-
The Science of the Total Environment Jun 2024Fiber film have received widespread attention due to its green friendliness. We can use microorganisms to degrade lignin in straw to obtain cellulose and make fiber...
Fiber film have received widespread attention due to its green friendliness. We can use microorganisms to degrade lignin in straw to obtain cellulose and make fiber films. Herein, a group of high-temperature (50 °C) lignin degrading bacterial consortium (LDH) was enriched and culture conditions for lignin degradation were optimized. Combined with high-throughput sequencing technology, the synergistic effect of LDH-composited bacteria was analyzed. Then LDH was used to treat rice straw for the bio-pulping experiment. The results showed that the lignin of rice straw was degraded 32.4 % by LDH at 50 °C for 10 d, and after the optimization of culture conditions, lignin degradation rate increased by 9.05 % (P < 0.001). The bacteria that compose in LDH can synergistically degrade lignin. Paenibacillus can encode all lignin-degrading enzymes present in the LDH. Preliminary tests of LDH in the pulping industry have been completed. This study is the first to use high temperature lignin degrading bacteria to fabricate fiber film.
Topics: Lignin; Oryza; Biodegradation, Environmental; Microbial Consortia; Bacteria; Cellulose
PubMed: 38604360
DOI: 10.1016/j.scitotenv.2024.172386 -
ACS Chemical Biology May 2024The prevalence of multidrug-resistant (MDR) pathogens combined with a decline in antibiotic discovery presents a major challenge for health care. To refill the discovery...
The prevalence of multidrug-resistant (MDR) pathogens combined with a decline in antibiotic discovery presents a major challenge for health care. To refill the discovery pipeline, we need to find new ways to uncover new chemical entities. Here, we report the global genome mining-guided discovery of new lipopeptide antibiotics tridecaptin A and tridecaptin D, which exhibit unusual bioactivities within their class. The change in the antibacterial spectrum of Oct-TriA was explained solely by a Phe to Trp substitution as compared to Oct-TriA, while Oct-TriD contained 6 substitutions. Metabolomic analysis of producer sp. JJ-21 validated the predicted amino acid sequence of tridecaptin A. Screening of tridecaptin analogues substituted at position 9 identified Oct-His9 as a potent congener with exceptional efficacy against and reduced hemolytic and cytotoxic properties. Our work highlights the promise of tridecaptin analogues to combat MDR pathogens.
Topics: Anti-Bacterial Agents; Pseudomonas aeruginosa; Humans; Microbial Sensitivity Tests; Host Specificity; Drug Discovery; Lipopeptides; Peptides
PubMed: 38602492
DOI: 10.1021/acschembio.4c00034 -
Frontiers in Microbiology 2024is a delicious and nutritious ectomycorrhizal fungus. However, its cultivation is hindered owing to limited studies on its symbiotic relationships. The symbiotic...
is a delicious and nutritious ectomycorrhizal fungus. However, its cultivation is hindered owing to limited studies on its symbiotic relationships. The symbiotic relationship between and its host is closely related to the shiro, a complex network composed of mycelium, mycorrhizal roots, and surrounding soil. To explore the symbiotic relationship between and its host, soil samples were collected from shiro (Tb) and corresponding rhizosphere (CK) in four cities in Liaoning Province, China. The physicochemical properties of all the soil samples were then analyzed, along with the composition and function of the fungal and bacterial communities. The results revealed a significant increase in total potassium, available nitrogen, and sand in Tb soil compared to those in CK soil, while there was a significant decrease in pH, total nitrogen, total phosphorus, available phosphorus, and silt. The fungal community diversity in shiro was diminished, and altered the community structure of its shiro by suppressing other fungi, such as (ectomycorrhizal fungus) and (phytopathogenic fungus). The bacterial community diversity in shiro increased, with the aggregation of mycorrhizal-helper bacteria, such as and , and plant growth-promoting bacteria, such as and , facilitated by . Microbial functional predictions revealed a significant increase in pathways associated with sugar and fat catabolism within the fungal and bacterial communities of shiro. The relative genetic abundance of carboxylesterase and gibberellin 2-beta-dioxygenase in the fungal community was significantly increased, which suggested a potential symbiotic relationship between and . These findings elucidate the microbial community and relevant symbiotic environment to better understand the relationship between and .
PubMed: 38601932
DOI: 10.3389/fmicb.2024.1361117 -
Scientific Reports Apr 2024Vulvar lichen sclerosus (VLS) is a chronic and progressive dermatologic condition that can cause physical dysfunction, disfigurement, and impaired quality of life....
