Currently,the most cost-effective and efficient method for phosphorus(P)removal from wastewater is enhanced biological P removal(EPBR)via polyphosphate-accumulating organisms(PAOs).This study integrates a literature r...Currently,the most cost-effective and efficient method for phosphorus(P)removal from wastewater is enhanced biological P removal(EPBR)via polyphosphate-accumulating organisms(PAOs).This study integrates a literature review with genomic analysis to uncover the phylogenetic and metabolic diversity of the relevant PAOs for wastewater treatment.The findings highlight significant differences in the metabolic capabilities of PAOs relevant to wastewater treatment.Notably,Candidatus Dechloromonas and Candidatus Accumulibacter can synthesize polyhydroxyalkanoates,possess specific enzymes for ATP production from polyphosphate,and have electrochemical transporters for acetate and C4-dicarboxylates.In contrast,Tetrasphaera,Candidatus Phosphoribacter,Knoellia,and Phycicoccus possess PolyP-glucokinase and electrochemical transporters for sugars/amino acids.Additionally,this review explores various detection methods for polyphosphate and PAOs in activated sludge wastewater treatment plants.Notably,FISH-Raman spectroscopy emerges as one of the most advanced detection techniques.Overall,this review provides critical insights into PAO research,underscoring the need for enhanced strategies in biological phosphorus removal.展开更多
Fruits,vegetables,and dairy products are typically the primary sources of household food waste.Currently,anaerobic digestion is the most used bioprocess for the treatment of food waste with concomitant generation of b...Fruits,vegetables,and dairy products are typically the primary sources of household food waste.Currently,anaerobic digestion is the most used bioprocess for the treatment of food waste with concomitant generation of biogas.However,to achieve a circular carbon economy,the organics in food waste should be converted to new chemicals with higher value than energy.Here we demonstrate the feasibility of medium-chain carboxylic acid(MCCA)production from expired dairy and beverage waste via a chain elongation platform mediated by lactate.In a two-stage fermentation process,the first stage with optimized operational conditions,including varying temperatures and organic loading rates,transformed expired dairy and beverage waste into lactate at a concentration higher than 900 mM C at 43℃.This lactate was then used to produce>500 mM C caproate and>300 mM C butyrate via microbial chain elongation.Predominantly,lactate-producing microbes such as Lactobacillus and Lacticaseibacillus were regulated by temperature and could be highly enriched under mesophilic conditions in the firststage reactor.In the second-stage chain elongation reactor,the dominating microbes were primarily from the genera Megasphaera and Caproiciproducens,shaped by varying feed and inoculum sources.Cooccurrence network analysis revealed positive correlations among species from the genera Caproiciproducens,Ruminococcus,and CAG-352,as well as Megasphaera,Bacteroides,and Solobacterium,indicating strong microbial interactions that enhance caproate production.These findings suggest that producing MCCAs from expired dairy and beverage waste via lactate-mediated chain elongation is a viable method for sustainable waste management and could serve as a chemical production platform in the context of building a circular bioeconomy.展开更多
基金supported by King Abdullah University of Science and Technology(KAUST).
文摘Currently,the most cost-effective and efficient method for phosphorus(P)removal from wastewater is enhanced biological P removal(EPBR)via polyphosphate-accumulating organisms(PAOs).This study integrates a literature review with genomic analysis to uncover the phylogenetic and metabolic diversity of the relevant PAOs for wastewater treatment.The findings highlight significant differences in the metabolic capabilities of PAOs relevant to wastewater treatment.Notably,Candidatus Dechloromonas and Candidatus Accumulibacter can synthesize polyhydroxyalkanoates,possess specific enzymes for ATP production from polyphosphate,and have electrochemical transporters for acetate and C4-dicarboxylates.In contrast,Tetrasphaera,Candidatus Phosphoribacter,Knoellia,and Phycicoccus possess PolyP-glucokinase and electrochemical transporters for sugars/amino acids.Additionally,this review explores various detection methods for polyphosphate and PAOs in activated sludge wastewater treatment plants.Notably,FISH-Raman spectroscopy emerges as one of the most advanced detection techniques.Overall,this review provides critical insights into PAO research,underscoring the need for enhanced strategies in biological phosphorus removal.
基金supported by a Competitive Research Grant(URF/1/4069-01-01)Research Translation Fund(REI/1/4576-01-01)from King Abdullah University of Science and Technology(KAUST),Saudi Arabia.
文摘Fruits,vegetables,and dairy products are typically the primary sources of household food waste.Currently,anaerobic digestion is the most used bioprocess for the treatment of food waste with concomitant generation of biogas.However,to achieve a circular carbon economy,the organics in food waste should be converted to new chemicals with higher value than energy.Here we demonstrate the feasibility of medium-chain carboxylic acid(MCCA)production from expired dairy and beverage waste via a chain elongation platform mediated by lactate.In a two-stage fermentation process,the first stage with optimized operational conditions,including varying temperatures and organic loading rates,transformed expired dairy and beverage waste into lactate at a concentration higher than 900 mM C at 43℃.This lactate was then used to produce>500 mM C caproate and>300 mM C butyrate via microbial chain elongation.Predominantly,lactate-producing microbes such as Lactobacillus and Lacticaseibacillus were regulated by temperature and could be highly enriched under mesophilic conditions in the firststage reactor.In the second-stage chain elongation reactor,the dominating microbes were primarily from the genera Megasphaera and Caproiciproducens,shaped by varying feed and inoculum sources.Cooccurrence network analysis revealed positive correlations among species from the genera Caproiciproducens,Ruminococcus,and CAG-352,as well as Megasphaera,Bacteroides,and Solobacterium,indicating strong microbial interactions that enhance caproate production.These findings suggest that producing MCCAs from expired dairy and beverage waste via lactate-mediated chain elongation is a viable method for sustainable waste management and could serve as a chemical production platform in the context of building a circular bioeconomy.
