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Perullini M, Dulhoste S, Ribot F, Pehau-Arnaudet G, Bouvet OMM, Livage J, Nassif N. Bacteria metabolic adaptation to oxidative stress: the case of silica. J Biotechnol 2023; 374:80-89. [PMID: 37567503 DOI: 10.1016/j.jbiotec.2023.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 07/25/2023] [Accepted: 08/07/2023] [Indexed: 08/13/2023]
Abstract
Although the presence of silica in many living organisms offers advanced properties including cell protection, the different in vitro attempts to build living materials in pure silica never favoured the cells viability. Thus, little attention has been paid to host-guest interactions to modify the expected biologic response. Here we report the physiological changes undergone by Escherichia coli K-12 in silica from colloidal solution to gel confinement. We show that the physiological alterations in growing cultures are not triggered by the initial oxidative Reactive Oxygen Species (ROS) response. Silica promotes the induction of alternative metabolic pathways along with an increase of growth suggesting the existence of rpoS polymorphisms. Since the functionality of hybrid materials depends on the specific biologic responses of their guests, such cell physiological adaptation opens perspectives in the design of bioactive devices attracting for a large field of sciences.
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Affiliation(s)
- Mercedes Perullini
- CONICET - Universidad de Buenos Aires, Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE), Laboratorio de materiales funcionales con actividad biológica, Buenos Aires, Argentina.
| | - Sophie Dulhoste
- CONICET - Universidad de Buenos Aires, Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE), Laboratorio de materiales funcionales con actividad biológica, Buenos Aires, Argentina
| | - François Ribot
- Sorbonne Université, CNRS, Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), F-75252 Paris Cedex 05, France
| | | | - Odile M M Bouvet
- IAME, UMR 1137, INSERM, Univ Paris Diderot, Sorbonne Paris Cité, F-75018 Paris, France
| | - Jacques Livage
- Sorbonne Université, CNRS, Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), F-75252 Paris Cedex 05, France.
| | - Nadine Nassif
- Sorbonne Université, CNRS, Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), F-75252 Paris Cedex 05, France
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Vlajkov V, Pajčin I, Loc M, Budakov D, Dodić J, Grahovac M, Grahovac J. The Effect of Cultivation Conditions on Antifungal and Maize Seed Germination Activity of Bacillus-Based Biocontrol Agent. BIOENGINEERING (BASEL, SWITZERLAND) 2022; 9:bioengineering9120797. [PMID: 36551004 PMCID: PMC9774550 DOI: 10.3390/bioengineering9120797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/28/2022] [Accepted: 12/06/2022] [Indexed: 12/15/2022]
Abstract
Aflatoxin contamination is a global risk and a concerning problem threatening food safety. The biotechnological answer lies in the production of biocontrol agents that are effective against aflatoxins producers. In addition to their biocontrol effect, microbial-based products are recognized as efficient biosolutions for plant nutrition and growth promotion. The present study addresses the characterization of the representative of Phaseolus vulgaris rhizosphere microbiome, Bacillus sp. BioSol021, regarding plant growth promotion traits, including the activity of protease, cellulase, xylanase, and pectinase with the enzymatic activity index values 1.06, 2.04, 2.41, and 3.51, respectively. The potential for the wider commercialization of this kind of product is determined by the possibility of developing a scalable bioprocess solution suitable for technology transfer to an industrial scale. Therefore, the study addresses one of the most challenging steps in bioprocess development, including the production scale-up from the Erlenmeyer flask to the laboratory bioreactor. The results indicated the influence of the key bioprocess parameters on the dual mechanism of action of biocontrol effects against the aflatoxigenic Aspergillus flavus, as well on maize seed germination activity, pointing out the positive impact of high aeration intensity and agitation rate, resulting in inhibition zone diameters of 60 mm, a root length 96 mm, and a shoot length 27 mm.
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Affiliation(s)
- Vanja Vlajkov
- Faculty of Technology Novi Sad, University of Novi Sad, Bulevar cara Lazara 1, 21000 Novi Sad, Serbia
- Correspondence: (V.V.); (J.G.)
| | - Ivana Pajčin
- Faculty of Technology Novi Sad, University of Novi Sad, Bulevar cara Lazara 1, 21000 Novi Sad, Serbia
| | - Marta Loc
- Faculty of Agriculture, University of Novi Sad, Trg Dositeja Obradovića 8, 21000 Novi Sad, Serbia
| | - Dragana Budakov
- Faculty of Agriculture, University of Novi Sad, Trg Dositeja Obradovića 8, 21000 Novi Sad, Serbia
| | - Jelena Dodić
- Faculty of Technology Novi Sad, University of Novi Sad, Bulevar cara Lazara 1, 21000 Novi Sad, Serbia
| | - Mila Grahovac
- Faculty of Agriculture, University of Novi Sad, Trg Dositeja Obradovića 8, 21000 Novi Sad, Serbia
| | - Jovana Grahovac
- Faculty of Technology Novi Sad, University of Novi Sad, Bulevar cara Lazara 1, 21000 Novi Sad, Serbia
- Correspondence: (V.V.); (J.G.)