Vulvar lichen sclerosus (VLS) is a chronic and progressive dermatologic condition that can cause physical dysfunction, disfigurement, and impaired quality of life. However, the etiology of VLS remains unknown. The vulvar skin, intestinal and vaginal microbiomes have been postulated to play important roles in the pathogenesis of this disease. The aim of this study was to compare the compositional characteristics of the vulvar skin, vagina, and gut microbiota between perimenopausal or postmenopausal VLS patients and healthy controls. The study involved six perimenopausal or postmenopausal VLS patients which were based on characteristic clinical manifestations and histologic confirmation and five healthy controls. The pruritus severity of each patient was evaluated using the NRS scale, and the dermatology-specific health-related quality of life was assessed using the Skindex-16. Metagenomic sequencing was performed, and the results were analyzed for alpha and beta diversity. LEfSe analysis were used to investigate the microbial alterations in vulvar skin, gut and vagina. KEGG databases were used to analyze differences in functional abundance. The study found significant differences in alpha diversity between the two groups in stool and vaginal samples (P < 0.05). Patients with VLS had a higher abundance of Enterobacter cloacae, Flavobacterium_branchiophilum, Mediterranea_sp._An20, Parabacteroides_johnsoniiand Streptococcus_bovimastitidis on the vulvar skin, while Corynebacterium_sp._zg-913 was less abundant compared to the control group. The relative abundance of Sphingomonas_sp._SCN_67_18, Sphingobium_sp._Ant17, and Pontibacter_sp_BT213 was significantly higher in the gut samples of patients with VLS.Paenibacillus_popilliae,Gemella_asaccharolytica, and Coriobacteriales_bacterium_DNF00809 compared to the control group. Additionally, the vaginal samples of patients with VLS exhibited a significantly lower relative abundance of Bacteroidales_bacterium_43_8, Bacteroides_sp._CAG:20, Blautia_sp._AM28-10, Fibrobacter_sp._UWB16, Lachnospiraceae_bacterium_AM25-39, Holdemania_filiformis, Lachnospiraceae_bacterium_GAM79, and Tolumonas_sp. Additionally, the butyrate-producing bacterium SS3/4 showed a significant difference compared to the controls. The study found a negative relationship between Sphingobium_sp._Ant17 in stool and Skindex-16 (P < 0.05), while Mediterranea_sp._An20 had a positive correlation with Skindex-16 (P < 0.05) in the skin. Additionally, our functional analysis revealed alterations in Aminoacyl_tRNA_biosynthesis, Glutathione_metabolism, the pentose phosphate pathway, and Alanine__aspartate_and_glutamate_metabolism in the VLS patient group. The study suggests that perimenopausal or postmenopausal patients with VLS have a modified microbiome in the vulvar skin, gut, and vagina. This modification is linked to abnormal energy metabolism, increased oxidative stress, and abnormal amino acid metabolism.
Topics: Female; Humans; Vulvar Lichen Sclerosus; Postmenopause; Perimenopause; Quality of Life; Microbiota; Arrhythmias, Cardiac; Vagina
PubMed: 38600101
DOI: 10.1038/s41598-024-58983-y -
Frontiers in Microbiology 2024A new strain of xanthan-degrading bacteria identified as sp. has been isolated from a xanthan thickener for food production. The strain was able to utilize xanthan as...
A new strain of xanthan-degrading bacteria identified as sp. has been isolated from a xanthan thickener for food production. The strain was able to utilize xanthan as the only carbon source and to reduce the viscosity of xanthan-containing medium during cultivation. Comparative analysis of the secretomes of sp. after growth on different media led to the identification of a xanthanase designated as Xan9, which was isolated after recombinant production in . Xan9 could efficiently degrade the β-1,4-glucan backbone of xanthan after previous removal of pyruvylated mannose residues from the ends of the native xanthan side chains by xanthan lyase treatment (XLT-xanthan). Compared with xanthanase from , xanthanase Xan9 had a different module composition at the N- and C-terminal ends. The main putative oligosaccharides released from XLT-xanthan by Xan9 cleavage were tetrasaccharides and octasaccharides. To explore the functions of the N- and C-terminal regions of the enzyme, truncated variants lacking some of the non-catalytic modules (Xan9-C, Xan9-N, Xan9-C-N) were produced. Enzyme assays with the purified deletion derivatives, which all contained the catalytic glycoside hydrolase family 9 (GH9) module, demonstrated substantially reduced specific activity on XLT-xanthan of Xan9-C-N compared with full-length Xan9. The C-terminal module of Xan9 was found to represent a novel carbohydrate-binding module of family CBM66 with binding affinity for XLT-xanthan, as was shown by native affinity polyacrylamide gel electrophoresis in the presence of various polysaccharides. The only previously known binding function of a CBM66 member is exo-type binding to the non-reducing fructose ends of the β-fructan polysaccharides inulin and levan.
