Pub Date : 2024-07-02DOI: 10.1016/j.biortech.2024.131062
Xiaotong Ji, Lin Chen, Guanpin Yang, Chunlei Tang, Wenjun Zhou, Tianzhong Liu, Xuefeng Lu
Acquiring lipid-producing strains of Saccharomyces cerevisiae is necessary for producing high-value palmitoleic acid. This study sought to generate oleaginous S. cerevisiae mutants through a combination of zeocin mutagenesis and fluorescence-activated cell sorting, and then to identify key mutations responsible for enhanced lipid accumulation by multi-omics sequencing. Following three consecutive rounds of mutagenesis and sorting, a mutant, MU310, with the lipid content of 44%, was successfully obtained. Transcriptome and targeted metabolome analyses revealed that a coordinated response involving fatty acid precursor biosynthesis, nitrogen metabolism, pentose phosphate pathway, ethanol conversion, amino acid metabolism and fatty acid β-oxidation was crucial for promoting lipid accumulation. The carbon fluxes of acetyl-CoA and NADPH in lipid biosynthesis were boosted in these pathways. Certain transcriptional regulators may also play significant roles in modulating lipid biosynthesis. Results of this study provide high-quality resource for palmitoleic acid production and deepen the understanding of lipid synthesis in yeast.
{"title":"Mutagenesis and fluorescence-activated cell sorting of oleaginous Saccharomyces cerevisiae and the multi-omics analysis of its high lipid accumulation mechanisms.","authors":"Xiaotong Ji, Lin Chen, Guanpin Yang, Chunlei Tang, Wenjun Zhou, Tianzhong Liu, Xuefeng Lu","doi":"10.1016/j.biortech.2024.131062","DOIUrl":"https://doi.org/10.1016/j.biortech.2024.131062","url":null,"abstract":"<p><p>Acquiring lipid-producing strains of Saccharomyces cerevisiae is necessary for producing high-value palmitoleic acid. This study sought to generate oleaginous S. cerevisiae mutants through a combination of zeocin mutagenesis and fluorescence-activated cell sorting, and then to identify key mutations responsible for enhanced lipid accumulation by multi-omics sequencing. Following three consecutive rounds of mutagenesis and sorting, a mutant, MU310, with the lipid content of 44%, was successfully obtained. Transcriptome and targeted metabolome analyses revealed that a coordinated response involving fatty acid precursor biosynthesis, nitrogen metabolism, pentose phosphate pathway, ethanol conversion, amino acid metabolism and fatty acid β-oxidation was crucial for promoting lipid accumulation. The carbon fluxes of acetyl-CoA and NADPH in lipid biosynthesis were boosted in these pathways. Certain transcriptional regulators may also play significant roles in modulating lipid biosynthesis. Results of this study provide high-quality resource for palmitoleic acid production and deepen the understanding of lipid synthesis in yeast.</p>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":null,"pages":null},"PeriodicalIF":9.7,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141533020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-02DOI: 10.1016/j.biortech.2024.131063
Bianchi Greta, Pessina Alex, Ami Diletta, Signorelli Samuele, de Divitiis Marcella, Natalello Antonino, Lotti Marina, Brambilla Luca, Brocca Stefania, Mangiagalli Marco
Responsible use of natural resources and waste reduction are key concepts in bioeconomy. This study demonstrates that agro-food derived-biomasses from the Italian food industry, such as crude glycerol and cheese whey permeate (CWP), can be combined in a high-density fed-batch culture to produce a recombinant β-galactosidase from Marinomonas sp. Ef1 (M-βGal). In a small-scale process (1.5 L) using 250 mL of crude glycerol and 300 mL of lactose-rich CWP, approximately 2000 kU of recombinant M-βGal were successfully produced along with 30 g of galactose accumulated in the culture medium. The purified M-βGal exhibited high hydrolysis efficiency in lactose-rich matrices, with hydrolysis yields of 82 % in skimmed milk at 4 °C and 94 % in CWP at 50 °C, highlighting its biotechnological potential. This approach demonstrates the effective use of crude glycerol and CWP in sustainable and cost-effective high-density E. coli cultures, potentially applicable to recombinant production of various proteins.
