scholarly journals Compost bacteria as potential agents in biological plant control

2021 ◽  
Vol 61 (4) ◽  
pp. 319-326
Keyword(s):  
Pathogenic Fungi ◽  
16S Rrna Gene Sequencing ◽  
Alcaligenes Faecalis ◽  
Diffusion Method ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
Fungistatic Activity ◽  
Activity Spectrum ◽  
Rrna Gene Sequencing

The assumptions of integrated pest management put great emphasis on the development of non-chemical methods which increases the interest in biological methods and the search for microorganisms that would be an alternative to the most frequently used fungicides. The aim of the experiments was the isolation of the compost bacteria, in vitro determination of their fungistatic activity against some pathogenic fungi of the genus Fusarium, Alternaria, Sclerotinia, Botrytis, Rhizoctonia and Pythium and identification of selected isolates. From the backyard compost, 44 bacterial strains were isolated and assessed for the fungistatic properties by the well diffusion method. The obtained results allowed for the selection of 12 isolates of compost bacteria, characterised by the broadest and the strongest fungistatic activity spectrum against tested fungi. Identification of bacterial isolates by: MALDI-TOF mass spectrometry and 16S rRNA gene sequencing methods showed their belonging to the species Bacillus subtilis, Alcaligenes faecalis, Stenotrophomonas maltophilia and Serratia liquefaciens.

scholarly journals Identification and control of endophytic bacteria during in vitro cultures of Staphylea pinnata L.

2020 ◽  
Vol 32 (1) ◽  
pp. 47-55
Author(s):  
Bożena Szewczyk-Taranek ◽  
Anita Jaglarz ◽  
Piotr Pałka ◽  
Paulina Supel ◽  
Paweł Kaszycki ◽  
...  
Keyword(s):  
16S Rrna Gene Sequencing ◽  
Identification System ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
Axillary Shoots ◽  
Gram Staining ◽  
Agar Disc ◽  
The Media ◽  
Rrna Gene Sequencing

AbstractThis study focused on the identification and elimination of endophytic bacterial contaminations during in vitro propagation of European bladdernut (Staphylea pinnata). Axillary shoots were propagated on Murashige and Skoog medium with 20 mg ∙ dm−3 FeEDDHA, 5 μM BA and 0.5 μM NAA at 20/18°C (day/night) and a 16-h photoperiod. Clouding by endophytic bacterial colonies was observed where shoots contacted the media. Bacteria were isolated and separated by repeated streaking as two strains. Gram staining revealed that both strains were Gram-negative. The colonies were very precisely identified as Acinetobacter johnsonii, strain ATCC 17909, and Methylobacterium rhodesianum, strain DSM 5687, using VITEK®2—a rapid bacterial identification system—and the 16S rRNA gene sequencing method. The agar disc-diffusion test proved that both bacterial strains were susceptible to 13 antibiotics (out of 25 tested), derived from the groups of fluoroquinolones, aminoglycosides and tetracyclines. Doxycycline or gentamicin (100–300 mg ∙ dm−3) was added to the S. pinnata shoot propagation medium to eliminate bacteria. Gentamicin 100 mg ∙ dm−3 showed the best effect, inhibiting the growth of endogenous bacteria (63%) when applied in the medium for 4 weeks. After the following transfer to media without antibiotics, shoots developed axillary buds and bacterial colonies were not observed.

scholarly journals Antifouling activities of extracellular polymeric substances produced by marine bacteria associated with the gastropod (Babylonia sp.)

2018 ◽  
Vol 17 (2) ◽  
pp. 115-124 ◽  
Author(s):  
Nadarajan Viju ◽  
Nagarajan Ezhilraj ◽  
Chellamnadar Vaikundavasagom Sunjai Shankar ◽  
Stanislaus Mary Josephine Punitha ◽  
Sathianeson Satheesh
Keyword(s):  
Extracellular Polymeric Substances ◽  
16S Rrna Gene Sequencing ◽  
Bioactive Metabolites ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
Ft Ir ◽  
Rrna Gene Sequencing

