Nicotinamide mononucleotide (NMN), a precursor of NAD+, can be synthesized by the conversion of n... more Nicotinamide mononucleotide (NMN), a precursor of NAD+, can be synthesized by the conversion of nicotinamide with the help of nicotinamide phosphoribosyl transferase (NAMPT) via the salvage pathway. NMN has recently gained great attention as an excellent therapeutic option due to its long-term effective pharmacological activities. In this study, we constructed a recombinant strain of Escherichia coli by inserting NAMPT and phosphoribosyl pyrophosphate synthetase 1 (PRPS1) and PRPS2 (from Homo sapiens) genes to investigate the effect of PRPS1 and PRPS2 on NMN synthesis. The metabolically engineered strain of E. coli BL21 (DE3) exhibited 1.57 mM NMN production in the presence of Mg2+ and phosphates in batch fermentation studies. For further improvement in NMN production levels, effects of different variables were studied using a response surface methodology approach. A significant increment was achieved with a maximum of 2.31 mM NMN production when supplemented with 1% ribose, 1 mM Mg2+ and phosphate, and 0.5% nicotinamide in the presence of a lactose (1%) inducer. Additionally, insertion of the PRPS1 and PRPS2 genes in the phosphoribosyl pyrophosphate synthesis pathway and individual gene expression studies facilitated a higher NMN production at the intracellular level than the reported studies. The strain exhibited intracellular production of NMN from cheap substrates such as glucose, lactose, and nicotinamide. Hence, the overall optimized process can be further scaled up for the economical production of NMN using a recombinant strain of E. coli BL21 (DE3), which is the future perspective of the current study.
High-density polycycloalkanes were first produced with cellulose by a highly integrated route tha... more High-density polycycloalkanes were first produced with cellulose by a highly integrated route that features a selective hydrogenolysis of cellulose to 2,5hexanedione under mild conditions, followed by the direct synthesis of polycycloalkanes with 2,5-hexanedione and hydrogen over a dual-bed catalyst system. The polycycloalkane mixture as obtained has a high density (0.88 g mL À1) and low freezing point (225 K). In real application, they can be used as advanced aviation fuel or additives to improve the volumetric heat values of conventional aviation fuels.
Method for production and regeneration of Acetobacter pasteurianum NCIM 2314 protoplasts are desc... more Method for production and regeneration of Acetobacter pasteurianum NCIM 2314 protoplasts are described. The protoplasts were obtained by treatment with lysozyme in protoplast buffer at pH 8.0 with different osmotic stabilizers. The protoplasts were regenerated on Acetobacter medium with various osmotic stabilizers. Maximum protoplasts formation was obtained in protoplasts buffer with NaC1 as an osmotic stabilizer using lysozyme (0.5mg/mL). Maximum protoplast regeneation was obtained on Acetobacter medium with NaCl (0.5M) as an osmotic stabilizer. The regeneration medium was also applicable to other species of Acetobactor as well. This is, to our knowledge, the first report on protoplast formation and efficient regeneration in case of Acetobacter pasteurianum. izLrkouk lw {etho ds lq /kkj es a iz ks Vks IykLV la y;u ,d mi;q Dr rduhd gS A ;g rduhd lw {ethoks a ds vla ca f/kr oa 'k ds chp es a la iw .kZ dks j dk fofue; djus es a mi;ks xh gS A ;g thu LFkkuka rj.k dh la LFkkfir vkS j...
Biodegradation of poly(ethylene terephthalate) modified with polyester "Bionolle Ò " by Penicilli... more Biodegradation of poly(ethylene terephthalate) modified with polyester "Bionolle Ò " by Penicillium funiculosum Summary-The purpose of the study was to determine the degree of biodegradation of poly(ethylene terephthalate) films modified with "Bionolle ® " polyester in comparison with films made of neat commercial poly(ethylene terephthalate). After 84-day incubation in the presence of filamentous fungi Penicillium funiculosum or their extracellular hydrolytic enzymes secreted by "Bionolle Ò " weight loss of the films was measured. The texture of the polymeric samples was observed with a scanning electron microscope. Important chemical changes of polymeric chains were detected by FT-IR and XPS analysis. Significant reduction in quantity of aromatic rings derived from terephthalic acid indicated that decomposition of films by fungi occurred not only due to hydrolytic enzymes but also oxidative ones. Moreover, we observed rather unilateral influence of poly(ethylene terephthalate) on biodegradation: addition of "Bionolle Ò " didn't accelerate significantly degradation of modified films and-what is more important-the presence of PET inhibited decomposition of easily biodegradable "Bionolle Ò ".