负责任地利用自然资源和减少废物是生物经济的关键概念。本研究表明,来自意大利食品工业的农产食品衍生生物质,如粗甘油和奶酪乳清渗透物(CWP),可在高密度喂料批次培养中结合使用,以生产来自马林单胞菌 Ef1 的重组β-半乳糖苷酶(M-βGal)。在使用 250 mL 粗甘油和 300 mL 富含乳糖的 CWP 的小规模工艺(1.5 L)中,成功生产了约 2000 kU 重组 M-βGal,以及培养基中积累的 30 g 半乳糖。纯化的 M-βGal 在富含乳糖的基质中表现出很高的水解效率,在 4 °C 的脱脂奶中的水解率为 82%,在 50 °C 的 CWP 中的水解率为 94%,突显了其生物技术潜力。这种方法证明了在可持续和具有成本效益的高密度大肠杆菌培养物中有效利用粗甘油和 CWP,可用于重组生产各种蛋白质。
{"title":"Sustainable production of a biotechnologically relevant β-galactosidase in Escherichia coli cells using crude glycerol and cheese whey permeate.","authors":"Bianchi Greta, Pessina Alex, Ami Diletta, Signorelli Samuele, de Divitiis Marcella, Natalello Antonino, Lotti Marina, Brambilla Luca, Brocca Stefania, Mangiagalli Marco","doi":"10.1016/j.biortech.2024.131063","DOIUrl":"https://doi.org/10.1016/j.biortech.2024.131063","url":null,"abstract":"<p><p>Responsible use of natural resources and waste reduction are key concepts in bioeconomy. This study demonstrates that agro-food derived-biomasses from the Italian food industry, such as crude glycerol and cheese whey permeate (CWP), can be combined in a high-density fed-batch culture to produce a recombinant β-galactosidase from Marinomonas sp. Ef1 (M-βGal). In a small-scale process (1.5 L) using 250 mL of crude glycerol and 300 mL of lactose-rich CWP, approximately 2000 kU of recombinant M-βGal were successfully produced along with 30 g of galactose accumulated in the culture medium. The purified M-βGal exhibited high hydrolysis efficiency in lactose-rich matrices, with hydrolysis yields of 82 % in skimmed milk at 4 °C and 94 % in CWP at 50 °C, highlighting its biotechnological potential. This approach demonstrates the effective use of crude glycerol and CWP in sustainable and cost-effective high-density E. coli cultures, potentially applicable to recombinant production of various proteins.</p>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":null,"pages":null},"PeriodicalIF":9.7,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141533021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-02DOI: 10.1016/j.biortech.2024.131064
Joris Bergman, Annemerel R Mol, Annemiek Ter Heijne, Karel J Keesman, Rikke Linssen
Sulfide oxidizing bacteria are used in industrial biodesulfurization processes to convert sulfide to sulfur. These bacteria can spatially separate sulfide removal from terminal electron transfer, thereby acting as sulfide shuttles. The mechanisms underlying sulfide shuttling are not yet clear. In this work, newly obtained sulfide removal data were used to develop a new model for anaerobic sulfide removal and this model was shown to be an improvement over two previously published models. The new model describes a fast chemical step and a consecutive slow enzymatic step. The improved model includes the effect of pH, with higher total sulfide removal at increasing pH, as well as partial sulfide removal at higher sulfide concentrations. The two-stage model is supported by recent developments in anaerobic sulfide removal research and contributes to a better understanding of the underlying mechanisms. The model is a step toward accurately modelling anaerobic sulfide removal in industrial systems.