PubMed: 38596379
DOI: 10.3389/fmicb.2024.1386552 -
Canadian Journal of Veterinary Research... Apr 2024Honey bees can be affected by a variety of pathogens, which impacts their vital role as pollinators in agriculture. A cross-sectional study was conducted in southwestern...
Honey bees can be affected by a variety of pathogens, which impacts their vital role as pollinators in agriculture. A cross-sectional study was conducted in southwestern Quebec to: i) estimate the prevalence of 11 bee pathogens; ii) assess the agreement between beekeeper suspicion of a disease and laboratory detection of the causative pathogen; and iii) explore the association between observed clinical signs and pathogen detection in a colony. A total of 242 colonies in 31 apiaries owned by 15 beekeepers was sampled in August 2017. The prevalence of detection was estimated as 48% for colonies and 93% for apiaries. The apparent prevalence of colonies infected by spp. and was estimated as 40% and 21%, respectively. At least 180 colonies were tested by polymerase chain reaction (PCR) for deformed wing virus (DWV), acute-Kashmir-Israeli complex (AKI complex), and black queen cell virus (BQCV), which were detected in 33%, 9%, and 95% of colonies, respectively. , and were not detected. Varroasis was suspected by beekeepers in 14 of the 15 beekeeping operations in which the mite was detected. However, no correlation was found between suspected European foulbrood and detection of or between suspected nosemosis and detection of spp. Colony weakness was associated with spore counts of at least 0.5 × 10 per bee. was more frequently detected in colonies showing scattered brood.
Topics: Bees; Animals; Quebec; Cross-Sectional Studies; Prevalence; RNA Viruses; Enterococcaceae
PubMed: 38595951
DOI: No ID Found -
Frontiers in Microbiology 2024In recent years, bacterial-based biocontrol agents (BCA) have become a new trend for the control of fungal diseases such as fusarium wilt that seriously threaten the...
In recent years, bacterial-based biocontrol agents (BCA) have become a new trend for the control of fungal diseases such as fusarium wilt that seriously threaten the yield and quality of cucumber, which are transmitted through infested soil and water. This study was set out with the aim of figuring the mechanism of the isolated rhizobacterial strain PJH16 in preventing f. sp. (). Biocontrol and growth-promoting experiments revealed that bacterial strain causes effective inhibition of the fungal disease through a significant growth-promoting ability of plants, and had activities of β-1,3-glucanase, cellulase, amylase and protease. It could produce siderophore and indole-3-acetic acid, too. Using the high-throughput sequencing tool PacBio Sequel II system and the database annotation, the bacterial strain was identified as PJH16 and contained genes encoding for presence of biofilm formation, antimicrobial peptides, siderophores and hydrolyases. From comparing data between the whole genome of PJH16 with four closely related strains, findings revealed markedly the subtle differences in their genome sequences and proposed new antifungal substances present in PJH16. Therefore, PJH16 could be utilized in bioengineering a microbial formulation for application as biocontrol agent and bio-stimulant, in the future.
PubMed: 38591040
DOI: 10.3389/fmicb.2024.1359263 -
Frontiers in Microbiology 2024L. is a versatile edible plant that is widely explored due to its medicinal properties and as a key element in intercropping systems. Its growth could be improved by...
L. is a versatile edible plant that is widely explored due to its medicinal properties and as a key element in intercropping systems. Its growth could be improved by the use of biofertilizers that can enhance nutrient uptake by the plant or provide tolerance to different abiotic and biotic stresses. In a previous study, 101 endophytes isolated from roots showed more than three plant growth-promoting (PGP) features , such as phosphate mineralization/solubilization, production of siderophores, antimicrobial substances and indole-related compounds, and presence of the gene. To provide sustainable alternatives for biofertilization, the genomes of two promising endophytes-CAPE95 and CAPE238-were sequenced to uncover metabolic pathways related to biofertilization. Greenhouse experiments were conducted with 216 seeds and 60 seedlings, half co-inoculated with the endophytes (treatment) and half inoculated with 1X PBS (control), and the impact of the co-inoculation on the plant's bacteriome was accessed through 16S rRNA gene metabarcoding. The strains CAPE95 and CAPE238 were taxonomically assigned as and , respectively. Metabolic pathways related to the enhancement of nutrient availability (nitrogen fixation, sulfate-sulfur assimilation), biosynthesis of phytohormones (indole-3-acetic acid precursors) and antimicrobial substances (bacilysin, paenibacillin) were found in their genomes. The experiments showed that treated seeds exhibited faster germination, with a 20.3% higher germination index than the control on the eleventh day of the experiment. Additionally, treated seedlings showed significantly higher plant height and leaf diameters ( < 0.05). The bacterial community of the treated plants was significantly different from that of the control plants ( < 0.001) and showed a higher richness and diversity of species (Chao and Shannon indexes, < 0.001). A higher relative abundance of potential synergistic PGP bacteria was also shown in the bacteriome of the treated plants, such as and . For the first time, co-inoculation of and was shown to have great potential for application as a biofertilizer to plants. The bacterial consortium used here could also be explored in other plant species in the future.
