Bioresource Technology (BIORESOURCE TECHNOL)

Publications in this journal

• Article: Biomass production by novel strains of Yarrowia lipolytica using raw glycerol, derived from biodiesel production

  Juszczyk P, Tomaszewska L, Kita A, Rymowicz W
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  ABSTRACT: This study demonstrated the potential applicability of the isolated strains of Yarrowia lipolytica for the valorization of glycerol waste generated during biodiesel production, throughout biomass production. Twenty-one strains were isolated from different environments and identified as Y. lipolytica. Biomass production from pure glycerol (25 g L−1) was performed in the shake-flasks experiment. Eight strains with the best biomass production ability were chosen for studies in bioreactor (pH 3.5). The analysis of technological process parameters and biomass chemical composition demonstrated that S6 strain was the most suitable for biomass production. Its application allowed obtaining 11.7 and 12.3 g L−1 of the biomass with 1.30 and 1.37 g L−1 h−1 productivity, respectively when pure and raw glycerol (25 g L−1) was used. In the yeast protein amino acid profile the contents of lysine, threonine and phenylalanine/tyrosine were higher than required by FAO/WHO. According to the EAAI, the nutritional value of the biomass reached up to 72.3%.
  Bioresource Technology 06/2013;
• Article: A biorefinery from Nannochloropsis sp. microalga – Energy and CO2 emission and economic analyses

  Ana F. Ferreira, Lauro A. Ribeiro, Ana P. Batista, Paula A.S.S. Marques, Beatriz P. Nobre, António M.F. Palavra, Patrícia Pereira da Silva, Luísa Gouveia, Carla Silva
  Bioresource Technology 06/2013;
• Article: Low strength ultrasonication positively affects the methanogenic granules toward higher AD performance. Part I: physico-chemical characteristics

  Si-Kyung Cho, Yu-Hoon Hwang, Dong-Hoon Kim, In-Seok Jeong, Hang-Sik Shin, Sae-Eun Oh
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  ABSTRACT: To elucidate the correlation between enhanced biogas production and changed physico-chemical properties of methanogenic granules after low strength ultrasonication, in this study, the effects of low strength ultrasonication on the settling velocity, permeability, porosity, and fluid collection efficiency of the methanogenic granules were investigated. In addition, their morphological changes were visualized using a scanning electron microscopic technique. The experimental results indicate that low strength ultrasonication increased both the permeability (37%) and specific surface area (230%) of the granules through the generation of greater craters and cracks on the granular surface compared to the control granules. The penetration of nutrients and substrate into the granules was thereby enhanced, and more favorable conditions for achieving higher anaerobic performance were provided to the ultrasonicated granules. The microbial community shift caused by the changed physico-chemical properties of the methanogenic granules will be further analyzed in part II of this study.
  Bioresource Technology 05/2013; 136:66-72.
• Article: Robust nanobioconjugates of Candida antarctica lipase B - multiwalled carbon nanotubes: characterization and application for multiple usages in non-aqueous biocatalysis

  Tripti Raghavendra, Arpana Basak, Lalit.M. Manocha, Amita R Shah, Datta Madamwar
  Bioresource Technology 04/2013;
• Article: Scale-up potential of cultivating Chlorella zofingiensis in piggery wastewater for biodiesel production

  Zhu, Wang, Takala, Hiltunen, Qin, Xu, Yuan
  Bioresource Technology 04/2013;
• Article: Development and characterization of the partial nitrification aerobic granules in a sequencing batch airlift reactor

  Song Y, Ishii S, Rathnayake L, Ito T, Satoh H, Okabe S
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  ABSTRACT: In this study, partial nitrifying (PN) aerobic granules were developed in a sequencing batch airlift reactor by controlling the airflow rate and NH4+ loading rate. The PN reactor produced an effluent with a NO� 2-/NH4+ ratio of approximately one and with an NH4+ conversion rate of 1.22 kg N m�-3 day-�1. More than 95% of the total organic carbon was removed during the process. On the basis of clone library analysis and fluorescence in situ hybridization, ammonia-oxidizing bacteria (AOB) closely related to Nitrosomonas eutropha and putative heterotrophic denitrifiers were mainly present near the surface of the PN aerobic granules. Microelectrode measurements revealed that both NH4+ and NO�2- were consumed near the surface (<200 lm), whereas no nitrate (NO3-�) accumulation was observed throughout the granules. These results indicate that PN by AOB and nitrite denitrification by heterotrophs, but not nitrite oxidation, simultaneously occurred near the surface of the PN aerobic granules.
  Bioresource Technology 04/2013; 139:285–291.
• Article: Effect of growth phase on harvesting characteristics, autoflocculation and lipid content of Ettlia texensis for microalgal biodiesel production

