Publications by authors named "Junqiu Wu"

36 Publications

δ-MnO changed the structure of humic-like acid during co-composting of chicken manure and rice straw.

Waste Manag 2021 Jun 3;128:16-24. Epub 2021 May 3.

College of Life Science, Northeast Agricultural University, Harbin 150030, China.

Improving the structure and quantity of humus is important to reduce agriculture organic waste by composting. The present study was aimed to assess the role of δ-MnO on humus fractions formation during co-composting of chicken manure and rice straw. Two tests (control group (CK), the addition of δ-MnO (M)) were carried out. The results showed that organic matter content decreased by 34% and 29% at M and CK, suggesting the process of organic waste disposal was accelerated by adding δ-MnO. The structures and quantity of fulvic acid (FA) and humic acid (HA) (as the main fractions of humus) were investigated. The δ-MnO had no significant effect on improving the concentration of FA and HA (p > 0.05). However, the addition of δ-MnO caused different effects on the FA and HA structure. The humification degree of FA improved, while bioavailability of HA increased through adding δ-MnO. The addition of δ-MnO rephased the bacterial community structure, slowing down the succession rate of the bacterial community in M composting. After adding δ-MnO the structural equation modeling results showed that environmental factors could directly drive changes in FA and HA by modulating the bacterial community. Furthermore, the role of FA and HA in the soil amendment was also demonstrated. Therefore, the addition of MnO might be promising for agriculture organic waste treatment and environmental repair during composting.
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http://dx.doi.org/10.1016/j.wasman.2021.04.039DOI Listing
June 2021

Manganese dioxide driven the carbon and nitrogen transformation by activating the complementary effects of core bacteria in composting.

Bioresour Technol 2021 Jun 11;330:124960. Epub 2021 Mar 11.

College of Life Science, Northeast Agricultural University, Harbin 150030, China.

This study revealed core bacterial metabolic mechanisms involved in carbon (C) and nitrogen (N) in composting with adding MnO. Two tests (control group (CK), adding MnO (M)) were performed. The results indicated that the MnO accelerated the transformation of carbon and nitrogen in composting. Core bacteria involved in the C and N conversion were identified, the complementarity effects of core bacteria were stimulated in M composting. Additionally, the influence of core bacteria on the C and N conversion could be divided into two pathways in M composting. One was that core bacteria promoted C and N conversion by accelerating the flow of amino acids into the tricarboxylic acid cycle. Another was that the complementarity effects of core bacteria increased the overall bacterial diversity, which contributed to C and N conversion. These findings showed that the addition of MnO to composting was a promising application to treat agricultural organic waste.
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http://dx.doi.org/10.1016/j.biortech.2021.124960DOI Listing
June 2021

Oxytetracycline stress reconstruct the core microbial community related to nitrogen transformation during composting.

Bioresour Technol 2021 Jan 18;319:124142. Epub 2020 Sep 18.

Heilongjiang Province Environmental Science Research Institute, Harbin 150056, China.

This study investigated oxytetracycline (OTC) effects on nitrogen (N) transformation and bacterial community diversity during chicken manure composting. The addition of OTC inhibited nitrifying bacteria, resulted in a decrease in the transformation of NH-N to NO-N during composting, and affected in the order T3 (32.76%) > T2 (28.76%) > T1 (17.02%) > CK. The OTC could act as an inhibitor against core microbial growth, leading to a delay effect during composting. 16S rRNA sequencing was employed for the functional prediction, and results indicated the bacterial community related to N transformation reconstructed under OTC stress. The core microorganisms were changed after OTC addition, with the emergence of Bacillus and Thermobifida, which could inhibit the N transformation by network analysis. Therefore, core microorganisms could be regulated to reduce the negative of OTC impacts on N transformation and thus reduce N loss during composting.
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http://dx.doi.org/10.1016/j.biortech.2020.124142DOI Listing
January 2021

Modified montmorillonite and illite adjusted the preference of biotic and abiotic pathways of humus formation during chicken manure composting.

Bioresour Technol 2021 Jan 13;319:124121. Epub 2020 Sep 13.

Heilongjiang Province Environmental Monitoring Centre, Harbin 150056, China.

The study aimed to identify the preference of pathways of humus formation. Five lab-scale composting experiments were established: the control (CK), montmorillonite addition (M), illite addition (I), thermal treatment montmorillonite addition (M-) and thermal treatment illite addition (I-). Results showed humus content was increased by 11.5%, 39.3%, 37.2%, 30.9% and 27.6% during CK, M-, M, I- and I composting. Meanwhile, Redundancy analysis indicated the bands of bacteria community related to humic acid (HA) were more abundant in the M- and I- treatments. Furthermore, structural equation model and variance partitioning analysis demonstrated that M- and I- treatments promoted precursors to synthesize HA by coordinated regulation of biotic pathway and abiotic pathway, the increase of HA in the M and I treatments mainly through the abiotic pathway. In summary, an effective method was proposed to improve humus production by adjusting the preference of biotic and abiotic pathways of humus formation.
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http://dx.doi.org/10.1016/j.biortech.2020.124121DOI Listing
January 2021

Influence of malonic acid and manganese dioxide on humic substance formation and inhibition of CO release during composting.

