1
|
Lei X, Zhang F, Zhang J. Gut Microbiota Accelerate the Insecticidal Activity of Plastid-Expressed Bacillus thuringiensis Cry3Bb to a Leaf Beetle, Plagiodera versicolora. Microbiol Spectr 2023; 11:e0504922. [PMID: 36976001 PMCID: PMC10101071 DOI: 10.1128/spectrum.05049-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 02/27/2023] [Indexed: 03/29/2023] Open
Abstract
Bacillus thuringiensis is widely used as a biopesticide, and its crystal protein expressed in transgenic crops has been successfully used for the management of insect pests. However, whether the midgut microbiota contribute to the Bt insecticidal mechanism remains controversial. We previously demonstrated that transplastomic poplar plants expressing Bt Cry3Bb are highly lethal to willow leaf beetle (Plagiodera versicolora), one of the major pests causing severe damage to Salicaceae plants such as willows and poplars. Here, we demonstrate that feeding poplar leaves expressing Cry3Bb to nonaxenic P. versicolora larvae leads to significantly accelerated mortality, and overgrowth and dysbiosis of the gut microbiota, compared with axenic larvae. Corroborating work done with Lepidopteran insects, plastid-expressed Cry3Bb can cause the lysis of the beetle's intestinal cells, lead to the entry of intestinal bacteria into the body cavity, and thus cause the dynamic changes in the flora of the midgut and blood cavity in P. versicolora. Reintroduction of Pseudomonas putida, a gut bacterium of P. versicolora, into axenic P. versicolora larvae further enhances mortality upon feeding on Cry3Bb-expressing poplar. Our results indicate the important contribution of host gut microbiota in promoting the B. thuringiensis crystal protein insecticidal activity and provide new insights into the mechanism of pest control by Bt-transplastomic approaches. IMPORTANCE The contribution of gut microbiota to Bacillus thuringiensis Cry3Bb insecticidal activity in a leaf beetle was demonstrated using transplastomic poplar plants, providing a potential new approach to improve the efficiency of plastid transformation technology for pest control by expression of Bt toxins.
Collapse
Affiliation(s)
- Xiaoyu Lei
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Hongshan Laboratory, School of Life Sciences, Hubei University, Wuhan, China
| | - Fengjuan Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Hongshan Laboratory, School of Life Sciences, Hubei University, Wuhan, China
| | - Jiang Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Hongshan Laboratory, School of Life Sciences, Hubei University, Wuhan, China
- Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| |
Collapse
|
2
|
Kumar LR, Ndao A, Valéro J, Tyagi RD. Production of Bacillus thuringiensis based biopesticide formulation using starch industry wastewater (SIW) as substrate: A techno-economic evaluation. BIORESOURCE TECHNOLOGY 2019; 294:122144. [PMID: 31542498 DOI: 10.1016/j.biortech.2019.122144] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 09/06/2019] [Accepted: 09/07/2019] [Indexed: 06/10/2023]
Abstract
In this study, cost simulation was made to produce Bacillus thuriengiensis based biopesticide formulation using starch industry wastewater (SIW) as substrate. The results obtained at pilot plant (2000L capacity fermenter) were used for cost simulation of the process. The unit production cost for annual production of 5 million L of formulated biopesticide (20.2 Billion International Units (BIU)/L) was estimated to be $ 2.54/L, which is competitive to chemical pesticides. The techno-economic evaluation revealed that the profitability of the biopesticide manufacturing process was sensitive to the plant capacity and selling price of the biopesticide. The manufacturer should target 5 million L annual plant capacity and selling price of $ 15/L for payback period to be less than 5 years. The process serves many advantages (1) alternate disposal or bio-valorisation of industry wastewater and (2) use of industry wastewater as inexpensive carbon source reducing cost of raw materials for fermentation.