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Díaz Pacheco A, Delgado-Macuil RJ, Larralde-Corona CP, Dinorín-Téllez-Girón J, Martínez Montes F, Martinez Tolibia SE, López Y López VE. Two-methods approach to follow up biomass by impedance spectroscopy: Bacillus thuringiensis fermentations as a study model. Appl Microbiol Biotechnol 2022; 106:1097-1112. [PMID: 35037996 DOI: 10.1007/s00253-022-11768-7] [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: 09/25/2021] [Revised: 12/06/2021] [Accepted: 01/06/2022] [Indexed: 11/24/2022]
Abstract
Impedance spectroscopy is used for the characterization of electrochemical systems as well as for the monitoring of bioprocesses. However, the data obtained using this technique allow multiple interpretations, depending on the methodology implemented. Hence, it is necessary to establish a robust methodology to reliably follow-up biomass in fermentations. In the present work, two methodological approaches, mainly used for the characterization of electrochemical systems, were employed to characterize and determine a frequency that allows the monitoring of biomass in Bacillus thuringiensis fermentations by impedance spectroscopy. The first approach, based on a conventional analysis, revealed a single distribution with a characteristic frequency of around 2 kHz. In contrast, the second approach, based on the distribution of relaxation times, gave three distributions (A, B, and C). The C distribution, found near 9 kHz, was more related to the microbial biomass than the distribution at 2 kHz using the equivalent circuits. The time course of the B. thuringiensis fermentation was followed; bacilli, spores, glucose, and acid and base consumption for pH were determined out of line; and capacitance at 9 kHz was monitored. The correlation between the time course data and the capacitance profile indicated that the monitoring of B. thuringiensis at 9 kHz mainly corresponds to extracellular activity and, in a second instance, to the cellular concentration. These results show that it is necessary to establish a robust and reliable methodology to monitor fermentation processes by impedance spectroscopy, and the distribution of relaxation times was more appropriate. KEY POINTS: • Application of impedance spectroscopy for bioprocess monitoring • Low-frequency monitoring of biomass in fermentations • Analysis of impedance data by two methodological approaches.
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Affiliation(s)
- Adrián Díaz Pacheco
- Instituto Politécnico Nacional, Centro de Investigación en Biotecnología Aplicada, Carretera Estatal Santa Inés Tecuexcomac- Tepetitla, km 1.5, Tepetitla de Lardizábal, Tlaxcala, C.P. 90700, México
| | - Raul Jacobo Delgado-Macuil
- Instituto Politécnico Nacional, Centro de Investigación en Biotecnología Aplicada, Carretera Estatal Santa Inés Tecuexcomac- Tepetitla, km 1.5, Tepetitla de Lardizábal, Tlaxcala, C.P. 90700, México
| | - Claudia Patricia Larralde-Corona
- Instituto Politécnico Nacional, Centro de Biotecnología Genómica, Blvd. del Maestro S/N Esq. Elías Piña. Col. Narciso Mendoza, Reynosa, Tamaulipas, C.P. 88710, México
| | - Jabel Dinorín-Téllez-Girón
- Universidad Politécnica de Tlaxcala, Av. Universidad Politécnica No.1 San Pedro Xalcaltzinco, 90180, Tepeyanco, Tlaxcala, México
| | - Francisco Martínez Montes
- Instituto Politécnico Nacional, Centro de Investigación en Biotecnología Aplicada, Carretera Estatal Santa Inés Tecuexcomac- Tepetitla, km 1.5, Tepetitla de Lardizábal, Tlaxcala, C.P. 90700, México
| | - Shirlley E Martinez Tolibia
- Instituto Politécnico Nacional, Centro de Investigación en Biotecnología Aplicada, Carretera Estatal Santa Inés Tecuexcomac- Tepetitla, km 1.5, Tepetitla de Lardizábal, Tlaxcala, C.P. 90700, México
| | - Victor Eric López Y López
- Instituto Politécnico Nacional, Centro de Investigación en Biotecnología Aplicada, Carretera Estatal Santa Inés Tecuexcomac- Tepetitla, km 1.5, Tepetitla de Lardizábal, Tlaxcala, C.P. 90700, México.