Bioresour Technol 2020 Dec 4;318:124075. Epub 2020 Sep 4.

Heilongjiang Province Environmental Science Research Institute, Harbin 150056, China.

The aim of thisstudy was to explore the effects of malonic acid (MA), manganese dioxide (MnO), malonic acid combined with manganese dioxide (MA + MnO) additionon reducing CO emission and promoting humic substance (HS) formation during composting. The result showed that the addition of MA and MnO were an efficient way to reduce CO emission. Meanwhile, the CO emissions in the MA + MnO treatment was 36.8% less than that of the CK, and the amount of humic acid (HA) produced in the MnO treatment was 38.7% higher than that of the CK. Structural equation models demonstrated that the addition of exogenoussubstance promoted the conversion of amino acids and reducing sugars to HA. The addition of exogenous substances was the main reason for influencing the concentration of HA. In general, this research provided theoretical supports for the addition of exogenous substances to promote HA formation during composting.
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http://dx.doi.org/10.1016/j.biortech.2020.124075DOI Listing
December 2020

Reconstruction of core microbes based on producing lignocellulolytic enzymes causing by bacterial inoculation during rice straw composting.

Bioresour Technol 2020 Nov 17;315:123849. Epub 2020 Jul 17.

Ecological and Environmental Monitoring Center of Suihua, 152052, China.

The aim of this paper was to identify the core microbes of producing lignocellulolytic enzymes during rice straw composting with functional bacterial agents inoculation. The results indicated that inoculation functional bacterial agents accelerated the degradation of organic matter and coarse fiber content by 7.58%, 8.82%, which were due to the fact that key enzymes and core microbes were stimulated. In addition, inoculation have reconstructed core microbes of producing lignocellulase. Meanwhile, inoculation functional bacterial agents not only as core bacteria to produce cellulase, xylanase and manganese peroxidase (MnP), but also increased most core microbial abundance. Redundancy analysis indicated that CMCase, xylanase, total nitrogen and MnP as key factors to affect the degradation of organic fractions in the core bacterial communities, while in the core fungal communities, were mainly affected by environmental factors (except for MnP). This study provided a theoretical basis for the efficiently degradation during agricultural wastes composting.
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http://dx.doi.org/10.1016/j.biortech.2020.123849DOI Listing
November 2020

Selective pressures of heavy metals on microbial community determine microbial functional roles during composting: Sensitive, resistant and actor.

J Hazard Mater 2020 11 19;398:122858. Epub 2020 May 19.

Heilongjiang Province Environmental Science Research Institute, Harbin 150056, China.

Heavy metals (HM) pollution exerts an effect on microbial community composition and structure during composting, the way how microbial community responses to HM pressure is remain poorly understood though. The aim of this study was to explore functional roles of microorganisms based on selective pressures of HM (Cu, Zn and Cd). The results of microbial resistance showed that the toxicity of metals to microorganisms were Cu > Zn > Cd during composting. Cu and Zn were more toxic for microorganisms during composting when compared with Cd. However, microorganisms had a longer lag period to grow under Zn stress through microbial tolerance determination. In addition, the microbial catalase activity generally decreased and protease activity generally increased, thus microorganisms became more adaptable to HM stress during composting. The experimental results confirmed the existence of sensitive, resistant and actor microorganisms during beef cattle and chicken manures composting. Ultimately, the resistant, sensitive and actor microorganisms at genus level were distinguished under HM pressure based on the network analysis and structural equation models, including 85 resistant microorganisms, 5 sensitive microorganisms and 6 actor microorganisms. This would be helpful to understand the microbial succession process under HM stress and identify functional strains of HM remediation.
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http://dx.doi.org/10.1016/j.jhazmat.2020.122858DOI Listing
November 2020

Humus formation driven by ammonia-oxidizing bacteria during mixed materials composting.

Bioresour Technol 2020 Sep 7;311:123500. Epub 2020 May 7.

Institute of Natural Resources and Ecology, Heilongjiang Academy of Sciences, Harbin 150030, China.