AbstractBacteria associated with surfaces have been frequently cited as a potential source for the isolation of bioactive metabolites. In this study, bacteria associated with marine gastropod, Babylonia sp. were isolated and screened for antibacterial activity against biofilm-forming bacteria. The antibiofilm and antifouling effect of the selected surface- associated bacterial strains were examined under in vitro and in vivo conditions. Results showed that the extracellular polymeric substances (EPS) of the bacterial strain CML associated with gastropod species considerably reduced the adhesion of biofilm-forming bacteria on glass coupons. Besides, the antifouling coat prepared by incorporating of this EPS into polyurethane varnish prevented the settlement of biofoulers on test substratum submerged in marine waters. The functional groups present in the EPS were analyzed using FT-IR. The bacterium responsible for the production of the bioactive EPS was identified as Bacillus subtilis subsp. by 16S rRNA gene sequencing. More detailed characterization of the identified bioactive EPS could lead to the isolation of a novel natural antifouling product.

scholarly journals The growth response of rice (Oryza sativa L. var. FARO 44) in vitro after inoculation with bacterial isolates from a typical ferruginous ultisol

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Musa Saheed Ibrahim ◽  
Beckley Ikhajiagbe
Keyword(s):  
16S Rrna ◽  
Bacillus Cereus ◽  
Proteus Mirabilis ◽  
Growth Response ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Rice Seedlings ◽  
Rrna Gene Sequencing

Abstract Background Rice forms a significant portion of food consumed in most household worldwide. Rice production has been hampered by soil factors such as ferruginousity which has limited phosphorus availability; an important mineral component for the growth and yield of rice. The presence of phosphate-solubilizing bacteria (PSB) in soils has been reported to enhance phosphate availability. In view of this, the present study employed three bacteria species (BCAC2, EMBF2 and BCAF1) that were previously isolated and proved P solubilization capacities as inocula to investigate the growth response of rice germinants in an in vitro setup. The bacteria isolates were first identified using 16S rRNA gene sequencing and then applied as inoculum. The inolula were prepared in three concentrations (10, 7.5 and 5.0 ml) following McFarland standard. Viable rice (var. FARO 44) seeds were sown in petri dishes and then inoculated with the three inocula at the different concentrations. The setup was studied for 28 days. Results 16S rRNA gene sequencing identified the isolates as: isolate BCAC2= Bacillus cereus strain GGBSU-1, isolate BCAF1= Proteus mirabilis strain TL14-1 and isolate EMBF2= Klebsiella variicola strain AUH-KAM-9. Significant improvement in rice germination, morphology, physiology and biomass parameters in the bacteria-inoculated setups was observed compared to the control. Germination percentage after 4 days was 100 % in the inoculated rice germinants compared to 65% in the control (NiS). Similarly, inoculation with the test isolates enhanced water-use efficiency by over 40%. The rice seedlings inoculated with Bacillus cereus strain GGBSU-1 (BiS) showed no signs of chlorosis and necrosis throughout the study period as against those inoculated with Proteus mirabilis strain TL14-1 (PiS) and Klebsiella variicola strain AUH-KAM-9 (KiS). Significant increase in chlorophyll-a, chlorophyll-b and alpha amylase was observed in the rice seedlings inoculated with BiS as against the NiS. Conclusion Inoculating rice seeds with Bacillus cereus strain GGBSU-1, Proteus mirabilis strain TL14-1 and Klebsiella variicola strain AUH-KAM-9 in an in vitro media significantly improved growth parameters of the test plant. Bacillus cereus strain GGBSU-1 showed higher efficiency due to a more improved growth properties observed.

scholarly journals Identification and Genomic Characterization of Pathogenic Bacillus altitudinis from Common Pear Trees in Morocco

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1344
Author(s):  
Naima Lemjiber ◽  
Khalid Naamani ◽  
Annabelle Merieau ◽  
Abdelhi Dihazi ◽  
Nawal Zhar ◽  
...  
Keyword(s):  
16S Rrna Gene Sequencing ◽  
Genomic Islands ◽  
Rrna Gene ◽  
In Planta ◽  
Bacterial Strains ◽  
Bacillus Altitudinis ◽  
Genes Encoding ◽  
Bacillus Spp ◽  
Pear Trees ◽  
Rrna Gene Sequencing

