scholarly journals Behavior of the Biological Control Agent Bacillus thuringiensis subsp. aizawai ABTS-1857 and Salmonella enterica on Spinach Plants and Cut Leaves

2021 ◽  
Vol 12 ◽  
Author(s):  
Xingchen Zhao ◽  
Marcelo Belchior Rosendo da Silva ◽  
Inge Van der Linden ◽  
Bernadette D. G. M. Franco ◽  
Mieke Uyttendaele

Fresh produce has been identified as an important vehicle for the transmission of foodborne pathogens. This study evaluated the behavior of vegetative cells and spores of Bacillus thuringiensis, one of the main biological control agents (BCAs) used in the world, and Salmonella enterica on spinach plants (pre-harvest) and spinach cut leaves (post-harvest) at 12°C, experimentally inoculated as single or co-cultures. The results evidenced that spray-inoculated commercial BCA containing Bacillus thuringiensis subsp. aizawai ABTS-1857 (BTa ABTS-1857) spores persisted well on spinach leaves in both pre- and post-harvest simulations. However, when BTa ABTS-1857 vegetative cells were spray-inoculated, more than 2 log reductions in the counts of B. thuringiensis were observed during 20 days pre- and 5 days post-harvest simulations, respectively. The counts of S. Montevideo on the spinach cut leaves during post-harvest storage at 12°C for 5 days remained unchanged, whereas 1 log reduction was noted during pre-harvest. Moreover, during pre-harvest simulation, when co-inoculated with BTa ABTS-1857 vegetative cells or spores, additional 0.5 or 1.0 log reductions were detected on the counts of S. Montevideo in the spinach leaves on the 10th day. These results were obtained under laboratory conditions, and further findings in longitudinal studies from farm (in the agricultural field) to retail (end of shelf life) will contribute to understanding of the role of B. thuringiensis as a BCA on growth/survival of Salmonella spp. in fresh produce.

1991 ◽  
Vol 31 (5) ◽  
pp. 709 ◽  
Author(s):  
SC McKillup ◽  
DG Brown

Waxmoths cause significant damage to stored honeycombs of the Western honeybee Apis mellifera in Australia. A field experiment was designed to evaluate the effectiveness of a commercial formulation (Certan) of the biological control agent Bacillus thuringiensis in preventing this damage.Treatment applied at the manufacturer's recommended rate of 855 units per cm2 of honeycomb almost completely prevented damage, while untreated combs showed an average of 76% damage. The cost and practicality of applying the formulation of B. thuringiensis are discussed, together with the recommendation that new control methods for waxmoths should be researched.


2022 ◽  
Vol 951 (1) ◽  
pp. 012106
Author(s):  
R Sriwati ◽  
T Chamzurni ◽  
F Razi ◽  
Syaifullah ◽  
Yunita ◽  
...  

Abstract To increase plant resistance from an early age, it is necessary to introduce biological control agents from groups of fungi and bacteria. This study aims to determine the effect of Trichoderma harziaunum and Bacillus thuringiensis Aceh isolates in increasing the superiority of Aceh patchouli plants that are resistant to pests and plant diseases. The study used non-factorial RAL method with cover and uncovered seedling methods. Both series were treated with the same biological control agent, the control without any treatment, the treatment of T. harzianum and B. thuringiensis while the observations were made when the seedling covered was opened. Observations included plant morphological characters, plant growth development and peroxidase enzymes. The results showed that morphologically the original patchouli growing in Lhoong district had similar morphological characters to the Lhokseumawe variety. The application of biological control agents of the T. harzianum and B. thuringiensis groups was more effective in increasing plant growth in the closed seedling treatment compared to the uncovered seedling. T. harzianum gave the best effect at a dose range of 1-1.5 while B. thuringensis showed a better effect at a concentration of 10-15 ml. Both treatments increased the growth of patchouli seedlings as indicated by the better plant height and number of shoots. Furthermore, higher peroxidation enzymes were found in the closed seedling treatment with 1.5 g T harzianum and 15 ml B. thuringiensis. The high peroxidase enzyme as an indicator of the more resistant plants have been induced to pests and diseases. From the screen house experiment, T. harzianum and B. thuringiensis were more efficient in inducing plant growth and disease resistance of local varieties of patchouli using the closed seedling method.


2017 ◽  
Vol 5 (18) ◽  
Author(s):  
Iker Hernández ◽  
Carolina Fernàndez

ABSTRACT Lysobacter enzymogenes strain B25, an isolate from an agricultural field, acts as a biological control agent against root knot nematodes in tomato plants. B25 also controls several fungal diseases and promotes plant growth under abiotic stress. We hereby report on the draft genome sequence and assembly of B25.


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