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da Silva TAF, de Freitas LS, da Silva LVJB, Duarte Neto JMW, da Silva GR, Maranhão LMDAC, de Lacerda CA, Oliveira JDP, Bezerra RP, Porto ALF. Effect of the volumetric oxygen mass transfer coefficient on producing δ-endotoxins by Bacillus thuringiensis in culture medium based on forage palm. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2021. [DOI: 10.1016/j.bcab.2021.101960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Mass Transfer and Rheological Characteristics in a Stirred Tank Bioreactor for Cultivation of Escherichia coli BL21. BIOTECHNOL BIOPROC E 2020. [DOI: 10.1007/s12257-020-0028-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Jallouli W, Driss F, Fillaudeau L, Rouis S. Review on biopesticide production by Bacillus thuringiensis subsp. kurstaki since 1990: Focus on bioprocess parameters. Process Biochem 2020. [DOI: 10.1016/j.procbio.2020.07.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Mejias L, Estrada M, Barrena R, Gea T. A novel two-stage aeration strategy for Bacillus thuringiensis biopesticide production from biowaste digestate through solid-state fermentation. Biochem Eng J 2020. [DOI: 10.1016/j.bej.2020.107644] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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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: 1.0] [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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Wang T, Lu Y, Yan H, Li X, Wang X, Shan Y, Yi Y, Liu B, Zhou Y, Lü X. Fermentation optimization and kinetic model for high cell density culture of a probiotic microorganism: Lactobacillus rhamnosus LS-8. Bioprocess Biosyst Eng 2019; 43:515-528. [PMID: 31712884 DOI: 10.1007/s00449-019-02246-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 10/30/2019] [Indexed: 12/15/2022]
Abstract
To develop a practical food-grade medium and optimal fermentation process for the cost-effective fermentation of Lactobacillus rhamnosus LS-8, both culture medium and conditions were optimized by combining single-factor experimental design, Plackett-Burman design and Box-Behnken design. The medium was simplified to five ingredients (g/L): whey powder (62.5), maltose syrup (50), corn steep liquor (55), NaCl (1) and lysine (0.05), and the optimal culture conditions were initial pH (6.28), constant fermentation pH (4.7), neutralizing agent (NaOH), aeration rate (0.2 v/v/min) and stirrer speed (200 rpm). After culturing in this optimized medium and conditions, the cell density of L. rhamnosus LS-8 was improved to 4.5 × 109 CFU/mL, which was elevated about 9 times higher than that obtained in MRS medium. Moreover, cell growth and substrate consumption kinetic constants were determined by the logistic equation and Luedeking-Piret model, and the R2 values from the model equation were 0.9900 and 0.9971, respectively, indicating that these models were able to simulate the growth and substrate consumption of L. rhamnosus LS-8 accurately. In addition, a high-efficient production process of L. rhamnosus LS-8 was developed by repeated-batch operation, which was verified by five cycles of fermentation with good stability and repeatability. In conclusion, the efficiency of L. rhamnosus LS-8 fermentation was greatly improved as well as the reduction of the cost using the medium and process developed in the present study.
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Affiliation(s)
- Tao Wang
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Yingying Lu
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Hong Yan
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Xin Li
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Xin Wang
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Yuanyuan Shan
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Yanglei Yi
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Bianfang Liu
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Yuan Zhou
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Xin Lü
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi Province, China.
