Advanced Laboratory for Environmental Research and Technology

Suzhou, China

Advanced Laboratory for Environmental Research and Technology

Suzhou, China
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Yu L.,Advanced Laboratory for Environmental Research and Technology | Chen Z.-X.,Advanced Laboratory for Environmental Research and Technology | Tong X.,Anhui Agricultural University | Li K.,National University of Defense Technology | Li W.-W.,Hefei University of Technology
Chemosphere | Year: 2012

The degradation kinetics and micro-scale structure change of microcrystalline cellulose during anaerobic biodegradation were investigated. A modified Logistic model was established to properly describe the kinetics, which showed good fitness and wide applicability for cellulose degradation. A maximum degradation rate of 0.14gL -1h -1 was achieved after cultivating for 51.5h. This result was in good agreement with the scanning electron microscope and X-ray diffraction analysis. Channels of 400-500nm size started to occur on the crystalline surface of cellulose at around the inflexion time. Accordingly, the crystallinity significantly decreased at this point, indicating a degradation of the crystalline structure zones by anaerobic bacteria. This study offers direct morphological evidence and quantitative analysis of the biodegradation process of cellulose, and is beneficial to a better understanding of the cellulose degradation mechanism. © 2011 Elsevier Ltd.


PubMed | Hefei University of Technology, Suzhou University of Science and Technology, Advanced Laboratory for Environmental Research and Technology and Hong Kong University of Science and Technology
Type: | Journal: Water research | Year: 2016

Anaerobic oxidation of methane (AOM) contributes significantly to the global methane sink. Previously, studies of anaerobic methanotrophic (ANME) archaea have been limited as they have not been separable from their bacterial partners during the AOM process because of their dependence on the bacteria. A microbial fuel cell (MFC) is a device capable of directly transforming chemical energy to electrical energy via electrochemical reactions involving biochemical pathways. In this study, decoupling of denitrifying anaerobic methane oxidation (DAMO) archaea and DAMO bacteria was investigated in an microbial fuel cell (MFC) using methane as the fuel. The DAMO fuel cell worked successfully but demonstrated weak electrogenic capability with around 25mV production. After 45 days enrichment, the sequencing and fluorescence in situ hybridization results showed the DAMO archaea percentage had increased from 26.96% (inoculum) to 65.77% (electrode biofilm), while the DAMO bacteria percentage decreased from 24.39% to 2.07%. Moreover, the amount of ANME-2d had doubled in the electrode biofilm compared with the inoculum. The sequencing results also showed substantial enrichment of the Ignavibacterium and Geobacter genera. The roles of Ignavibacterium and Geobacter in the MFC system need to be further investigated. Nevertheless, these results illustrate that an MFC device may provide a possible approach to separate DAMO archaea from DAMO bacteria.


Chu F.-F.,Advanced Laboratory for Environmental Research and Technology | Chu P.-N.,Hefei University of Technology | Cai P.-J.,Advanced Laboratory for Environmental Research and Technology | Li W.-W.,Hefei University of Technology | And 4 more authors.
Bioresource Technology | Year: 2013

To investigate the role of phosphorus in lipid production under nitrogen starvation conditions, five types of media possessing different nitrogen and phosphorus concentrations or their combination were prepared to culture Chlorella vulgaris. It was found that biomass production under nitrogen deficient condition with sufficient phosphorus supply was similar to that of the control (with sufficient nutrition), resulting in a maximum lipid productivity of 58.39mg/L/day. Meanwhile, 31P NMR showed that phosphorus in the medium was transformed and accumulated as polyphosphate in cells. The uptake rate of phosphorus in cells was 3.8 times higher than the uptake rate of the control. This study demonstrates that phosphorus plays an important role in lipid production of C. vulgaris under nitrogen deficient conditions and implies a potential to combine phosphorus removal from wastewater with biodiesel production via microalgae. © 2013 Elsevier Ltd.