The aim of this study was to identify the effects of ammonia-oxidizing bacteria (AOB) inoculation on humus formation. Both nitrogen conversion and humus formation were considered as the main processes, because NH-N-like compounds not only substrates of nitrification, but also precursors of humus. During composting, the inoculation of AOB indeed increased humus concentration by fixing NH emission as NH-N, but it has also promoted nitrogen transformation. While the main reason was the changed bacteria community structure caused by inoculating AOB. Moreover, the relationship between bacteria and nitrogen transformation and humus formation has become closer. And bacteria were more likely to synthesize humus. Therefore, it is conjectured that AOB inoculation could not only provide NH-N for humus formation, but also enhance the anabolism of microorganisms. This suppose has been confirmed by structural equation model in this study. Therefore, AOB inoculation has a driving effect on promoting humus formation.
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http://dx.doi.org/10.1016/j.biortech.2020.123500DOI Listing
September 2020

Identifying the action ways of function materials in catalyzing organic waste transformation into humus during chicken manure composting.

Bioresour Technol 2020 May 29;303:122927. Epub 2020 Jan 29.

College of Life Science, Northeast Agricultural University, Harbin 150030, China. Electronic address:

The aim of this study is to detect the action properties of functional materials (FM) in transforming waste into resource products with high humus content. FM (MnO and reducing sugar) were added in different periods of chicken manure composting. During composting, concentration of humic acids (HA) as aromatic fraction of humus, was increased by FM. The promotive effects of adding FM in later period was the most obvious. While adding FM in the beginning period could accelerate organic matter degradation, but it did not promote HA formation. Meanwhile, the microbial diversity was higher in groups by adding FM in the beginning and thermophilic periods. Therefore, it was speculated that FM might improve HA formation by promoting the abiotic polymerization of precursors. Eventually, structural equation model showed that FM was beneficial to abiotic pathway of HA formation. But the formation efficiency was reduced by interfering with biotic pathway.
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http://dx.doi.org/10.1016/j.biortech.2020.122927DOI Listing
May 2020

Elucidating the negative effect of denitrification on aromatic humic substance formation during sludge aerobic fermentation.

J Hazard Mater 2020 04 13;388:122086. Epub 2020 Jan 13.

College of Life Science, Northeast Agricultural University, Harbin 150030, China. Electronic address:

Humic substance (HS), as an aromatic compound, is the core product of aerobic fermentation. Denitrification-dependent degradation of aromatic compounds have been repeatedly observed in environment. However, few studies have elucidated the relationship between denitrification and aromatic HS during sludge aerobic fermentation. This study was conducted to investigate the effect of enhanced denitrification on aromatic HS formation. On the 24th day of sludge aerobic fermentation, five tests (CK, Run1, Run2, Run3 and Run4) were executed, and nitrate concentrations were adjusted to 480 ± 20, 500 ± 20, 1000 ± 20, 1500 ± 20 and 2000 ± 20 mg/kg with potassium nitrate, respectively. Analytical results demonstrated that nitrate addition increased denitrifying genes abundance and enhanced denitrification, which further reduced aromatic HS formation (p < 0.05). Especially in Run3, the concentrations of HS and humic acid on the 52nd day dramatically decreased by 12.9 % and 34.2 % in comparison with those on the 31st day. High-throughput sequencing revealed that enhanced denitrification effectively stimulated the metabolism of denitrifying microorganisms with aromatic-degrading capability. Co-occurring network analysis indicated that some keystone taxa of denitrification aromatic-degrading microorganisms involved in the conversion of nitrate to nitrite were the most crucial for enhancing denitrification and reducing aromatic HS formation.
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http://dx.doi.org/10.1016/j.jhazmat.2020.122086DOI Listing
April 2020

Effect of manganese dioxide on the formation of humin during different agricultural organic wastes compostable environments: It is meaningful carbon sequestration.

Bioresour Technol 2020 Mar 13;299:122596. Epub 2019 Dec 13.

College of Life Science, Northeast Agricultural University, Harbin 150030, China. Electronic address:

The study aims to accelerate the formation of humin (HM) with the addition MnO to achieve carbon sequestration during different material composting. The results indicated that the addition of MnO could improve the concentration of HM by increasing of the content in functional groups during corn straw (CS) and chicken manure (CM) composting. With the addition of MnO, non-aromatic functional groups were responsible for the increase of the HM concentration in CM, while aromatic functional groups were dominating for CS. Although the formation mechanism of HM varied significantly across different materials, the MnO promoted more abundant functional groups to participate the formation of recalcitrant fluorescence components in CS and CM. In addition, the aromatization of HM structure was improved by adding the MnO. Therefore, the addition of MnO not only increase carbon sequestration but also increase the compost product resilience during the decompose of agricultural organic wastes.
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http://dx.doi.org/10.1016/j.biortech.2019.122596DOI Listing
March 2020

Core microorganisms promote the transformation of DOM fractions with different molecular weights to improve the stability during composting.

Bioresour Technol 2020 Mar 9;299:122575. Epub 2019 Dec 9.