Bacterial burn is one of the major diseases affecting pear trees worldwide, with serious impacts on producers and economy. In Morocco, several pear trees (Pyrus communis) have shown leaf burns since 2015. To characterize the causal agent of this disease, we isolated fourteen bacterial strains from different parts of symptomatic pear trees (leaves, shoots, fruits and flowers) that were tested in planta for their pathogenicity on Louise bonne and Williams cultivars. The results showed necrotic lesions with a significant severity range from 47.63 to 57.77% on leaves of the Louise bonne cultivar inoculated with isolate B10, while the other bacterial isolates did not induce any disease symptom. 16S rRNA gene sequencing did not allow robust taxonomic discrimination of the incriminated isolate. Thus, we conducted whole-genome sequencing (WGS) and phylogenetic analyzes based on gyrA, gyrB and cdaA gene sequences, indicating that this isolate belongs to the Bacillus altitudinis species. This taxonomic classification was further confirmed by the Average Nucleotide Identity (ANI) and the in silico DNA-DNA hybridization (isDDH) analyzes compared to sixty-five Bacillus spp. type strains. The genome was mined for genes encoding carbohydrate-active enzymes (CAZymes) known to play a role in the vegetal tissue degradation. 177 candidates with functions that may support the in planta phytopathogenicity results were identified. To the best of our knowledge, this is the first data reporting B. altitudinis as agent of leaf burn in P. communis in Morocco. Our dataset will improve our knowledge on spread and pathogenicity of B. altitudinis genotypes that appears as emergent phytopathogenic agent, unveiling virulence factors and their genomic location (i.e., within genomic islands or the accessory genome) to induce trees disease.

scholarly journals Evaluation of Commercial Disinfectants against Staphylococcus lentus and Micrococcus spp. of Poultry Origin

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Otun Saha ◽  
Nadira Naznin Rakhi ◽  
Arif Istiaq ◽  
Israt Islam ◽  
Munawar Sultana ◽  
...  
Keyword(s):  
Micrococcus Luteus ◽  
Bacterial Species ◽  
16S Rrna Gene Sequencing ◽  
Average Diameter ◽  
Diffusion Method ◽  
Dilution Method ◽  
Rrna Gene ◽  
Poultry Farms ◽  
Rrna Gene Sequencing ◽  
Selection Of

Introduction. Effective sanitation strategies for poultry farms require an appropriate selection of the disinfectant based on the contaminants present and their sensitivity to the disinfectants. Aim. The current study investigated the prevalence of streptococci/micrococci in poultry farms of Bangladesh and the efficacy of commercial disinfectants (Savlon, Lysol, Quatovet, Virkon S, and Virocid) along with alcohol against these pathogens to adopt appropriate strategies. Materials and Methods. Conventional approaches and the 16S rRNA gene sequencing were performed to confirm the isolates at the species level along with microtiter biofilm assay to determine their biofilm-forming ability. Efficacy of the disinfectants was tested against those isolates using agar well diffusion and minimum inhibitory concentration (MIC) test by broth dilution method using different dilutions of the disinfectants. Results. Staphylococcus lentus (n = 32), Micrococcus luteus (n = 7), and Micrococcus aloeverae (n = 4) were confirmed among 102 presumptively screened streptococci/micrococci isolates from 43 samples. No single disinfectant showed equally high efficacy against all three bacterial species in agar well diffusion test, although Virocid showed the lowest MIC against all three of them. Lysol was least effective among the commercial disinfectants by both MIC and diffusion method, although each commercial disinfectant was more effective than alcohol. Considering both the average diameter of the inhibition zones and the MIC values, efficacy can be interpreted as Virocid > Quatovet > Savlon > Virkon S > Lysol. Although the efficacy decreased with decreasing concentration, the disinfectants retained a satisfactory level of efficacy at 50% concentration. Among test pathogens, M. aloeverae was the most sensitive to the disinfectants and the weakest biofilm producers, whereas 4/14 S. lentus and 1/5 M. luteus were strong biofilm producers, which may cause more reduction in the efficacy in environmental conditions. Conclusion. As no ideal disinfectant was found in the study, the efficacy of the disinfectants should be routinely evaluated and validated to ensure the sanitation standards in the poultry sector.

scholarly journals Live Bacillus subtilis natto Promotes Rumen Fermentation by Modulating Rumen Microbiota In Vitro

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1519
Author(s):  
Meinan Chang ◽  
Fengtao Ma ◽  
Jingya Wei ◽  
Junhao Liu ◽  
Xuemei Nan ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
16S Rrna ◽  
Rumen Fluid ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Rumen Fermentation ◽  
Rrna Gene ◽  
Bacillus Subtilis Natto ◽  
Rrna Gene Sequencing