Shen X.-F.,Advanced Laboratory for Environmental Research and Technology | Chu F.-F.,Advanced Laboratory for Environmental Research and Technology | Lam P.K.S.,Advanced Laboratory for Environmental Research and Technology | Lam P.K.S.,City University of Hong Kong | And 2 more authors.
Water Research | Year: 2015

In this study the heterotrophic cultivation of Chlorella vulgaris NIES-227 fed with glucose was investigated systematically using six media types; combinations of nitrogen repletion/depletion and phosphorus repletion/limitation/depletion. It was found that a high yield of fatty acids (0.88 of fed glucose-COD) and a high content of fatty acid methyl esters (FAMEs) (89% of dry weight) were obtained under nitrogen starved conditions. To our knowledge it is the first report on such high COD conversion yield and FAME content in microalgae. The dominant fatty acid (>50%) was methyl oleate (C18:1), a desirable component for biodiesel synthesis. FAME content under nitrogen starved conditions was significantly higher than under nitrogen sufficient conditions, while phosphorus had no significant influence, indicating that nitrogen starvation was the real "fatty acids trigger" in heterotrophic cultivation. These findings could simplify the downstream extraction process, such as the extrusion of oil from soybeans, and could reduce operating costs by improving the fatty acid yield from waste COD. © 2015 Elsevier Ltd.


Ding Z.-W.,Hefei University of Technology | Ding J.,Hefei University of Technology | Ding J.,Advanced Laboratory for Environmental Research and Technology | Fu L.,Hefei University of Technology | And 2 more authors.
Applied Microbiology and Biotechnology | Year: 2014

Interaction between denitrifying anaerobic methane oxidation (DAMO) and anaerobic ammonium oxidation (anammox) processes may play an important role in global carbon and nitrogen cycles. In this study, a coculture of denitrifying methanotrophs (DAMO archaea and DAMO bacteria) and anammox bacteria, initially sourced from the environment, was enriched with a supply of methane, nitrate, and ammonium. After a 4.5-month enrichment, simultaneous oxidation of methane and ammonium and reduction of nitrate were observed. The highest rate of nitrate reduction in the suspended DAMO culture was 4.84 mmol/L/day, and simultaneously, the highest ammonium removal rate was 4.07 mmol/L/day. Fluorescence in situ hybridization and analysis of 16S rRNA gene clone libraries revealed the coexistence of DAMO archaea, DAMO bacteria, and anammox bacteria. The development of anammox bacteria might reduce the enrichment time of DAMO microorganisms and promote the activity of DAMO archaea. The activity of the reactor fluctuated during the long-term operation, which might be caused by the formation of microbial clusters whereby DAMO archaea grew in aggregates that were surrounded by anammox and DAMO bacteria. This study is the first to demonstrate that it is feasible to establish a coculture of DAMO archaea, DAMO bacteria, and anammox bacteria from environmental inocula. © 2014, Springer-Verlag Berlin Heidelberg.


Chu F.-F.,Advanced Laboratory for Environmental Research and Technology | Chu P.-N.,Hefei University of Technology | Shen X.-F.,Advanced Laboratory for Environmental Research and Technology | Lam P.K.S.,Advanced Laboratory for Environmental Research and Technology | And 3 more authors.
Bioresource Technology | Year: 2014

In order to study the effect of phosphorus on biodiesel production from Scenedesmus obliquus especially under nitrogen deficiency conditions, six types of media with combinations of nitrogen repletion/depletion and phosphorus repletion/limitation/depletion were investigated in this study. It was found that nitrogen starvation compared to nitrogen repletion enhanced biodiesel productivity. Moreover, biodiesel productivity was further strengthened by varying the supply level of phosphorus from depletion, limitation, through to repletion. The maximum FAMEs productivity of 24.2. mg/L/day was obtained in nitrogen depletion with phosphorus repletion, which was two times higher than that in nutrient complete medium. More phosphorus was accumulated in cells under the nitrogen starvation with sufficient phosphorus condition, but no polyphosphate was formed. This study indicated that nitrogen starvation plus sufficient P supply might be the real "lipid trigger". Furthermore, results of the current study suggest a potential application for utilizing microalgae to combine phosphorus removal from wastewater with biodiesel production. © 2013 Elsevier Ltd.


Yu L.,Advanced Laboratory for Environmental Research and Technology | Yu L.,Hefei University of Technology | Yu L.,City University of Hong Kong | Li W.-W.,Advanced Laboratory for Environmental Research and Technology | And 5 more authors.
Applied Microbiology and Biotechnology | Year: 2012

A facultative anaerobic bacteria strain GS-4-08, isolated from an anaerobic sequence batch reactor for synthetic dye wastewater treatment, was investigated for azo-dye decolorization. This bacterium was identified as a member of Klebsiella oxytoca based on Gram staining, morphology characterization and 16S rRNA gene analysis. It exhibited a good capacity of simultaneous decolorization and hydrogen production in the presence of electron donor. The hydrogen production was less affected even at a high Methyl Orange (MO) concentration of 0.5 mM, indicating a superior tolerability of this strain to MO. This efficient bio-hydrogen production from electron donor can not only avoid bacterial inhibition due to accumulation of volatile fatty acids during MO decolorization, but also can recover considerable energy from dye wastewater. © 2011 Springer-Verlag.