College of Life Science, Northeast Agricultural University, Harbin 150030, China. Electronic address:

Transformation of DOM fractions with different molecular weights during composting of chicken manure (CM), garden waste (GW) and municipal solid waste (MSW) was evaluated in this study. The results revealed that DOM concentrations decreased by 49.8%, 53.9% and 86.4% during CM, GW and MSW composting, respectively. Meanwhile, low molecular weight (<650 Da) DOM was visibly transformed into high molecular weight (>10 kDa) DOM for enhancing their stability during composting. Core microorganisms promoting DOM stabilization were identified by network analysis, such as Prosthecobacter, Paenalcaligenes and Solibacillus. In addition, DOM composition was also related to the relative abundance of microbial metabolic function, such as chemoheterotrophy and aerobic chemoheterotrophy. Moreover, temperature, moisture and pH were identified as the key physicochemical factors affecting the DOM stabilization mediated by core microorganisms during composting. These above findings are helpful to regulate the DOM stabilization during composting and improve the quality of final composts.
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http://dx.doi.org/10.1016/j.biortech.2019.122575DOI Listing
March 2020

Driving effects of minerals on humic acid formation during chicken manure composting: Emphasis on the carrier role of bacterial community.

Bioresour Technol 2019 Dec 3;294:122239. Epub 2019 Oct 3.

College of Life Science, Northeast Agricultural University, Harbin 150030, China. Electronic address:

This work was aimed to determine the effects of different minerals on humic acid (HA) formation. Minerals can stimulate the formation of complex compounds, however, whether they can promote the conversion of complex compounds to HA has not been verified. Four treatments were setup from chicken manure mixed with rice hull and then added biochar (BC), montmorillonite (MMT) and biochar combined with montmorillonite (BC-MMT) for composting, while the control check (CK) was composted without minerals. The results showed that HA concentration was increased by 28.09%, 40.79%, 45.39% and 38.96% during CK, BC, BC-MMT and MMT composting. However, the bacterial community was the main reason for affecting HA concentration. Network analysis showed that obligate and facultative core microbes drove HA formation, and these driving effects were affected by minerals. Therefore, the core bacterial community promoted HA formation, which provided an insightful method to improve HA production.
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http://dx.doi.org/10.1016/j.biortech.2019.122239DOI Listing
December 2019

Improved lignocellulose degradation efficiency based on Fenton pretreatment during rice straw composting.

Bioresour Technol 2019 Dec 7;294:122132. Epub 2019 Sep 7.

Environmental Monitoring Center of Heilongjiang Province, Harbin 150056, China.

This study aims to explore the effect of Fenton pretreatment on organic fractions, enzymes activities and microbial communities during composting. In this study, rice straw was chosen to be composted after pretreatment. The results indicated that Fenton pretreatment significantly increased the degradation of organic matter and coarse fiber contents, which might be the reason that Fenton pretreatment enhanced lignocellulose-degrading enzymes activities during composting, including CMCase, FPase, xylanase, manganese peroxidase, lignin peroxidase and laccase. Additionally, Fenton pretreatment reshaped bacteria community. The key enzymes and environmental factors, which affected organic fractions degradation were identified by redundancy analysis. Furthermore, structural equation modeling and variation partitioning analysis further revealed possible mechanisms of organic fractions degradation in different treatments during composting. In summary, the combined application Fenton pretreatment and composting improved lignocellulose degradation efficiency, which provided for an effective and environment-friendly way to manage lignocellulose wastes.
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http://dx.doi.org/10.1016/j.biortech.2019.122132DOI Listing
December 2019

Effect of tricarboxylic acid cycle regulators on the formation of humic substance during composting: The performance in labile and refractory materials.

Bioresour Technol 2019 Nov 2;292:121949. Epub 2019 Aug 2.

College of Life Science, Northeast Agricultural University, Harbin 150030, China.

The aims of this study are to reveal the roles of tricarboxylic acid (TCA) cycle regulators in reducing CO emission and promoting humic substance (HS) formation during composting with different materials. The results showed that the addition of adenosine tri-phosphate (ATP) or malonic acid (MA) reduced CO emission during chicken manure composting. However, only the addition of MA reduced CO emission during lawn waste and garden waste composting. In addition, both of the two inhibitors promoted HS formation, especially for ATP. Structural equation models further confirmed that ATP and MA reduced CO emission by inhibiting the decomposition of amino acid by microorganisms. Meanwhile, ATP promoted the conversion of amino acid and soluble sugars to HS, while MA only promoted the conversion of soluble sugars to HS. In summary, this study provides a theoretical basis for the application of inhibitors to reduce CO emission and promote HS formation during composting.
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http://dx.doi.org/10.1016/j.biortech.2019.121949DOI Listing
November 2019

Chemi-Net: A Molecular Graph Convolutional Network for Accurate Drug Property Prediction.

Int J Mol Sci 2019 Jul 10;20(14). Epub 2019 Jul 10.

