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Guangguo Ying - One of the best experts on this subject based on the ideXlab platform.

  • co metabolism of sulfamethoxazole by a freshwater microalga Chlorella pyrenoidosa
    Water Research, 2020
    Co-Authors: Qian Xiong, Yousheng Liu, Zhouqi Shi, Wenwen Cai, Guangguo Ying
    Abstract:

    Abstract Microalgae-mediated biodegradation of antibiotics has recently gained increased attention from international scientific community. However, limited information is available regarding microalgae-mediated biodegradation of SMX in a co-metabolic system. Here we investigated the biodegradation of sulfamethoxazole (SMX) by five algal species (Pseudokirchneriella subcapitata, Scenedesmus quadricauda, Scenedesmus obliquus, Scenedesmus acuminatus and Chlorella pyrenoidosa), and its transformation pathways by C. pyrenoidosa in a sodium acetate (3 mM) co-metabolic system. The results showed that the highest SMX dissipation (14.9%) was detected by C. pyrenoidosa after 11 days of cultivation among the five tested algal species in the absence of other carbon sources. The addition of sodium acetate (0–8 mM) significantly enhanced the dissipation efficiency of SMX (0.4 μM) from 6.05% to 99.3% by C. pyrenoidosa after 5 days of cultivation, and the dissipation of SMX followed the first-order kinetic model with apparent rate constants (k) ranging from 0.0107 to 0.9811 d−1. Based on the results of mass balance analysis, biodegradation by C. pyrenoidosa was the main mechanism for the dissipation of SMX in the culture medium. Fifteen phase I and phase II metabolites were identified, and subsequently the transformation pathway was proposed, including oxidation, hydroxylation, formylation and side chain breakdown, as well as pterin-related conjugation. The majority of metabolites of SMX were only observed in the culture medium and varied with cultivation time. The findings of the present study showed effective co-metabolism of a sulfonamide by microalgae, and it may be applied in the aquatic environment remediation and wastewater treatment in the future.

  • biosorption of zinc and copper from aqueous solutions by two freshwater green microalgae Chlorella pyrenoidosa and scenedesmus obliquus
    Environmental Science and Pollution Research, 2012
    Co-Authors: Guangjie Zhou, Fuqiang Peng, Lijuan Zhang, Guangguo Ying
    Abstract:

    Purpose The objective of this study was to determine the removal of zinc and copper by two freshwater green microalgae Chlorella pyrenoidosa and Scenedesmus obliquus and to investigate changes of algal ultrastructure and photosynthetic pigment.

Jianguo Liu - One of the best experts on this subject based on the ideXlab platform.

  • proteomic analysis of hydrogen production in Chlorella pyrenoidosa under nitrogen deprivation
    Algal Research-Biomass Biofuels and Bioproducts, 2021
    Co-Authors: Litao Zhang, Jianguo Liu
    Abstract:

    Abstract Previously, Chlorella pyrenoidosa strain IOAC707S was found to produce hydrogen under nitrogen deprivation in seawater medium, without dark incubation, N2 flushing or addition of uncoupler, which made it a candidate for clean and renewable energy production. To understand the molecular mechanism underlying hydrogen production by C. pyrenoidosa under nitrogen deprivation, iTRAQ-based proteomic analysis was conducted to investigate the differences in protein abundance under nitrogen deprivation (L1-N) compared with the control (CK). In total, 119 KEGG pathways were mapped for 2383 proteins, among which, the expression levels of most proteins involved in chlorophyll synthesis were down-regulated, while those involved in chlorophyll degradation were up-regulated in the L1-N culture; the expression level of serine glyoxylate aminotransferase involved in photorespiration was up-regulated 1.25 fold in the L1-N culture at 44 h, and the expression levels of most proteins involved in mitochondrial respiration were up-regulated in the L1-N culture. These results indicated a decrease of chlorophyll and an increase of respiration, which favored the establishment of anaerobiosis and hydrogen production.