{"title":"Modelling anaerobic sulfide removal by sulfide shuttling bacteria.","authors":"Joris Bergman, Annemerel R Mol, Annemiek Ter Heijne, Karel J Keesman, Rikke Linssen","doi":"10.1016/j.biortech.2024.131064","DOIUrl":"https://doi.org/10.1016/j.biortech.2024.131064","url":null,"abstract":"<p><p>Sulfide oxidizing bacteria are used in industrial biodesulfurization processes to convert sulfide to sulfur. These bacteria can spatially separate sulfide removal from terminal electron transfer, thereby acting as sulfide shuttles. The mechanisms underlying sulfide shuttling are not yet clear. In this work, newly obtained sulfide removal data were used to develop a new model for anaerobic sulfide removal and this model was shown to be an improvement over two previously published models. The new model describes a fast chemical step and a consecutive slow enzymatic step. The improved model includes the effect of pH, with higher total sulfide removal at increasing pH, as well as partial sulfide removal at higher sulfide concentrations. The two-stage model is supported by recent developments in anaerobic sulfide removal research and contributes to a better understanding of the underlying mechanisms. The model is a step toward accurately modelling anaerobic sulfide removal in industrial systems.</p>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":null,"pages":null},"PeriodicalIF":9.7,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141533019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Starch is an attractive feedstock in biorefinery processes, while the low natural conversion rate of most microorganisms limits its applications. Herein, starch metabolic pathway was systematically investigated using DW2 as the host organism. Initially, the effects of overexpressing amylolytic enzymes on starch hydrolysis were evaluated. Subsequently, the transmembrane transport system and intracellular degradation module were modified to accelerate the uptake of hydrolysates and their further conversion to glucose-6-phosphate. The DW2-derived strains exhibited robust growth in starch medium, and productivity of bacitracin and subtilisin were improved by 38.5% and 32.6%, with an 32.3% and 22.9% increase of starch conversion rate, respectively. Lastly, the employment of engineering strategies enabled another WX-02 to produce poly-γ-glutamic acid from starch with a 2.1-fold increase of starch conversion rate. This study not only provided excellent chassis for sustainable bioproduction from starch, but shed light on researches of substrate utilization.
{"title":"Engineering Bacillus licheniformis as industrial chassis for efficient bioproduction from starch","authors":"Jiang Zhu, Min Liu, Jianling Kang, Shiyi Wang, Ziyan Zha, Yangyang Zhan, Zhi Wang, Junhui Li, Dongbo Cai, Shouwen Chen","doi":"10.1016/j.biortech.2024.131061","DOIUrl":"https://doi.org/10.1016/j.biortech.2024.131061","url":null,"abstract":"Starch is an attractive feedstock in biorefinery processes, while the low natural conversion rate of most microorganisms limits its applications. Herein, starch metabolic pathway was systematically investigated using DW2 as the host organism. Initially, the effects of overexpressing amylolytic enzymes on starch hydrolysis were evaluated. Subsequently, the transmembrane transport system and intracellular degradation module were modified to accelerate the uptake of hydrolysates and their further conversion to glucose-6-phosphate. The DW2-derived strains exhibited robust growth in starch medium, and productivity of bacitracin and subtilisin were improved by 38.5% and 32.6%, with an 32.3% and 22.9% increase of starch conversion rate, respectively. Lastly, the employment of engineering strategies enabled another WX-02 to produce poly-γ-glutamic acid from starch with a 2.1-fold increase of starch conversion rate. This study not only provided excellent chassis for sustainable bioproduction from starch, but shed light on researches of substrate utilization.","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":null,"pages":null},"PeriodicalIF":11.4,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141495864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bio-oil derived from biomass fast pyrolysis can be upgraded to gasoline and diesel alternatives by catalytic hydrodeoxygenation (HDO). Here, the novel nitrogen-doped carbon-alumina hybrid supported cobalt (Co/NCAn, n = 1, 2.5, 5) catalyst is established by a coagulation bath technique. The optimized Co/NCA2.5 catalyst presented 100 % conversion of guaiacol, high selectivity to cyclohexane (93.6 %), and extremely high deoxygenation degree (97.3 %), respectively. Therein, the formation of cyclohexanol was facilitated by stronger binding energy and greater charge transfer between Co and NC which was unraveled by density functional theory calculations. In addition, the appropriate amount of Lewis acid sites enhanced the cleavage of the C-O bond in cyclohexanol, finally resulting in a remarkable selectivity for cyclohexane. Finally, the Co/NCA2.5 catalyst also exhibited excellent selectivity (93.1 %) for high heating value hydrocarbon fuel in crude bio-oil HDO. This work provides a theoretical basis on N dopants collaborating alumina hybrid catalysts for efficient HDO reaction.