  S. Salim, Z. Shi, M.H. Vermuë, R.H. Wijffels
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  ABSTRACT: The effect of growth phase on the recovery of the autoflocculating microalgae Ettlia texensis was studied. In the stationary phase, 90% recovery was achieved after three hours settling. Scanning electron microscopic pictures revealed that extracellular polymeric substances (EPS) on the cell surface were involved in autoflocculation. During the stationary phase an increase of the protein fraction in the EPS was observed while the total fatty acids content increased. The autoflocculating properties of E. texensis combined with favourite fatty acid content and composition make this microalgae an excellent candidate for biodiesel production if harvested at the end of the stationary phase.
  Bioresource Technology 04/2013;
• Article: A novel process for recovery of fermentation-derived succinic acid: process design and economic analysis

  Alvaro Orjuela, Andrea Orjuela, Carl Lira, Dennis Miller
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  ABSTRACT: Recovery and purification of organic acids produced in fermentation constitutes a significant fraction of total production cost. In this paper, the design and economic analysis of a process to recover succinic acid (SA) via dissolution and acidification of succinate salts in ethanol, followed by reactive distillation to form succinate esters, is presented. Process simulation was performed for a range of plant capacities (13 to 55 million kg/yr SA) and SA fermentation titers (50 to 100 kg/m3). Economics were evaluated for a recovery system installed within an existing fermentation facility producing succinate salts at a cost of $0.66/kg SA. For a SA processing capacity of 54.9 million kg/yr and a titer of 100 kg/m3 SA, the model predicts a capital investment of $75 million and a net processing cost of $1.85 per kilogram SA. Required selling price of diethyl succinate for a 30% annual return on investment is $1.57 per kilogram.
  Bioresource Technology 04/2013;
• Article: Addressing the challenge of optimum polyhydroxyalkanoate harvesting: Monitoring real time process kinetics and biopolymer accumulation using dielectric spectroscopy

  Gopal Kedia, Pearl Passanha, Richard M. Dinsdale, Alan J. Guwy, Matthew Lee, Sandra R. Esteves
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  ABSTRACT: In this study, dielectric spectroscopy was utilised to evaluate and define the optimum harvesting time for polyhydroxyalkanoates (PHA) production. It is essential to harvest PHA at the optimum time during fermentation for maximum yield, otherwise cells start degrading. Two carbon sources (acetic and butyric acids) were used in laboratory based experiments and a number of samples were measured ex situ for PHA production. The real-time measured capacitance in addition of identifying the cells growth phase, it correlated very well with ex situ measured PHA produced within the cells. The probe has proven to be a useful tool to assess process kinetics, to monitor real-time cell growth, PHA produced and defining the optimum harvesting time.
  Bioresource Technology 04/2013; 134:143–150.
• Article: Sequential nitrification-denitrification process for nitrogenous, sulfurous and phenolic compounds removal in the same bioreactor

  De la Torre-Velasco A, Beristain-Cardoso R, Damian-Matzumura P, Gomez J
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  ABSTRACT: The kinetic and metabolic behavior of an aerobic granular sludge to nitrify, denitrify and nitrify-denitrify was evaluated in batch cultures. In nitrification control, ammonium, 4-methylphenol and sulfide were consumed efficiently (~100%) and recovered as NO3-, CO2, S0 and SO42-, respectively. In denitrification control, S0 and nitrate were efficiently consumed and recovered as SO42- and N2, respectively. Sequential nitrification-denitrification process was evaluated by applying oxic/anoxic conditions. Ammonium, 4-methylphenol and sulfide were oxidized to nitrate, CO2 and mainly S0, respectively, under aerobic conditions. After that, anoxic conditions were established where S0 reduced all nitrate to N2, with molecular nitrogen yield (YN2) of 1.03 ± 0.06 mg/mg NH4+-N consumed. This is the first study to show the capability of an aerobic granular sludge in simultaneous removal of ammonium, 4-methylphenol and sulfide by sequential nitrification-denitrification process in the same bioreactor.
  Bioresource Technology 04/2013; In press.
• Article: Role of extracellular cues to trigger the metabolic phase shifting from acidogenesis to solventogenesis in Clostridium acetobutylicum