PubMed | Hefei University of Technology and Advanced Laboratory for Environmental Research and Technology
Type: Journal Article | Journal: Applied microbiology and biotechnology | Year: 2016

The nitrate-dependent denitrifying anaerobic methane oxidation (DAMO) process, which is metabolized together by anaerobic methanotrophic archaea and NC10 phylum bacteria, is expected to be important for the global carbon and nitrogen cycles. However, there are little studies about the existence of this process and the functional microbes in environments. Therefore, the coexistence of DAMO archaea and bacteria in a paddy field was evaluated in this study. Next-generation sequencing showed that the two orders, Methanosarcinales and Nitrospirales, to which DAMO archaea and DAMO bacteria belong, were detected in the four soil samples. Then the in vitro experiments demonstrated both of nitrite- and nitrate-dependent DAMO activities, which confirmed the coexistence of DAMO archaea and DAMO bacteria. It was the first report about the coexistence of DAMO archaea and bacteria in a paddy field. Furthermore, anammox bacteria were detected in two of the four samples. The in vitro experiments did not show anammox activity in the initial period but showed low anammox activity after 20days enrichment. These results implicated that anammox bacteria may coexist with DAMO microorganisms in this field, but at a very low percentage.


PubMed | Hefei University of Technology and Advanced Laboratory for Environmental Research and Technology
Type: Journal Article | Journal: Applied microbiology and biotechnology | Year: 2016

The reverse methanogenesis hypothesis as the metabolic pathway of AOM has recently been supported in the novel ANME lineage ANME-2d in denitrifying anaerobic methane oxidation (DAMO). However, no previous studies have experimentally evaluated the reversal of methane oxidation and methane production in this archaea. In the present study, the metabolic reversibility of ANME-2d from AOM to methanogenesis was evaluated using H2/CO2 and acetate as substrates. The results showed that the system produced methane from H2/CO2 but not from acetate. However, the clone library and real-time PCR analysis of the culture showed that both the percentage and quantity of ANME-2d decreased significantly under this condition, while methanogen abundance increased. Further high-throughput sequencing results showed that the archaea community did not change at the fourth day after H2/CO2 was supplied, but changed profoundly after methanogenesis took place for 3days. The percentage of DAMO archaea in the total archaea decreased obviously, while more methanogens grew up during this period. Comparatively, the bacteria community changed profoundly at the fourth day. These results indicated that ANME-2d might not reverse its metabolism to produce methane from H2/CO2 or acetate. After archaea were returned to DAMO conditions, DAMO activity decreased and the amount of ANME-2d continued to fall, implying that the lineage had suffered from severe injury and required a long recovery time.


Zhang F.,Anhui University of Science and Technology | Ding J.,Advanced Laboratory for Environmental Research and Technology | Zhang Y.,Anhui University of Science and Technology | Chen M.,Anhui University of Science and Technology | And 4 more authors.
Water Research | Year: 2013

Gasification of waste to syngas (H2/CO2) is seen as a promising route to a circular economy. Biological conversion of the gaseous compounds into a liquid fuel or chemical, preferably medium chain fatty acids (caproate and caprylate) is an attractive concept. This study for the first time demonstrated in-situ production of medium chain fatty acids from H2 and CO2 in a hollow-fiber membrane biofilm reactor by mixed microbial culture. The hydrogen was for 100% utilized within the biofilms attached on the outer surface of the hollow-fiber membrane. The obtained concentrations of acetate, butyrate, caproate and caprylate were 7.4, 1.8, 0.98 and 0.42g/L, respectively. The biomass specific production rate of caproate (31.4mmol-C/(L day g-biomass)) was similar to literature reports for suspended cell cultures while for caprylate the rate (19.1mmol-C/(L day g-biomass)) was more than 6 times higher. Microbial community analysis showed the biofilms were dominated by Clostridium spp., such as Clostridium ljungdahlii and Clostridium kluyveri. This study demonstrates a potential technology for syngas fermentation in the hollow-fiber membrane biofilm reactors. © 2013 Elsevier Ltd.

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