scholarly journals Preliminary evaluation of the use of bacteria isolated from the digestive tract of shrimp Litopenaeus vannamei as a source to accelerate the process of formation and development of bioflocs

2021 ◽  
Vol 43 ◽  
pp. e52219
Author(s):  
Danyela Carla Elias Soares ◽  
Jade Oliveira Abreu ◽  
Jéssica Lucinda Saldanha da Silva ◽  
Oscarina Viana de Sousa
Keyword(s):  
Bacillus Thuringiensis ◽  
Microbial Communities ◽  
Sedimentation Rate ◽  
Litopenaeus Vannamei ◽  
Bacterial Consortium ◽  
Preliminary Evaluation ◽  
Bacillus Sp ◽  
Spontaneous Formation ◽  
Staphylococcus Cohnii

This study aims at investigating to follow the formation and development of biofloc aggregates in a system with the introduction of an in vitro selected bacterial consortium (Bacillus thuringiensis, Bacillus sp., Staphylococcus cohnii) in order to induce fast formation of biofloc and to compare it to the development of spontaneous formation biofloc. Two experimental groups were evaluated for biofloc formation, SFT and IFT. The first refers to spontaneous (conventional) formation of the flocs and the second to induced formation (IFT), achieved through the consortium of potentially inducing bacteria. Both treatments presented a constant increase of bioflocs, however, in the IFT treatment, the microbial aggregates were larger and more uniform. By the end of the experiment, we verified that the aggregates formed in the IFT showed higher volume and lower sedimentation rate in comparison to the spontaneously formed ones. The results show that domestication in microbial communities is efficient as related to bioflocs, reducing instability during its formation and development.

scholarly journals Generalizing game-changing species across microbial communities

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Jie Deng ◽  
Marco Tulio Angulo ◽  
Serguei Saavedra
Keyword(s):  
Microbial Communities ◽  
Context Dependency ◽  
Heuristic Rules ◽  
Resident Species ◽  
Experimental Systems ◽  
Environment And Health ◽  
Structuralist Theory ◽  
Context Specific

AbstractMicrobes form multispecies communities that play essential roles in our environment and health. Not surprisingly, there is an increasing need for understanding if certain invader species will modify a given microbial community, producing either a desired or undesired change in the observed collection of resident species. However, the complex interactions that species can establish between each other and the diverse external factors underlying their dynamics have made constructing such understanding context-specific. Here we integrate tractable theoretical systems with tractable experimental systems to find general conditions under which non-resident species can change the collection of resident communities—game-changing species. We show that non-resident colonizers are more likely to be game-changers than transients, whereas game-changers are more likely to suppress than to promote resident species. Importantly, we find general heuristic rules for game-changers under controlled environments by integrating mutual invasibility theory with in vitro experimental systems, and general heuristic rules under changing environments by integrating structuralist theory with in vivo experimental systems. Despite the strong context-dependency of microbial communities, our work shows that under an appropriate integration of tractable theoretical and experimental systems, it is possible to unveil regularities that can then be potentially extended to understand the behavior of complex natural communities.

scholarly journals Bacillus thuringiensis Bel Protein Enhances the Toxicity of Cry1Ac Protein to Helicoverpa armigera Larvae by Degrading Insect Intestinal Mucin

2009 ◽  
Vol 75 (16) ◽  
pp. 5237-5243 ◽  
Author(s):  
Shangling Fang ◽  
Li Wang ◽  
Wei Guo ◽  
Xia Zhang ◽  
Donghai Peng ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Helicoverpa Armigera ◽  
Trichoplusia Ni ◽  
Knockout Mutant ◽  
Gene Encoding ◽  
In Vitro Degradation ◽  
Intestinal Mucin ◽  
Helicoverpa Armígera ◽  
Cry1ac Protein

ABSTRACT Bacillus thuringiensis has been used as a bioinsecticide to control agricultural insects. Bacillus cereus group genomes were found to have a Bacillus enhancin-like (bel) gene, encoding a peptide with 20 to 30% identity to viral enhancin protein, which can enhance viral infection by degradation of the peritrophic matrix (PM) of the insect midgut. In this study, the bel gene was found to have an activity similar to that of the viral enhancin gene. A bel knockout mutant was constructed by using a plasmid-free B. thuringiensis derivative, BMB171. The 50% lethal concentrations of this mutant plus the cry1Ac insecticidal protein gene were about 5.8-fold higher than those of the BMB171 strain. When purified Bel was mixed with the Cry1Ac protein and fed to Helicoverpa armigera larvae, 3 μg/ml Cry1Ac alone induced 34.2% mortality. Meanwhile, the mortality rate rose to 74.4% when the same amount of Cry1Ac was mixed with 0.8 μg/ml of Bel. Microscopic observation showed a significant disruption detected on the midgut PM of H. armigera larvae after they were fed Bel. In vitro degradation assays showed that Bel digested the intestinal mucin (IIM) of Trichoplusia ni and H. armigera larvae to various degrading products, similar to findings for viral enhancin. These results imply Bel toxicity enhancement depends on the destruction of midgut PM and IIM, similar to the case with viral enhancin. This discovery showed that Bel has the potential to enhance insecticidal activity of B. thuringiensis-based biopesticides and transgenic crops.