Method for production and regeneration of Lactobacillus delbrueckii protoplasts are described. Th... more Method for production and regeneration of Lactobacillus delbrueckii protoplasts are described. The protoplasts were obtained by treatment with a mixture of lysozyme and mutanolysin in protoplast buffer at pH 6.5 with different osmotic stabilizers. The protoplasts were regenerated on deMan, Rogosa and Sharpe (MRS) with various osmotic stabilizers. Maximum protoplast formation was obtained in protoplast buffer with sucrose as an osmotic stabilizer using a combination of lysozyme (1 mg/ml) and mutanolysin (10 µg/ml). Maximum protoplast regeneration was obtained on MRS medium with sucrose (0.5 M) as an osmotic stabilizer. The regeneration medium was also applicable to other species of lactobacilli as well. This is, to our knowledge, the first report on protoplast formation and efficient regeneration in case of L. delbrueckii.
... Mamta Singhvia, Dipti Joshia, Mukund Adsula, Anjani Varmab and Digambar Gokhale*a. a NCIM Res... more ... Mamta Singhvia, Dipti Joshia, Mukund Adsula, Anjani Varmab and Digambar Gokhale*a. a NCIM Resource Center, National Chemical laboratory, Dr Homi ... 15, SR Kadam, SS Patil, KB Bastawde, JM Khire and DV Gokhale, Process Biochem., 2006, 41, 120126 Article ChemPort ...
The present review mainly discusses advanced pretreatment techniques for converting lignocellulos... more The present review mainly discusses advanced pretreatment techniques for converting lignocellulosic biomass into hydrogen. The focus of this review is also to acquire knowledge concerning lignocellulosic biomass pretreatment processes and their impact on the efficiency of biohydrogen fermentation. The deconstruction of lignocellulosic biomass is presented using various pretreatment techniques albeit with several advantages and disadvantages, particularly about the interference due to the generated inhibitory compounds is toxic to microbes used for fermentation. The use of an appropriate pretreatment process can make the recalcitrant lignocellulosic biomass substrates amenable for further microbial fermentation to produce hydrogen. Although till date there is no ideal pretreatment step available to develop a cost-effective process for conversion of lignocellulosic materials into fermentable sugars, nanotechnology seem to be a more sustainable approach as compared to the traditional p...
Nicotinamide mononucleotide (NMN), a precursor of NAD+, can be synthesized by the conversion of n... more Nicotinamide mononucleotide (NMN), a precursor of NAD+, can be synthesized by the conversion of nicotinamide with the help of nicotinamide phosphoribosyl transferase (NAMPT) via the salvage pathway. NMN has recently gained great attention as an excellent therapeutic option due to its long-term effective pharmacological activities. In this study, we constructed a recombinant strain of Escherichia coli by inserting NAMPT and phosphoribosyl pyrophosphate synthetase 1 (PRPS1) and PRPS2 (from Homo sapiens) genes to investigate the effect of PRPS1 and PRPS2 on NMN synthesis. The metabolically engineered strain of E. coli BL21 (DE3) exhibited 1.57 mM NMN production in the presence of Mg2+ and phosphates in batch fermentation studies. For further improvement in NMN production levels, effects of different variables were studied using a response surface methodology approach. A significant increment was achieved with a maximum of 2.31 mM NMN production when supplemented with 1% ribose, 1 mM Mg2+ and phosphate, and 0.5% nicotinamide in the presence of a lactose (1%) inducer. Additionally, insertion of the PRPS1 and PRPS2 genes in the phosphoribosyl pyrophosphate synthesis pathway and individual gene expression studies facilitated a higher NMN production at the intracellular level than the reported studies. The strain exhibited intracellular production of NMN from cheap substrates such as glucose, lactose, and nicotinamide. Hence, the overall optimized process can be further scaled up for the economical production of NMN using a recombinant strain of E. coli BL21 (DE3), which is the future perspective of the current study.
Lignin degradation from corn cob utilizing doped nanoparticles for biofuel and biochemical produc... more Lignin degradation from corn cob utilizing doped nanoparticles for biofuel and biochemical production.
Employment of cellulase mimicking functionalized few-layer graphene (FFG) nanosheets for cellulos... more Employment of cellulase mimicking functionalized few-layer graphene (FFG) nanosheets for cellulose hydrolysis to replace enzymes completely/partially could aid in developing a sustainable process for bioethanol fermentation.
