scholarly journals PEMANFAATAN BAKTERI ENTOMOPATOGENIK Bacillus cereus TERHADAP HAMA Spodoptera litura PADA TANAMAN KUBIS

EUGENIA ◽  
2012 ◽  
Vol 21 (3) ◽  
Author(s):  
Emmy Senewe ◽  
Redsway Maramis ◽  
Christina L. Salaki

ABSTRACT This study aims to obtain entomopatogenik bacteria (Bacillus cereus) as a potential biological control of pests Spodoptera litura and determine the morphological characteristics and the potential power to kill isolate B. cereus. Explored endogenous bacteria from 99 soil samples from Minahasa regency, South Minahasa and Tomohon. Bacteria were isolated by selectively using methods Ohba and Aizawa  identified by colony and cell morphology. The results showed that of the 99 soil samples obtained 141 isolates were identified as Bacillus cereus. Screening 141 isolates of the 80 isolates contained S.litura larvae that can cause deadly diseases and test larvae  >50% after 96 hours with a dose of inoculum  1.5 x 107 spores / ml. Isolates that could potentially then be selected based on the pathogenicity then be developed into a biopesticide for pest control S. litura on cauliflower and broccoli plants. Keywords: Entomoopatogenic bacteria, Spodoptera litura, cabbage plants

2021 ◽  
Vol 5 ◽  
Author(s):  
Ju-Chun Chang ◽  
Shin-Shan Wu ◽  
Yao-Chia Liu ◽  
Yu-Hong Yang ◽  
Yi-Fang Tsai ◽  
...  

Chemical pesticides have been used for pest control for many decades, but they cause serious problems, including insecticide resistance, secondary pest resurgence, and negative environmental impacts. Therefore, sustainable alternatives to chemical pesticides are necessary for pest control. Entomopathogenic fungi (EPF) are natural epizootic pathogens of insects, and some of them have been used as microbial biocontrol agents. Herein, we attempted to construct an entomopathogenic fungal library (EFLib) via the “Tenebrio molitor pathogenicity-based fungal collection method (TmPC)” to select EPF for control of the serious agricultural pest Spodoptera litura. A total of 172 soil samples were collected in northern and central Taiwan for the EFLib construction. The isolation efficiency of TmPC was 64.02%. The EFLib consisted of 101 isolates and was designated as the National Chung Hsing University (NCHU) EFLib. Among these isolates, 26 showed high virulence (mortality = 100%) to T. molitor larvae. Based on the results of molecular identification, the highly virulent isolates belonged to seven genera, including Beauveria, Clonostachys, Fusarium, Cordyceps, Penicillium, Purpureocillium, and Metarhizium. To evaluate the potential of these isolates for Spodoptera litura control, 12 isolates were selected for pathogenicity screening against S. litura larvae. A total of six EPF isolates belonging to the genera Beauveria and Metarhizium showed rapid eradication of the S. litura larvae. To rank the potential of these fungal strains for pest management, the six isolates were subjected to thermotolerance and conidial production assays, and a novel effective conidia number (ECN) formula was applied. The results indicated that the ECN index of Beauveria australis (NCHU-113) was much higher than that of Metarhizium isolates. However, among the Metarhizium isolates, NCHU-95 showed the highest ECN index. Altogether, NCHU-69 and NCHU-113 should be further tested in field trials. To our knowledge, this is the first attempt to integrate pathogenicity or virulence and ECN data into EPF screening and ranking, providing a baseline for mass selection of potential EPF strains for further applications.


Author(s):  
Zaid Raad Abbas ◽  
Aqeel Mohammed Majeed Al-Ezee ◽  
Sawsan H

This study was conducted to explore the ability of Pseudomonas fluorescens and Bacillus cereus to solubilizing a phosphate in soil for enhancing the planting growth and, its relation with soill characterization. The isolates were identified as P.fluorescens and B. cereus using convential analysis and, its phosphate solubilization ability and sidrophore was shown by the clear zone formation on National Botanical Research Institute���s Phosphate medium. Moreover, Pseudomonas fluorescens isolates (n = 9) and three of B. cereus isolated from agricultural area in Baghdad university, Mustansiriyah university and Diyala bridge. Results displayed that bacterial count were varied in soil samples according to their region, and ranging from 30 to 60 *10 2 CFU/g in Baghdad university soil to 10���20 *10 2 CFU/g in Mustansiriyah university soil, the Baghdad soil macronutrient which included: NH4, NO3, P, and K were, 8.42, 20.53, 19.09, 218.73 respectively, While the physio analysis revealed that the mean of pH was 7.3 and EC was 8.63. on the other hand the micronutrient analysis indicated that the soil samples were included Ca, Fe, Mn, Zn and Cu which gave their mean 5025.9, 8.9, 4.9, 0.5 and 1.5 respectevily. Results revealed that all isolated bacteria (9 isolates of P.fluorescens and three isolates of B. cereus gave ahalo zone which mean their ability to be phosphate solubilizing bacteria at 100%. Results revealed that all isolated bacteria were detected a ability to produce high levels from chelating agents (siderophores)) by P.fluorescens and. B cereus at 100%, when appeared ahalo clear zone. Furthermore, the high levels of phosphate solubilization and siderophore production were grouped in bacterial species isolated from Iraqi soils. might be attributed to many soil factors such as soil nutrient status, soil acidity, water content, organic matter and soil enzyme activities.