In vitro studies of the effects of aflatoxin B1 and fumonisin B1 on trypsin-like and collagenase-like activity from the hepatopancreas of white shrimp (Litopenaeus vannamei)

Aquaculture ◽  
2005 ◽  
Vol 250 (1-2) ◽  
pp. 399-410 ◽  
Author(s):  
Armando Burgos-Hernández ◽  
Sergio I. Farias ◽  
Wilfrido Torres-Arreola ◽  
Josafat M. Ezquerra-Brauer
Keyword(s):  
Aflatoxin B1 ◽  
Litopenaeus Vannamei ◽  
Fumonisin B1 ◽  
In Vitro Studies ◽  
White Shrimp

Pilocarpine hydrochloride liposomes: characterization in vitro and preliminary evaluation in vivo in rabbit eye

1984 ◽  
Vol 1 (3) ◽  
pp. 203-216 ◽  
Author(s):  
S. Benita ◽  
J. D. Plenecassagne ◽  
G. Cavé ◽  
D. Drouin ◽  
P. Le Hao Dong ◽  
...  
Keyword(s):  
Preliminary Evaluation ◽  
Rabbit Eye

scholarly journals Plasmid Transfer between the Bacillus thuringiensis Subspecies kurstaki andtenebrionis in Laboratory Culture and Soil and in Lepidopteran and Coleopteran Larvae

2000 ◽  
Vol 66 (1) ◽  
pp. 118-124 ◽  
Author(s):  
D. John I. Thomas ◽  
J. Alun W. Morgan ◽  
John M. Whipps ◽  
Jon R. Saunders
Keyword(s):  
Bacillus Thuringiensis ◽  
Bacterial Population ◽  
Laboratory Culture ◽  
Plasmid Transfer ◽  
Donor Strain ◽  
Lepidopteran Insect ◽  
Lepidopteran Insects ◽  
Rapid Formation ◽  
Coleopteran Insect

ABSTRACT Plasmid transfer between Bacillus thuringiensis subsp.kurstaki HD1 and B. thuringiensis subsp.tenebrionis donor strains and a streptomycin-resistantB. thuringiensis subsp. kurstaki recipient was studied under environmentally relevant laboratory conditions in vitro, in soil, and in insects. Plasmid transfer was detected in vitro at temperatures of 5 to 37°C, at pH 5.9 to 9.0, and at water activities of 0.965 to 0.995, and the highest transfer ratios (up to 10−1 transconjugant/donor) were detected within 4 h. In contrast, no plasmid transfer was detected in nonsterile soil, and rapid formation of spores by the introduced strains probably contributed most to the lack of plasmid transfer observed. When aB. thuringiensis subsp. kurstaki strain was used as the donor strain, plasmid transfer was detected in killed susceptible lepidopteran insect (Lacanobia oleracea) larvae but not in the nonsusceptible coleopteran insect Phaedon chocleriae. When a B. thuringiensis subsp.tenerbrionis strain was used as the donor strain, no plasmid transfer was detected in either of these insects even when they were killed. These results show that in larger susceptible lepidopteran insects there is a greater opportunity for growth of B. thuringiensis strains, and this finding, combined with decreased competition due to a low initial background bacterial population, can provide suitable conditions for efficient plasmid transfer in the environment.

Enhanced Toxicity of Bacillus thuringiensis Subspecies kurstaki and aizawai to Black Cutworm Larvae (Lepidoptera: Noctuidae) With Bacillus sp. NFD2 and Pseudomonas sp. FNFD1

2011 ◽  
Vol 104 (1) ◽  
pp. 41-46 ◽  
Author(s):  
Tamer A. Mashtoly ◽  
Assem Abolmaaty ◽  
Mohamed El-Said El-Zemaity ◽  
Mohamed I. Hussien ◽  
Steven R. Alm
Keyword(s):  
Bacillus Thuringiensis ◽  
Pseudomonas Sp ◽  
Bacillus Sp ◽  
Black Cutworm ◽  
Lepidoptera Noctuidae
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