  • transcriptomic analysis of hydrogen photoproduction in Chlorella pyrenoidosa under nitrogen deprivation
    Algal Research-Biomass Biofuels and Bioproducts, 2020
    Co-Authors: Litao Zhang, Fengying Gong, Jianguo Liu
    Abstract:

    Abstract H2 photoproduction by green algae is a very attractive way to produce clean and renewable energy. In our previous study, Chlorella pyrenoidosa strain IOAC707S was found to produce hydrogen under nitrogen deprivation in seawater medium; however the mechanism is not entirely clear. In this work, it was found that under nitrogen deprivation, the efficiency of photosystem II photochemical activity and the photosynthetic O2 evolution rate of C. pyrenoidosa strain IOAC707S decreased, while the respiratory rate increased, which were favorable for the establishment of anoxia and H2 photoproduction. Transcriptomic analysis indicated that photosynthetic activity did not simply decline but underwent a complex adjustment to prepare for H2 photoproduction. The activities of glycolysis and the pentose phosphate pathway were up-regulated, suggesting more electron transport from endogenous substrate to H2 photoproduction. The decrease of the tricarboxylic acid cycle activity resulted in decreased levels of CO2, which would limit Calvin cycle activity, and subsequently lead to the accumulation of NADPH and a reduction of the photosynthetic electron transport chain. Under these conditions, the induced hydrogenase served as an electron valve, and H2 was produced.

  • new methods for hydrogen production by marine microalga Chlorella pyrenoidosa in natural seawater
    International Journal of Hydrogen Energy, 2019
    Co-Authors: Evgeny Shastik, Jianguo Liu
    Abstract:

    Abstract In this study, we demonstrated a new method of achieving long-term photodependent hydrogen production under nitrogen limiting conditions in a medium with natural seawater. Moreover, centrifugation stage in pretreatment of culture was avoided. Chlorella pyrenoidosa passed into deprivation conditions after exhaustion of nitrogen source. Microalgae began to release hydrogen at 144 h of cultivation after stages of evolution and consumption of oxygen. C. pyrenoidosa produced 45 ml (183 μM) of hydrogen per liter of culture. A significant effect of the initial oxygen concentration in the gas phase on the release of hydrogen was found. When initial oxygen content was 3.5%, the final H2 yields reduced by 20%, while under 9.7%–21% of O2, it reduced by 50% (compared to argon gas phase). Perhaps this was due to the low content of cells. We also demonstrated a decrease in the release of hydrogen by C. pyrenoidosa by 85% when using double stress conditions: phosphate-deprivation and limiting nitrogen source.

  • the enhancement of hydrogen photoproduction in marine Chlorella pyrenoidosa under nitrogen deprivation
    International Journal of Hydrogen Energy, 2015
    Co-Authors: Litao Zhang, Jianguo Liu
    Abstract:

    Previously, we found that marine Chlorella pyrenoidosa strain IOAC707S could generate hydrogen (H-2) under nitrogen deprivation in seawater medium, without dark incubation, N-2 flushing or addition of protonophore. In this work, the H-2 yield of C. pyrenoidosa was enhanced, and the mechanism of H-2 photoproduction was investigated. It was found that C. pyrenoidosa could produce H-2 under hypoxic conditions, which indicated the hydrogenase of C.pyrenoidosa could tolerate a low concentration of O-2. Nitrogen deprivation could lower the efficiency of photosyntem (PS) II photochemical activity and PSII oxygenic activities, which were favorable for rapid establishment of anoxia and efficient H-2 photoproduction, and thus significantly enhance H-2 photoproduction of C. pyrenoidosa. Preculture in nitrogen-deprived medium could further increase the H-2 yield of C. pyrenoidosa, for its more severe inhibition of the oxygen-evolving complex, electron transport and photochemical efficiency of PSII, and PSII oxygenic activities, which facilitated the establishment of anaerobiosis and activation of hydrogenase. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Libin Yang - One of the best experts on this subject based on the ideXlab platform.

  • strategies for enhanced biomass and lipid production by Chlorella pyrenoidosa culture in starch processing wastewater
    Journal of Cleaner Production, 2019
    Co-Authors: Xiaobo Tan, Xianchao Zhao, Libin Yang
    Abstract:

    Abstract Starch wastewater contains various nutrients, as a potential medium for cultivating microalgae. In this study, strategies including wastewater treatments and mixing were investigated to enhance biomass and lipid production. The microalgae Chlorella pyrenoidosa performed normal growth in anaerobic digested and secondary treated starch wastewater. However, their lipid yields were very low (6.7–22.9 mg L−1·d−1) due to the low biomass production or lipid content. Therefore, the strategy for mixing different treatment stages of starch wastewater was tested to improve algal growth and lipid accumulation. In comparison to blank culture, adding 50% acidified starch wastewater into anaerobic and secondary treated starch wastewater significantly increased biomass concentration by 78.1% (to 3.3 g L−1) and 105.2% (to 1.2 g L−1), while achieving higher lipid content to 18.7–28.0%. Moreover, the mixed culture improved the degree of saturated fatty acids (typically in palmitic and stearic acid). This provides a promising approach to improve algal lipid yield and quality using starch wastewater.

