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Frontiers in Bioengineering and... 2022Production of some antimicrobial peptides by bacterial producers is a resource-intensive process, thus, using inexpensive growth media and simplifying antimicrobial...
Production of some antimicrobial peptides by bacterial producers is a resource-intensive process, thus, using inexpensive growth media and simplifying antimicrobial extraction and down-stream processing are highly desirable. Acid whey, a dairy industry waste, is explored as a medium for production of broad-spectrum antimicrobials from selected bacteriocinogenic bacteria. Neutralized and yeast extract-supplemented acid whey was suitable for production of antimicrobials by four tested strains, but OSY-EC was the most prolific antimicrobial producer. Concentrating synthesized antimicrobials during culture incubation using beads of polymeric adsorbent resin, followed by solvent extraction and freeze-drying, resulted in antimicrobials-rich powder (AMRP). Under these conditions, OSY-EC produced paenibacillin, polymyxin E, and fusaricidin, which are active against Gram-positive and Gram-negative bacteria and fungi, respectively. When media containing 2x and 4x minimum inhibitory concentrations of AMRP were inoculated with and , microbial populations decreased by ≥4-log CFU ml in tryptic soy broth and ≥3.5-log CFU ml in milk. The antimicrobial mechanism of action of AMRP solutions was attributed to the disruption of cytoplasmic membrane of indicator strains, and . These findings exemplify promising strategies for valorization of acid whey microbial bioreactions to yield potent antimicrobials.
PubMed: 35646844
DOI: 10.3389/fbioe.2022.869778 -
Biotechnology Reports (Amsterdam,... Jun 2022We report the phenotypic variation in E681 (E681), a plant growth-promoting rhizobacterium (PGPR) isolated from a winter barley root in Korea. Phenotypic variation...
We report the phenotypic variation in E681 (E681), a plant growth-promoting rhizobacterium (PGPR) isolated from a winter barley root in Korea. Phenotypic variation (F-type) occurred when E681 (B-type) was grown in the media, and F-type was generated from B-type. B- and F-types were characterized by their morphological, Biolog, and GC-MIDI analyses. F-type cells altered the original biological capacity of B-type cells on endospore and flagella formation, changes in pH in culture, and carbon utilization. In growth curve analysis, B-type variants recovered bacterial growth as the variation occurred after the decline phase, but F-type variants did not. To determine this cause, we conducted comparative proteome analysis between B- and F-types using two-dimensional gel electrophoresis (2-DE). Of the identified proteins, 47% were involved in glycolysis and other metabolic pathways associated with carbohydrate metabolism. Therefore, our findings provide new knowledge on the mechanism of phenotypic variation and insights into agricultural biotechnology.
PubMed: 35686012
DOI: 10.1016/j.btre.2022.e00719 -
Scientific Reports Sep 2022Pectin is one of the main structural components in fruits and an indigestible fiber made of D-galacturonic acid units with α (1-4) linkage. This study investigates the...
Pectin is one of the main structural components in fruits and an indigestible fiber made of D-galacturonic acid units with α (1-4) linkage. This study investigates the microbial degradation of pectin in apple waste and the production of bioactive compounds. Firstly, pectin-degrading bacteria were isolated and identified, then pectinolytic activity was assessed by DNS. The products were evaluated by TLC and LC-MS-ESI. The antioxidative effects were investigated using DPPH and anti-cancer effects and cytotoxicity were analyzed by MTT and flow cytometry. In this study two new bacterial isolates, Alcaligenes faecalis AGS3 and Paenibacillus polymyxa S4 with the pectinolytic enzyme were introduced. Structure analysis showed that the products of enzymatic degradation include unsaturated mono, di, tri, and penta galacturonic acids with 74% and 69% RSA at 40 mg/mL for A. faecalis and P. polymyxa S4, respectively. The results of anti-tumor properties on MCF-7 cells by MTT assay, for products of AGS3 and S4 at 40 mg/mL after 48 h, showed 7% and 9% survival, respectively. In the flow cytometric assessment, the compounds of AGS3 at 40 mg/mL were 100% lethal in 48 h and regarding S4 isolate caused 98% death. Cytotoxicity evaluation on L-929 cells showed no significant toxicity on living cells.
Topics: Alcaligenes faecalis; Hexuronic Acids; Malus; Paenibacillus; Paenibacillus polymyxa; Pectins; Polygalacturonase
PubMed: 36138114
DOI: 10.1038/s41598-022-20011-2 -
Microorganisms Mar 2023Polymyxin-producing bacteria within the complex have broad-spectrum activities against fungi and bacteria. Their antibacterial activities against soft rot and...
