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Frontiers in Microbiology 2023Plant growth-promoting bacteria are one of the most interesting methods of controlling fungal phytopathogens. These bacteria can participate in biocontrol via a variety... (Review)
Review
Plant growth-promoting bacteria are one of the most interesting methods of controlling fungal phytopathogens. These bacteria can participate in biocontrol via a variety of mechanisms including lipopeptide production, hydrolytic enzymes (e.g., chitinase, cellulases, glucanase) production, microbial volatile organic compounds (mVOCs) production, and induced systemic resistance (ISR) triggering. Among the bacterial genera most frequently studied in this aspect are spp. including . Due to the range of biocontrol traits, is one of the most interesting members of spp. that can be used in the biocontrol of fungal phytopathogens. So far, a number of strains that exhibit biocontrol properties against fungal phytopathogens have been described, e.g., HR10, PTB180, SS-10.7, MCB-7, INR7, SE52, SE34, SE49, RST25, JK-SX001, and KUDC1732. strains are capable of suppressing phytopathogens such as , , , , , and . Importantly, can promote plant growth regardless of whether it alters the native microbiota or not. However, in order to increase its efficacy, research is still needed to clarify the relationship between the native microbiota and . Despite that, it can already be concluded that strains are good candidates to be environmentally friendly and commercially effective biocontrol agents.
PubMed: 37560520
DOI: 10.3389/fmicb.2023.1194606 -
Microbial Cell Factories Aug 2023Despite being necessary, copper is a toxic heavy metal that, at high concentrations, harms the life system. The parameters that affect the bioreduction and biosorption...
BACKGROUND
Despite being necessary, copper is a toxic heavy metal that, at high concentrations, harms the life system. The parameters that affect the bioreduction and biosorption of copper are highly copper-resistant bacteria.
RESULTS
In this work, the ability of the bacterial biomass, isolated from black shale, Wadi Nakheil, Red Sea, Egypt, for Cu attachment, was investigated. Two Cu resistance Bacillus species were isolated; Bacillus pumilus OQ931870 and Bacillus subtilis OQ931871. The most tolerant bacterial isolate to Cu was B. pumilus. Different factors on Cu biosorption were analyzed to estimate the maximum conditions for Cu biosorption. The q for Cu by B. pumilus and B. subtilis determined from the Langmuir adsorption isotherm was 11.876 and 19.88 mg. g, respectively. According to r, the biosorption equilibrium isotherms close-fitting with Langmuir and Freundlich model isotherm. Temkin isotherm fitted better to the equilibrium data of B. pumilus and B. subtilis adsorption. Additionally, the Dubinin-Radushkevich (D-R) isotherm suggested that adsorption mechanism of Cu is predominately physisorption.
CONCLUSION
Therefore, the present work indicated that the biomass of two bacterial strains is an effective adsorbent for Cu removal from aqueous solutions.
Topics: Copper; Bacillus subtilis; Bacillus pumilus; Egypt; Indian Ocean; Adsorption; Kinetics; Hydrogen-Ion Concentration; Biomass
PubMed: 37573310
DOI: 10.1186/s12934-023-02166-3 -
Microorganisms Jun 2023Due to their capacity to produce antimicrobial peptides that can prevent the growth of diseases, many spp. are beneficial to plants. In this study, we looked into the...
Due to their capacity to produce antimicrobial peptides that can prevent the growth of diseases, many spp. are beneficial to plants. In this study, we looked into the antagonistic activity of the 3-19 strain and its derivatives following targeted genome editing. Two peptide genes with antibacterial action, bacilysin () and bacteriocin (), and the F gene, which encodes the sigma factor of sporulation, were specifically inactivated using the CRISPR-Cas9 system in the genome of 3-19. Antibacterial activity against and decreased as a result of the inactivation of target genes in the 3-19 genome, with a noticeable effect against bacilysin. The growth dynamics of the culture changed when the , , and F genes were inactivated, and the altered strains had less proteolytic activity. An asporogenic mutant of 3-19 was obtained by inactivating the F gene. It has been proven that bacilysin plays a unique part in the development of 3-19's antagonistic action against soil microorganisms.