Due to the structural complexity and recalcitrance nature of lignin, its depolymerization into mo... more Due to the structural complexity and recalcitrance nature of lignin, its depolymerization into monomeric units becomes one of the biggest challenges in bioconversion of lignin into valueadded products. Depolymerization of lignin produces a blend of many compounds that are problematic for isolating components in a cost-effective way. Lignin valorization using a biological approach facilitates sustainable and commercially viable biorefineries. The use of microbes for the conversion of depolymerized lignin compounds into target products can be a solution to the heterogeneity issue. Several studies have been carried out to develop robust strains that can utilize all relevant lignin-derived compounds, but constructing these strains is difficult. As an alternative, designing multiple microbes to convert a mixture of various compounds into the desired product seems realistic. This review provides an overview of lignin bioconversion using various approaches such as metabolic engineering and synthetic biology. Ligninolytic strains have a broad enzymatic machine for depolymerization of lignin and its conversion into intermediates such as catechol or protocatechuate. These intermediates can be further converted to metabolite products such as polyhydroxyalkanoates and triacylglycerol. Synthetic biology offers encouraging methodologies to construct pathways for lignin conversion and to engineer ligninolytic microbes as prospective strains for lignin bioconversion.
The conversion of lignocellulosic biomass (LB) to sugar is an intricate process which is the cost... more The conversion of lignocellulosic biomass (LB) to sugar is an intricate process which is the costliest part of the biomass conversion process. Even though acid/enzyme catalysts are usually being used for LB hydrolysis, enzyme immobilization has been recognized as a potential strategy nowadays. The use of nanobiocatalysts increases hydrolytic efficiency and enzyme stability. Furthermore, biocatalyst/enzyme immobilization on magnetic nanoparticles enables easy recovery and reuse of enzymes. Hence, the exploitation of nanobiocatalysts for LB to biofuel conversion will aid in developing a lucrative and sustainable approach. With this perspective, the effects of nanobiocatalysts on LB to biofuel production were reviewed here. Several traits, such as switching the chemical processes using nanomaterials, enzyme immobilization on nanoparticles for higher reaction rates, recycling ability and toxicity effects on microbial cells, were highlighted in this review. Current developments and viabi...
Nicotinamide mononucleotide (NMN), a precursor of NAD+, can be synthesized by the conversion of n... more Nicotinamide mononucleotide (NMN), a precursor of NAD+, can be synthesized by the conversion of nicotinamide with the help of nicotinamide phosphoribosyl transferase (NAMPT) via the salvage pathway. NMN has recently gained great attention as an excellent therapeutic option due to its long-term effective pharmacological activities. In this study, we constructed a recombinant strain of Escherichia coli by inserting NAMPT and phosphoribosyl pyrophosphate synthetase 1 (PRPS1) and PRPS2 (from Homo sapiens) genes to investigate the effect of PRPS1 and PRPS2 on NMN synthesis. The metabolically engineered strain of E. coli BL21 (DE3) exhibited 1.57 mM NMN production in the presence of Mg2+ and phosphates in batch fermentation studies. For further improvement in NMN production levels, effects of different variables were studied using a response surface methodology approach. A significant increment was achieved with a maximum of 2.31 mM NMN production when supplemented with 1% ribose, 1 mM Mg2+ and phosphate, and 0.5% nicotinamide in the presence of a lactose (1%) inducer. Additionally, insertion of the PRPS1 and PRPS2 genes in the phosphoribosyl pyrophosphate synthesis pathway and individual gene expression studies facilitated a higher NMN production at the intracellular level than the reported studies. The strain exhibited intracellular production of NMN from cheap substrates such as glucose, lactose, and nicotinamide. Hence, the overall optimized process can be further scaled up for the economical production of NMN using a recombinant strain of E. coli BL21 (DE3), which is the future perspective of the current study.
High-density polycycloalkanes were first produced with cellulose by a highly integrated route tha... more High-density polycycloalkanes were first produced with cellulose by a highly integrated route that features a selective hydrogenolysis of cellulose to 2,5hexanedione under mild conditions, followed by the direct synthesis of polycycloalkanes with 2,5-hexanedione and hydrogen over a dual-bed catalyst system. The polycycloalkane mixture as obtained has a high density (0.88 g mL À1) and low freezing point (225 K). In real application, they can be used as advanced aviation fuel or additives to improve the volumetric heat values of conventional aviation fuels.