Accutar Biotechnology Inc., 760 Parkside Ave., Brooklyn, NY 11226, USA.

Absorption, distribution, metabolism, and excretion (ADME) studies are critical for drug discovery. Conventionally, these tasks, together with other chemical property predictions, rely on domain-specific feature descriptors, or fingerprints. Following the recent success of neural networks, we developed Chemi-Net, a completely data-driven, domain knowledge-free, deep learning method for ADME property prediction. To compare the relative performance of Chemi-Net with Cubist, one of the popular machine learning programs used by Amgen, a large-scale ADME property prediction study was performed on-site at Amgen. For all 13 data sets, Chemi-Net resulted in higher R values compared with the Cubist benchmark. The median R increase rate over Cubist was 26.7%. We expect that the significantly increased accuracy of ADME prediction seen with Chemi-Net over Cubist will greatly accelerate drug discovery.
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http://dx.doi.org/10.3390/ijms20143389DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6678642PMC
July 2019

Assessment contributions of physicochemical properties and bacterial community to mitigate the bioavailability of heavy metals during composting based on structural equation models.

Bioresour Technol 2019 Oct 15;289:121657. Epub 2019 Jun 15.

College of Life Science, Northeast Agricultural University, Harbin 150030, China. Electronic address:

The aim of this study was to explore the pathways to mitigate the bioavailability of heavy metals (HM) during chicken and beef cattle manures composting. For raw materials, HM contents in animal manures from breeding farm were 1.5-3 times as much as that of domestic animal manures. Structural equation models (SEMs) based on denaturing gradient gel electrophoresis (DGGE) showed that mitigating bioavailability of HM was mainly attributed to physicochemical properties (organic matters content and temperature) during beef cattle manures composting. However, both physicochemical properties (organic matters content, temperature, pH and moisture) and bacterial community were critical factors during chicken manures composting. Furthermore, the statistical analysis from high-throughput sequencing verified the results of SEMs. Therefore, the bioavailability of HM will be mitigated by different deactivation pathways according to diverse raw materials composting.
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http://dx.doi.org/10.1016/j.biortech.2019.121657DOI Listing
October 2019

Effect of MnO on biotic and abiotic pathways of humic-like substance formation during composting of different raw materials.

Waste Manag 2019 Mar 14;87:326-334. Epub 2019 Feb 14.

Heihe Branch of Heilongjiang Academy of Agricultural Sciences, Heihe, Heilongjiang 164300, China.

The humic-like substances (HLS) are proposed to be formed by biotic and abiotic pathways. The abiotic pathways were neglected in existed composting studies. The present study aims to accelerate the abiotic pathways, and to investigate how MnO drives the HLS transformation via changing the contribution of abiotic and biotic pathways during composting with different materials. Parallel factor analysis model (PARAFAC), hetero two-dimensional correlation spectra (hetero-2DCOS) and variance partitioning were used to identify the effects of MnO on the formation of humic acid (HA) and fluvic acid (FA) during composting of chicken manure (CM) and corn straw (CS). The addition of MnO could change the structures of HLS during CS and CM composting, mainly promoting the formation of complex components in HA and FA during CS composting, as well as the complex components of FA during CM composting. Meanwhile, the addition of MnO could reshape the microbial ecology, which enhanced the correlation between microbes and complex components formation during composting, especially in CM composting. Variance partitioning showed that both abiotic and biotic pathways were stimulated in conversion of HLS components after adding MnO during CS composting, especially for the abiotic pathways. During CM composting, the MnO promoted biotic effects on the conversion of HLS components. Above all, the addition of MnO could stimulate pathways of biotic, abiotic or both of them to improve the humification degree of HLS by changing microbial ecology, which could be a promising way for promoting the application value of composting products.
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http://dx.doi.org/10.1016/j.wasman.2019.02.022DOI Listing
March 2019

Diversity in the Mechanisms of Humin Formation during Composting with Different Materials.

Environ Sci Technol 2019 04 25;53(7):3653-3662. Epub 2019 Mar 25.

College of Life Science , Northeast Agricultural University , Harbin 150030 , China.

Humins (HMs) play a very important role in various environmental processes and are crucial for regulating global carbon and nitrogen cycles in various ecosystems. Composting is a controlled decomposition process accompanied by the stabilization of organic solid waste materials. During composting, active fractions of organic substances can be transformed into HMs containing stable and complex macromolecules. However, the structural heterogeneity and formation mechanisms of HMs during composting with various substrates have not been clarified. Here, the structure and composition of HMs extracted from livestock manure (LM) and straw (SW) during composting were investigated by excitation-emission matrices spectroscopy and Fourier transform infrared spectroscopy. The results showed that the stability and humification of LM-HM were lower than that of SW-HM. The parallel factor analysis components of the HM in LM composting contained the same fluorescent unit, and the intermediate of cellulose degradation affected the structure of the HM from SW composting. Structural equation modeling demonstrated that low-molecular-weight compounds were key factors in humification. On the basis of the structure and key factors impacting HM, we constructed two mechanisms for the formation of HM from different composting processes. The LM-HMs from different humification processes have multiple identical fluorescent structural units, and the high humification of SW is affected by its polysaccharide constituents, which contains a fluorescent component in their skeleton, providing a basis for studying HM in composting.
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http://dx.doi.org/10.1021/acs.est.8b06401DOI Listing
April 2019

Effect of semi-continuous replacements of compost materials after inoculation on the performance of heat preservation of low temperature composting.

