Introduction Unconventional alternatives such as aerobic and anaerobic effluent from starch industry contain essential nutrients for Btk active ingredient synthesis.Effluent from starch industry is rich in carbon and ...Introduction Unconventional alternatives such as aerobic and anaerobic effluent from starch industry contain essential nutrients for Btk active ingredient synthesis.Effluent from starch industry is rich in carbon and nitrogen and can replace expensive feedstock used during the fermentation process.Objectives The main objective of this study was to achieve a biopesticide formulation from starch industry wastewater(SIW)with high entomotoxicity(UI/ml)of larvae comparable to Foray 76B,which is a commercial biopesticide.Methods Bacillus thuringiensis var kurstaki HD1(Btk)strain was cultivated and sub-cultured to aerobic,anaerobic digested effluent and SIW.Pre-treatment was carried on these different substrates to enhance the residual carbon required for Btk growth and delta endotoxin synthesis.After 48 hours of fermentation,cells count and delta-endotoxin were determined.A biopesticide formulation containing fermented broth and adjuvants was fed to larvae to determine larvae mortality.Results Btk cell growth and sporulation profile in SIW media displayed a high total cell count and viable spores compared to btk growth in anaerobic or aerobic media after 48h fermentation.The maximum endotoxin concentration in the SIW medium was 435μg/mL,whereas,in anaerobic and aerobic effluent,the maximum concentrations were at 161μg/mL and 136μg/mL,respectively.When acidic treatment was performed at pH 2 for these substrates,entomotoxicity obtained from aerobic and anaerobic biopesticide formulations displayed significantly higher entomoxicity than the untreated ones.The entomotoxicity of SIW treated at pH 2 was equivalent to the standard Foray 76B which is 20,000 IU/μL.Conclusion Anaerobic and aerobic effluent did not contain enough total organic carbon to augment Btk growth and entomo-toxicity.Substrates pre-treated at pH 2 provided significant organic matter for Btk growth and resulted in larval mortality equivalent to the com ercial biopesticide Foray 76B.展开更多
Extracellular polymeric substances(EPS)are eco-friendly and economical biopolymers with a significant role in pollutant removal,bio-flocculation,settling and dewatering of activated sludge.In this study,growth profile...Extracellular polymeric substances(EPS)are eco-friendly and economical biopolymers with a significant role in pollutant removal,bio-flocculation,settling and dewatering of activated sludge.In this study,growth profile and EPS production by an EPS-producing microbial strain(isolated from wastewater sludge or WWS)was studied using activated sludge fortified with glycerol.The study compared three crude glycerol samples as carbon sources from different biodiesel companies(BIO-LIQ,BIOCARDEL,ROTHSAY)and their effect on EPS production and characterisation was observed.The maximum slime EPS(S-EPS)concentration(12.34 g/L)was produced when sludge fortified with BIO-LIQ crude glycerol was used,higher than pure glycerol(10 g/L)at 72 h.The S-EPS was enhanced(16 g/L)when purified BIO-LIQ glycerol(by acid treatment)was used.It was also observed that S-EPS concentration increased 1.6-2.6 times by using sludge fortified with glycerol as compared to only glycerol(no sludge)as EPS production medium.In addition,the S-EPS produced from different glycerol samples yielded different characteristics in terms of protein-carbohydrate content,flocculation activity and dewaterability.The S-EPS from purified BIO-LIQ glycerol(with sludge)gave maximum flocculation activity and dewaterability i.e.93.71%and 60.2%respectively.The comparison between Ca(OH)2 and NaOH used as alkaline sludge pre-treatment methods revealed that the EPS produced from Ca(OH)_(2)-treated sludge fortified with glycerol solutions to be better in terms of protein content,flocculation activity and dewaterability.Structural composition analysis using Fourier Transform Infrared Spectroscopy(FT-IR)revealed the presence of distinct functional groups(carboxyl,hydroxyl,amine groups)in the produced S-EPS.展开更多
In the present study,municipal secondary sludge and purified glycerol(obtained after acid treatment of crude glycerol)were used together for lipid production using intermittent feeding strategy.Intermittent sludge fee...In the present study,municipal secondary sludge and purified glycerol(obtained after acid treatment of crude glycerol)were used together for lipid production using intermittent feeding strategy.Intermittent sludge feeding strategy(sludge SS 30 g/L)resulted in a higher biomass(54.99 g/L)and lipid concentration(25.35 g/L)at 96 h when compared to 35 g/L SS single sludge feeding or control strategy(45.67 g/L biomass&19.16 g/L lipid).Moreover,the intermittent sludge feeding strategy significantly reduced foaming and requirement of anti-foam during fermentation when compared to control strategy.The energy balance of biodiesel production from lipid obtained by intermittent sludge feeding strategy(30 g/L SS)was energeti-cally favorable.It was also revealed from yield coefficients and energy balance that sludge had an important contribution in microbial lipid and biodiesel production.展开更多
