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BMC Microbiology Aug 2021In unfavourable environment, such as nutrient limitation, some bacteria encased themselves into a three dimensional polymer matrix called biofilm. The majority of...
BACKGROUND
In unfavourable environment, such as nutrient limitation, some bacteria encased themselves into a three dimensional polymer matrix called biofilm. The majority of microbial infections in human are biofilm related, including chronic lung, wound, and ear infections. The matrix of biofilm which consists of extracellular polymeric substances (EPS) causes bacterial colonization on medical implanted device in patients, such as catheter and lead to patient's death. Biofilm infections are harder to treat due to increasing antibiotic resistance compared to planktonic microbial cells and escalating the antibiotic concentration may result into in vivo toxicity for the patients. Special compounds which are non-microbicidal that could inhibit or destroy biofilm formation are called antibiofilm compounds, for example enzymes, anti-quorum sensing, and anti-adhesins. Arthrobacter sp. CW01 produced antibiofilm compound known as amylase. This time our preliminary study proved that the antibiofilm compound was not only amylase, but also protease. Therefore, this research aimed to optimize the production of antibiofilm agents using amylase and protease inducing media. The five types of production media used in this research were brain heart infusion (BHI) (Oxoid), BHI with starch (BHIS), casein with starch (CS), yeast extract with starch (YS), and casein-yeast extract with starch (CYS). Biofilm eradication and inhibition activities were assayed against Pseudomonas aeruginosa (ATCC 27,853) and Staphylococcus aureus (ATCC 25,923).
RESULTS
The results showed that different production media influenced the antibiofilm activity. Addition of starch, casein and yeast extract increased the production of amylase and protease significantly. Higher amylase activity would gradually increase the antibiofilm activity until it reached the certain optimum point. It was shown that crude extracts which contained amylase only (BHI, BHIS and YS) had the optimum eradication activity against P. aeruginosa and S. aureus biofilm around 60-70 %. Meanwhile, CS and CYS crude extracts which contained both amylase and protease increased the biofilm eradication activity against both pathogens, which were around 70-90 %.
CONCLUSIONS
It was concluded that the combination of amylase and protease was more effective as antibiofilm agents against P. aeruginosa and S. aureus rather than amylase only.
Topics: Amylases; Anti-Bacterial Agents; Arthrobacter; Biofilms; Caseins; Culture Media; Humans; Microbial Sensitivity Tests; Peptide Hydrolases; Pseudomonas aeruginosa; Staphylococcus aureus; Starch; Yeasts
PubMed: 34425755
DOI: 10.1186/s12866-021-02294-z -
Current Microbiology Jul 2023A study was undertaken to determine the effects of a strain of Arthrobacter sp., a Plant Growth-Promoting Bacteria (PGPB), on plant phenology and qualitative composition...
A study was undertaken to determine the effects of a strain of Arthrobacter sp., a Plant Growth-Promoting Bacteria (PGPB), on plant phenology and qualitative composition of Opuntia ficus-indica (L.) Mill. fruits and cladodes. The strain was inoculated in soil, and its effects on cactus pear plants were detected and compared to nontreated plants. Compared to the latter, the treatment with bacteria promoted an earlier plant sprouting (2 months before the control) and fruitification, ameliorating fruit quality (i.e., improved fresh and dry weight: + 24% and + 26%, respectively, increased total solid content by 30% and polyphenols concentrations by 22%). The quality and quantity of monosaccharides of cladodes were also increased by Arthrobacter sp. with a positive effect on their nutraceutical value. In summer, the mean values of xylose, arabinose, and mannose were significantly higher in treated compared to not treated plants (+ 3.54; + 7.04; + 4.76 mg/kg d.w. respectively). A similar trend was observed in autumn, when the cladodes of inoculated plants had higher contents, i.e., 33% xylose, 65% arabinose, and 40% mannose, respect to the controls. In conclusion, Arthrobacter sp. plays a role in the improvement of nutritional and nutraceutical properties of cactus pear plants due to its capabilities to promote plant growth. Therefore, these results open new perspectives in PGPB application in the agro-farming system as alternative strategy to improve cactus pear growth, yield, and cladodes quality, being the latter the main by-product to be utilized for additional industrial uses.
Topics: Fruit; Opuntia; Arthrobacter; Mannose; Arabinose; Xylose; Dietary Supplements
PubMed: 37400738
DOI: 10.1007/s00284-023-03368-z -
Frontiers in Microbiology 2023Microbial colonization represents one of the main threats to the conservation of subterranean cultural heritage sites. Recently, the microbial colonization on murals in...
BACKGROUND
Microbial colonization represents one of the main threats to the conservation of subterranean cultural heritage sites. Recently, the microbial colonization on murals in tombs has gradually attracted attention.