PubMed: 37375011
DOI: 10.3390/microorganisms11061508 -
Journal of Nematology Feb 2023Vineyards, covering over seven million hectares worldwide, hold significant socio-cultural importance. Traditionally reliant on conventional practices and agrochemicals,...
Vineyards, covering over seven million hectares worldwide, hold significant socio-cultural importance. Traditionally reliant on conventional practices and agrochemicals, this agroecosystem faces environmental challenges, including soil and water pollution. Sustainable viticulture, driven by eco-friendly practices and cost reduction, has gained prominence, underlining the importance of biological control agents such as entomopathogenic nematodes (EPNs). EPNs naturally occurr in vineyard soils and play a crucial role in controlling pest damage. Ensuring compatibility between EPNs and the commonly used vineyard fungicides is critical, as these applications constitute the predominant pest-management practice during the productive grapevine cycle. This study assessed the impact of authorized grapevine fungicides on EPNs, focusing on the survival of populations and sublethal effects on their virulence. We investigated the compatibility of two EPN populations ( 107 and 'All') with three organic production-approved products (, sulfur, and copper oxychloride) and two synthetic chemicals (Trifloxystrobin and Mancozeb). Our findings revealed that the viability of 107 was reduced when exposed to sulfur and copper oxychloride, and its virulence was affected by copper oxychloride and Mancozeb, although only two days after exposure and with no significant differences for larval mortality at five days. In contrast, 'All' exhibited full compatibility with all five fungicides, with no impact on its viability or virulence. Consequently, our results suggested that the evaluated fungicides could be co-applied on both EPN populations if they were employed on the same day. However, further research on multi-target interactions is needed to ensure the successful implementation of this kind of co-application.
PubMed: 38026548
DOI: 10.2478/jofnem-2023-0057 -
Microorganisms Jun 2023The adoption of intensive farming has exacerbated disease outbreaks in aquaculture, particularly vibriosis caused by . The use of probiotics to control is recognized as...
The adoption of intensive farming has exacerbated disease outbreaks in aquaculture, particularly vibriosis caused by . The use of probiotics to control is recognized as a good alternative to antibiotics for avoiding the development of antibiotic-resistant bacteria. In this study, two strains of B. HLJ1 and B. C1 with strong inhibitory activity on were isolated from aquaculture water and identified as and , respectively. Both B. HLJ1 and B. C1 lacked antibiotic resistance and virulence genes, suggesting that they are safe for use in aquaculture. In addition, these two strains can tolerate acid environments, produce spores, secrete extracellular enzymes, and co-aggregate as well as auto-aggregate with . B. HLJ1 and B. C1 produced the same anti- substance, which was identified as AI-77-F and belongs to amicoumacins. Both B. C1 and B. HLJ1 showed inhibitory activity against 11 different and could effectively control the growth of in simulated aquaculture wastewater when the concentration of B. C1 and B. HLJ1 reached 1 × 10 CFU/mL. This study shows that B. HLJ1 and B. C1 have great potential as aquaculture probiotics.
PubMed: 37512840
DOI: 10.3390/microorganisms11071667 -
Journal of Taibah University Medical... Jun 2023This study highlighted the dissemination of species (including drug-resistant species) in public hospital environments and calls for the design of optimal strategies to...
OBJECTIVE
This study highlighted the dissemination of species (including drug-resistant species) in public hospital environments and calls for the design of optimal strategies to curb their spread. This a critical consideration for all health care systems such as caring for the increasing number of immune-compromised patient.
