Pub Date : 2024-11-13DOI: 10.1016/j.biortech.2024.131810
Dan Li , Ruiqing Liu , Ying Chu , Qiang Wang , Meilin He , Changhai Wang
Microalgal-bacterial consortia can treat biogas slurry and produce high-value products. This study found that co-cultures of Desmodesmus sp. and Bacillus megaterium improved nutrient removal, biomass production, and lipid accumulation in Desmodesmus sp. Dual transcriptomic analyses revealed that B. megaterium upregulated genes associated with glycolysis, the Calvin cycle, tricarboxylic acid cycle, indole acetic acid synthesis, and fatty acid biosynthesis in Desmodesmus sp. Under a high C/N ratio, key genes involved in fatty acid degradation were downregulated, promoting lipid accumulation in co-cultured Desmodesmus sp. Effective NH4+-N removal in the co-culture under a high C/N ratio was attributed to microbial interactions. Desmodesmus sp. downregulated the URE gene in bacteria, inhibiting urea hydrolysis, while B. megaterium upregulated the URE and gdhA genes in microalgae, promoting urea utilization and NH4+-N assimilation. This study provides new insights into the transcriptional regulation in nutrient assimilation and lipid metabolism in microalgal-bacterial consortia.
{"title":"Physiological and transcriptomic responses of microalgal-bacterial co-culture reveal nutrient removal and lipid production during biogas slurry treatment","authors":"Dan Li , Ruiqing Liu , Ying Chu , Qiang Wang , Meilin He , Changhai Wang","doi":"10.1016/j.biortech.2024.131810","DOIUrl":"10.1016/j.biortech.2024.131810","url":null,"abstract":"<div><div>Microalgal-bacterial consortia can treat biogas slurry and produce high-value products. This study found that co-cultures of <em>Desmodesmus</em> sp. and <em>Bacillus megaterium</em> improved nutrient removal, biomass production, and lipid accumulation in <em>Desmodesmus</em> sp. Dual transcriptomic analyses revealed that <em>B. megaterium</em> upregulated genes associated with glycolysis, the Calvin cycle, tricarboxylic acid cycle, indole acetic acid synthesis, and fatty acid biosynthesis in <em>Desmodesmus</em> sp. Under a high C/N ratio, key genes involved in fatty acid degradation were downregulated, promoting lipid accumulation in co-cultured <em>Desmodesmus</em> sp. Effective NH<sub>4</sub><sup>+</sup>-N removal in the co-culture under a high C/N ratio was attributed to microbial interactions. <em>Desmodesmus</em> sp. downregulated the <em>URE</em> gene in bacteria, inhibiting urea hydrolysis, while <em>B. megaterium</em> upregulated the <em>URE</em> and <em>gdhA</em> genes in microalgae, promoting urea utilization and NH<sub>4</sub><sup>+</sup>-N assimilation. This study provides new insights into the transcriptional regulation in nutrient assimilation and lipid metabolism in microalgal-bacterial consortia.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"416 ","pages":"Article 131810"},"PeriodicalIF":9.7,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610754","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 : 2024-11-13DOI: 10.1016/j.biortech.2024.131807
Zhuoqi Xu , Wenbo Gu , Yuwei Shi , Baibing Li , Zhenya Zhang , Zhongfang Lei , Tian Yuan , Yanfei Cheng , Mijung Kim , Akio Shoji
High-solid anaerobic digestion (HSAD) is a promising technology for treating livestock manure and agricultural waste; however, the wide application has been limited due to homogenization problems. This study established a novel HSAD system by integrating liquid and biogas recirculation (RBL), aiming to enhance the biogas conversion efficiency of high-solid substrates at low costs. Results showed that the highest methane yield was 357 mL/gVSadded in the novel HSAD system (RBL), 30.7 % and 251.7 % higher than those with only liquid recirculation (RL) or with no recirculation (RNo). Biogas recirculation helped enhance dissolution and degradation of organic matter, and prevented the VFAs accumulation, contributing to the enhanced methane production in the novel HSAD system. The net electric energy benefit of RBL was 301.2 kWh for treating 1-ton raw materials, suggesting the high economic feasibility of the novel HSAD system for the sustainable treatment of high-solid organic wastes.