{"title":"Selective production of high-value fuel via catalytic upgrading of bio-oil over nitrogen-doped carbon-alumina hybrid supported cobalt catalysts.","authors":"Qin Peng, Xia Jiang, Guangmei Cao, Tianqiao Xie, Ziheng Jin, Lingling Xie, Fengli Gan, Shenggui Ma, Mingming Peng","doi":"10.1016/j.biortech.2024.131059","DOIUrl":"https://doi.org/10.1016/j.biortech.2024.131059","url":null,"abstract":"<p><p>Bio-oil derived from biomass fast pyrolysis can be upgraded to gasoline and diesel alternatives by catalytic hydrodeoxygenation (HDO). Here, the novel nitrogen-doped carbon-alumina hybrid supported cobalt (Co/NCA<sub>n</sub>, n = 1, 2.5, 5) catalyst is established by a coagulation bath technique. The optimized Co/NCA<sub>2.5</sub> catalyst presented 100 % conversion of guaiacol, high selectivity to cyclohexane (93.6 %), and extremely high deoxygenation degree (97.3 %), respectively. Therein, the formation of cyclohexanol was facilitated by stronger binding energy and greater charge transfer between Co and NC which was unraveled by density functional theory calculations. In addition, the appropriate amount of Lewis acid sites enhanced the cleavage of the C-O bond in cyclohexanol, finally resulting in a remarkable selectivity for cyclohexane. Finally, the Co/NCA<sub>2.5</sub> catalyst also exhibited excellent selectivity (93.1 %) for high heating value hydrocarbon fuel in crude bio-oil HDO. This work provides a theoretical basis on N dopants collaborating alumina hybrid catalysts for efficient HDO reaction.</p>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":null,"pages":null},"PeriodicalIF":9.7,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141475556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-29DOI: 10.1016/j.biortech.2024.131060
Jishao Jiang , Rui Hou , Huilin Cui , Zhuyu Tang , Yousif Abdelrahman Yousif Abdellah , Caspar C.C. Chater , Ke Cheng , Fuqiang Yu , Dong Liu
This study surveyed the fates of artificial sweeteners in influent, effluent, and sewage sludge (SS) in wastewater treatment plant, and investigated the effects of Micro-Kaolin (Micro-KL) and Nano-Kaolin (Nano-KL) on nitrogen transformation and sucralose (SUC) and acesulfame (ACE) degradation during SS composting. Results showed the cumulative rate of ACE and SUC in SS was ∼76 %. During SS composting, kaolin reduced NH3 emissions by 30.2–45.38 %, and N2O emissions by 38.4–38.9 %, while the Micro-KL and Nano-KL reduced nitrogen losses by 14.8 % and 12.5 %, respectively. Meanwhile, Micro-KL and Nano-KL increased ACE degradation by 76.8 % and 84.2 %, and SUC degradation by 75.3 % and 77.7 %, and significantly shifted microbial community structure. Furthermore, kaolin caused a positive association between Actinobacteria and sweetener degradation. Taken together, kaolin effectively inhibited nitrogen loss and promoted the degradation of ACE and SUC during the SS composting, which is of great significance for the removal of emerging organic pollutants in SS.
