1.Impact of Bacillus thuringiensis on inhibiting certain Alternaria alternata’s mycotoxins isolated from infected potatoes
Nesrine Hassan Youssef ; Mayada Ali Sabra
Malaysian Journal of Microbiology 2022;18(2):163-169
Aims:
Potatoes are considered one of the most strategic vegetable crops all over the world. Alternaria alternata has recently contaminated certain potatoes farms in different regions in Egypt. Among thirteen samples from fifteen regions were studied in a precedent study. Our study was aimed to investigate the effect of Bacillus thuringiensis subsp. Kurosaki suspension on inhibiting the growth of the three tested isolates of A. alternata and minimizing their mycotoxins production in vitro using three isolates with three levels of highly, moderate and low pathogenicity with unequal amounts of dual mycotoxins production.
Methodology and results:
Three isolates of A. alternata from three regions, Kom Hamada (KH3), Alamin (Alam1) and Nobaria (NO3), which were determined as a producer of tenuazonic acid (TeA) and alternariol monomethyl ether (AME) toxins. Bacillus thuringiensis (Bt) use as commercial fungicide was applied with three suspension concentrations (75, 150 and 300 μg/mL) as inhibitor for the two mycotoxins. Our results illustrated that the three tested isolates recorded high TeA and AME inhibition efficacies by increasing the Bt suspension concentration. The highest inhibitory concentration of Bt was at concentration 75 μg/mL for isolated from Nobaria third region (NO3) and Alam1 it was (99.83 and 99.74%) for mycotoxin (AME) while, TeA mycotoxin had the most inhibition percentage (99.58%) at concentration 150 μg/mL for the isolate (NO3).
Conclusion, significance and impact of study
The preliminary results of the study suggest that B. thuringiensis spores’ suspension with different concentrations can be used as anti-mycotoxigenic agents to inhibit the (TeA) and (AME) mycotoxins produced by Alternaria alternata.
Bacillus thuringiensis
;
Alternaria--isolation &
;
purification
;
Solanum tuberosum
2.Bacillus thuringiensis isolated from soil in oil palm plantation with high toxicity against Oryctes rhinoceros larvae
Flatya Indah Anggraini ; Maria Sugiharti ; Antonius Suwanto ; Nisa Rachmania ; Bibiana Widiawati Lay
Malaysian Journal of Microbiology 2021;17(4):345-351
Aims:
Oryctes rhinoceros beetle is one of the most damaging pests of oil palm and cause high oil palm mortality. The
empty fruit bunch mulch and rotten old trunk of oil palm in the field provide the organic matter for the breeding sites and
increases the number of O. rhinoceros larvae. Bacillus thuringiensis as bioinsecticide can synthesize crystal proteins
toxic to the larvae. The present study was aimed to find effective B. thuringiensis isolates as biopesticide against O.
rhinoceros larvae.
Methodology and results:
Screening process was carried out through heating of soil sample suspension at 80 °C to
eliminate the non-spore formers and plated onto T3 medium. Colony morphology was observed, followed by Gram and
endospore staining. The crystal protein was observed by Coomassie Brilliant Blue (CBB) staining. Bioassay test was
conducted by force-feed method followed by food contamination method. The results showed isolates SBB33 and
SBB35 were able to infect and caused high mortality to the O. rhinoceros larvae. Isolates SBB33 and SBB35 showed
the highest mortality against 1st instar larvae (94.44% and 75% respectively) and 3rd instar larvae (64.8% and 60%
respectively) compared to control treatments. The 16S rRNA gene sequencing showed SBB33 has high similarity with B.
thuringiensis strain 3S2-3, while SBB35 has high similarity with B. thuringiensis strain GCU_BTi10. Protein separation of
the spore-crystal mixture by SDS-PAGE showed the prominence of 66 kDa protein band that was predicted to be Cry
toxins which is specific to coleopterans insect.
Conclusion, significance and impact of study
Bacillus thuringiensis isolates SBB33 and SBB35 have high potential
as biopesticides against O. rhinoceros larvae and could be used to control major pests in oil palm plantation.
Bacillus thuringiensis--isolation &
;
purification
;
Coleoptera
3.Identification of endophytic bacteria BZJN1 and research on biological control of root rot of Atractylodes macrocephala.