Collapse
Affiliation(s)
- Lalit R Kumar
- INRS Eau, Terre et Environnement, 490, rue de la Couronne, Québec G1K 9A9, Canada
| | - Adama Ndao
- INRS Eau, Terre et Environnement, 490, rue de la Couronne, Québec G1K 9A9, Canada
| | - Jose Valéro
- INRS Eau, Terre et Environnement, 490, rue de la Couronne, Québec G1K 9A9, Canada
| | - R D Tyagi
- INRS Eau, Terre et Environnement, 490, rue de la Couronne, Québec G1K 9A9, Canada.
| |
Collapse
|
3
|
Jeong SY, Chang SW, Ngo HH, Guo W, Nghiem LD, Banu JR, Jeon BH, Nguyen DD. Influence of thermal hydrolysis pretreatment on physicochemical properties and anaerobic biodegradability of waste activated sludge with different solids content. WASTE MANAGEMENT (NEW YORK, N.Y.) 2019; 85:214-221. [PMID: 30803575 DOI: 10.1016/j.wasman.2018.12.026] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 12/11/2018] [Accepted: 12/20/2018] [Indexed: 05/22/2023]
Abstract
The influence of thermal hydrolysis pretreatment (THP) on physicochemical properties (pH, total solids, volatile solids, chemical oxygen demand, total nitrogen, ammonium nitrogen, volatile fatty acids, viscosity, and cell morphology) and anaerobic biodegradability of highly concentrated waste activated sludge (WAS) with TS content ranging from 1 to 7% was evaluated at different temperatures ranging from 100 to 220 °C. The biomethane potential (BMP) of the WAS was systematically analyzed and evaluated. Images of its cellular structure were also analyzed. The results indicated that THP is a useful method for solubilizing volatile solids and enhancing CH4 production regardless of the TS content of the WAS feed. The ultimate CH4 production determined from the BMP analysis was 313-348 L CH4/kg VS (72.6-74.1% CH4) at the optimum THP temperature of 180 °C. The results showed that THP could improve both the capacity and efficiency of anaerobic digestion, even at a high TS content, and could achieve the dual purpose of sludge reduction and higher energy recovery.
Collapse
Affiliation(s)
- Seong Yeob Jeong
- Department of Environmental Energy Engineering, Kyonggi University, 442-760, Republic of Korea
| | - Soon Woong Chang
- Department of Environmental Energy Engineering, Kyonggi University, 442-760, Republic of Korea.
| | - Huu Hao Ngo
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney (UTS), Australia
| | - Wenshan Guo
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney (UTS), Australia
| | - Long D Nghiem
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney (UTS), Australia
| | - J Rajesh Banu
- Department of Civil Engineering, Anna University Regional Campus, Tirunelveli 627007, Tamil Nadu, India
| | - Byong-Hun Jeon
- Department of Earth Resources and Environmental Engineering, Hanyang University, Seoul, Republic of Korea
| | - Dinh Duc Nguyen
- Department of Environmental Energy Engineering, Kyonggi University, 442-760, Republic of Korea; Institute of Research and Development, Duy Tan University, Da Nang, Vietnam.
| |
Collapse
|
4
|
Ndao A, Sellamuthu B, Gnepe JR, Tyagi RD, Valero JR. Pilot-scale biopesticide production by Bacillus thuringiensis subsp. kurstaki using starch industry wastewater as raw material. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART. B, PESTICIDES, FOOD CONTAMINANTS, AND AGRICULTURAL WASTES 2017; 52:623-630. [PMID: 28586277 DOI: 10.1080/03601234.2017.1330071] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Pilot-scale Bacillus thuringiensis based biopesticide production (2000 L bioreactor) was conducted using starch industry wastewater (SIW) as a raw material using optimized operational parameters obtained in 15 L and 150 L fermenters. In pilot scale fermentation process the oxygen transfer rate is a major limiting factor for high product yield. Thus, the volumetric mass transfer coefficient (KLa) remains a tool to determine the oxygen transfer capacity [oxygen utilization rate (OUR) and oxygen transfer rate (OTR)] to obtain better bacterial growth rate and entomotoxicity in new bioreactor process optimization and scale-up. This study results demonstrated that the oxygen transfer rate in 2000 L bioreactor was better than 15 L and 150 L fermenters. The better oxygen transfer in 2000 L bioreactor augmented the bacterial growth [total cell (TC) and viable spore count (SC)] and delta-endotoxin yield. Prepared a stable biopesticide formulation for field use and its entomotoxicity was also evaluated. This study result corroborates the feasibility of industrial scale operation of biopesticide production using starch industry wastewater as raw material.