Bioresour Technol 2019 May 23;279:50-56. Epub 2019 Jan 23.

College of Life Science, Northeast Agricultural University, Harbin 150030, China.

Development of cold-adapted microbial agent is an efficient approach for composting in low temperature. The study was conducted to evaluate the effect of semi-continuous replacements of compost materials after inoculation (SRMI) on the heat preservation of low temperature composting derived from chicken manure. Results revealed that SRMI could significantly improve the heat preservation of the pile, although the time of start-up in two inoculation groups was approximately the same. Due to the increase in the number of replacements of materials led to the changes in microbial community structures and enzyme activity. Non-metric multidimensional and colorimetric methods indicated that microbial community structures and enzyme activity was completely different in SRMI. Structural equation model was constructed by key factors involved in diversity of the microbial community, enzyme activity, temperature and bio-heat generation. In summary, SRMI decidedly increase the heat preservation time of the pile and start-up efficiency of the low temperature composting.
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http://dx.doi.org/10.1016/j.biortech.2019.01.090DOI Listing
May 2019

Effects of aeration rates on the structural changes in humic substance during co-composting of digestates and chicken manure.

Sci Total Environ 2019 Mar 14;658:510-520. Epub 2018 Dec 14.

College of Life Science, Northeast Agricultural University, Harbin 150030, China.

High humidity and potential threat of pathogen of anaerobic digestates are unfavorable to the environment by direct utilization. To achieve the sustainable utilization of digestates, composting might be a good choice. Meanwhile, the aeration rate of composting has been optimized. Co-composting of digestates and chicken manure was performed under different aeration conditions (0.05, 0.1 and 0.15 L·min·kg·organic matter (OM)). During composting, internal transformation of humic substance (HS) has been studied for obtaining the potential application value of the co-composting products. Results suggested that the HS concentration was increased by 21.1%, 26.4% and 22.4% with the aeration rates were 0.05, 0.1 and 0.15 L·min·kg·OM, respectively. The aeration rate of 0.15 L·min·kg·OM was more conducive to germination. Parallel factor analysis and dimensional correlation spectra (2DCOS) have been combined to reveal the conversion relationships of HS components for understanding the compost application pattern. Hetero-2DCOS indicated that aeration of 0.05 min·kg·OM and 0.1 L·min·kg·OM contributed to the formation of complex compounds at long wavelength, and aeration of 0.15 L·min·kg·OM was beneficial for labile compounds formation at short wavelength. In views of the aeration of 0.1 L·min·kg·OM was more beneficial to improve HS concentration than 0.05 L·min·kg·OM, 0.1 L·min·kg·OM and 0.15 L·min·kg·OM were consider as the most important aeration rate to conduct digestates composting. Overall, the aeration affected the HS composition which, in turn, might affect the application ways of composting products. This study could provide a reference for industrial composting production and applications.
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http://dx.doi.org/10.1016/j.scitotenv.2018.12.198DOI Listing
March 2019

Insight into transformation of dissolved organic matter in the Heilongjiang River.

Environ Sci Pollut Res Int 2019 Feb 3;26(4):3340-3349. Epub 2018 Dec 3.

College of Life Science, Northeast Agricultural University, Harbin, 150030, China.

Heilongjiang is a "browning" river that receives substantial terrestrial organic matter, where reactivity of dissolved organic matter (DOM) may have important effect on ecosystem function and carbon biogeochemical cycle. However, little is known about microbial transformations of different DOM components, which could provide valuable insight into biogeochemical reactivity of DOM. In this study, bioavailability experiments were conducted for 55 days to determine changes of different DOM components by microbial transformations. Labile matter (C1) was detected only in initial DOM, and tryptophan-like substances (C4) were observed from day 5 onwards. Thus, three individual components were identified at each sampling time of the bioavailability experiment. The increase of F in DOM components revealed that microbial humic-like substances (C2), terrestrial humic-like substances (C3), and C4 were produced by microbial transformation, especially in the spring samples. Further, two-dimensional correlation spectroscopy (2D-COS) indicated that shorter wavelength tryptophan-like and microbial humic-like substances can be degraded by microbes or transformed into longer wavelength complex substances. Relatively simple microbial humic-like substances were preferentially produced compared to complex terrestrial humic-like substances. The results make sense to understand the biogeochemical cycling and environmental effects of DOM in the Heilongjiang River.
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http://dx.doi.org/10.1007/s11356-018-3761-9DOI Listing
February 2019

Effect of the addition of exogenous precursors on humic substance formation during composting.