METHODS
A total of 528 swab samples were collected from the environments of different Saudi hospitals. Swab samples were collected by swabbing approximately 5 cm of different surfaces at each site using pre-moisturized cotton swabs with 1 mL of neutralizing buffer. The swabs were transported in cool boxes with ice packs within 2 h of collection. Isolation and identification were performed according to conventional bacteriological, semi-automated and molecular characterization methods. Antibiogram typing was carried against different groups of antimicrobial agents.
RESULTS
The most prevalent of the isolated species were (46.6%) followed by (38.1%); the least prevalent was (1.1%). Most isolates (25.6%) were isolated from the Department of Internal Medicine followed by the Emergency Department (18.8%), while the operating rooms had the lowest prevalence (4.5%). Antimicrobial susceptibility testing revealed high levels of resistance in isolates to β-lactams and tetracycline. Overall, 21.6% of isolates showed multi-drug resistance to three or more antibiotics (21.6%). Antibiogram typing of the 176 isolates revealed 45 antibiotypes; the most common was antibiotype 31, which included 32 isolates (18.2%); this particular antibiotype was resistant to both penicillin and cefoxitin.
CONCLUSIONS
Analyses identified the high dissemination of species in several hospital environments with high resistance to β-lactams and tetracycline antibiotics. Molecular analysis also revealed the existence of genetic diversity among the isolates investigated. Thus, monitoring the hospital environment is an important tool in the prevention of hospital-associated infection by species.
PubMed: 36818182
DOI: 10.1016/j.jtumed.2022.10.016 -
Frontiers in Veterinary Science 2024Intensive poultry farming faces challenges like gut inflammation in the absence of antibiotics, resulting in reduced productivity, heightened susceptibility to enteric...
The impact of TS2 isolated from yaks on growth performance, gut microbial community, antioxidant activity, and cytokines related to immunity and inflammation in broilers.
Intensive poultry farming faces challenges like gut inflammation in the absence of antibiotics, resulting in reduced productivity, heightened susceptibility to enteric diseases, and other complications. Alternative strategies are needed to manage inflammation and maintain sustainable poultry production. Yaks living in high-altitude hypoxic environments have specialized gut microbes. However, yak probiotics remain largely uncharacterized. We previously isolated a strain of (named TS2) from yaks and demonstrated its potential as a probiotic . Therefore, in this study, we evaluated the growth-promoting, antioxidant, immune, and anti-inflammatory effects of isolated from yaks in broilers. We demonstrated the safety of TS2 isolated from yaks in broilers. Furthermore, we found that TS2 increased the average daily weight gain (ADWG) and reduced the feed conversion ratio (FCR). Supplementation with TS2 also improved the mucosal morphology, the ratio of villi to crypt cells, and enzyme activity. High-throughput sequencing showed that the abundance of was higher in the TS2 treated broilers. Importantly, the serum level of malondialdehyde (MDA) was reduced and the levels of total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) activity were increased in the low-dose TS2 group, while the inflammatory factors interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were downregulated compared with the control group. We demonstrated that TS2 supplementation can increase the overall growth performance and ameliorate the blood parameters related to inflammation and immunity in broilers.
PubMed: 38737458
DOI: 10.3389/fvets.2024.1383262 -
International Journal of Molecular... Dec 2023The minor secreted proteinase of 3-19 MprBp classified as the unique bacillary adamalysin-like enzyme of the metzincin clan. The functional role of this...
The minor secreted proteinase of 3-19 MprBp classified as the unique bacillary adamalysin-like enzyme of the metzincin clan. The functional role of this metalloproteinase in the bacilli cells is not clear. Analysis of the regulatory region of the gene showed the presence of potential binding sites to the transcription regulatory factors Spo0A (sporulation) and DegU (biodegradation). The study of activity in mutant strains of defective in regulatory proteins of the Spo- and Deg-systems showed that the gene is partially controlled by the Deg-system of signal transduction and independent from the Spo-system.