{"title":"Removal of artificial sweeteners in wastewater treatment plants and their degradation during sewage sludge composting with micro- and nano-sized kaolin","authors":"Jishao Jiang , Rui Hou , Huilin Cui , Zhuyu Tang , Yousif Abdelrahman Yousif Abdellah , Caspar C.C. Chater , Ke Cheng , Fuqiang Yu , Dong Liu","doi":"10.1016/j.biortech.2024.131060","DOIUrl":"10.1016/j.biortech.2024.131060","url":null,"abstract":"<div><p>This study surveyed the fates of artificial sweeteners in influent, effluent, and sewage sludge (SS) in wastewater treatment plant, and investigated the effects of Micro-Kaolin (Micro-KL) and Nano-Kaolin (Nano-KL) on nitrogen transformation and sucralose (SUC) and acesulfame (ACE) degradation during SS composting. Results showed the cumulative rate of ACE and SUC in SS was ∼76 %. During SS composting, kaolin reduced NH<sub>3</sub> emissions by 30.2–45.38 %, and N<sub>2</sub>O emissions by 38.4–38.9 %, while the Micro-KL and Nano-KL reduced nitrogen losses by 14.8 % and 12.5 %, respectively. Meanwhile, Micro-KL and Nano-KL increased ACE degradation by 76.8 % and 84.2 %, and SUC degradation by 75.3 % and 77.7 %, and significantly shifted microbial community structure. Furthermore, kaolin caused a positive association between Actinobacteria and sweetener degradation. Taken together, kaolin effectively inhibited nitrogen loss and promoted the degradation of ACE and SUC during the SS composting, which is of great significance for the removal of emerging organic pollutants in SS.</p></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":null,"pages":null},"PeriodicalIF":9.7,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141475555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-28DOI: 10.1016/j.biortech.2024.131056
Xin Zou, Yiduo Yao, Mengjiao Gao, Yihui Zhang, Hengbo Guo, Yang Liu
This study addressed the treatment of high ammonia, low biodegradable chemical oxygen demand (bCOD) anaerobically digested molasses wastewater, utilizing an aerobic granular sludge (AGS) reactor. The AGS achieved 99 % ammonia removal regardless of the bCOD supplementation. By adding low ammonia (<60 mg/L), high bCOD raw molasses wastewater (before anaerobic digestion) as a carbon source, enhanced nitrogen removal, increasing from 10 % to 97 %, and improved sludge settleability via bio-induced calcite precipitation were observed. Functional genes prediction suggested two potential denitrification pathways, including heterotrophic denitrification by Paracoccus and Thauera, and autotrophic denitrification, specifically sulfide-oxidizing autotrophic denitrification by Thiobacillus. An increase in the relative abundance of microorganisms involved in heterotrophic denitrification was observed with the addition of high bCOD raw molasses wastewater. Consequently, incorporating raw molasses wastewater into the AGS presents a sustainable approach to achieve mixotrophic denitrification, maintain stable granular sludge and ensure stable treatment performance when treating anaerobically digested molasses wastewater.