Polymyxin-producing bacteria within the complex have broad-spectrum activities against fungi and bacteria. Their antibacterial activities against soft rot and phytopathogens containing multiple polymyxin-resistant genes were not clear. Here, we selected nine strains within the complex having broad-spectrum antagonistic activities against phytopathogenic fungi and a polymyxin-resistant strain causing stem and root rot disease of sweet potato and did antagonistic assays on nutrient agar and sweet potato tuber slices. These strains within the complex showed clear antagonistic activities against in vitro and in vivo. The most effective antagonistic strain ShX301 showed broad-spectrum antagonistic activities against all the test and strains, completely eliminated from sweet potato seed tubers, and promoted the growth of sweet potato seedlings. Cell-free culture filtrate of ShX301 inhibited growth, swimming motility, and biofilm formation and disrupted plasma membranes, releasing nucleic acids and proteins. Multiple lipopeptides produced by ShX301 may play a major role in the bactericidal and bacteriostatic actions. This study clarifies that the antimicrobial spectrum of polymyxin-producing bacteria within the complex includes the polymyxin-resistant and phytopathogens and strengthens the fact that bacteria within the complex have high probability of being effective biocontrol agents and plant growth promoters.
PubMed: 37110240
DOI: 10.3390/microorganisms11040817 -
Microbial Biotechnology Mar 2024Paenibacillus polymyxa is a non-pathogenic, Gram-positive bacterium endowed with a rich and versatile metabolism. However interesting, this bacterium has been seldom...
Paenibacillus polymyxa is a non-pathogenic, Gram-positive bacterium endowed with a rich and versatile metabolism. However interesting, this bacterium has been seldom used for bioproduction thus far. In this study, we engineered P. polymyxa for isobutanol production, a relevant bulk chemical and next-generation biofuel. A CRISPR-Cas9-based genome editing tool facilitated the chromosomal integration of a synthetic operon to establish isobutanol production. The 2,3-butanediol biosynthesis pathway, leading to the main fermentation product of P. polymyxa, was eliminated. A mutant strain harbouring the synthetic isobutanol operon (kdcA from Lactococcus lactis, and the native ilvC, ilvD and adh genes) produced 1 g L isobutanol under microaerobic conditions. Improving NADPH regeneration by overexpression of the malic enzyme subsequently increased the product titre by 50%. Network-wide proteomics provided insights into responses of P. polymyxa to isobutanol and revealed a significant metabolic shift caused by alcohol production. Glucose-6-phosphate 1-dehydrogenase, the key enzyme in the pentose phosphate pathway, was identified as a bottleneck that hindered efficient NADPH regeneration through this pathway. Furthermore, we conducted culture optimization towards cultivating P. polymyxa in a synthetic minimal medium. We identified biotin (B7), pantothenate (B5) and folate (B9) to be mutual essential vitamins for P. polymyxa. Our rational metabolic engineering of P. polymyxa for the production of a heterologous chemical sheds light on the metabolism of this bacterium towards further biotechnological exploitation.
Topics: Paenibacillus polymyxa; Carbon; NADP; Oxidation-Reduction; Paenibacillus; Metabolic Engineering; Butanols
PubMed: 38529712
DOI: 10.1111/1751-7915.14438 -
Microbiological Research Jul 2021The diseases caused by phytopathogens account for huge economic losses in the agricultural sector. Paenibacillus polymyxa is one of the agriculturally important...
The diseases caused by phytopathogens account for huge economic losses in the agricultural sector. Paenibacillus polymyxa is one of the agriculturally important biocontrol agents and plant growth promoting bacterium. This study describes the antifungal potential of P. polymyxa HK4 against an array of fungal phytopathogens and its ability to stimulate seed germination of cumin and groundnut under in vitro conditions. The cumin and groundnut seeds bacterized with HK4 exhibited enhanced germination efficiency in comparison to controls. The use of HK4 as a soil inoculant significantly promoted the shoot length and fresh weight of groundnut plants in pot studies. The draft genome analysis of HK4 revealed the genetic attributes for motility, root colonization, antagonism, phosphate solubilization, siderophore production and production of volatile organic compounds. The bacterium HK4 harnessed several hydrolytic enzymes that may assist its competence in the rhizosphere. The PCR amplification and sequence analysis of the conserved region of the fusA gene amplicon revealed the ability of HK4 to produce fusaricidin. Furthermore, the LC-ESI-MS/MS of crude cell pellet extract of HK4 confirmed the presence of fusaricidin as a major antifungal metabolite. This study demonstrated the potential of HK4 as a biocontrol agent and a plant growth promoter.
Topics: Antifungal Agents; Bacterial Proteins; Crop Protection; Cuminum; Depsipeptides; Fungi; Genome, Bacterial; Genomics; Mass Spectrometry; Paenibacillus polymyxa; Phylogeny; Plant Diseases; Plant Roots; Plant Shoots
PubMed: 33690069
DOI: 10.1016/j.micres.2021.126734 -
BMC Genomics Feb 2023Paenibacillus polymyxa WLY78 is a Gram-positive, endospore-forming and N-fixing bacterium. Our previous study has demonstrated that GlnR acts as both an activator and a...