Collapse
Affiliation(s)
- Adama Ndao
- a INRS-ETE, Université du Québec , Québec , Canada
| | | | - Jean R Gnepe
- a INRS-ETE, Université du Québec , Québec , Canada
| | | | | |
Collapse
|
5
|
Jallouli W, Sellami S, Sellami M, Tounsi S. Impact of liquid formulation based on ultrafiltration-recovered bioactive components on toxicity of Bacillus thuringiensis subsp. kurstaki strain BLB1 against Ephestia kuehniella. Process Biochem 2014. [DOI: 10.1016/j.procbio.2014.07.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
6
|
Eshtiaghi N, Markis F, Yap SD, Baudez JC, Slatter P. Rheological characterisation of municipal sludge: a review. WATER RESEARCH 2013; 47:5493-5510. [PMID: 23899879 DOI: 10.1016/j.watres.2013.07.001] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 06/28/2013] [Accepted: 07/01/2013] [Indexed: 05/28/2023]
Abstract
Sustainable sludge management is becoming a major issue for wastewater treatment plants due to increasing urban populations and tightening environmental regulations for conventional sludge disposal methods. To address this problem, a good understanding of sludge behaviour is vital to improve and optimize the current state of wastewater treatment operations. This paper provides a review of the recent experimental works in order for researchers to be able to develop a reliable characterization technique for measuring the important properties of sludge such as viscosity, yield stress, thixotropy, and viscoelasticity and to better understand the impact of solids concentrations, temperature, and water content on these properties. In this context, choosing the appropriate rheological model and rheometer is also important.
Collapse
Affiliation(s)
- Nicky Eshtiaghi
- Rheology and Materials Processing Centre, Dept. of Chemical Engineering, RMIT University, Victoria 3001, Australia.
| | | | | | | | | |
Collapse
|
7
|
Bezawada J, Yan S, John RP, Tyagi RD, Surampalli RY. Recovery of Bacillus licheniformis Alkaline Protease from Supernatant of Fermented Wastewater Sludge Using Ultrafiltration and Its Characterization. BIOTECHNOLOGY RESEARCH INTERNATIONAL 2011; 2011:238549. [PMID: 21876816 PMCID: PMC3160599 DOI: 10.4061/2011/238549] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2011] [Revised: 04/30/2011] [Accepted: 05/03/2011] [Indexed: 11/29/2022]
Abstract
Investigation on recovery of alkaline protease from B. licheniformis ATCC 21424 fermented wastewater sludge was carried out by centrifugation and ultrafiltration. Optimization of ultrafiltration parameters (transmembrane pressure (TMP) and feed flux) was carried out with 10 kDa membrane. TMP of 90 kPa and feed flux of 714 L/h/m2 gave highest recovery (83%) of the enzyme from the centrifuged supernatant. The recovered enzyme had given maximum activity at temperature of 60°C and at pH 10. It was stable between pH 8 to 10 and retained 97% activity at 60°C after 180 min of incubation. Enzyme activity was significantly augmented by metal ions like Ca2+ and Mn2+. Protease inhibitors like phenylmethyl sulphonyl fluoride (PMSF) and diisopropyl fluorophosphates (DFPs) completely inhibited the enzyme activity. The partially purified protease showed excellent stability and compatibility with various commercial detergents. The detergent (Sunlight) removed the blood stains effectively along with the enzyme as additive.