  Manish Kumar, Kalyan Gayen, Supreet Saini
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  ABSTRACT: Clostridium acetobutylicum exhibits a two-step metabolic pathway where substrates are first converted to organic acids accompanied by a decrease in pH. The acids are then assimilated to organic solvents. The transition from the acid-producing (acidogenesis) to the solventproducing phase (solventogenesis) is controlled by integration of a number of cellular and environmental cues, whose precise mode of action are not well understood. In this study, a series of batch experiments were performed to understand the impact of extracellular cues in regulating the dynamics of acidogenesis and solventogenesis. It is demonstrated that the two phases operate independently of each other and the growth phase of the cell, i.e. the cues controlling a phase are not linked to the status of the other phase or the growth phase of the cell. Kinetic experiments demonstrated that there exist two previously uncharacterized negative feedback loops controlling the amounts of acids produced in the acidogenesis phase.
  Bioresource Technology 04/2013;
• Article: Nannochloropsis sp. biomass recovery by Electro-Coagulation for biodiesel and pigment production

  Cristina T. Matos, Marta Santos, Beatriz P. Nobre, Luisa Gouveia
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  ABSTRACT: Biofuel production from microalgal biomass could be an alternative solution to conventional biofuels typically dependent on food and high land/water demanding crops. However, the economic and energetic viability of microalgal biofuels is limited by their harvesting processes. The finding of innovative, low cost and efficient harvesting method(s) is imperative. In this study, the Electro-Coagulation (EC) was studied as a process to harvest the marine Nannochloropsis sp. microalga. Several EC operational conditions were studied and the best EC recovery efficiency (>97%) was achieved using a current density of 8.3 mA cm−2 for 10 min. The quality of the recovered microalgal biomass was evaluated in terms of total lipids, fatty acid and pigment profile where no significant differences were observed after EC treatment. The energy requirements of the harvesting process were estimated and the combination of EC and centrifugation processes proved to decrease significantly the energy demand when compared with the individual process. --------------------------------------------------------------------------------
  Bioresource Technology 04/2013; 134:219.
• Article: A simple methodology for rate-limiting step determination for anaerobic digestion of complex substrates and effect of microbial community ratio.

  Jingwei Ma, Craig Frear, Zhi-Wu Wang, Liang Yu, Quanbao Zhao, Xiujin Li, Shulin Chen
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  ABSTRACT: Anaerobic digestion (AD) of complex substrates is a multi-step process, which is kinetically controlled by an individual rate-limiting step. A methodology for determining the rate-limiting step during AD of complex substrates was developed by supplementation of metabolic intermediates from each digestion step with dairy manure as an emblematic complex substrate. This method elucidated that hydrolysis of dairy manure was the rate-limiting step when normal anaerobic sludge was used as inoculum. Furthermore, the concept and effect of microbial community ratio was introduced by manipulating two different inocula, i.e. normal anaerobic sludge and heated anaerobic sludge, so that varying ratios (r) of hydrolytic and methanogenic bacteria could be studied. Results revealed that the rate-limiting step changed with the variation of r. For dairy manure, results indicated a critical ratio r(∗)=24 between hydrolytic bacteria and methanogens, whereby as r decreased or exceeded from this value, hydrolysis or methanogenesis limited the AD process, respectively.
  Bioresource Technology 04/2013; 134:391-395.
• Article: Co-gasification of tire and biomass for enhancement of tire-char reactivity in CO2 gasification process

  Pooya Lahijani, Zainal Alimuddin Zainal, Abdul Rahman Mohamed, Maedeh Mohammadi
  Bioresource Technology 04/2013;
• Article: Effects of Salinity on the Characteristics of Biomass and Membrane Fouling in Membrane Bioreactors

  Duksoo Jang, Yuhoon Hwang, Hangsik Shin, Wontae Lee
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  ABSTRACT: This study investigated the effects of high salinity on the performance and membrane fouling of membrane bioreactor (MBR) with saline wastewater. Synthetic wastewaters containing 5 to 20 g/L salts (NaCl) were treated in identical lab-scale (7 L) MBRs monitoring removals of dissolved organic carbon (DOC) and ammonia. Increase in salt concentrations did not significantly change the removal efficiency of DOC in the MBRs. However, the ammonia removals decreased from 87% to 46% with increasing salt concentrations. PCR-DGGE analysis indicated changes in the microbial communities’ composition due to high salinity; and the changes in microbial composition in turn have affected the performance of the MBRs. Membrane fouling was accelerated by the increased pore blocking resistance at higher salt concentrations. Analysis results of physicochemical and biological characteristics of biomass (EPS, floc size, zeta potential) verified the impacts of high salinity on the increased membrane fouling.
  Bioresource Technology 03/2013; in press.