PubMed: 38585693
DOI: 10.3389/fmicb.2024.1356891 -
Protein Expression and Purification Jul 2024GH11 enzyme is known to be specific and efficient for the hydrolysis of xylan. It has been isolated from many microorganisms, and its enzymatic characteristics and...
GH11 enzyme is known to be specific and efficient for the hydrolysis of xylan. It has been isolated from many microorganisms, and its enzymatic characteristics and thermostability vary between species. In this study, a GH11 enzyme PphXyn11 from a novel xylan-degrading strain of Paenibacillus physcomitrellae XB was characterized, and five mutants were constructed to try to improve the enzyme's thermostability. The results showed that PphXyn11 was an acidophilic endo-β-1,4-xylanase with the optimal reaction pH of 3.0-4.0, and it could deconstruct different kinds of xylan substrates efficiently, such as beechwood xylan, wheat arabinoxylan and xylo-oligosaccharides, to produce xylobiose and xylotriose as the main products at the optimal reaction temperature of 40 °C. Improvement of the thermal stability of PphXyn11 using site-directed mutagenesis revealed that three mutants, W33C/N47C, S127C/N174C and S49E, designed by adding the disulfide bonds at the N-terminal, C-terminal and increasing the charged residues on the surface of PphXyn11 respectively, could increase the enzymatic activity and thermal stablility significantly and make the optimal reaction temperature reach 50 °C. Molecular dynamics simulations as well as computed the numbers of salt bridges and hydrogen bonds indicated that the protein structures of these three mutants were more stable than the wild type, which provided theoretical support for their improved thermal stability. Certainly, further research is necessary to improve the enzymatic characteristics of PphXyn11 to achieve the bioconversion of hemicellulosic biomass on an applicable scale.
Topics: Paenibacillus; Enzyme Stability; Endo-1,4-beta Xylanases; Bacterial Proteins; Xylans; Hydrogen-Ion Concentration; Mutagenesis, Site-Directed; Recombinant Proteins; Temperature; Substrate Specificity
PubMed: 38583789
DOI: 10.1016/j.pep.2024.106482 -
The Science of the Total Environment Jun 2024Due to the inappropriate disposal of waste materials containing lead (Pb) and irrigation with sewage containing Pb, the migration of Pb within the soil profile has been...
Due to the inappropriate disposal of waste materials containing lead (Pb) and irrigation with sewage containing Pb, the migration of Pb within the soil profile has been extensively investigated. The conventional Pb block method is challenging to implement due to its complex operational procedures and high construction costs. To address this issue, this study introduces the microbial-induced carbonate precipitation (MICP) technique as a novel approach to impede the migration of Pb in the soil profile. Soil acclimatization with urea resulted in an increased proportion of urease-producing microorganisms, including Bacillus, Paenibacillus, and Planococcaceae, along with heightened expression of urea-hydrolyzing genes (UreA, UreB, UreC, and UreG). This indicates that urea-acclimatized soil (Soil-MICP) possesses the potential to induce carbonate precipitation. Batch Pb fixation experiments confirmed that the fixation efficiency of Soil-MICP on Pb exceeded that of soil without MICP, attributed to the MICP process within the Soil-MICP group. Dynamic migration experiments revealed that the MICP reaction transformed exchangeable lead into carbonate-bound Pb, effectively impeding Pb migration in the soil profile. Additionally, the migration rate of Pb in Soil-MICP was influenced by varying urea amounts, pH levels, and pore flow rates, leading to a slowdown in migration. The Two-site sorption model aptly described the Pb migration process in the Soil-MICP column. This study aims to elucidate the MICP biomineralization process, uncover the in-situ blocking mechanism of MICP on lead in soil, investigate the impact of Pb on key genes involved in urease metabolism, enhance the comprehension of the chemical morphology of lead mineralization products, and provide a theoretical foundation for MICP technology in preventing the migration of Pb in soil profiles.
Topics: Lead; Soil Pollutants; Carbonates; Soil Microbiology; Soil; Urease; Chemical Precipitation
PubMed: 38583629
DOI: 10.1016/j.scitotenv.2024.172268