Waste Manag 2018 Sep 13;79:462-471. Epub 2018 Aug 13.

College of Life Science, Northeast Agricultural University, Harbin 150030, China. Electronic address:

The aim of this work was to explore the effect of the addition of exogenous precursors on humic substance (HS) formation during composting. HS formation is a complex biochemical process that occurs during composting. In addition, HS precursors and bacterial communities were recognized as the key factors that affect HS formation. The addition of exogenous precursors can promote the humification process during composting, but few studies have explored the potential relationships between the proportion of additional exogenous precursors, the bacterial community and HS formation. Jointly adding benzoic acid (BA) and soybean residue after extracted oil (SR) treatment can promote HS formation, especially humic acid formation. In addition, the increase in the proportion of exogenous precursors added could strengthen the relationship among different precursors, thereby changing the bacterial community composition and further promoting the humification process during composting. In addition, a structural equation model (SEM) showed that precursors were the key factors to regulate HS formation and certain bacteria as the direct drivers to affect HS formation. This model provides more possibilities to regulate HS formation during composting and enhances its potential applicability under real conditions.
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http://dx.doi.org/10.1016/j.wasman.2018.08.025DOI Listing
September 2018

Improved lignocellulose-degrading performance during straw composting from diverse sources with actinomycetes inoculation by regulating the key enzyme activities.

Bioresour Technol 2019 Jan 17;271:66-74. Epub 2018 Sep 17.

College of Life Science, Northeast Agricultural University, Harbin 150030, China. Electronic address:

This study was conducted to assess the effect of thermophilic actinomycetes inoculation on the lignocellulose degradation, enzyme activities and microbial community during different types of straw composting from wheat, rice, corn and soybean. The results showed that actinomycetes inoculation not only changed the structure of actinomycetic and bacterial community but also accelerated the degradation of cellulose, hemicellulose and lignin and increased the key enzymes activities including CMCase, Xylanase, manganese peroxidase, lignin peroxidase and laccase during composting particularly from wheat straw and rice straw. The key enzyme and physiochemical parameters which affected organic fractions degradation have been identified by redundancy analysis. The combined application of actinomycete inoculation and urea addition as a source of nitrogen was suggested to regulate the key enzyme activities and lignocellulose degradation, which lays a foundation for effectively managing organic wastes from different types of crop straws by composting.
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http://dx.doi.org/10.1016/j.biortech.2018.09.081DOI Listing
January 2019

How does manganese dioxide affect humus formation during bio-composting of chicken manure and corn straw?

Bioresour Technol 2018 Dec 20;269:169-178. Epub 2018 Aug 20.

College of Life Science, Northeast Agricultural University, Harbin 150030, China.

The aim of this study is to reveal the roles of MnO in Maillard reaction of biotic composting, and to identify its effectiveness in promoting humus formation. Corn straw (CS) and chicken manure (CM) have been chosen to be composted. During CS composting, addition of MnO rapidly reduced reducing sugars concentration (decreased by 84.0%) in 5 days and significantly improved humus production by 38.7% compared with treatment without MnO. Whereas in CM composting, the promoting effect of MnO on humus formation was relatively weak by comparing with the treatment group of CS. Additionally, the presence of MnO has reshaped bacteria community, which might be the reason of MnO stimulated bacteria to utilize organic matter during CM composting. Therefore, the structural equation modeling has confirmed that MnO mainly performed as chemical catalyst to promote humus formation during CS composting. Besides catalyst, MnO also played as a bioactive activator in CM composting.
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http://dx.doi.org/10.1016/j.biortech.2018.08.079DOI Listing
December 2018

Response of humic acid formation to elevated nitrate during chicken manure composting.

Bioresour Technol 2018 Jun 14;258:390-394. Epub 2018 Mar 14.

College of Life Science, Northeast Agricultural University, Harbin 150030, China. Electronic address:

Nitrate can stimulate microbes to degrade aromatic compounds, whereas humic acid (HA) as a high molecular weight aromatic compound, its formation may be affected by elevated nitrate during composting. Therefore, this study is conducted to determine the effect of elevated nitrate on HA formation. Five tests were executed by adding different nitrate concentrations to chicken manure composting. Results demonstrate that the concentration of HA in treatment group is significantly decreased compared with control group (p < 0.05), especially in the highest nitrate concentration group. RDA indicates that the microbes associated with HA and environmental parameters are influenced by elevated nitrate. Furthermore, structural equation model reveals that elevated nitrate reduces HA formation by mediating microbes directly, or by affecting ammonia and pH as the indirect drivers to regulate microbial community structure.
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http://dx.doi.org/10.1016/j.biortech.2018.03.056DOI Listing
June 2018

Effect of tricarboxylic acid cycle regulator on carbon retention and organic component transformation during food waste composting.