METHODS
In this study, a total of 33 samples, including 27 aerosol samples and 6 mural painting samples, were collected from different sites of Xu Xianxiu's Tomb and analyzed using culture-dependent methods. We compared the diversities of culturable bacteria and fungi isolated from the air and murals and explored the potential impacts of microorganisms on the biodeterioration of the murals.
RESULTS
Phylogenetic analyses revealed that the culturable bacteria belonged to Bacillus, Microbacterium, Lysobacter and Arthrobacter. And the most of fungal belonged to the Penicillium, Cladosporium and Aspergillus genera. The composition and structure of airborne bacteria and fungi outside the tomb were both significantly different from that inside the tomb. The variation trends of airborne bacterial and fungal concentrations at different sampling sites were remarkably similar. Bacillus frigoritolerans, Bacillus halotolerans, Bacillus safensis, Exiguobacterium mexicanum, Microbacterium trichothecenolyticum, and Micrococcus yunnanensis were bacterial species commonly isolated from both the mural and air environments. Fungal species commonly isolated from aerosol samples and mural painting samples were Alternaria alternata, Cladosporium cladosporioides, Penicillium brevicompactum, and Peyronellaea glomerata. The prediction of the ecological functions of the bacteria revealed that chemoheterotrophy or aerobic_chemoheterotrophy accounted for substantial relative proportions in all sample types.
CONCLUSION
These results suggest that the aerosol circulation between the inside and outside environments of the tomb was weak and that the outside environment had yet to have an impact on the air microbial community inside the tomb. Selective colonization of microorganisms, which is mediated by interaction between microorganisms and special microenvironmental factors, is an important reason for the biodeterioration of murals.
PubMed: 37954248
DOI: 10.3389/fmicb.2023.1253461 -
Frontiers in Microbiology 2023The HSE-12 strain isolated from peanut rhizosphere soil was identified as by observation of phenotypic characteristics, physiological and biochemical tests, 16S rDNA...
The HSE-12 strain isolated from peanut rhizosphere soil was identified as by observation of phenotypic characteristics, physiological and biochemical tests, 16S rDNA and gyrB gene sequencing. experiments showed that the strain possessed biocontrol activity against a variety of pathogens including . The strain has the ability to produce hydrolytic enzymes, as well as volatile organic compounds with antagonistic and probiotic effects such as ethyleneglycol and 2,3-butanediol. In addition, HSE-12 showed potassium solubilizing (10.54 ± 0.19 mg/L), phosphorus solubilization (168.34 ± 8.06 mg/L) and nitrogen fixation (17.35 ± 2.34 mg/g) abilities, and was able to secrete siderophores [(Ar-A)/Ar × 100%: 56%] which promoted plant growth. After inoculating peanut with HSE-12, the available phosphorus content in rhizosphere soil increased by 27%, urease activity increased by 43%, catalase activity increased by 70% and sucrase activity increased by 50% ( < 0.05). The dry weight, fresh weight and the height of the first pair of lateral branches of peanuts increased by 24.7, 41.9, and 36.4%, respectively, compared with uninoculated peanuts. In addition, compared with the blank control, it increased the diversity and richness of peanut rhizosphere bacteria and changed the community structure of bacteria and fungi. The relative abundance of beneficial microorganisms such as , , , and in rhizosphere soil was increased, while the relative abundance of pathogenic microorganisms such as , , and was decreased.
PubMed: 37901825
DOI: 10.3389/fmicb.2023.1274346 -
Molecules (Basel, Switzerland) Jul 2022Incubation of , , and MPI764 with the microbial 2-benzoxazolinone (BOA)-degradation-product -acetamido-phenol, produced from 2-aminophenol, led to the recently...
Incubation of , , and MPI764 with the microbial 2-benzoxazolinone (BOA)-degradation-product -acetamido-phenol, produced from 2-aminophenol, led to the recently identified -(2-hydroxy-5-nitrophenyl) acetamide, to the hitherto unknown (2-hydroxy-5-nitrosophenyl)acetamide, and to (2-hydroxy-3-nitrophenyl)acetamide. As an alternative to the formation of phenoxazinone derived from aminophenol, dimers- and trimers-transformation products have been found. Identification of the compounds was carried out by LC/HRMS and MS/MS and, for the new structure (2-hydroxy-5-nitrosophenyl)acetamide, additionally by 1D- and 2D-NMR. Incubation of microorganisms, such as the soil bacteria , MPI763, the yeast and and the plants var. L. (kohlrabi) and Col-0, with -(2-hydroxy-5-nitrophenyl) acetamide, led to its glucoside derivative as a prominent detoxification product; in the case of , this was together with the corresponding glucoside succinic acid ester. In contrast, consortium synthesized 2-acetamido-4-nitrophenyl sulfate. 1 mM bioactive -(2-hydroxy-5-nitrophenyl) acetamide elicits alterations in the expression profile of several genes. The most responsive upregulated gene was pathogen-inducible terpene synthase The bioactivity of the compound is rapidly annihilated by glucosylation.