Purified glycerol obtained after acid treatment of crude glycerol solution was used as the carbon source for lipid and citric acid production using Y.lipolytica SKY7.Although purified glycerol was high in phosphorus,i...Purified glycerol obtained after acid treatment of crude glycerol solution was used as the carbon source for lipid and citric acid production using Y.lipolytica SKY7.Although purified glycerol was high in phosphorus,it was important to inves-tigate the impact of fortification of trace elements in the medium on cell growth,lipid and citric acid(CA)production.When all the trace elements(including phosphates and sulfates)required for growth and lipid production were added to the purified glycerol medium,high biomass(51.67 g/L)and lipid concentration(19.47 g/L)were observed at 96 h of fed-batch fermentation with low CA concentration of 5.42 g/L.The purified glycerol medium without additional trace elements gave low biomass(27.67 g/L),lipid concentration(9.35 g/L)at 80 h of fed-batch fermentation,but gave high CA concentration(24.51 g/L).When purified glycerol was provided with only sulfates or all elements except KH_(2)PO_(4),low biomass(32.59 g/L and 38.52 g/L)and citric acid concentration(1 g/L and 2.42 g/L)were obtained at 96 h.展开更多
Extracellular polymeric substances(EPSs)play a crucial role in various applications,especially in wastewater treatment.This review explores the importance of EPS in modern treatment methods,emphasizing its organic pol...Extracellular polymeric substances(EPSs)play a crucial role in various applications,especially in wastewater treatment.This review explores the importance of EPS in modern treatment methods,emphasizing its organic polymeric nature and properties that aid in effective pollutant removal and resource conservation.The study focuses on biological strategies utilizing microbial and bacterial communities,as well as electrolyte precipitate systems containing various components such as uronic acids,proteins,and carbohydrates that are essential for treatment processes.This review also describes the complex mechanisms regulating EPS biosynthesis,highlighting the impact of factors such as temperature,light intensity,and carbon to nitrogen ratio on EPS production.These findings emphasizes the influence of carbon supply and nitrogen sources on EPS formation,shedding light on the relationship between environmental conditions and EPS synthesis.In addition,this study discusses the significance of EPS extraction techniques for maintaining material integrity.Furthermore,the review explores the broad applications of EPS beyond wastewater treatment,including soil aggregation,pharmaceuticals,the food industry,and sustainable energy generation through EPS-driven microbial fuel cells.Understanding the diverse functions of EPS has the potential to improve environmental practices,mitigate climate change effects,and enhance industrial processes towards sustainability and efficiency.The versatility of EPS underscores its transformative impact on environmental and industrial practices.展开更多
基金The research has been funded by Natural Sciences and Engineering Research Council of Canada(Grants A4984,STR 202047,SCF 192190-96 and Canada Research Chair).
文摘Introduction Unconventional alternatives such as aerobic and anaerobic effluent from starch industry contain essential nutrients for Btk active ingredient synthesis.Effluent from starch industry is rich in carbon and nitrogen and can replace expensive feedstock used during the fermentation process.Objectives The main objective of this study was to achieve a biopesticide formulation from starch industry wastewater(SIW)with high entomotoxicity(UI/ml)of larvae comparable to Foray 76B,which is a commercial biopesticide.Methods Bacillus thuringiensis var kurstaki HD1(Btk)strain was cultivated and sub-cultured to aerobic,anaerobic digested effluent and SIW.Pre-treatment was carried on these different substrates to enhance the residual carbon required for Btk growth and delta endotoxin synthesis.After 48 hours of fermentation,cells count and delta-endotoxin were determined.A biopesticide formulation containing fermented broth and adjuvants was fed to larvae to determine larvae mortality.Results Btk cell growth and sporulation profile in SIW media displayed a high total cell count and viable spores compared to btk growth in anaerobic or aerobic media after 48h fermentation.The maximum endotoxin concentration in the SIW medium was 435μg/mL,whereas,in anaerobic and aerobic effluent,the maximum concentrations were at 161μg/mL and 136μg/mL,respectively.When acidic treatment was performed at pH 2 for these substrates,entomotoxicity obtained from aerobic and anaerobic biopesticide formulations displayed significantly higher entomoxicity than the untreated ones.The entomotoxicity of SIW treated at pH 2 was equivalent to the standard Foray 76B which is 20,000 IU/μL.Conclusion Anaerobic and aerobic effluent did not contain enough total organic carbon to augment Btk growth and entomo-toxicity.Substrates pre-treated at pH 2 provided significant organic matter for Btk growth and resulted in larval mortality equivalent to the com ercial biopesticide Foray 76B.
