycline, ciprofloxacin, norfloxacin, cefixime, azithromycin, meropenem, and cotrimoxazole. Whole-genome sequencing and comparative analysis identified 12 AMR genes, including aadK, vanT (within the vanG cluster), ykkC, ykkD, vanW (within the vanI cluster), FosBx1, qacJ, qacG, tet(45), vanY (within the vanM cluster), and blt. The observed resistance mechanisms included antibiotic efflux, target modification, and enzymatic inactivation. Comparative genomic analysis of 15 closely related strains revealed variability in the distribution of AMR genes, with B. subtilis strain MB415 carrying all 12 resistance genes.
The detection of antibiotic-resistant B. subtilis in the Southern Ocean suggests potential anthropogenic influences on microbial communities, underscoring the need for continuous surveillance of AMR in remote marine environments to prevent its proliferation and mitigate its ecological consequences.