Jing-Mao YOU ; Kun XIONG ; Sen MU ; Jie GUO ; Xiao-Liang GUO ; Yuan-Yuan DUAN ; Juan LI ; Fan CAO ; Zong-Cheng ZOU ; Hai TAN
China Journal of Chinese Materia Medica 2018;43(3):478-483
In this study, an endophytic bacteria strain BZJN1 was isolated from Atractylodes macrocephala, and identified as Bacillus subtilis by physiological and biochemical tests and molecular identification. Strain BZJN1 could inhibit the growth of mycelia of Ceratobasidium sp. significantly, and the inhibition rate was more than 70%. The mycelium growth deformity with bulge as spherical and partially exhaustible in apex or central with microscopic observation. The inhibitory rates under 3% and 6% concentrations of the cell free fermentation were 22.7% and 38.7% expectively. The field test proved that the control efficacy of treatment of 1×10⁸ cfu·mL⁻¹ is 75.27% and 72.37% after 10 and 20 days. All the treatments of strain BZJN1 was able to promote the growth of A. macrocephala, the treatment of 1×10⁸ cfu·mL⁻¹ could able to increase the yield to 14.1%.
Atractylodes
;
microbiology
;
Bacillus subtilis
;
physiology
;
Basidiomycota
;
pathogenicity
;
Biological Control Agents
;
Endophytes
;
classification
;
isolation & purification
;
Plant Diseases
;
microbiology
;
prevention & control
4.Optimization of Pulsed-field Gel Electrophoresis Procedure for Bacillus cereus.
Hui Juan ZHANG ; Zhuo PAN ; Jian Chun WEI ; En Min ZHANG ; Hong CAI ; Xu Dong LIANG ; Wei LI ;
Biomedical and Environmental Sciences 2016;29(3):233-237
In order to develop a rapid and reliable method for B. cereus genotyping, factors influencing PFGE results, including preparation of bacterial cells embedded in agarose, lysis of embedded cells, enzymatic digestion of intact genomic DNA, and electrophoresis parameters allowing for reproducible and meaningful DNA fragment separation, were controlled. Optimal cellular growth (Luria-Bertani agar plates for 12-18 h) and lysis conditions (4 h incubation with 500 µg/mL lysozyme) produced sharp bands on the gel. Restriction enzyme NotI was chosen as the most suitable. Twenty-two isolates were analyzed by NotI digestion, using three electrophoretic parameters (EPs). The EP-a was optimal for distinguishing between isolates. The optimized protocol could be completed within 40 h which is a significant improvement over the previous methods.
Bacillus cereus
;
genetics
;
isolation & purification
;
Bacteriological Techniques
;
DNA, Bacterial
;
chemistry
;
genetics
;
Electrophoresis, Gel, Pulsed-Field
;
methods
5.Two novel antimicrobial peptides from skin venoms of spadefoot toad Megophrys minor.
Hong-Ling YANG ; Zhi-Qiang SHEN ; Xuan LIU ; Yi KONG
Chinese Journal of Natural Medicines (English Ed.) 2016;14(4):294-298
Amphibian skin contains rich bioactive peptides. Especially, a large amount of antimicrobial peptides have been identified from amphibian skin secretions. Antimicrobial peptides display potent cytolytic activities against a range of pathogenic bacteria and fungi and play important defense roles. No antimicrobial peptides have been reported from toads belonging to the family of Pelobatidae. In this work, two novel antimicrobial peptides (Megin 1 and Megin 2) were purified and characterized from the skin venoms of spadefoot toad Megophrys minor (Pelobatidae, Anura, Amphibia). Megin 1 had an amino acid sequence of FLKGCWTKWYSLKPKCPF-NH2, which was composed of 18 amino acid residues and contained an intra-molecular disulfide bridge and an amidated C-terminus. Megin 2 had an amino acid sequence of FFVLKFLLKWAGKVGLEHLACKFKNWC, which was composed of 27 amino acid residues and contained an intra-molecular disulfide bridge. Both Megin 1 and Megin 2 showed potential antimicrobial abilities against bacteria and fungi. The MICs of Megin 1 against Escherichia coli, Bacillus dysenteriae, Staphylococcus aureus, Bacillus subtilis, and Candida albicans were 25, 3, 6.25, 3, and 50 μg·mL(-1), respectively. The corresponding MICs for Megin 2 were 6.25, 1.5, 12.5, 1.5, and 12.5 μg·mL(-1), respectively. They also exerted strong hemolytic activity against human and rabbit red cells. The results suggested that megin peptides in the toad skin of M. minor displayed toxic effects on both eukaryotes and prokaryotes. This was the first report of antimicrobial peptides from amphibians belonging to the family of Pelobatidae.