  • enhanced lipid and biomass production using alcohol wastewater as carbon source for Chlorella pyrenoidosa cultivation in anaerobically digested starch wastewater in outdoors
    Bioresource Technology, 2018
    Co-Authors: Xiaobo Tan, Libin Yang, Yalei Zhang, Xianchao Zhao, Yueyun Zhou, Wenwen Zhang
    Abstract:

    Alcohol wastewater (AW) as carbon source for enhancing Chlorella pyrenoidosa growth and lipid accumulation in anaerobically digested starch wastewater (ADSW) was performed in outdoor cultivation. The biomass and lipid production significantly increased while adding optimal amount of AW (AW/ADSW=1:15) during exponential phase. In comparison with blank ADSW culture, the optimal AW addition increased the biomass production, lipid content and productivity by 35.29%, 102.68% and 227.91%, respectively. However, AW addition caused severe bacterial contamination and the total bacterial increased by 4.62-fold. Simultaneously, the optimal consortia of microalgae/bacteria effectively removed nutrients from the wastewater, including 405.18±36.47mgCODCr/L/day, 49.15±5.54mgN/L/day and 6.72±1.24mgP/L/day.

  • continuous cultivation of Chlorella pyrenoidosa using anaerobic digested starch processing wastewater in the outdoors
    Bioresource Technology, 2015
    Co-Authors: Huaqiang Chu, Libin Yang, Yalei Zhang, Xiaobo Tan, Fangchao Zhao, Jun Guo
    Abstract:

    Microalgae cultivation using wastewater might be a suitable approach to support sustainable large-scale biomass production. Its compelling characteristics included the recycling of nutrients and water resources, reducing carbon emissions and harvesting available biomass. In outdoor batch and continuous cultures, Chlorella pyrenoidosa completely adapted to anaerobic digested starch processing wastewater and was the dominant microorganism in the photobioreactor. However, seasonal changes of environmental conditions significantly influenced biomass growth and lipid production. The long-term outdoor operation demonstrated that the biomass concentration and productivity in continuous operations at different hydraulic retention times (HRTs) can be successfully predicted using the kinetic growth parameters obtained from the batch culture. A moderate HRT (4days) in the summer provided the best microalgae and lipid production and achieved relatively high biomass concentrations of 1.29-1.62g/L, biomass productivities of 342.6±12.8mg/L/d and lipids productivities of 43.37±7.43mg/L/d.

  • nutrients removal and lipids production by Chlorella pyrenoidosa cultivation using anaerobic digested starch wastewater and alcohol wastewater
    Bioresource Technology, 2015
    Co-Authors: Libin Yang, Deyi Li, Xuefei Zhou, Yalei Zhang, Hong Yu
    Abstract:

    Abstract The cultivation of microalgae Chlorella pyrenoidosa ( C. pyrenoidosa ) using anaerobic digested starch wastewater (ADSW) and alcohol wastewater (AW) was evaluated in this study. Different proportions of mixed wastewater (AW/ADSW = 0.176:1, 0.053:1, 0.026:1, v/v) and pure ADSW, AW were used for C. pyrenoidosa cultivation. The different proportions between ADSW and AW significantly influenced biomass growth, lipids production and pollutants removal. The best performance was achieved using mixed wastewater (AW/ADSW = 0.053:1, v/v), leading to a maximal total biomass of 3.01 ± 0.15 g/L (dry weight), lipids productivity of 127.71 ± 6.31 mg/L/d and pollutants removal of COD = 75.78 ± 3.76%, TN = 91.64 ± 4.58% and TP = 90.74 ± 4.62%.