文摘Extracellular polymeric substances(EPS)are eco-friendly and economical biopolymers with a significant role in pollutant removal,bio-flocculation,settling and dewatering of activated sludge.In this study,growth profile and EPS production by an EPS-producing microbial strain(isolated from wastewater sludge or WWS)was studied using activated sludge fortified with glycerol.The study compared three crude glycerol samples as carbon sources from different biodiesel companies(BIO-LIQ,BIOCARDEL,ROTHSAY)and their effect on EPS production and characterisation was observed.The maximum slime EPS(S-EPS)concentration(12.34 g/L)was produced when sludge fortified with BIO-LIQ crude glycerol was used,higher than pure glycerol(10 g/L)at 72 h.The S-EPS was enhanced(16 g/L)when purified BIO-LIQ glycerol(by acid treatment)was used.It was also observed that S-EPS concentration increased 1.6-2.6 times by using sludge fortified with glycerol as compared to only glycerol(no sludge)as EPS production medium.In addition,the S-EPS produced from different glycerol samples yielded different characteristics in terms of protein-carbohydrate content,flocculation activity and dewaterability.The S-EPS from purified BIO-LIQ glycerol(with sludge)gave maximum flocculation activity and dewaterability i.e.93.71%and 60.2%respectively.The comparison between Ca(OH)2 and NaOH used as alkaline sludge pre-treatment methods revealed that the EPS produced from Ca(OH)_(2)-treated sludge fortified with glycerol solutions to be better in terms of protein content,flocculation activity and dewaterability.Structural composition analysis using Fourier Transform Infrared Spectroscopy(FT-IR)revealed the presence of distinct functional groups(carboxyl,hydroxyl,amine groups)in the produced S-EPS.
基金This research has been funded by the Natural Sciences and Engineering Research Council of Canada(Grant A4984).
文摘In the present study,municipal secondary sludge and purified glycerol(obtained after acid treatment of crude glycerol)were used together for lipid production using intermittent feeding strategy.Intermittent sludge feeding strategy(sludge SS 30 g/L)resulted in a higher biomass(54.99 g/L)and lipid concentration(25.35 g/L)at 96 h when compared to 35 g/L SS single sludge feeding or control strategy(45.67 g/L biomass&19.16 g/L lipid).Moreover,the intermittent sludge feeding strategy significantly reduced foaming and requirement of anti-foam during fermentation when compared to control strategy.The energy balance of biodiesel production from lipid obtained by intermittent sludge feeding strategy(30 g/L SS)was energeti-cally favorable.It was also revealed from yield coefficients and energy balance that sludge had an important contribution in microbial lipid and biodiesel production.
文摘Purified glycerol obtained after acid treatment of crude glycerol solution was used as the carbon source for lipid and citric acid production using Y.lipolytica SKY7.Although purified glycerol was high in phosphorus,it was important to inves-tigate the impact of fortification of trace elements in the medium on cell growth,lipid and citric acid(CA)production.When all the trace elements(including phosphates and sulfates)required for growth and lipid production were added to the purified glycerol medium,high biomass(51.67 g/L)and lipid concentration(19.47 g/L)were observed at 96 h of fed-batch fermentation with low CA concentration of 5.42 g/L.The purified glycerol medium without additional trace elements gave low biomass(27.67 g/L),lipid concentration(9.35 g/L)at 80 h of fed-batch fermentation,but gave high CA concentration(24.51 g/L).When purified glycerol was provided with only sulfates or all elements except KH_(2)PO_(4),low biomass(32.59 g/L and 38.52 g/L)and citric acid concentration(1 g/L and 2.42 g/L)were obtained at 96 h.
基金National Sciences and Engineering Research Council of Canada(NSERC),No.498017-2017,Allali Patrick Drogui.
文摘Extracellular polymeric substances(EPSs)play a crucial role in various applications,especially in wastewater treatment.This review explores the importance of EPS in modern treatment methods,emphasizing its organic polymeric nature and properties that aid in effective pollutant removal and resource conservation.The study focuses on biological strategies utilizing microbial and bacterial communities,as well as electrolyte precipitate systems containing various components such as uronic acids,proteins,and carbohydrates that are essential for treatment processes.This review also describes the complex mechanisms regulating EPS biosynthesis,highlighting the impact of factors such as temperature,light intensity,and carbon to nitrogen ratio on EPS production.These findings emphasizes the influence of carbon supply and nitrogen sources on EPS formation,shedding light on the relationship between environmental conditions and EPS synthesis.In addition,this study discusses the significance of EPS extraction techniques for maintaining material integrity.Furthermore,the review explores the broad applications of EPS beyond wastewater treatment,including soil aggregation,pharmaceuticals,the food industry,and sustainable energy generation through EPS-driven microbial fuel cells.Understanding the diverse functions of EPS has the potential to improve environmental practices,mitigate climate change effects,and enhance industrial processes towards sustainability and efficiency.The versatility of EPS underscores its transformative impact on environmental and industrial practices.