{"title":"Integration of biogas and liquid recirculation enhance methane production in high-solid anaerobic digestion of pig manure and rice husks","authors":"Zhuoqi Xu , Wenbo Gu , Yuwei Shi , Baibing Li , Zhenya Zhang , Zhongfang Lei , Tian Yuan , Yanfei Cheng , Mijung Kim , Akio Shoji","doi":"10.1016/j.biortech.2024.131807","DOIUrl":"10.1016/j.biortech.2024.131807","url":null,"abstract":"<div><div>High-solid anaerobic digestion (HSAD) is a promising technology for treating livestock manure and agricultural waste; however, the wide application has been limited due to homogenization problems. This study established a novel HSAD system by integrating liquid and biogas recirculation (R<sub>BL</sub>), aiming to enhance the biogas conversion efficiency of high-solid substrates at low costs. Results showed that the highest methane yield was 357 mL/gVS<sub>added</sub> in the novel HSAD system (R<sub>BL</sub>), 30.7 % and 251.7 % higher than those with only liquid recirculation (R<sub>L</sub>) or with no recirculation (R<sub>No</sub>). Biogas recirculation helped enhance dissolution and degradation of organic matter, and prevented the VFAs accumulation, contributing to the enhanced methane production in the novel HSAD system. The net electric energy benefit of R<sub>BL</sub> was 301.2 kWh for treating 1-ton raw materials, suggesting the high economic feasibility of the novel HSAD system for the sustainable treatment of high-solid organic wastes.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"416 ","pages":"Article 131807"},"PeriodicalIF":9.7,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142613432","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 : 2024-11-13DOI: 10.1016/j.biortech.2024.131829
Carla Pereira Magalhães, M Salomé Duarte, M Alcina Pereira, Alfons J M Stams, Ana J Cavaleiro
Trace amounts of oxygen stimulate facultative anaerobic bacteria (FAB) within anaerobic bioreactors, which was shown to correlate with enhanced methane production from long-chain fatty acids. The relationship between FAB and fatty acid-degrading syntrophic communities under micro-aerobic conditions is still not clear. In this work, two syntrophic co-cultures, Syntrophomonas wolfei + Methanospirillum hungatei and Syntrophomonas zehnderi + Methanobacterium formicicum, were assembled and incubated with short, medium and long-chain fatty acids, with 0-10 % O2, in the presence and absence of FAB, here represented by Pseudomonas spp. Without Pseudomonas, the syntrophic activity was inhibited by 79 % at 0.5 %O2, but with Pseudomonas, the syntrophic co-cultures successfully converted the fatty acids to methane with up to 2 %O2. These findings underscore the pivotal role of FAB in the protection of syntrophic fatty acid-degrading communities under micro-aerobic conditions and emphasizes its significance in real-scale anaerobic digesters where strictly anaerobic conditions may not consistently be maintained.
{"title":"Facultative anaerobic bacteria enable syntrophic fatty acids degradation under micro-aerobic conditions.","authors":"Carla Pereira Magalhães, M Salomé Duarte, M Alcina Pereira, Alfons J M Stams, Ana J Cavaleiro","doi":"10.1016/j.biortech.2024.131829","DOIUrl":"https://doi.org/10.1016/j.biortech.2024.131829","url":null,"abstract":"<p><p>Trace amounts of oxygen stimulate facultative anaerobic bacteria (FAB) within anaerobic bioreactors, which was shown to correlate with enhanced methane production from long-chain fatty acids. The relationship between FAB and fatty acid-degrading syntrophic communities under micro-aerobic conditions is still not clear. In this work, two syntrophic co-cultures, Syntrophomonas wolfei + Methanospirillum hungatei and Syntrophomonas zehnderi + Methanobacterium formicicum, were assembled and incubated with short, medium and long-chain fatty acids, with 0-10 % O<sub>2</sub>, in the presence and absence of FAB, here represented by Pseudomonas spp. Without Pseudomonas, the syntrophic activity was inhibited by 79 % at 0.5 %O<sub>2</sub>, but with Pseudomonas, the syntrophic co-cultures successfully converted the fatty acids to methane with up to 2 %O<sub>2</sub>. These findings underscore the pivotal role of FAB in the protection of syntrophic fatty acid-degrading communities under micro-aerobic conditions and emphasizes its significance in real-scale anaerobic digesters where strictly anaerobic conditions may not consistently be maintained.</p>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":" ","pages":"131829"},"PeriodicalIF":9.7,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637991","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 : 2024-11-13DOI: 10.1016/j.biortech.2024.131742