  • Chlorella pyrenoidosa cultivation using anaerobic digested starch processing wastewater in an airlift circulation photobioreactor
    Bioresource Technology, 2014
    Co-Authors: Xiaobo Tan, Libin Yang, Yalei Zhang, Huaqiang Chu, Fangchao Zhao, Xuefei Zhou
    Abstract:

    To explore the integration of microalgae cultivation and anaerobic processing for wastewater treatment, we utilized an airlift circulation photobioreactor and a dynamic membrane reactor for microalgae cultivation in combination with an upflow anaerobic sludge bed (UASB) reactor for starch processing wastewater (SPW) treatment. Chlorella pyrenoidosa completely adapted to the digested SPW without any chemical additives, and it grew normally under a wide temperature range in different seasons. C. pyrenoidosa was always the dominant microorganism in the photobioreactors although bacteria and some wild type microalgae were observed. Optimal biomass growth and pollutants removal was achieved at temperatures between 35 and 38°C in summer, removing 65.99% of COD, 83.06% of TN, 96.97% of TP and a biomass productivity of 0.37gL(-1)d(-1). Temperature fluctuation significantly influenced lipid contents and FAMEs compositions in biomass. The results demonstrate the successful integration of microalgae biomass production and anaerobic processing for wastewater treatment.

Xiaowei Peng - One of the best experts on this subject based on the ideXlab platform.

  • combustion performance of biocrude oil from solvolysis liquefaction of Chlorella pyrenoidosa by thermogravimetry fourier transform infrared spectroscopy
    Bioresource Technology, 2017
    Co-Authors: Xiaowei Peng, Yousheng Lin, Jingjing Wang, Xiaoyu Wei, Xinfei Chen
    Abstract:

    Abstract The kinetic behavior and evolution characteristics of gaseous products during the combustion of biocrude oil from solvolysis liquefaction of Chlorella pyrenoidosa were investigated by thermogravimetry–Fourier transform infrared spectroscopy (TG–FTIR). The results indicated the biocrude oil obtained from different ethanol/water mixed ratio had obvious difference with each other. The ignition temperature of biocrude oil from ethanol–water co-solvent was lower than that from pure water solvent, which promoted the comprehensive combustion index. Especially, BO40 (biocrude oil obtained from 40% ethanol content) achieved the lowest ignition temperature (163.4 °C) and high comprehensive combustion index (1.24 × 10 −06  min −2  °C −3 ). C H, C O, C C, CO 2 , CO and HCN were the main gaseous products. Compared to other biocrude oil samples, BO40 had high first peak intensity of C H, C O and C C, and low peak intensity of CO, which performed better combustion characteristic.

  • investigation on characteristics of liquefied products from solvolysis liquefaction of Chlorella pyrenoidosa in ethanol water systems
    Energy & Fuels, 2016
    Co-Authors: Xiaowei Peng, Yousheng Lin
    Abstract:

    The current work presented the characteristics of liquefied products from solvolysis liquefaction of Chlorella pyrenoidosa in ethanol–water systems. The effect of different ethanol/water volume ratios on the physical and chemical characteristics of solid residue, dichloromethane-insoluble solid product (DCM-insoluble solid product), aqueous product, light bio-oil, and biocrude oil was systematically carried out. Elemental analysis and scanning electron microscopy revealed that the addition of ethanol contributed to the decomposition of solid residue. However, when the ethanol content exceeded 60%, the repolymerization of solid residue occurred. Moreover, on the basis of Fourier transform infrared spectroscopy, a plausible reaction mechanism of solid residues and DCM-insoluble solid products with respect to ethanol addition and reaction temperature was presented. The main chemical compositions of aqueous product, light bio-oil, and biocrude oil were identified by gas chromatography–mass spectrometry. It in...

  • effect of process parameters on solvolysis liquefaction of Chlorella pyrenoidosa in ethanol water system and energy evaluation
    Energy Conversion and Management, 2016
    Co-Authors: Xiaowei Peng, Yousheng Lin, Xusheng Wang, Xiaoshen Zhang, Cheng Yang
    Abstract:

    Abstract In this work, Chlorella pyrenoidosa was converted into bio-oil via solvolysis liquefaction in sub/supercritical ethanol–water system. The influence of reaction temperature (220–300 °C), retention time (0–120 min), solid/liquid ratio (6.3/75–50.0/75 g/mL) and ethanol content (0–100%) on bio-oil yield and property was investigated. The increase of reaction temperature and retention time both improved the bio-oil yield. The bio-oil yield increased firstly and then decreased when the solid/liquid ratio and ethanol content exceeded 18.8/75 g/mL and 80%, respectively. As the reaction temperature

Xuewu Zhang - One of the best experts on this subject based on the ideXlab platform.