Previous studies have shown that Bacillus subtilis natto affects rumen fermentation and rumen microbial community structure, which are limited to detect a few microbial abundances using traditional methods. However, the regulation of B. subtilis natto on rumen microorganisms and the mechanisms of microbiota that affect rumen fermentation is still unclear. This study explored the effects of live and autoclaved B. subtilis natto on ruminal microbial composition and diversity in vitro using 16S rRNA gene sequencing and the underlying mechanisms. Rumen fluid was collected, allocated to thirty-six bottles, and divided into three treatments: CTR, blank control group without B. subtilis natto; LBS, CTR with 109 cfu of live B. subtilis natto; and ABS, CTR with 109 cfu of autoclaved B. subtilis natto. The rumen fluid was collected after 0, 6, 12, and 24 h of fermentation, and pH, ammonia nitrogen (NH3-N), microbial protein (MCP), and volatile fatty acids (VFAs) were determined. The diversity and composition of rumen microbiota were assessed by 16S rRNA gene sequencing. The results revealed LBS affected the concentrations of NH3-N, MCP, and VFAs (p < 0.05), especially after 12 h, which might be attributed to changes in 18 genera. Whereas ABS only enhanced pH and NH3-N concentration compared with the CTR group (p < 0.05), which might be associated with changes in six genera. Supplementation with live B. subtilis natto improved ruminal NH3-N and propionate concentrations, indicating that live bacteria were better than autoclaved ones. This study advances our understanding of B. subtilis natto in promoting ruminal fermentation, providing a new perspective for the precise utilization of B. subtilis natto in dairy rations.

scholarly journals Xylanolytic Psychotrophs From Andosolic Sedge Fens and Moss Heaths in Iceland

Fine Focus ◽  
2018 ◽  
Vol 4 (2) ◽  
pp. 171-186
Author(s):  
Olivia J. Rickman ◽  
M. Auður Sigurbjörnsdóttir ◽  
Oddur Vilhemsson
Keyword(s):  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
Cold Environments ◽  
Specific Pcr ◽  
Xylanolytic Activity ◽  
Cold Active ◽  
Rrna Gene Sequencing ◽  
Stenotrophomonas Rhizophila

Nine xylanolytic bacterial strains were isolated from fen and heath soils in northern Iceland. They were found by 16S rRNA gene sequencing to belong to the genera Paenibacillus, Bacillus, Pseudomonas, and Stenotrophomonas. Using a simple, plate-based semiquantitative assay with azo-crosslinked xylan as the substrate, it was determined that although isolated from cold environments, most of the strains displayed greater xylanolytic activity under mesophilic conditions, with only the paenibacilli displaying markedly cold-active xylanolytic activity. Indeed, for one isolate, Paenibacillus castaneae OV2122, xylanolytic activity was only detected at 15°C and below under the conditions tested. Of the nine strains, Paenibacillus amylolyticus OV2121 displayed the greatest activity at 5°C. Glycohydrolase family-specific PCR indicated that the paenibacilli produced multiple xylanases of families 10 and 11, whereas a family 8 xylanase was detected in Pseudomonas kilonensis AL1515, and a family 11 xylanase in Stenotrophomonas rhizophila AL1610.

Mechanism of boron tolerance in soil bacteria

2010 ◽  
Vol 56 (1) ◽  
pp. 22-26 ◽  
Author(s):  
Iftikhar Ahmed ◽  
Toru Fujiwara
Keyword(s):  
Soil Bacteria ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Soil Samples ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
Tolerance Mechanisms ◽  
Boron Tolerance ◽  
Rrna Gene Sequencing ◽  
Comparative Phylogenetic Analysis

Boron (B) is toxic to living cells at levels above a certain threshold. We isolated several B-tolerant bacterial strains from soil samples and studied them for possible mechanisms of B tolerance. 16S rRNA gene sequencing and comparative phylogenetic analysis demonstrated that the isolates belong to the following 6 genera: Arthrobacter , Rhodococcus , Lysinibacillus , Algoriphagus , Gracilibacillus , and Bacillus . These isolates exhibited B-tolerance levels of 80, 100, 150, 300, 450, and 450 mmol/L, respectively, whilst maintaining a significantly lower intracellular B concentration than in the medium. Statistical analysis showed a negative correlation between the protoplasmic B concentration and the degree of tolerance to a high external B concentration. The kinetic assays suggest that the high B efflux and (or) exclusion are the tolerance mechanisms against a high external B concentration in the isolated bacteria.

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