Hong Chen , Jun Sheng , Qinhui Ye , Jun Li , Xin Yu , Hanyue Wu , Rui Zhang , Shiyi Zhao , Xiaoming Zou , Xiang Li , Gang Xue , Baoling Yuan
With the continuous recognition of green, organic and non-polluting products, organic fertilizers play an increasingly vital role in agricultural production. Among them, hydrochar-based organic fertilizer has attracted widespread attention recently. The present study evaluated the potential of digestate from anaerobic digestion of food waste for the preparation of hydrochar-based organic fertilizer by straw-based, FeCl3-catalyzed hydrothermal carbonization (HTC). Under the optimal conditions, a hydrochar-based organic fertilizer with > 25 wt% humus content and limited pollution risk was successfully prepared. The pot experiment demonstrated the feasibility of improving the physicochemical properties of red soil and promoting crop growth after adding hydrochar in place of commercial fertilizer. In addition, the function of zeolite on nutrient recovery in hydrothermal liquid (HTL) was analyzed, and preparing the slow-release organic fertilizer by mixing the nutrient-rich zeolite with hydrochar in a mass ratio of 1:4 was proposed. This work has significant implications for achieving the efficient resource recovery of digestate.
{"title":"Efficient resource recovery from food waste digestate via hydrothermal treatment and its application as organic fertilizer","authors":"Hong Chen , Jun Sheng , Qinhui Ye , Jun Li , Xin Yu , Hanyue Wu , Rui Zhang , Shiyi Zhao , Xiaoming Zou , Xiang Li , Gang Xue , Baoling Yuan","doi":"10.1016/j.biortech.2024.131742","DOIUrl":"10.1016/j.biortech.2024.131742","url":null,"abstract":"<div><div>With the continuous recognition of green, organic and non-polluting products, organic fertilizers play an increasingly vital role in agricultural production. Among them, hydrochar-based organic fertilizer has attracted widespread attention recently. The present study evaluated the potential of digestate from anaerobic digestion of food waste for the preparation of hydrochar-based organic fertilizer by straw-based, FeCl<sub>3</sub>-catalyzed hydrothermal carbonization (HTC). Under the optimal conditions, a hydrochar-based organic fertilizer with > 25 wt% humus content and limited pollution risk was successfully prepared. The pot experiment demonstrated the feasibility of improving the physicochemical properties of red soil and promoting crop growth after adding hydrochar in place of commercial fertilizer. In addition, the function of zeolite on nutrient recovery in hydrothermal liquid (HTL) was analyzed, and preparing the slow-release organic fertilizer by mixing the nutrient-rich zeolite with hydrochar in a mass ratio of 1:4 was proposed. This work has significant implications for achieving the efficient resource recovery of digestate.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"416 ","pages":"Article 131742"},"PeriodicalIF":9.7,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142613414","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 : 2024-11-13DOI: 10.1016/j.biortech.2024.131817
Shiqi Yang , Sultan Arslan-Tontul , Vincenzo Fogliano , Melania Casertano , Wenlai Fan , Yan Xu , Yao Nie , Arnau Vilas-Franquesa
This study investigated the upcycling of distilled spent grain (DSG), a melanoidin-rich by-product of the Chinese liquor industry, via fungal solid-state fermentation (SSF). Two fungi, Aspergillus oryzae and Aspergillus awamori, were tested, with A. awamori growing better on DSG than A. oryzae. SSF with A. awamori increased the concentration of water-soluble protein and phenolic compounds in DSG extracts by 46.5 % and 52.5 %, respectively, and reduced melanoidin level by 73.5 % w/w of DSG, suggesting A. awamori could metabolize melanoidins. Submerged fermentation (SmF) using isolated DSG melanoidins as sole carbon and nitrogen sources confirmed this observation. After 3 days of fermentation, A. awamori and A. oryzae biomass reached 2.5 g/L and 1.5 g/L, quenching melanoidin color by 24.4 % and 12.4 %, respectively. SmF by A. awamori also released free arabinose, glucose, and xylose. Data highlighted the possibility of converting melanoidins into edible mycelia resources, potentially applicable to various melanoidin-rich food by-products.