Collapse
Affiliation(s)
- Jyothi Bezawada
- INRS-ETE, Université du Québec, 490, Rue de la Couronne, QC, Canada G1K 9A9
| | | | | | | | | |
Collapse
|
8
|
Effects of neutralizing agents on lactic acid production by Rhizopus oryzae using sweet potato starch. World J Microbiol Biotechnol 2009. [DOI: 10.1007/s11274-009-0186-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
9
|
Brar SK, Verma M, Tyagi RD, Valéro JR, Surampalli RY. Entomotoxicity, protease and chitinase activity of Bacillus thuringiensis fermented wastewater sludge with a high solids content. BIORESOURCE TECHNOLOGY 2009; 100:4317-4325. [PMID: 19447031 DOI: 10.1016/j.biortech.2007.09.093] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2006] [Revised: 09/12/2007] [Accepted: 09/12/2007] [Indexed: 05/27/2023]
Abstract
This study investigated the production of biopesticides, protease and chitinase activity by Bacillus thuringiensis grown in raw wastewater sludge at high solids concentration (30 g/L). The rheology of wastewater sludge was modified with addition of Tween-80 (0.2% v/v). This addition resulted in 1.6 and 1.3-fold increase in cell and spore count, respectively. The maximum specific growth rate (micro(max)) augmented from 0.17 to 0.22 h(-1) and entomotoxicity (Tx) increased by 29.7%. Meanwhile, volumetric mass transfer coefficient (k(L)a) showed marked variations during fermentation, and oxygen uptake rate (OUR) increased 2-fold. The proteolytic activity increased while chitinase decreased for Tween amended wastewater sludge, but the entomotoxicity increased. The specific entomotoxicity followed power law when plotted against spore concentration and the relation between Tx and protease activity was linear. The viscosity varied and volume percent of particles increased in Tween-80 amended wastewater sludge and particle size (D(50)) decreased at the end of fermentation. Thus, there was an increase in entomotoxicity at higher suspended solids (30 g/L) as Tween addition improved rheology (viscosity, particle size, surface tension); enhanced maximum growth rate and OUR.
Collapse
|
10
|
Adjalle K, Brar S, Tyagi R, Valéro J, Surampalli R. Photostabilization of Bacillus thuringiensis fermented wastewater and wastewater sludge based biopesticides using additives. Acta Trop 2009; 111:7-14. [PMID: 19100704 DOI: 10.1016/j.actatropica.2008.11.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2007] [Revised: 05/23/2008] [Accepted: 11/25/2008] [Indexed: 10/21/2022]
Abstract
Photoprotection (against UV-A and UV-B radiations) of the active components of Bacillus thuringiensis var. kurstaki obtained from the fermentation of various culture media was investigated. The culture media comprised: starch industry wastewater; secondary wastewater sludge (non-hydrolyzed and hydrolyzed) and soya (used as a reference). Photoprotection was carried out by using various UV-protection additives, namely, para-aminobenzoic acid, lignosulfonic acid and molasses at different concentrations (0.1%, 0.15% and 0.2%, w/w). In the absence of UV-protection agents, secondary sludge demonstrated natural UV protection with half-lives ranging from 3.25 to 3.4 d. The half-life for soya and starch industry wastewater was 1.9 and 1.8 d, respectively. Para-amino-benzoic acid as a UV-protection agent at 0.20% (w/w) gave excellent UV-protection for soya and starch industry wastewater with half-lives being 5.9 and 7 d, respectively. Likewise, lignosulfonic acid at 0.20% (w/w) was an effective photostabilizer for hydrolyzed and non-hydrolyzed secondary sludge with half-lives of 7.25 and 8 d, respectively. Hence, when similar concentration of the UV-protection additives was used, photoprotection was higher for the alternative media than the conventional soya medium, validating the technical feasibility of using three additives.