Topics: Acetamides; Acetanilides; Arabidopsis; Glucosides; Nitrates; Pantoea; Tandem Mass Spectrometry
PubMed: 35897961
DOI: 10.3390/molecules27154786 -
Pharmaceutics Aug 2021Urate oxidase derived from has been investigated as a treatment for tumor lysis syndrome, hyperuricemia, and gout. However, its long-term use is limited owing to...
Urate oxidase derived from has been investigated as a treatment for tumor lysis syndrome, hyperuricemia, and gout. However, its long-term use is limited owing to potential immunogenicity, low thermostability, and short circulation time in vivo. Recently, urate oxidase isolated from (AgUox) has been reported to be thermostable and less immunogenic than the -derived urate oxidase. Conjugation of human serum albumin (HSA) to therapeutic proteins has become a promising strategy to prolong circulation time in vivo. To develop a thermostable and long-circulating urate oxidase, we investigated the site-specific conjugation of HSA to AgUox based on site-specific incorporation of a clickable non-natural amino acid (frTet) and an inverse electron demand Diels-Alder reaction. We selected 14 sites for frTet incorporation using the ROSETTA design, a computational stability prediction program, among which AgUox containing frTet at position 196 (Ag12) exhibited enzymatic activity and thermostability comparable to those of wild-type AgUox. Furthermore, Ag12 exhibited a high HSA conjugation yield without compromising the enzymatic activity, generating well-defined HSA-conjugated AgUox (Ag12-HSA). In mice, the serum half-life of Ag12-HSA was approximately 29 h, which was roughly 17-fold longer than that of wild-type AgUox. Altogether, this novel formulated AgUox may hold enhanced therapeutic efficacy for several diseases.
PubMed: 34452259
DOI: 10.3390/pharmaceutics13081298 -
Biotechnologia 2022Phytate-mineralizing bacteria (PMB) with plant growth-promoting activity can be considered as a potential biofertilizer for plant nutrition. PMB catalyzes the conversion...
Phytate-mineralizing bacteria (PMB) with plant growth-promoting activity can be considered as a potential biofertilizer for plant nutrition. PMB catalyzes the conversion of insoluble sugar phosphates, inositols, nucleic acids, phospholipids, nucleotides, phytate, and phytin into soluble forms that can be assimilated by plants. The present study aimed to isolate potential PMB from rhizospheric soils and to study their plant growth-promoting potential for the possible development of a potential phosphobacterium biofertilizer. For this purpose, 34 PMB isolates were isolated that showed potent phytate-mineralizing potential. These isolates were tested for their potential to solubilize tricalcium phosphate (TCP) and for various other plant growth-promoting activities. Significant differences were found among the isolates with regard to phytate mineralization and other plant growth-promoting characteristics. The bacterial isolates biochemically identified as , , , and exhibited high/medium P solubilization, medium/high phytohormone production, and medium/low siderophore and ammonia production. Among all these isolates, isolate A14 ( strain FDAARGOS_7) was the promising isolate with high TCP solubilization, medium phytate mineralization, high enzyme production, medium/high phytohormone production, and medium ammonia production. This strain also showed nitrogen fixation activity, zinc solubilizing potential, potassium solubilization, ACC deaminase production, and catalase production. Hence, it can be concluded that can be the potential candidate for biofertilizer development. Future studies are planned for exploring the role of PMB in biofertilizer formulations.
PubMed: 36606074
DOI: 10.5114/bta.2022.116204 -
Frontiers in Microbiology 2021Cover crops can improve soil biological health and alter the composition of soil microbial communities in agricultural systems. However, the effects of diversified cover...