{"title":"Upcycling of melanoidin-rich Chinese distilled spent grain through solid-state fermentation by Aspergillus awamori","authors":"Shiqi Yang , Sultan Arslan-Tontul , Vincenzo Fogliano , Melania Casertano , Wenlai Fan , Yan Xu , Yao Nie , Arnau Vilas-Franquesa","doi":"10.1016/j.biortech.2024.131817","DOIUrl":"10.1016/j.biortech.2024.131817","url":null,"abstract":"<div><div>This study investigated the upcycling of distilled spent grain (DSG), a melanoidin-rich by-product of the Chinese liquor industry, via fungal solid-state fermentation (SSF). Two fungi, <em>Aspergillus oryzae</em> and <em>Aspergillus awamor</em>i, were tested, with <em>A. awamori</em> growing better on DSG than <em>A. oryzae</em>. SSF with <em>A. awamori</em> increased the concentration of water-soluble protein and phenolic compounds in DSG extracts by 46.5 % and 52.5 %, respectively, and reduced melanoidin level by 73.5 % w/w of DSG, suggesting <em>A. awamori</em> could metabolize melanoidins. Submerged fermentation (SmF) using isolated DSG melanoidins as sole carbon and nitrogen sources confirmed this observation. After 3 days of fermentation, <em>A. awamori</em> and <em>A. oryzae</em> biomass reached 2.5 g/L and 1.5 g/L, quenching melanoidin color by 24.4 % and 12.4 %, respectively. SmF by <em>A. awamori</em> also released free arabinose, glucose, and xylose. Data highlighted the possibility of converting melanoidins into edible mycelia resources, potentially applicable to various melanoidin-rich food by-products.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"416 ","pages":"Article 131817"},"PeriodicalIF":9.7,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610761","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 : 2024-11-13DOI: 10.1016/j.biortech.2024.131812
Jinming Fu , Tingting Guo , Haibo Li , Wenli Liu , Zhi Chen , Xiaoping Wang , Jianbo Guo
In this study, a functionally stable insoluble Cu/Fe nanoparticles (Cu/Fe NPs) were synthesized and applied denitrification with different contaminants. The results showed that 50 mg/L Cu/Fe NPs increased NO3–-N reduction rate up to 14.3 mg/(L·h) about 3 folds compared with the control system (4.7 mg/(L·h)), and Cu/Fe NPs exhibited excellent restorative effects on NO3–-N reduction under the stress of Cd2+, Nitrovin and Methyl Orange. Meanwhile, electrochemical analyses, enzyme activities, and related genes abundance together showed that pilus, cytochrome c and flavin mononucleotide were electron carriers to tandem extracellular and intracellular, increasing electron flux acting on NO3–-N in the respiratory chain. Metagenomic sequencing showed that microbial metabolic activity, electroactive bacteria (EAB) abundance with bi-directional electron transfer and Cu/Fe-compatible bacterial abundance were increased. Furthermore, denitrification performance was maintained by establishing C-EAB-Cu/Fe NPs cycling network. This study provided insights and applications for expanding the use of insoluble mediators in denitrification systems.