Method for production and regeneration of Acetobacter pasteurianum NCIM 2314 protoplasts are desc... more Method for production and regeneration of Acetobacter pasteurianum NCIM 2314 protoplasts are described. The protoplasts were obtained by treatment with lysozyme in protoplast buffer at pH 8.0 with different osmotic stabilizers. The protoplasts were regenerated on Acetobacter medium with various osmotic stabilizers. Maximum protoplasts formation was obtained in protoplasts buffer with NaC1 as an osmotic stabilizer using lysozyme (0.5mg/mL). Maximum protoplast regeneation was obtained on Acetobacter medium with NaCl (0.5M) as an osmotic stabilizer. The regeneration medium was also applicable to other species of Acetobactor as well. This is, to our knowledge, the first report on protoplast formation and efficient regeneration in case of Acetobacter pasteurianum. izLrkouk lw {etho ds lq /kkj es a iz ks Vks IykLV la y;u ,d mi;q Dr rduhd gS A ;g rduhd lw {ethoks a ds vla ca f/kr oa 'k ds chp es a la iw .kZ dks j dk fofue; djus es a mi;ks xh gS A ;g thu LFkkuka rj.k dh la LFkkfir vkS j...
Biodegradation of poly(ethylene terephthalate) modified with polyester "Bionolle Ò " by Penicilli... more Biodegradation of poly(ethylene terephthalate) modified with polyester "Bionolle Ò " by Penicillium funiculosum Summary-The purpose of the study was to determine the degree of biodegradation of poly(ethylene terephthalate) films modified with "Bionolle ® " polyester in comparison with films made of neat commercial poly(ethylene terephthalate). After 84-day incubation in the presence of filamentous fungi Penicillium funiculosum or their extracellular hydrolytic enzymes secreted by "Bionolle Ò " weight loss of the films was measured. The texture of the polymeric samples was observed with a scanning electron microscope. Important chemical changes of polymeric chains were detected by FT-IR and XPS analysis. Significant reduction in quantity of aromatic rings derived from terephthalic acid indicated that decomposition of films by fungi occurred not only due to hydrolytic enzymes but also oxidative ones. Moreover, we observed rather unilateral influence of poly(ethylene terephthalate) on biodegradation: addition of "Bionolle Ò " didn't accelerate significantly degradation of modified films and-what is more important-the presence of PET inhibited decomposition of easily biodegradable "Bionolle Ò ".
Method for production and regeneration of Lactobacillus delbrueckii protoplasts are described. Th... more Method for production and regeneration of Lactobacillus delbrueckii protoplasts are described. The protoplasts were obtained by treatment with a mixture of lysozyme and mutanolysin in protoplast buffer at pH 6.5 with different osmotic stabilizers. The protoplasts were regenerated on deMan, Rogosa and Sharpe (MRS) with various osmotic stabilizers. Maximum protoplast formation was obtained in protoplast buffer with sucrose as an osmotic stabilizer using a combination of lysozyme (1 mg/ml) and mutanolysin (10 µg/ml). Maximum protoplast regeneration was obtained on MRS medium with sucrose (0.5 M) as an osmotic stabilizer. The regeneration medium was also applicable to other species of lactobacilli as well. This is, to our knowledge, the first report on protoplast formation and efficient regeneration in case of L. delbrueckii.
... Mamta Singhvia, Dipti Joshia, Mukund Adsula, Anjani Varmab and Digambar Gokhale*a. a NCIM Res... more ... Mamta Singhvia, Dipti Joshia, Mukund Adsula, Anjani Varmab and Digambar Gokhale*a. a NCIM Resource Center, National Chemical laboratory, Dr Homi ... 15, SR Kadam, SS Patil, KB Bastawde, JM Khire and DV Gokhale, Process Biochem., 2006, 41, 120126 Article ChemPort ...
The present review mainly discusses advanced pretreatment techniques for converting lignocellulos... more The present review mainly discusses advanced pretreatment techniques for converting lignocellulosic biomass into hydrogen. The focus of this review is also to acquire knowledge concerning lignocellulosic biomass pretreatment processes and their impact on the efficiency of biohydrogen fermentation. The deconstruction of lignocellulosic biomass is presented using various pretreatment techniques albeit with several advantages and disadvantages, particularly about the interference due to the generated inhibitory compounds is toxic to microbes used for fermentation. The use of an appropriate pretreatment process can make the recalcitrant lignocellulosic biomass substrates amenable for further microbial fermentation to produce hydrogen. Although till date there is no ideal pretreatment step available to develop a cost-effective process for conversion of lignocellulosic materials into fermentable sugars, nanotechnology seem to be a more sustainable approach as compared to the traditional p...