Author(s):  
Carmen Emilia PUIA ◽  
Daniela Andreea GRIGORESCU ◽  
Raluca Vasilica MICLEA

Cryphonectria parasitica  (Murr.) Bar [syn. Endothia parasitica (Murr. And.] (anamorf: Endothiella sp .) is the causal agent of chestnut bark disease or chestnut blight, disease which produced great damages throughout the world, for example, in Europe, the European chestnut tree ( Castanea sativa (P.) Mill) was heavily affected. Environmental concerns have focused attention on natural forms of disease control as an effective alternative to chemical pesticides. In the chestnut blight fungus, Cryphonectria parasitica deals with a natural form of biological control in which the virulence of a fungal pathogen is attenuated by an endogenous viral RNA genetic element- the hypovirulent strain. In our researches we picked samples of chestnut bark from different areas in Maramures county. We’ve isolated the fungus on PDA medium and we’ve studied the morphological characteristics of the usual virulent strain and we looked for a possible hypovirulent strain in order to study its capacity for biological control. The fungus develops in the bark and in cambium where forms a yellowish or brownish stroma and produces both conidia and ascospores. The pycnidia stromata break through the lenticels producing conidia and later in the same stroma develop the perithecia which produce ascospores. Both strains of the fungus were found in the research area. The hypovirulent strain had a slower development, showed no sporu lation and pigmentation “white cultural strain” and was tested in vitro for the capacity to convert the virulent isolates by dual culture tests.


2017 ◽  
Vol 17 (2) ◽  
Author(s):  
I Made Indra Agastya ◽  
Aminudin Afandhi ◽  
Luqman Qurata Aini

This research was conducted in vitro in the laboratory. Studies conducted in the Laboratory of Bacteriology Department of Plant Pests and Diseases of the Faculty of Agriculture, University of Brawijaya, on the effectiveness of the bacteria Bacillus cereus and Bacillus megaterium as biological pesticides controlling Spodoptera litura. The objective of this study was to determine the effectiveness of the bacteria Bacillus sp as biological control. Effectiveness pesticide was measured by testing the incubation period and mortality in larvae of S. litura instar 3. This study used a completely randomized design (CRD), conducted observations every 6 hours until the larvae dead. The results showed that the percentage of mortality of S. litura reached 94.66% compared to the control, while the incubation time of the bacteria B. cereus cause disease until 29.84 hours. B. cereus and B. megaterium have the ability to incubate third instar larvae of S. litura up to 29.84 hours and caused the death of larvae up to 94.66%. Keywords: Biological pesticides, Bacillus cereus, Bacillus megaterium, entomopatogen, Spodoptera litura


2021 ◽  
Vol 12 ◽  
Author(s):  
Yang Qu ◽  
Chao Wei ◽  
Xiaohang Dai ◽  
Yalong Bai ◽  
Xin Zhao ◽  
...  

Bacillus cereus is a well-characterized human pathogen that produces toxins associated with diarrheal and emetic foodborne diseases. To investigate the possible transmission of B. cereus on lettuce farms in China and determine its enterotoxicity, (I) a total of 524 samples (lettuce: 332, soil: 69, water: 57, manure: 57, pesticide: 9) were collected from 46 lettuce farms in five Chinese provinces, (II) multilocus sequence typing (MLST) was used to classify B. cereus isolates and for trace analysis, and (III) the presence of toxin genes and enterotoxins (Hbl and Nhe) was detected in 68 strains. The results showed that one hundred and sixty-one lettuce samples (48.5%) tested positive for B. cereus at levels ranging from 10 to 5.3 × 104 CFU/g. Among the environmental sample categories surveyed, the highest positive rate was that of the pesticide samples at 55.6%, followed by soil samples at 52.2% and manure samples at 12.3%. Moreover, one hundred isolates of B. cereus yielded 68 different sequence types (STs) and were classified into five phylogenetic clades. Furthermore, Nhe toxin genes (nheA, nheB, nheC) were broadly distributed and identified in all 68 strains (100%), while Hbl toxin genes (hblA, hblC, hblD) were present in 61 strains (89.7%), entFM was detected in 62 strains (91.2%), and cytK was found in 29 strains (42.6%). All strains were negative for ces. As for the enterotoxin, Nhe was observed in all 68 isolates carrying nheB, while Hbl was present in 76.5% (52/68) of the strains harboring hblC. This study is the first report of possible B. cereus transmission and of its potential enterotoxicity on lettuce farms in China. The results showed that soil and pesticides are the main sources of B. cereus on lettuce farms in China, and the possible transmission routes are as follows: soil-lettuce, manure-lettuce, pesticide-lettuce, manure-soil-lettuce, and water-manure-soil-lettuce. Furthermore, the B. cereus isolates, whether from lettuce or the environment, pose a potential risk to health.


Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2256
Author(s):  
Konstantina Kyriakopoulou ◽  
Eirini Riti ◽  
Zoi Piperigkou ◽  
Konstantina Koutroumanou Sarri ◽  
Heba Bassiony ◽  
...  

Breast cancer accounts for almost one in four cancer diagnoses in women. Studies in breast cancer patients have identified several molecular markers, indicators of aggressiveness, which help toward more individual therapeutic approaches. In triple-negative breast cancer (TNBC), epidermal growth factor receptor (EGFR) overexpression is associated with increased metastatic potential and worst survival rates. Specifically, abnormal EGFR activation leads to altered matrix metalloproteinases’ (MMPs) expression and, hence, extracellular matrix (ECM) degradation, resulting in induced migration and invasion. The use of matrix substrates for cell culture gives the opportunity to mimic the natural growth conditions of the cells and their microenvironment, as well as cell–cell and cell–matrix interactions. The aim of this study was to evaluate the impact of EGFR inhibition, estrogen receptor beta (ERβ) and different matrix substrates [type I collagen and fibronectin (FN)] on the functional properties, expression of MMPs and cell morphology of ERβ-positive TNBC cells and shERβ ones. Our results highlight EGFR as a crucial regulator of the expression and activity levels of MMPs, while ERβ emerges as a mediator of MMP7 and MT1-MMP expression. In addition, the EGFR/ERβ axis impacts the adhesion and invasion potential of breast cancer cells on collagen type I. Images obtained by scanning electron microscope (SEM) from cultures on the different matrix substrates revealed novel observations regarding various structures of breast cancer cells (filopodia, extravesicles, tunneling nanotubes, etc.). Moreover, the significant contribution of EGFR and ERβ in the morphological characteristics of these cells is also demonstrated, hence highlighting the possibility of dual pharmacological targeting.


Our Nature ◽  
1970 ◽  
Vol 5 (1) ◽  
pp. 67-69
Author(s):  
Upendra Thapa Shrestha ◽  
Gyan Sunder Shahukhal ◽  
Kiran Babu Tiwari ◽  
Subarna Pokhrel ◽  
Anjana Singh ◽  
...  

Bacillus thuringiensis strains were isolated from soil samples collected from Khumbu Base Camp of the Everest region and characterized by standard microbiological techniques viz. colonial and morphological characteristics, and biochemical tests. Insect bioassay of each isolate was performed by standard method using mosquito larva. Among ten randomly selected isolates, one isolate showed the highest insecticidal activity against Dipteron insects. Keywords: Insect-bioassay, Isolates, Khumbu region, Mosquitocidal, Mosquito larvadoi:10.3126/on.v5i1.800Our Nature (2007)5:67-69


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Saijun Zhou ◽  
Andrew Hursthouse ◽  
Tengshu Chen

Major sources of pollution during the antimony (Sb) mining and processing are mining waste rock, smelting waste, tailings dam, and underground tunnel wastewater. The aim of the present study was to assess magnitude of pollution from Sb mine by taking four types of samples: soil in the mining waste rock zone, soil in the smelting zone, soil in tailings zone, and soil in underground tunnel wastewater zone. Sixty soil samples from the four zones were taken for experimental work, and the contents and morphological characteristics of the six potentially toxic elements (PTEs) such as Sb, As, Hg, Pb, Cd, and Zn in the soil samples were measured by using a hydride generation atomic fluorescence spectrometer (AFS-9700). The results show that the soil of the mine area is seriously polluted. The average contents of Sb, As, Hg, Pb, Cd, and Zn in the soil reach 1267.20 mg·kg−1, 94.44 mg·kg−1, 1.46 mg·kg−1, 184.19 mg·kg−1, 8.54 mg·kg−1, and 1054.11 mg·kg−1, respectively. There exists good correlation between the PTEs in the soil, with Sb strongly positively correlated with As, Hg, Pb, and Zn. The intensity of pollution is highest in the antimony-smelting zone, where the potential ecological risk index is over 15,000, followed by the tailings zone and mining waste rock zone, with the underground tunnel wastewater zone being the lowest. Using sequential chemical extraction, the elements are associated with the residual fraction, followed by organic-sulfide fraction, and smaller portions in the Fe-Mn oxide, carbonate, and exchangeable fractions. There are great differences in the speciation content of different elements in different sampling zones. The study implicates that Sb-smelting zone is the potential source of PTEs and maximum metals are associated with residual phase, out of which significant portion is associated with mobile fraction or phase.


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