{"title":"Amorphous Cu/Fe nanoparticles with tandem intracellular and extracellular electron capacity for enhancing denitrification performance and recovery of co-contaminant suppressed denitrification","authors":"Jinming Fu , Tingting Guo , Haibo Li , Wenli Liu , Zhi Chen , Xiaoping Wang , Jianbo Guo","doi":"10.1016/j.biortech.2024.131812","DOIUrl":"10.1016/j.biortech.2024.131812","url":null,"abstract":"<div><div>In this study, a functionally stable insoluble Cu/Fe nanoparticles (Cu/Fe NPs) were synthesized and applied denitrification with different contaminants. The results showed that 50 mg/L Cu/Fe NPs increased NO<sub>3</sub><sup>–</sup>-N reduction rate up to 14.3 mg/(L·h) about 3 folds compared with the control system (4.7 mg/(L·h)), and Cu/Fe NPs exhibited excellent restorative effects on NO<sub>3</sub><sup>–</sup>-N reduction under the stress of Cd<sup>2+</sup>, Nitrovin and Methyl Orange. Meanwhile, electrochemical analyses, enzyme activities, and related genes abundance together showed that pilus, cytochrome <em>c</em> and flavin mononucleotide were electron carriers to tandem extracellular and intracellular, increasing electron flux acting on NO<sub>3</sub><sup>–</sup>-N in the respiratory chain. Metagenomic sequencing showed that microbial metabolic activity, electroactive bacteria (EAB) abundance with bi-directional electron transfer and Cu/Fe-compatible bacterial abundance were increased. Furthermore, denitrification performance was maintained by establishing C-EAB-Cu/Fe NPs cycling network. This study provided insights and applications for expanding the use of insoluble mediators in denitrification systems.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"416 ","pages":"Article 131812"},"PeriodicalIF":9.7,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142613410","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 : 2024-11-12DOI: 10.1016/j.biortech.2024.131804
Naga Sai Tejaswi Uppuluri , Xueling Ran , Joachim Müller , Jianbin Guo , Hans Oechsner
Phosphorus (P) is critical for plant growth, but global reserves are exhausting within 250–300 years, therefore enhancing phosphate recycling is crucial for the future. Biogas digestate, rich with nutrients is a promising resource for nutrient recovery. Conventional solid–liquid separation shifts approximately 35 % of the total P in the digestate to the solid phase. Separation trials with additive treatment using a screw press with a 0.75 mm sieve were performed at University of Hohenheim’s full-scale biogas plant. After 22 h, 67.41 % (kieserite treatment) and 52.35 % (straw flour treatment) of total P shifted to the solid phase. Treatment with kieserite enhanced P shift into the solid phase by forming non-labile fractions through a chemical bond between P and Mg2+ ions. Kieserite treatment for 22 h effectively increases the share of total P in the separated solid phase, it also ensures a sustainable nutrient supply and mitigates the risk of nutrient runoff.
磷（P）对植物生长至关重要，但全球磷储量将在 250-300 年内耗尽，因此加强磷酸盐回收利用对未来至关重要。富含养分的沼气沼渣是一种很有前景的养分回收资源。传统的固液分离法会将沼渣中大约 35% 的磷转移到固相中。霍恩海姆大学的全规模沼气厂利用带 0.75 毫米筛网的螺旋压榨机进行了添加剂处理的分离试验。22 小时后，67.41%（铁矿石处理）和 52.35%（稻草粉处理）的总磷转移到固相中。通过 P 和 Mg2+ 离子之间的化学键形成非易挥发馏分，铁矿石处理增强了 P 向固相的转移。经过 22 小时的铁矿石处理，可有效增加分离固相中总磷的比例，还能确保可持续的养分供应，降低养分流失的风险。
{"title":"Effects of additives on shifting phosphorus to solid phase during Solid-Liquid separation of digestate in full-scale biogas plant","authors":"Naga Sai Tejaswi Uppuluri , Xueling Ran , Joachim Müller , Jianbin Guo , Hans Oechsner","doi":"10.1016/j.biortech.2024.131804","DOIUrl":"10.1016/j.biortech.2024.131804","url":null,"abstract":"<div><div>Phosphorus (P) is critical for plant growth, but global reserves are exhausting within 250–300 years, therefore enhancing phosphate recycling is crucial for the future. Biogas digestate, rich with nutrients is a promising resource for nutrient recovery. Conventional solid–liquid separation shifts approximately 35 % of the total P in the digestate to the solid phase. Separation trials with additive treatment using a screw press with a 0.75 <!--> <!-->mm sieve were performed at University of Hohenheim’s full-scale biogas plant. After 22 <!--> <!-->h, 67.41 % (kieserite treatment) and 52.35 % (straw<!--> <!-->flour treatment) of total P shifted to the solid phase. Treatment with kieserite enhanced P shift into the solid phase by forming non-labile fractions through a chemical bond between P and Mg<sup>2+</sup> ions. Kieserite treatment for 22 h effectively increases the share of total P in the separated solid phase, it also ensures a sustainable nutrient supply and mitigates the risk of nutrient runoff.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"416 ","pages":"Article 131804"},"PeriodicalIF":9.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study investigated compost quality and gaseous emissions during the algal sludge composting. The experiment explored the feasibility of low initial carbon to nitrogen (C/N) ratio composting by using different volume ratios of algal sludge and spent mushroom substrates (1:1, 1:2, 1:3, and 1:4, corresponding to C/N ratios of 9.5, 12.3, 14.6, 16.0, respectively). The results showed that increasing the proportion of algal sludge in the initial material led to a longer maturation time and higher nitrogen losses but also enhanced the mineralization of organic nitrogen (converted to NH4+ and NO3-) and reduced carbon losses. The addition of carbon-rich bulking agents within a certain range improved the diversity and interactions of bacterial communities during algal sludge composting. In conclusion, considering the nitrogen and carbon lost, retained, and made available across the four treatments, treatment 3 (C/N = 14.6) appears to be the optimal choice for low C/N composting.