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Lima-Pérez J, López-Pérez M, Viniegra-González G, Loera O. Solid-state fermentation of Bacillus thuringiensis var kurstaki HD-73 maintains higher biomass and spore yields as compared to submerged fermentation using the same media. Bioprocess Biosyst Eng 2019; 42:1527-1535. [DOI: 10.1007/s00449-019-02150-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 05/08/2019] [Indexed: 01/02/2023]
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Fulazzaky MA, Nuid M, Aris A, Muda K. Mass transfer kinetics of biosorption of nitrogenous matter from palm oil mill effluent by aerobic granules in sequencing batch reactor. ENVIRONMENTAL TECHNOLOGY 2018; 39:2151-2161. [PMID: 28675960 DOI: 10.1080/09593330.2017.1351494] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 07/01/2017] [Indexed: 06/07/2023]
Abstract
Understanding of mass transfer kinetics is important for biosorption of nitrogen compounds from palm oil mill effluent (POME) to gain a mechanistic insight into future biological processes for the treatment of high organic loading wastewater. In this study, the rates of global and sequential mass transfer were determined using the modified mass transfer factor equations for the experiments to remove nitrogen by aerobic granular sludge accumulation in a sequencing batch reactor (SBR). The maximum efficiencies as high as 97% for the experiment run at [kLa]g value of 1421.8 h-1 and 96% for the experiment run at [kLa]g value of 9.6 × 1037 h-1 were verified before and after the addition of Serratia marcescens SA30, respectively. The resistance of mass transfer could be dependent on external mass transfer that controls the transport of nitrogen molecule along the experimental period of 256 days. The increase in [kLa]g value leading to increased performance of the SBR was verified to contribute to the future applications of the SBR because this phenomenon provides new insight into the dynamic response of biological processes to treat POME.
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Affiliation(s)
- Mohamad Ali Fulazzaky
- a Directorate General of Water Resources, Ministry of Public Works and Housing , Jakarta , Indonesia
- b Islamic Science Research Network , Muhammadiyah University of Hamka , Jakarta , Indonesia
- c Centre for Environmental Sustainability and Water Security , Research Institute for Sustainable Environment, Universiti Teknologi Malaysia , Johor Bahru , Malaysia
| | - Maria Nuid
- c Centre for Environmental Sustainability and Water Security , Research Institute for Sustainable Environment, Universiti Teknologi Malaysia , Johor Bahru , Malaysia
- d Department of Environmental Engineering, Faculty of Civil Engineering , Universiti Teknologi Malaysia , Johor Bahru , Malaysia
| | - Azmi Aris
- c Centre for Environmental Sustainability and Water Security , Research Institute for Sustainable Environment, Universiti Teknologi Malaysia , Johor Bahru , Malaysia
| | - Khalida Muda
- d Department of Environmental Engineering, Faculty of Civil Engineering , Universiti Teknologi Malaysia , Johor Bahru , Malaysia
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Rojas NL, Lewkowicz ES, Nobile ML. Alternative low-cost process for large-scale production of Bacillus thuringiensis in a simple and novel culture system. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART. B, PESTICIDES, FOOD CONTAMINANTS, AND AGRICULTURAL WASTES 2018; 53:719-728. [PMID: 29869930 DOI: 10.1080/03601234.2018.1480156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 04/28/2018] [Indexed: 06/08/2023]
Abstract
An industrial-scale, profitable method for production of the most widely used bioinsecticide, Bacillus thuringiensis (Bt), is challenging because of its widespread application. The aim of this study is to present a strategy to develop a low-cost, large-scale bioprocess to produce Bt H14. This study was first focused on the design of a culture medium composed of economical and available components, such as glycerol and lysed Saccharomyces cerevisiae. The production goal of 1200 ITU was achieved using a medium composed of 20:20 g L-1of glycerol:lysed yeast in batch cultures. Efforts were subsequently focused on the design of an appropriate culture system, and an original two-stage culture system was proposed. First, yeast (the primary component of the culture medium) are cultivated using a minimal mineral medium and lysed, and in the second stage, Bt is cultivated in the same bioreactor using the lysed yeasts as culture medium (supplemented with a feeding pulse of 10 g L-1 glycerol). This system was called fed batch one pot (FOP). A new inoculation strategy is also presented in this study, since these Bt cultures were inoculated directly with heat pre-treated spores instead of vegetative bacteria to facilitate the bioprocess. This study was developed from the laboratory to production-scale bioreactors (measuring from 500 mL to 2500 L), and the efficiency of the proposed strategy was evident in LD50 tests results, achieving 1796 ITU in large-scale processes. Both the use of non-conventional sources and the process development for biomass production are important for cost-effective production of Bt-based insecticides in mosquito control projects.
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Affiliation(s)
- Natalia L Rojas
- a Universidad Nacional de Quilmes , CONICET, Departamento de Ciencia y Tecnología, IMBA , Quilmes , Argentina
| | - Elizabeth S Lewkowicz
- b Universidad Nacional de Quilmes , CONICET, Departamento de Ciencia y Tecnología, LBB , Quilmes , Argentina
| | - Matias L Nobile
- b Universidad Nacional de Quilmes , CONICET, Departamento de Ciencia y Tecnología, LBB , Quilmes , Argentina
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