Topics: Bacillus pumilus; Metalloendopeptidases; Biodegradation, Environmental; Bacillus; Firmicutes; Lacticaseibacillus casei
PubMed: 38203233
DOI: 10.3390/ijms25010062 -
Molecules (Basel, Switzerland) Nov 2023This study aims to optimize the processing of Houtt. by talcum powder simmering using single-factor and orthogonal experimental methods, and the overall desirability...
This study aims to optimize the processing of Houtt. by talcum powder simmering using single-factor and orthogonal experimental methods, and the overall desirability values of dehydrodiisoeugenol and essential oils content were selected as indicators of the process. The new process reduced the total content of the three toxic components, namely myristicin, safrole and elemicin, from 1.91% to 1.16% before and after processing, indicating that the toxic components were reduced by 39%. The IC of the essential oils before and after processing were 1.002 ± 0.05 and 0.233 ± 0.05 mg/mL for DPPH scavenging activity and 0.132 ± 0.04 and 0.057 ± 0.05 mg/mL for ABTS scavenging activity, respectively. And the absorbance of the antioxidant activity against Ferric reducing power ranged from 0.213 to 0.709 and from 0.225 to 0.755, respectively. The minimum inhibitory concentration for , and were all lower after processing than before. The antioxidant activity and antibacterial activity of the essential oils after processing were better than before. The results of the survival of zebrafish embryos at different concentrations of essential oils at 0-168 h post fertilisation were higher after processing than before. These findings suggest that processing plays the role of reducing toxicity and increasing beneficial effects. They provide a scientific basis not only for the processing of , but also for the processing of other foods.
Topics: Animals; Myristica; Antioxidants; Gas Chromatography-Mass Spectrometry; Zebrafish; Seeds; Oils, Volatile
PubMed: 38005349
DOI: 10.3390/molecules28227627 -
Veterinary World Dec 2023The rapid development of aquaculture as a major food sector is accompanied by challenges, including diseases that affect tilapia farming worldwide. One such infectious...
BACKGROUND AND AIM
The rapid development of aquaculture as a major food sector is accompanied by challenges, including diseases that affect tilapia farming worldwide. One such infectious disease caused by poses a serious threat to tilapia populations. Probiotics have emerged as a potentially safe preventive measure against infection. However, antimicrobial resistance from antibiotic-resistant bacteria remains a concern because it can lead to the spread of resistant bacteria and serve as a reservoir of antibiotic-resistant genes in fishes and the surrounding environment. This study aimed to identify candidate probiotic bacteria capable of promoting tilapia growth, providing resistance to infection, devoid of potential pathogenicity, and free from antibiotic resistance genes. Subsequently, the performance of these probiotic candidates in tilapia was evaluated.
MATERIALS AND METHODS
spp., and were examined to assess their antibacterial properties, hemolytic patterns, and antibiotic resistance genes. We used the specific primers , , , , , , , and that were used for antibiotic resistance gene detection. probiotic efficacy was evaluated by administering probiotic candidates in tilapia feed at a concentration of 1 × 10 colonies/mL/50 g of feed over a 60-day maintenance period. Resistance to infection was observed for 14 days after the challenge test.
RESULTS
, , and spp. were identified as promising probiotic candidates among the bacterial isolates. On the other hand, , , and carried resistance genes and exhibited a β hemolytic pattern, rendering them unsuitable as probiotic candidates. The selected probiotic candidates (, , and spp.) demonstrated the potential to enhance tilapia growth, exhibited no pathogenic tendencies, and were free from antibiotic resistance genes. Supplementation with and spp. enhanced tilapia resistance to infection, whereas supplementation showed an insignificant survival rate compared with controls after the challenge test period.
CONCLUSION
Probiotics, particularly , and spp., enhance growth and resistance against infection, without harboring antibiotic resistance genes. Selecting probiotic candidates based on antibiotic resistance genes is essential to ensure the safety of fish, the environment, and human health.
PubMed: 38328352
DOI: 10.14202/vetworld.2023.2504-2514