  • anti inflammatory and anti aging evaluation of pigment protein complex extracted from Chlorella pyrenoidosa
    Marine Drugs, 2019
    Co-Authors: Ruilin Zhang, Jian Chen, Xinwu Mao, Xuewu Zhang
    Abstract:

    Oxidative stress contributes to chronic inflammatory processes implicated in aging, referred to as "inflamm-aging." In this study, the potential anti-inflammatory and anti-aging effects of a pigment-protein complex (PPC) from Chlorella pyrenoidosa were investigated using lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and D-galactose (D-gal)-induced aging in a murine model. Results indicated that PPC inhibits the production of the inflammatory cytokines TNF-α and IL-6, and the inflammatory mediator nitric oxide (NO) in LPS-stimulated RAW 264.7 cells. It also protected mice from D-gal induced informatory aging by increasing the activity of the antioxidant enzyme, such as superoxide dismutase (SOD), inhibiting D-gal-induced NF-κB upregulation, and increasing PPARs expression in the brain and gut. The findings indicated that PPC has favorable anti-inflammatory and anti-aging properties, and could be useful in the treatment of acute inflammation and senescence diseases.

  • extraction of intracellular protein from Chlorella pyrenoidosa using a combination of ethanol soaking enzyme digest ultrasonication and homogenization techniques
    Bioresource Technology, 2018
    Co-Authors: Ruilin Zhang, Jian Chen, Xuewu Zhang
    Abstract:

    Due to the rigid cell wall of Chlorella species, it is still challenging to effectively extract significant amounts of protein. Mass methods were used for the extraction of intracellular protein from microalgae with biological, mechanical and chemical approaches. In this study, based on comparison of different extraction methods, a new protocol was established to maximize extract amounts of protein, which was involved in ethanol soaking, enzyme digest, ultrasonication and homogenization techniques. Under the optimized conditions, 72.4% of protein was extracted from the microalgae Chlorella pyrenoidosa, which should contribute to the research and development of Chlorella protein in functional food and medicine.

  • separation antitumor activities and encapsulation of polypeptide from Chlorella pyrenoidosa
    Biotechnology Progress, 2013
    Co-Authors: Xiaoqin Wang, Xuewu Zhang
    Abstract:

    Chlorella pyrenoidosa is a unicellular green algae and has been a popular foodstuff worldwide. However, no reports on the antitumor peptides from such a microalgae are available in the literature. In this study, using low-temperature high-pressure extraction, enzymatic hydrolysis, ion exchange, and gel filtration chromatography, we separated a polypeptide that exhibited inhibitory activity on human liver cancer HepG2 cells, and named the polypeptide CPAP (C. pyrenoidosa antitumor polypeptide). Furthermore, the micro- and nanoencapsulation of CPAP were investigated by using two methods: complex coacervation and ionotropic gelation. The in vitro release tests revealed that CPAP was well preserved against gastric enzymatic degradation after micro/nanoencapsulation and the slowly controlled release in the intestine could be potentially achieved. These results suggest that CPAP may be a useful ingredient in food, nutraceutical, and pharmaceutical applications.

  • optimal extraction and hydrolysis of Chlorella pyrenoidosa proteins
    Bioresource Technology, 2012
    Co-Authors: Xiaoqin Wang, Xuewu Zhang
    Abstract:

    In this study, for the first time, the applications of two new methods, ionic liquid and low-temperature high-pressure cell breakage methods, to the extraction of whole proteins in Chlorella pyrenoidosa cells were explored. Meanwhile, the comparison with three traditional methods was also made. The results indicated that the extraction rate for ionic liquid is only at moderate level, but the new low-temperature high-pressure cell breakage method can obviously increase the protein extraction rate up to 2- to 15-fold. Subsequently, the hydrolysis of the extracted proteins was conducted with three enzymes (papain, trypsin and alcalase). The data presented that the degree of hydrolysis for each enzyme under the optimal conditions is in the order of: alcalase (18.31%)>papain (14.33%)>trypsin (8.47%), demonstrating the potential of C. pyrenoidosa protein hydrolysates obtained here in nutritional supplement and medical foods.