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Polyurethane foam as an inert support using concentrated media improves quality and spore production from Bacillus thuringiensis. World J Microbiol Biotechnol 2021; 37:154. [PMID: 34398297 DOI: 10.1007/s11274-021-03122-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 08/07/2021] [Indexed: 11/27/2022]
Abstract
Bacillus thuringiensis (Bt) (Bacillales:Bacillaceae) is a gram-positive bacterium that produces spores, several virulence factors and insecticidal toxins, making this microorganism the most used biopesticide worldwide. The use of inert supports such as polyurethane foam (PUF) in solid cultures has been a great alternative to produce various metabolites, including those produced by Bt. In this study we compared the yields, productivity and quality of the spores by two wild strains of Bt, (Y15 and EA3), grown in media with high substrate concentration in both culture systems: liquid and solid (PUF as solid inert support). Both strains showed 2.5- to 30-fold increases in spore production and productivity in solid culture, which showed an even greater increase when considering the spores retained in the PUF observed by scanning electron microscopy. Moreover, spore produced in solid culture showed up to sevenfold higher survival after a heat-shock treatment, relative to spores from liquid culture. The infectivity against larvae of Galleria mellonella (Lepidoptera:Pyralidae) improved also in spores from solid cultures. This comparison showed that the culture of Bt on solid support has clear advantages over liquid culture in terms of the production and quality of spores, and that those advantages can be attributed only to the culture system, as the same media composition was used in both systems.
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Duarte Neto JMW, Wanderley MCDA, da Silva TAF, Marques DAV, da Silva GR, Gurgel JF, Oliveira JDP, Porto ALF. Bacillus thuringiensis endotoxin production: a systematic review of the past 10 years. World J Microbiol Biotechnol 2020; 36:128. [PMID: 32712871 DOI: 10.1007/s11274-020-02904-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 07/14/2020] [Indexed: 12/16/2022]
Abstract
Bacillus thuringiensis (Bt) is one of the most promising biological control agents used commercially. Its products can contribute to reducing ecological and environmental problems associated with the use of chemical pesticides. Among the limiting factors of using Bt as bioinsecticide are the costs and ensuring its biological activity, which may vary according to the strain and culture conditions. This systematic review aimed to collect state-of-the-art information on the production of Bt endotoxins and to score the methodological feasibility of the data obtained, thus highlighting possible incoherencies. In order to consolidate recent findings and guide future studies, a total of 47 original articles from the last 10 years was analysed, with special attention being given to corroborating data, identifying inconsistencies and suggesting future adjustments so as to increase data reliability. With a maximum score of 8 points, three production parameters were classified on the following scale: preferable (score: 2), adequate (score: 1) and inadequate (score: 0), and another two parameter were classified as adequate (score: 1) or inadequate (score: 0). No article scored more than 6 out of the maximum of 8, thus reflecting the need for more detailed studies regarding Bt endotoxin production. The lack of standardization of methods and units of measurement also have made a comparison of results and an overall analysis difficult. Standards are suggested in the present study. The inclusion of bioassays and quantifying toxin via alkaline dilution are strongly recommended for studies of this nature, along with LC50 expressed in mg/L. Sixteen articles (34%) did not use either of these suggested methods, which indicates the need for further supporting studies. These findings reinforce the need for robust studies in this area, which could include the development of more affordable and effective bioinsecticides, thus increasing their competitiveness against insecticides derived from unsustainable sources.
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Affiliation(s)
- José Manoel W Duarte Neto
- Biotechnology Laboratory, Agronomic Institute of Pernambuco, IPA, Av. General San Martin, Recife, PE, 137150761-000, Brazil.,Bioactives Technology Laboratory (LABTECBIO), Animal Morphology and Physiology Department, Federal Rural University of Pernambuco, UFRPE, Av. Dom Manoel de Medeiros, n/nr, Recife, PE, 52171-900, Brazil.,Keizo Asami Immunopathology Laboratory (LIKA), Federal University of Pernambuco, UFPE, Av. Prof. Moraes Lins Do Rego, n/nr, Recife, PE, 50670-901, Brazil
| | - Maria Carolina de A Wanderley
- Bioactives Technology Laboratory (LABTECBIO), Animal Morphology and Physiology Department, Federal Rural University of Pernambuco, UFRPE, Av. Dom Manoel de Medeiros, n/nr, Recife, PE, 52171-900, Brazil.,Keizo Asami Immunopathology Laboratory (LIKA), Federal University of Pernambuco, UFPE, Av. Prof. Moraes Lins Do Rego, n/nr, Recife, PE, 50670-901, Brazil
| | - Túlio Alexandre F da Silva
- Bioactives Technology Laboratory (LABTECBIO), Animal Morphology and Physiology Department, Federal Rural University of Pernambuco, UFRPE, Av. Dom Manoel de Medeiros, n/nr, Recife, PE, 52171-900, Brazil
| | - Daniela A Viana Marques
- University of Pernambuco (UPE), Serra Talhada Campus, Av. Afonso Magalhães, n/nr, Serra Talhada, PE, Brazil
| | - Gilvanda R da Silva
- Biotechnology Laboratory, Agronomic Institute of Pernambuco, IPA, Av. General San Martin, Recife, PE, 137150761-000, Brazil
| | - Josimar Fernandes Gurgel
- Biotechnology Laboratory, Agronomic Institute of Pernambuco, IPA, Av. General San Martin, Recife, PE, 137150761-000, Brazil
| | - José de Paula Oliveira
- Biotechnology Laboratory, Agronomic Institute of Pernambuco, IPA, Av. General San Martin, Recife, PE, 137150761-000, Brazil
| | - Ana Lúcia F Porto
- Biotechnology Laboratory, Agronomic Institute of Pernambuco, IPA, Av. General San Martin, Recife, PE, 137150761-000, Brazil. .,Bioactives Technology Laboratory (LABTECBIO), Animal Morphology and Physiology Department, Federal Rural University of Pernambuco, UFRPE, Av. Dom Manoel de Medeiros, n/nr, Recife, PE, 52171-900, Brazil. .,Keizo Asami Immunopathology Laboratory (LIKA), Federal University of Pernambuco, UFPE, Av. Prof. Moraes Lins Do Rego, n/nr, Recife, PE, 50670-901, Brazil.
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