Amino Acid Sequence
;
Amphibian Venoms
;
chemistry
;
immunology
;
isolation & purification
;
Animals
;
Anura
;
immunology
;
Bacillus
;
Candida albicans
;
Erythrocytes
;
physiology
;
Escherichia coli
;
Female
;
Hemolysis
;
Humans
;
Male
;
Peptides
;
chemistry
;
immunology
;
isolation & purification
;
Rabbits
;
Sequence Alignment
;
Skin
;
chemistry
;
immunology
;
Staphylococcus aureus
6.Colonization characteristics of endophytic bacteria NJ13 in Panax ginseng and its biocontrol efficiency against Alternaria leaf spot of ginseng.
Chang-Qing CHEN ; Tong LI ; Xin-Lian LI ; Yun JIANG ; Lei TIAN ; Peng XU
China Journal of Chinese Materia Medica 2014;39(10):1782-1787
To reveal the colonization characteristics in host of endophytic biocontrol bacteria NJ13 isolated from Panax ginseng, this study obtained the marked strain NJ13-R which was double antibiotic resistant to rifampicin and streptomycin through enhancing the method of inducing antibiotic. The colonization characteristics in ginseng and its biocontrol efficiency against Alternaria spot of ginseng in the field were studied. The results showed that the strain could colonize in root, stem and leaf of ginseng and the colonization amount was positive correlated with inoculation concentration. Meanwhile, the strain could infect and then transfer in different tissues of ginseng The colonization amount of strain in roots and leaves of ginseng increased first and then decreased. However, the tendency of colonization amount of strain in stems was ascend at first and then descend slowly, and was more than that in roots and leaves along with time, which had a preference to specific tissue of its host. In field experiment, the endophytic bacteria NJ13 was proved to be effective in controlling Alternaria leaf spot of ginseng. The biocontrol efficiency of fermentation broth at the concentration of 0.76 x 10(8) cfu x mL(-1) reached 75.62%, which was close to the controlling level (73.06%) of 0.67 mg x L(-1) 50% cyprodinil WG.
Alternaria
;
physiology
;
Antibiosis
;
Bacillus
;
growth & development
;
isolation & purification
;
physiology
;
Endophytes
;
growth & development
;
isolation & purification
;
physiology
;
Panax
;
growth & development
;
microbiology
;
Plant Diseases
;
microbiology
7.Fermentation of Bacillus subtilis ge25 strain and preliminary study on its antagonistic substances.
Chen-Yun HU ; Yong LI ; Min LIU ; Wan-Long DING ; Min-Jian QIN
China Journal of Chinese Materia Medica 2014;39(14):2624-2628
Panax ginseng is one of the most important traditional Chinese herbal medicine, soil borne diseases influenced the yield and quality severely. In our previous work, endophytic Bacillus subtilis ge25 strain was isolated from ginseng root, and which showed significant antagonistic activity against several most destructive ginseng phytopathogens. In the present work, crude protein and lipopeptid extracts were prepared from LB and Landy supernate by salting out, acid precipitation methods respectively. The antagonistic activity of crude extracts and stability to temperature and protease digestion were examined by ginseng phytopathogen Alternaria panax. Results showed that, the antagonistic activity of crude protein extracts from LB culture was complete and partially lost when treated by high temperature and proteinase K. However, crude lipopeptid from Landy culture showed significant stabile antagonistic activity to them. Acid-hydrolyzation and TLC-bioautography analysis showed, that the crude lipopeptide contained at least one cyclic lipopeptide. In consideration of the stability and perfect antagonistic activity of ge25, further researches will promote the biocontrol of ginseng diseases in the field.
Alternaria
;
drug effects
;
physiology
;
Bacillus subtilis
;
metabolism
;
physiology
;
Bacterial Proteins
;
isolation & purification
;
metabolism
;
pharmacology
;
Endopeptidase K
;
metabolism
;
Endophytes
;
metabolism
;
physiology
;
Fermentation
;
Lipopeptides
;
isolation & purification
;
pharmacology
;
Panax
;
microbiology
;
Plant Roots
;
microbiology
;
Temperature
8.Comparative Analysis of Pathogenic Organisms in Cockroaches from Different Community Settings in Edo State, Nigeria.
Clement ISAAC ; Philip Ogbeide ORUE ; Mercy Itohan IYAMU ; Joy Imuetiyan EHIAGHE ; Osesojie ISAAC
The Korean Journal of Parasitology 2014;52(2):177-181
Cockroaches are abundant in Nigeria and are seen to harbour an array of pathogens. Environmental and sanitary conditions associated with demographic/socio-economic settings of an area could contribute to the prevalence of disease pathogens in cockroaches. A total of 246 cockroaches (Periplaneta americana) in urban (Benin, n=91), semi-urban (Ekpoma, n=75) and rural (Emuhi, n=70) settings in Edo State, Nigeria were collected within and around households. The external body surfaces and alimentary canal of these cockroaches were screened for bacterial, fungal, and parasitological infections. Bacillus sp. and Escherichia coli were the most common bacteria in cockroaches. However, Enterococcus faecalis could not be isolated in cockroaches trapped from Ekpoma and Emuhi. Aspergillus niger was the most prevalent fungus in Benin and Ekpoma, while Mucor sp. was predominant in Emuhi. Parasitological investigations revealed the preponderance of Ascaris lumbricoides in Benin and Emuhi, while Trichuris trichura was the most predominant in Ekpoma. The prevalence and burden of infection in cockroaches is likely to be a reflection of the sanitary conditions of these areas. Also, cockroaches in these areas making incursions in homes may increase the risk of human infections with these disease agents.