{"title":"Treatment of high ammonia anaerobically digested molasses wastewater using aerobic granular sludge reactor.","authors":"Xin Zou, Yiduo Yao, Mengjiao Gao, Yihui Zhang, Hengbo Guo, Yang Liu","doi":"10.1016/j.biortech.2024.131056","DOIUrl":"https://doi.org/10.1016/j.biortech.2024.131056","url":null,"abstract":"<p><p>This study addressed the treatment of high ammonia, low biodegradable chemical oxygen demand (bCOD) anaerobically digested molasses wastewater, utilizing an aerobic granular sludge (AGS) reactor. The AGS achieved 99 % ammonia removal regardless of the bCOD supplementation. By adding low ammonia (<60 mg/L), high bCOD raw molasses wastewater (before anaerobic digestion) as a carbon source, enhanced nitrogen removal, increasing from 10 % to 97 %, and improved sludge settleability via bio-induced calcite precipitation were observed. Functional genes prediction suggested two potential denitrification pathways, including heterotrophic denitrification by Paracoccus and Thauera, and autotrophic denitrification, specifically sulfide-oxidizing autotrophic denitrification by Thiobacillus. An increase in the relative abundance of microorganisms involved in heterotrophic denitrification was observed with the addition of high bCOD raw molasses wastewater. Consequently, incorporating raw molasses wastewater into the AGS presents a sustainable approach to achieve mixotrophic denitrification, maintain stable granular sludge and ensure stable treatment performance when treating anaerobically digested molasses wastewater.</p>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":null,"pages":null},"PeriodicalIF":9.7,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141464790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The quinoid component of humic acids (HAs) had been studied as exogenous electron mediators (EMs), but the redox-mediating abilities of other functional groups remained unclear. This study evaluated the effects of various HAs functional groups on cellular respiration and extracellular electron transfer. The three EMs increased the current density compared to the control. Current density increased significantly after adding ultraviolet-irradiated HAs (UV-HAs), suggesting that nitrogenous group-mediated redox reactions contributed to high-density current generation. Structural equation model (SEM) results indicated that the contribution of nitrogen-containing groups to electron transfer could exceed 20%. This study proposed a synergistic mechanism: in the soil microbial fuel cells (soil-MFCs), HAs accelerated their component evolution through irreversible redox reactions and promoted extracellular electron transfer. Additionally, HAs-induced high expression of c-Cyts could further enhance high-density current generation. This study demonstrates that humic acids enhance electron transfer and current in bioelectrochemical systems, aiding sustainable energy optimization.
{"title":"Diversity in mechanisms of natural humic acid enhanced current production in soil bioelectrochemical systems.","authors":"Xintong Gao, Kaixuan Liu, Chong Zhang, Xian Cao, Takashi Sakamakic, Xianning Li","doi":"10.1016/j.biortech.2024.131057","DOIUrl":"10.1016/j.biortech.2024.131057","url":null,"abstract":"<p><p>The quinoid component of humic acids (HAs) had been studied as exogenous electron mediators (EMs), but the redox-mediating abilities of other functional groups remained unclear. This study evaluated the effects of various HAs functional groups on cellular respiration and extracellular electron transfer. The three EMs increased the current density compared to the control. Current density increased significantly after adding ultraviolet-irradiated HAs (UV-HAs), suggesting that nitrogenous group-mediated redox reactions contributed to high-density current generation. Structural equation model (SEM) results indicated that the contribution of nitrogen-containing groups to electron transfer could exceed 20%. This study proposed a synergistic mechanism: in the soil microbial fuel cells (soil-MFCs), HAs accelerated their component evolution through irreversible redox reactions and promoted extracellular electron transfer. Additionally, HAs-induced high expression of c-Cyts could further enhance high-density current generation. This study demonstrates that humic acids enhance electron transfer and current in bioelectrochemical systems, aiding sustainable energy optimization.</p>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":null,"pages":null},"PeriodicalIF":9.7,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141464784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-28DOI: 10.1016/j.biortech.2024.131048
Lin Zhu , Caihong Huang , Lipin Li , Simiao Wang , Xinxin Wu , Guangchun Shan , Yu Tian
The nitrogen loss in composting is primarily driven by the transformation of organic nitrogen, yet the mechanisms underlying the degradation process remain incompletely understood. This study employed protein family domains (Pfams) analysis based on metagenomic sequencing to investigate the functional characteristics, key microorganisms, and environmental parameters influencing organic nitrogen degradation in chicken manure and pig manure composting. 154 Pfams associated with ammonification function were identified. Predominant Pfams: proteolytic peptidase, followed by chitin/cell wall degraders, least involved in nucleic acid degradation. Ammonifying microbial diversity was basically consistent among compost types, particularly in the thermophilic stage with the peak of abundance of dominant ammonifying microorganisms. Viruses played an important role in ammonification process, especially Uroviricota. 26 key ammonifying genera were identified by the microbial network. pH dominated the metabolic activity of ammonifying microorganisms in various manure compost types, primarily consisting of protein-degrading bacteria with stable community structures.