BACKGROUND
Paenibacillus polymyxa WLY78 is a Gram-positive, endospore-forming and N-fixing bacterium. Our previous study has demonstrated that GlnR acts as both an activator and a repressor to regulate the transcription of the nif (nitrogen fixation) operon (nifBHDKENXhesAnifV) according to nitrogen availability, which is achieved by binding to the two GlnR-binding sites located in the nif promoter region. However, further study on the GlnR-mediated global regulation in this bacterium is still needed.
RESULTS
In this study, global identification of the genes directly under GlnR control is determined by using chromatin immunoprecipitation-quantitative PCR (ChIP-qPCR) and electrophoretic mobility shift assays (EMSA). Our results reveal that GlnR directly regulates the transcription of 17 genes/operons, including a nif operon, 14 nitrogen metabolism genes/operons (glnRA, amtBglnK, glnA1, glnK1, glnQHMP, nasA, nasD1, nasD2EF, gcvH, ansZ, pucR, oppABC, appABCDF and dppABC) and 2 carbon metabolism genes (ldh3 and maeA1). Except for the glnRA and nif operon, the other 15 genes/operons are newly identified targets of GlnR. Furthermore, genome-wide transcription analyses reveal that GlnR not only directly regulates the expression of these 17 genes/operons, but also indirectly controls the expression of some other genes/operons involved in nitrogen fixation and the metabolisms of nitrogen and carbon.
CONCLUSION
This study provides a GlnR-mediated regulation network of nitrogen fixation and the metabolisms of nitrogen and carbon.
Topics: Paenibacillus polymyxa; Nitrogen; Promoter Regions, Genetic; Bacterial Proteins; Binding Sites; Gene Expression Regulation, Bacterial
PubMed: 36823556
DOI: 10.1186/s12864-023-09147-1 -
3 Biotech Jul 2021Glycosylation is a prominent biological mechanism, affecting the structural and functional diversity of many natural products. In this study, a novel thermostable...
UNLABELLED
Glycosylation is a prominent biological mechanism, affecting the structural and functional diversity of many natural products. In this study, a novel thermostable uridine diphosphate-dependent glycosyltransferase gene PpGT1 was cloned from NJPI29 and recombinantly expressed in WB600. The purified PpGT1 had a molecular weight of 45 kDa, as estimated using SDS-PAGE. The PpGT1 could catalyze the glycosylation of vanillic acid, methyl vanillate, caffeic acid, cinnamic alcohol, and ferulic acid. Moreover, PpGT1 possessed good thermostability and retained 80% of its original activity even after 12 h of incubation at 45 °C. In addition, PpGT1 remained stable within a neutral to alkaline pH range as well as in the presence of metal ions. The synthesis of methyl vanillate 4--β-D-glucoside by purified PpGT1 reached a yield 3.58 mM in a system with pH 8.0, 45 °C, 12 mM UDP-Glc, and 4 mM methyl vanillate. 3D-structure-based amino acid sequence alignments revealed that the catalytic residues and C-terminated PSPG motif were conserved. These unusual properties indicated that PpGT1 is a candidate UGT for valuable natural product industrial applications.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s13205-021-02855-z.
PubMed: 34109099
DOI: 10.1007/s13205-021-02855-z -
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 -
Pathogens (Basel, Switzerland) Nov 2021are efficient producers of potent agents against bacterial and fungal pathogens, which are of great interest both for therapeutic applications in medicine as well as in...
are efficient producers of potent agents against bacterial and fungal pathogens, which are of great interest both for therapeutic applications in medicine as well as in agrobiotechnology. Lipopeptides produced by such organisms play a major role in their potential to inactivate pathogens. In this work we investigated two lipopeptide complexes, the fusaricidins and the polymyxins, produced by strains DSM 32871 and M1 by MALDI-TOF mass spectrometry. The fusaricidins show potent antifungal activities and are distinguished by an unusual variability. For strain DSM 32871 we identified numerous yet unknown variants mass spectrometrically. DSM 32871 produces polymyxins of type E (colistins), while M1 forms polymyxins P. For both strains, novel but not yet completely characterized polymyxin species were detected, which possibly are glycosylated. These compounds may be of interest therapeutically, because polymyxins have gained increasing attention as last-resort antibiotics against multiresistant pathogenic Gram-negative bacteria. In addition, the volatilomes of DSM 32781 and M1 were investigated with a GC-MS approach using different cultivation media. Production of volatile organic compounds (VOCs) was strain and medium dependent. In particular, strain M1 manifested as an efficient VOC-producer that exhibited formation of 25 volatiles in total. A characteristic feature of is the formation of volatile pyrazine derivatives.
PubMed: 34832640
DOI: 10.3390/pathogens10111485