Animals
;
Ascaris lumbricoides/isolation & purification
;
Aspergillus niger/isolation & purification
;
Bacillus/isolation & purification
;
Cockroaches/*microbiology/*parasitology
;
Escherichia coli/isolation & purification
;
Nigeria
;
Sanitation
;
Trichuris/isolation & purification
9.Metabolism of naringin produced by intestinal bacteria.
Wei ZHANG ; Shu JIANG ; Da-Wei QIAN ; Er-Xin SHANG ; Ye-Fei QIAN ; Hao REN ; Han-Liang GUAN ; Jin-Ao DUAN
Acta Pharmaceutica Sinica 2013;48(12):1817-1822
Naringin has been reported to possess a wild range of biological activities. However, the route and metabolites of naringin produced by intestinal bacteria are not well understood. In this paper, different bacteria were isolated from human feces and their abilities to convert naringin to different metabolites were studied. Ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) with automated data analysis software (MetaboLynx) was applied to fast analysis of naringin metabolites. Using MSE and mass defect filter techniques, three metabolites were detected and tentatively identified. The results indicated that acetylation, hydrolyzation and hydrolyzation with hydrogenation were the major metabolic pathways of naringin in vitro. Then, we studied the gene sequence of the 16S rRNA of the bacteria by extraction of genomic DNA of the strain, PCR amplification and clone of the 16S rRNA. The consequence proved that Enterococcus sp.30, Bacillus sp.46, Escherichia sp.54 and Escherichia sp.63 have the peculiar metabolism characteristic of naringin.
Bacillus
;
genetics
;
isolation & purification
;
metabolism
;
Chromatography, High Pressure Liquid
;
Enterococcus
;
genetics
;
isolation & purification
;
metabolism
;
Escherichia
;
genetics
;
isolation & purification
;
metabolism
;
Feces
;
microbiology
;
Female
;
Flavanones
;
metabolism
;
Humans
;
Metabolic Networks and Pathways
;
Phylogeny
;
RNA, Ribosomal, 16S
;
genetics
;
Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
10.Optimization of Douchi fibrinolytic enzyme production by statistical experimental methods.
Xu ZHANG ; Luo-jia YUN ; Liang-bin PENG ; Yi LU ; Kun-peng MA ; Fei TANG
Journal of Huazhong University of Science and Technology (Medical Sciences) 2013;33(1):153-158
Thrombus disease, one of the common cardiovascular diseases, has attracted worldwide attention for its rising mortality and morbidity. Due to the distinct shortages of current fibrinolytic drugs, new fibrinolytic agents warrant investigation. In this study, 8 fibrinolytic enzyme-producing strains were isolated from Douchi-a traditional Chinese food, and strain XY-1 which produced the largest amount of the enzyme was chosen for the following experiments. The enzyme produced by strain XY-1 was named Douchi fibrinolytic enzyme (DFE). We optimized the liquid culture medium of strain XY-1 for enzyme production using Plackett-Burman and Box-Behnken design. The predicted maximal DFE yield was 19.78 FU/mL with 11.4 g/L peptone, 0.5 g/L magnesium sulfate and 1 g/L sodium chloride. However, we acquired maximal production of 21.33 FU/mL in actual experiments, equal to 107.84% of the theoretical value, and the yield had been increased by 79.55% as compared to the yield of un-optimized culture. It was demonstrated that the combined use of Plackett-Burman design and response surface methodology in fermentation optimization can effectively and rapidly increase DFE production.
Bacillus
;
physiology
;
Bioreactors
;
microbiology
;
Blood Coagulation
;
drug effects
;
physiology
;
Cells, Cultured
;
Combinatorial Chemistry Techniques
;
Computer Simulation
;
Fabaceae
;
enzymology
;
growth & development
;
microbiology
;
Fibrinolytic Agents
;
isolation & purification
;
metabolism
;
pharmacology
;
Humans
;
Models, Biological
;
Models, Statistical


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