{"title":"Innovative insights into organic nitrogen degradation through protein family domains analysis in chicken and pig manure composting using metagenomic sequencing","authors":"Lin Zhu , Caihong Huang , Lipin Li , Simiao Wang , Xinxin Wu , Guangchun Shan , Yu Tian","doi":"10.1016/j.biortech.2024.131048","DOIUrl":"10.1016/j.biortech.2024.131048","url":null,"abstract":"<div><p>The nitrogen loss in composting is primarily driven by the transformation of organic nitrogen, yet the mechanisms underlying the degradation process remain incompletely understood. This study employed protein family domains (Pfams) analysis based on metagenomic sequencing to investigate the functional characteristics, key microorganisms, and environmental parameters influencing organic nitrogen degradation in chicken manure and pig manure composting. 154 Pfams associated with ammonification function were identified. Predominant Pfams: proteolytic peptidase, followed by chitin/cell wall degraders, least involved in nucleic acid degradation. Ammonifying microbial diversity was basically consistent among compost types, particularly in the thermophilic stage with the peak of abundance of dominant ammonifying microorganisms. Viruses played an important role in ammonification process, especially Uroviricota. 26 key ammonifying genera were identified by the microbial network. pH dominated the metabolic activity of ammonifying microorganisms in various manure compost types, primarily consisting of protein-degrading bacteria with stable community structures.</p></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":null,"pages":null},"PeriodicalIF":9.7,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141464786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Indigenous microalgae-bacteria consortium (IMBC) offers significant advantages for swine wastewater (SW) treatment including enhanced adaptability and resource recovery. In this review, the approaches for enriching IMBC both in situ and ex situ were comprehensively described, followed by symbiotic mechanisms for IMBC which involve metabolic cross-feeding and signal transmission. Strategies for enhancing treatment efficiencies of SW-originated IMBC were then introduced, including improving SW quality, optimizing system operating conditions, and adjusting microbial activities. Recommendations for maximizing treatment efficiencies were particularly proposed using a decision tree approach. Moreover, removal/recovery mechanisms for typical pollutants in SW using IMBC were critically discussed. Ultimately, a technical route termed SW-IMBC-Crop-Pig was proposed, to achieve a closed-loop economy for pig farms by integrating SW treatment with crop cultivation. This review provides a deeper understanding of the mechanism and strategies for IMBC's resource recovery from SW.
{"title":"Principles, Challenges, and optimization of Indigenous Microalgae-Bacteria consortium for sustainable swine wastewater treatment.","authors":"Sheng Yu, Zhipeng Chen, Mengting Li, Shuang Qiu, Zhe Lv, Shijian Ge","doi":"10.1016/j.biortech.2024.131055","DOIUrl":"https://doi.org/10.1016/j.biortech.2024.131055","url":null,"abstract":"<p><p>Indigenous microalgae-bacteria consortium (IMBC) offers significant advantages for swine wastewater (SW) treatment including enhanced adaptability and resource recovery. In this review, the approaches for enriching IMBC both in situ and ex situ were comprehensively described, followed by symbiotic mechanisms for IMBC which involve metabolic cross-feeding and signal transmission. Strategies for enhancing treatment efficiencies of SW-originated IMBC were then introduced, including improving SW quality, optimizing system operating conditions, and adjusting microbial activities. Recommendations for maximizing treatment efficiencies were particularly proposed using a decision tree approach. Moreover, removal/recovery mechanisms for typical pollutants in SW using IMBC were critically discussed. Ultimately, a technical route termed SW-IMBC-Crop-Pig was proposed, to achieve a closed-loop economy for pig farms by integrating SW treatment with crop cultivation. This review provides a deeper understanding of the mechanism and strategies for IMBC's resource recovery from SW.</p>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":null,"pages":null},"PeriodicalIF":9.7,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141464789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}