{"title":"Feedstock optimization with low carbon to nitrogen ratio during algal sludge aerobic composting: Quality and gaseous emissions.","authors":"Hainan Wu, Chengkai Wang, Jiahui Zhou, Haibing Cong, Yu Gao, Wei Cai, Shaoyuan Feng, Chi Zhang","doi":"10.1016/j.biortech.2024.131811","DOIUrl":"https://doi.org/10.1016/j.biortech.2024.131811","url":null,"abstract":"<p><p>This study investigated compost quality and gaseous emissions during the algal sludge composting. The experiment explored the feasibility of low initial carbon to nitrogen (C/N) ratio composting by using different volume ratios of algal sludge and spent mushroom substrates (1:1, 1:2, 1:3, and 1:4, corresponding to C/N ratios of 9.5, 12.3, 14.6, 16.0, respectively). The results showed that increasing the proportion of algal sludge in the initial material led to a longer maturation time and higher nitrogen losses but also enhanced the mineralization of organic nitrogen (converted to NH<sub>4</sub><sup>+</sup> and NO<sub>3</sub><sup>-</sup>) and reduced carbon losses. The addition of carbon-rich bulking agents within a certain range improved the diversity and interactions of bacterial communities during algal sludge composting. In conclusion, considering the nitrogen and carbon lost, retained, and made available across the four treatments, treatment 3 (C/N = 14.6) appears to be the optimal choice for low C/N composting.</p>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":" ","pages":"131811"},"PeriodicalIF":9.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142613417","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}
Global rubber industry, growing 4-6 % annually with 13.76 million Mt of rubber produced in 2019, significantly impacts the economy. This study explores coupling sulfate-dependent ammonium oxidation (Sulfammox) and sulfide-driven autotrophic denitrification (SDAD) within an anaerobic membrane bioreactor (AnMBR) to treat high-strength natural rubber wastewater. Over 225 days, the AnMBR system achieved maximal chemical oxygen demand (COD), total nitrogen (TN), ammonium nitrogen (NH4+-N), and sulfate sulfur (SO42--S) removal efficiencies of 58 %, 31 %, 13 %, and 45 %, respectively. TN is predominantly removed through Sulfammox (accounting for 49 % of NH4+-N removal), SDAD, and conventional denitrification pathways. Sulfate removal is achieved via Sulfammox (responsible for 43 % of SO42--S removal), and Dissimilatory sulfate-reducing (DSR) processes (contributing 57 % of SO42--S removal). Microbial analysis identified Desulfovibrio and Sulfurospirillum as key microbes, while metagenomic analysis highlighted crucial sulfur and nitrogen cycling pathways. The findings support Sulfammox and SDAD as promising eco-friendly strategies for treating ammonia- and sulfate-rich industrial wastewater.