Collapse
|
11
|
Pham TTH, Brar SK, Tyagi RD, Surampalli RY. Ultrasonication of wastewater sludge--consequences on biodegradability and flowability. JOURNAL OF HAZARDOUS MATERIALS 2009; 163:891-898. [PMID: 18768255 DOI: 10.1016/j.jhazmat.2008.07.091] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Revised: 06/09/2008] [Accepted: 07/08/2008] [Indexed: 05/26/2023]
Abstract
The present study deals with pre-treatment of wastewater sludge by ultrasonic waves at frequency of 20 kHz using fully automated lab-scale ultrasonication equipment. Different wastewater sludge solids concentrations, ultrasonication intensities, and exposure times of pre-treatment were investigated for the optimization of ultrasonication treatment process. The parameters of pre-treatment process were optimized by using response surface methodology. A 2(3) central composite design was performed for optimization. The screening experiment step comprised steepest ascent methodology to determine optimal domain. The effect of ultrasonication treatment was assessed in terms of increase in soluble solids and the biodegradability of the wastewater sludge. In addition, rheological parameter of wastewater sludge, namely, viscosity was also measured to ascertain the suitability of wastewater sludge for conventional treatment processes as well as submerged fermentation, a major step for the production of value-added products from sludge. It was observed that the ultrasonication intensity and pre-treatment exposure time significantly affected the efficiency of the ultrasonication process followed by the solids concentration. The optimal conditions of ultrasonic pre-treatment were 0.75 W/cm(2) ultrasonication intensity, 60 min, and 23 g/L total solids concentration. The increases in soluble chemical oxygen demand and biodegradability, by aerobic sludge digestion process, in terms of total solids consumption increased by 45.5% and 56%, respectively. The flowability of ultrasonicated sludge in terms of viscosity showed exponential behaviour at different total solids concentrations, and pseudoplastic and thixotropic behaviour similar to raw sludge. Nevertheless, the magnitude of viscosity values of ultrasonicated sludge was always lower than the raw sludge.
Collapse
Affiliation(s)
- T T H Pham
- INRS-ETE, Université du Québec, 490 Rue de la Couronne, Québec, Canada
| | | | | | | |
Collapse
|
12
|
Barnabé S, Brar SK, Tyagi RD, Beauchesne I, Surampalli RY. Pre-treatment and bioconversion of wastewater sludge to value-added products--fate of endocrine disrupting compounds. THE SCIENCE OF THE TOTAL ENVIRONMENT 2009; 407:1471-88. [PMID: 19110297 DOI: 10.1016/j.scitotenv.2008.11.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2008] [Revised: 10/25/2008] [Accepted: 11/09/2008] [Indexed: 05/05/2023]
Abstract
Development of processes for the production of value added products (VAPs), such as biopesticides, microbial inoculants or industrial enzymes through biotransformation of raw or pre-treated wastewater sludge (WWS) has undergone a substantial progress over the last decade. WWS based VAPs are low cost biological alternatives that can compete with chemicals or other cost intensive biological products in the current markets. However, when WWS is used as a raw material for VAPs production, questions still remains on the persistence of organic pollutants within the biotransformed WWS, especially, endocrine disrupting compounds (EDCs) and the production of their toxic intermediates. WWS pre-treatment prior to biotransformation as well as the microbial strains used for biotransformation can possibly remove these organic pollutants. The literature findings concerning the impact of WWS pre-treatment and value added products on EDCs removal are reviewed in this paper. The microbial potential to degrade or detoxify EDCs and toxic intermediates concomitant with value-addition is also discussed. The concept of obtaining EDCs free-WWS based VAPs and simultaneously achieving the objective of pollution control is presented.