Nicotinamide mononucleotide (NMN), a precursor of NAD+, can be synthesized by the conversion of n... more Nicotinamide mononucleotide (NMN), a precursor of NAD+, can be synthesized by the conversion of nicotinamide with the help of nicotinamide phosphoribosyl transferase (NAMPT) via the salvage pathway. NMN has recently gained great attention as an excellent therapeutic option due to its long-term effective pharmacological activities. In this study, we constructed a recombinant strain of Escherichia coli by inserting NAMPT and phosphoribosyl pyrophosphate synthetase 1 (PRPS1) and PRPS2 (from Homo sapiens) genes to investigate the effect of PRPS1 and PRPS2 on NMN synthesis. The metabolically engineered strain of E. coli BL21 (DE3) exhibited 1.57 mM NMN production in the presence of Mg2+ and phosphates in batch fermentation studies. For further improvement in NMN production levels, effects of different variables were studied using a response surface methodology approach. A significant increment was achieved with a maximum of 2.31 mM NMN production when supplemented with 1% ribose, 1 mM Mg2+ and phosphate, and 0.5% nicotinamide in the presence of a lactose (1%) inducer. Additionally, insertion of the PRPS1 and PRPS2 genes in the phosphoribosyl pyrophosphate synthesis pathway and individual gene expression studies facilitated a higher NMN production at the intracellular level than the reported studies. The strain exhibited intracellular production of NMN from cheap substrates such as glucose, lactose, and nicotinamide. Hence, the overall optimized process can be further scaled up for the economical production of NMN using a recombinant strain of E. coli BL21 (DE3), which is the future perspective of the current study.
Lignin degradation from corn cob utilizing doped nanoparticles for biofuel and biochemical produc... more Lignin degradation from corn cob utilizing doped nanoparticles for biofuel and biochemical production.
Employment of cellulase mimicking functionalized few-layer graphene (FFG) nanosheets for cellulos... more Employment of cellulase mimicking functionalized few-layer graphene (FFG) nanosheets for cellulose hydrolysis to replace enzymes completely/partially could aid in developing a sustainable process for bioethanol fermentation.
Due to the structural complexity and recalcitrance nature of lignin, its depolymerization into mo... more Due to the structural complexity and recalcitrance nature of lignin, its depolymerization into monomeric units becomes one of the biggest challenges in bioconversion of lignin into valueadded products. Depolymerization of lignin produces a blend of many compounds that are problematic for isolating components in a cost-effective way. Lignin valorization using a biological approach facilitates sustainable and commercially viable biorefineries. The use of microbes for the conversion of depolymerized lignin compounds into target products can be a solution to the heterogeneity issue. Several studies have been carried out to develop robust strains that can utilize all relevant lignin-derived compounds, but constructing these strains is difficult. As an alternative, designing multiple microbes to convert a mixture of various compounds into the desired product seems realistic. This review provides an overview of lignin bioconversion using various approaches such as metabolic engineering and synthetic biology. Ligninolytic strains have a broad enzymatic machine for depolymerization of lignin and its conversion into intermediates such as catechol or protocatechuate. These intermediates can be further converted to metabolite products such as polyhydroxyalkanoates and triacylglycerol. Synthetic biology offers encouraging methodologies to construct pathways for lignin conversion and to engineer ligninolytic microbes as prospective strains for lignin bioconversion.
The conversion of lignocellulosic biomass (LB) to sugar is an intricate process which is the cost... more The conversion of lignocellulosic biomass (LB) to sugar is an intricate process which is the costliest part of the biomass conversion process. Even though acid/enzyme catalysts are usually being used for LB hydrolysis, enzyme immobilization has been recognized as a potential strategy nowadays. The use of nanobiocatalysts increases hydrolytic efficiency and enzyme stability. Furthermore, biocatalyst/enzyme immobilization on magnetic nanoparticles enables easy recovery and reuse of enzymes. Hence, the exploitation of nanobiocatalysts for LB to biofuel conversion will aid in developing a lucrative and sustainable approach. With this perspective, the effects of nanobiocatalysts on LB to biofuel production were reviewed here. Several traits, such as switching the chemical processes using nanomaterials, enzyme immobilization on nanoparticles for higher reaction rates, recycling ability and toxicity effects on microbial cells, were highlighted in this review. Current developments and viabi...
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