Cover crops can improve soil biological health and alter the composition of soil microbial communities in agricultural systems. However, the effects of diversified cover crops on soil microbial communities in continuous cropping systems are unclear. Here, using different soil biochemical analysis, quantitative PCR and 16S rRNA amplicon sequencing, we investigated the effects of cover crops, alone or in mixture, on soil physicochemical properties in 2019 and 2020, and soil bacterial communities in 2020 in a continuous pepper cropping system. A field trial was established before pepper planting and eight treatments were included: fallow (no cover crop; CK); three sole cover crop treatments: wheat ( L.; W), faba bean ( L.; B), and wild rocket (; R); and four mixed treatments: wheat + wild rocket (WR), wheat + faba bean (WB), wild rocket + faba bean (RB), and wheat + wild rocket + faba bean (WRB). The pepper yield was increased in the WR and WB in 2019 and 2020, and in the WRB in 2020. Cover crops increased the soil pH, but decreased the concentrations of NH and available phosphorus. Bacterial abundance was increased by cover crop treatments, and community structure was altered in the W, WB, and WRB treatments. Moreover, we found that pH was the key factor associated with the changes in the abundance and structure of the bacterial community. Cover crop treatments altered the bacterial community structure with shifts in the dominant genera, which have plant-growth-promoting and/or pathogen-antagonistic potentials, e.g., increased the abundances of , , and spp. in the W and WRB, and spp. in the WB. Overall, we found that cover crops altered the soil physicochemical properties and bacterial community, and these changes varied with species composition of the cover crops, with wheat and its combination with legumes as most effective treatments. These results suggest that the diversification within cover crops could provide better crop yield stimulatory affects by altering soil biochemical environment.
PubMed: 35046916
DOI: 10.3389/fmicb.2021.789034 -
The ISME Journal Aug 2022Drought is a major abiotic stress limiting agricultural productivity. Previous field-level experiments have demonstrated that drought decreases microbiome diversity in...
Drought is a major abiotic stress limiting agricultural productivity. Previous field-level experiments have demonstrated that drought decreases microbiome diversity in the root and rhizosphere. How these changes ultimately affect plant health remains elusive. Toward this end, we combined reductionist, transitional and ecological approaches, applied to the staple cereal crop sorghum to identify key root-associated microbes that robustly affect drought-stressed plant phenotypes. Fifty-three Arabidopsis-associated bacteria were applied to sorghum seeds and their effect on root growth was monitored. Two Arthrobacter strains caused root growth inhibition (RGI) in Arabidopsis and sorghum. In the context of synthetic communities, Variovorax strains were able to protect plants from Arthrobacter-caused RGI. As a transitional system, high-throughput phenotyping was used to test the synthetic communities. During drought stress, plants colonized by Arthrobacter had reduced growth and leaf water content. Plants colonized by both Arthrobacter and Variovorax performed as well or better than control plants. In parallel, we performed a field trial wherein sorghum was evaluated across drought conditions. By incorporating data on soil properties into the microbiome analysis, we accounted for experimental noise with a novel method and were able to observe the negative correlation between the abundance of Arthrobacter and plant growth. Having validated this approach, we cross-referenced datasets from the high-throughput phenotyping and field experiments and report a list of bacteria with high confidence that positively associated with plant growth under drought stress. In conclusion, a three-tiered experimental system successfully spanned the lab-to-field gap and identified beneficial and deleterious bacterial strains for sorghum under drought.
Topics: Arabidopsis; Bacteria; Droughts; Edible Grain; Microbiota; Plant Roots; Sorghum
PubMed: 35523959
DOI: 10.1038/s41396-022-01245-4 -
Bioresources and Bioprocessing Jul 2023Bacterioruberin and its rare glycosylated derivatives are produced by Arthrobacter agilis as an adaptation strategy to low temperature conditions. The high antioxidant...
Bacterioruberin and its rare glycosylated derivatives are produced by Arthrobacter agilis as an adaptation strategy to low temperature conditions. The high antioxidant properties of bacterioruberin held great promise for different future applications like the pharmaceutical and food industries. Microbial production of bacterioruberin via a cost-effective medium will help increase its commercial availability and industrial use. The presented study aims to optimize the production of the rare C carotenoid bacterioruberin and its derivatives from the psychotrophic bacteria Arthrobacter agilis NP20 strain on a whey-based medium as a cost effective and readily available nutritious substrate. The aim of the study is extended to assess the efficiency of whey treatment in terms of estimating total nitrogen content in treated and untreated whey samples. The significance of medium ingredients on process outcome was first tested individually; then the most promising factors were further optimized using Box Behnken design (BBD). The produced carotenoids were characterized using UV-visible spectroscopy, FTIR spectroscopy, HPLC-DAD chromatography and HPLC-APCI-MS spectrometry. The maximum pigment yield (5.13 mg/L) was achieved after a 72-h incubation period on a core medium composed of 96% sweet whey supplemented with 0.46% MgSO & 0.5% yeast extract and inoculated with 6% (v/v) of a 24 h pre-culture (10 CFU/mL). The cost of the formulated medium was 1.58 $/L compared with 30.1 $/L of Bacto marine broth medium. The extracted carotenoids were identified as bacterioruberin, bis-anhydrobacteriouberin, mono anhydrobacterioruberin, and glycosylated bacterioruberin. The presented work illustrates the possibility of producing bacterioruberin carotenoid from Arthrobacter agilis through a cost-effective and eco-friendly approach using cheese whey-based medium.
PubMed: 38647623
DOI: 10.1186/s40643-023-00662-3