Collapse
Affiliation(s)
- S Barnabé
- Institut National de la Recherche Scientifique, Université du Québec, 490 rue de la Couronne, Québec, Québec, Canada G1K 9A9
| | | | | | | | | |
Collapse
|
13
|
Yan S, Subramanian SB, Tyagi RD, Surampalli RY. Bioplastics from Waste Activated Sludge-Batch Process. ACTA ACUST UNITED AC 2008. [DOI: 10.1061/(asce)1090-025x(2008)12:4(239)] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
|
14
|
Brar SK, Verma M, Tyagi RD, Surampalli RY, Valéro JR. Particle Size Variations during Production of Wastewater Sludge-BasedBacillus ThuringiensisBiopesticides. ACTA ACUST UNITED AC 2008. [DOI: 10.1061/(asce)1090-025x(2008)12:1(30)] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
|
15
|
Adjalle K, Brar S, Verma M, Tyagi R, Valero J, Surampalli R. Ultrafiltration recovery of entomotoxicity from supernatant of Bacillus thuringiensis fermented wastewater and wastewater sludge. Process Biochem 2007. [DOI: 10.1016/j.procbio.2007.06.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
16
|
|
17
|
Brar SK, Verma M, Tyagi RD, Valéro JR, Surampalli RY. Bacillus thuringiensis fermentation of hydrolyzed sludge--rheology and formulation studies. CHEMOSPHERE 2007; 67:674-83. [PMID: 17184817 DOI: 10.1016/j.chemosphere.2006.11.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2006] [Revised: 10/31/2006] [Accepted: 11/01/2006] [Indexed: 05/13/2023]
Abstract
Rheology of Bacillus thuringiensis fermentation of hydrolyzed sludge was investigated in bench scale fermenter. Stable liquid formulations were developed and optimized for two-year based studies comprising various physical/chemical (viscosity, particle size, corrosion and suspendibility) and biological (microbial contamination, viable spores and entomotoxicity) parameters at different pHs and temperatures. The hydrolyzed sludge depicted non-Newtonian and pseudoplastic behaviour during fermentation with 90% to 96% confidence of fits into Casson, Power and IPC paste models. Higher values of consistency and flow index during exponential growth and stationary phase, respectively, affected downstream processing. The power law was also followed by stable formulations. Sorbitol, sodium monophosphate and sodium metabisulfite (2.2:1:1) as suspending agents produced suspendibility ranging from 69% to 94%. The stable formulation (FH-4) comprising sorbitol, sodium monophosphate and sodium metabisulfite deteriorated at pHs 6, 6.5 and temperatures, 40 and 50 degrees C, with no signs of corrosion and microbial contamination. The viscosity of FH-4 formulations decreased with shear rate which could improve handling and consequent spraying.
Collapse
Affiliation(s)
- Satinder K Brar
- INRS-ETE, Université du Québec, 490, de la Couronne, Québec, Canada G1K 9A9
| | | | | | | | | |
Collapse
|
18
|
Brar SK, Verma M, Tyagi RD, Valéro JR, Surampalli RY. Efficient centrifugal recovery of Bacillus thuringiensis biopesticides from fermented wastewater and wastewater sludge. WATER RESEARCH 2006; 40:1310-20. [PMID: 16515801 DOI: 10.1016/j.watres.2006.01.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2005] [Revised: 11/27/2005] [Accepted: 01/21/2006] [Indexed: 05/06/2023]
Abstract
Studies were conducted on harvesting of Bacillus thuringiensis (Bt)-based biopesticides from fermented broths of starch industry wastewater (SIW), wastewater sludge (raw and hydrolyzed-NH and TH, respectively) and semi-synthetic soyameal to enhance entomotoxicity (Tx) by centrifugation. Pertinent factors influencing Tx, solids concentration, pH, temperature and centrifugal force were investigated. The centrifugate solids concentration beyond 100 g/l did not enhance Tx, instead caused pellet formation. Centrifugation efficiency (Tx recovery) was higher at pH 4, and temperature 20 degrees C for starch wastewater (98%), wastewater sludge (98% and 97.8% for non-hydrolyzed and hydrolyzed, respectively) and soya broth (83%). For maximum Tx recovery (SIW-95%; NH-90%; TH-98% and soya-78%), the centrifugal force and time required was 48,000 g and 30 min, respectively. Losses in recovery efficiency were lower for SIW and wastewater sludge in comparison to soya on adopting commercially recommended centrifugal force of 9000 g. The settling velocity computations for different fermented broths enabled calculation of Sigma factor for continuous commercial centrifuge of a given capacity and hence simulation of power requirements. It was established that power requirements for a given Tx recovery efficiency were highest for conventional medium (soya) in comparison to other waste-based fermented broths.
Collapse
Affiliation(s)
- Satinder K Brar
- INRS-ETE, Université du Québec, 490, Rue de la Couronne, Quebec, Canada G1K 9A9
| | | | | | | | | |
Collapse
|
19
|
|