{"title":"Synchronised removal of nitrogen and sulphate from rubber industrial wastewater by coupling of Sulfammox and sulphide-driven autotrophic denitrification in anaerobic membrane bioreactor.","authors":"Ishanka Wimalaweera, Fumin Zuo, Qihe Tang, Qianwen Sui, Shameen Jinadasa, Sujithra Weragoda, Tharindu Ritigala, Rohan Weerasooriya, Yawei Wang, Hui Zhong, Madhubhashini Makehelwala, Yuansong Wei","doi":"10.1016/j.biortech.2024.131785","DOIUrl":"https://doi.org/10.1016/j.biortech.2024.131785","url":null,"abstract":"<p><p>Global rubber industry, growing 4-6 % annually with 13.76 million Mt of rubber produced in 2019, significantly impacts the economy. This study explores coupling sulfate-dependent ammonium oxidation (Sulfammox) and sulfide-driven autotrophic denitrification (SDAD) within an anaerobic membrane bioreactor (AnMBR) to treat high-strength natural rubber wastewater. Over 225 days, the AnMBR system achieved maximal chemical oxygen demand (COD), total nitrogen (TN), ammonium nitrogen (NH<sub>4</sub><sup>+</sup>-N), and sulfate sulfur (SO<sub>4</sub><sup>2-</sup>-S) removal efficiencies of 58 %, 31 %, 13 %, and 45 %, respectively. TN is predominantly removed through Sulfammox (accounting for 49 % of NH<sub>4</sub><sup>+</sup>-N removal), SDAD, and conventional denitrification pathways. Sulfate removal is achieved via Sulfammox (responsible for 43 % of SO<sub>4</sub><sup>2-</sup>-S removal), and Dissimilatory sulfate-reducing (DSR) processes (contributing 57 % of SO<sub>4</sub><sup>2-</sup>-S removal). Microbial analysis identified Desulfovibrio and Sulfurospirillum as key microbes, while metagenomic analysis highlighted crucial sulfur and nitrogen cycling pathways. The findings support Sulfammox and SDAD as promising eco-friendly strategies for treating ammonia- and sulfate-rich industrial wastewater.</p>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":" ","pages":"131785"},"PeriodicalIF":9.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610760","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 : 2024-11-12DOI: 10.1016/j.biortech.2024.131808
Davi Benedito Oliveira , Guilherme Engelberto Kundlastsch , Richard Daniel Cruz , Bruno Batista , Marcelo Perencin de Arruda Ribeiro , Maria Teresa Marques Novo-Mansur , Adilson José da Silva
Current efforts to improve xanthan gum (XG) production by Xanthomonas have focused on the growth medium, operating parameters, and downstream steps. However, a key aspect is the development of optimal strains. The present work aimed to investigate the formation of XG monomers, using kinetic and stoichiometric models to identify possible bottlenecks, and to engineer a recombinant strain to overcome such limitations. The galU and ugd genes involved in the biosynthesis of the UDP-glucose and UDP-glucuronic acid monomers were overexpressed in Xanthomonas campestris pv. campestris. The strains were cultivated in shake flasks and bioreactor. As predicted by in silico analysis, overexpression of the ugd gene resulted in a significant increase in gum synthesis, up to 50% higher volumetric productivity in the bioreactor. To a lesser extent, galU overexpression was also shown to improve product formation. These findings validated the hypothesis that metabolic engineering of the monomer biosynthesis can enhance XG production.
{"title":"Xanthan gum production in Xanthomonas campestris is increased by favoring the biosynthesis of its monomers","authors":"Davi Benedito Oliveira , Guilherme Engelberto Kundlastsch , Richard Daniel Cruz , Bruno Batista , Marcelo Perencin de Arruda Ribeiro , Maria Teresa Marques Novo-Mansur , Adilson José da Silva","doi":"10.1016/j.biortech.2024.131808","DOIUrl":"10.1016/j.biortech.2024.131808","url":null,"abstract":"<div><div>Current efforts to improve xanthan gum (XG) production by <em>Xanthomonas</em> have focused on the growth medium, operating parameters, and downstream steps. However, a key aspect is the development of optimal strains. The present work aimed to investigate the formation of XG monomers, using kinetic and stoichiometric models to identify possible bottlenecks, and to engineer a recombinant strain to overcome such limitations. The <em>galU</em> and <em>ugd</em> genes involved in the<!--> <!-->biosynthesis of the UDP-glucose and UDP-glucuronic acid monomers were overexpressed in <em>Xanthomonas campestris</em> pv<em>. campestris.</em> The strains were cultivated in shake flasks and bioreactor. As predicted by <em>in silico</em> analysis, overexpression of the <em>ugd</em> gene resulted in a significant increase in gum synthesis, up to 50% higher volumetric productivity in the<!--> <!-->bioreactor. To a lesser extent, <em>galU</em> overexpression was also shown to improve product formation. These findings validated the hypothesis that metabolic engineering of the monomer biosynthesis can enhance XG production.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"416 ","pages":"Article 131808"},"PeriodicalIF":9.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610763","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}
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