Bioresour Technol 2018 May 2;256:128-136. Epub 2018 Feb 2.

College of Life Science, Northeast Agricultural University, Harbin 150030, China. Electronic address:

Composting is an environment friendly method to recycling organic waste. However, with the increasing concern about greenhouse gases generated in global atmosphere, it is significant to reduce the emission of carbon dioxide (CO). This study analyzes tricarboxylic acid (TCA) cycle regulators on the effect of reducing CO emission, and the relationship among organic component (OC) degradation and transformation and microorganism during composting. The results showed that adding adenosine tri-phosphate (ATP) and nicotinamide adenine dinucleotide (NADH) could enhance the transformation of OC and increase the diversity of microorganism community. Malonic acid (MA) as a competitive inhibitor could decrease the emission of CO by inhibiting the TCA cycle. A structural equation model was established to explore effects of different OC and microorganism on humic acid (HA) concentration during composting. Furthermore, added MA provided an environmental benefit in reducing the greenhouse gas emission for manufacture sustainable products.
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http://dx.doi.org/10.1016/j.biortech.2018.01.142DOI Listing
May 2018

Identifying the key factors that affect the formation of humic substance during different materials composting.

Bioresour Technol 2017 Nov 19;244(Pt 1):1193-1196. Epub 2017 Aug 19.

College of Life Science, Northeast Agricultural University, Harbin 150030, China. Electronic address:

The aim of this work was to identify the factors which can affect humic substance (HS) formation. Composting periods, HS precursors, bacteria communities and environment factors were recognized as the key factors and few studies explored the potential relationships among them. During composting, HS precursors were mainly formed in the heating and thermophilic phases, but HS were polymerized in the cooling and mature phases. Moreover, bacterial species showed similar classification of community structure in the same composting period of different materials. Furthermore, structural equation model showed that NH-N and NO-N were the indirect environmental factors for regulating HS formation by the bacteria and precursors as the indirect and direct driver, respectively. Therefore, both environmental factors and HS precursors can be the regulating factors to promote HS formation. Given that, a new staging regulating method had been proposed to improve the amount of HS during different materials composting.
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http://dx.doi.org/10.1016/j.biortech.2017.08.100DOI Listing
November 2017

Effect of cold-adapted microbial agent inoculation on enzyme activities during composting start-up at low temperature.

Bioresour Technol 2017 Nov 5;244(Pt 1):635-640. Epub 2017 Aug 5.

College of Life Science, Northeast Agricultural University, Harbin 150030, China. Electronic address:

In order to put forward a method to promote composting start-up at low ambient temperature, the cold-adapted microbial agent (CAMA) was inoculated in chicken manure (CM), and compared the enzymes activities, including urease, proteases, β-glucosidase and invertase, with no CAMA group (CK). In this study, the temperature of CM reached 50°C in 53h, but it in CK was only around 30°C during the composting process. Moreover, the enzymes exhibited higher activity in CM than CK, indicating the effectiveness of CAMA. Furthermore, redundancy analysis was conducted to study the relationships of CAMA, with enzymes activities and temperature. Results showed that the positive effect of CAMA on the enzyme activities were achieved by affecting the bacterial community structure. Accordingly, we provide a method to guide CAMA inoculation for promoting compost start-up in cold area.
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http://dx.doi.org/10.1016/j.biortech.2017.08.010DOI Listing
November 2017

Effect of precursors combined with bacteria communities on the formation of humic substances during different materials composting.

Bioresour Technol 2017 Feb 9;226:191-199. Epub 2016 Dec 9.

College of Life Science, Northeast Agricultural University, Harbin 150030, China. Electronic address:

The aim of this work was to put forward a method to improve HS amount by studying the formation regularity of HS. Five precursors have been detected and few researches combined them with bacteria to study HS formation. During composting, the polyphenols, carboxyl and amino acids concentration decreased by 75.8%, 63.2% and 68.3% on average, respectively. However, the polysaccharides, reducing sugars and HS concentration increased by 61.2%, 47.1% and 37.33% on average. Relationships between precursors and HS concentration showed that the HS formation were significantly affected (p<0.05). The key bacteria community and physical-chemical parameters which affected HS formation have also been identified by redundancy analysis. Twelve key bacteria communities have been selected, which were significantly affected by physical-chemical parameters (p<0.05). Accordingly, we proposed an adjusting method to promote HS amount during composting based on the relationship between the key bacteria communities and the precursors as well as physical-chemical parameters.
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http://dx.doi.org/10.1016/j.biortech.2016.12.031DOI Listing
February 2017