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Valorisation of fruit waste for enhanced exopolysaccharide production by Xanthomonas campestries using statistical optimisation of medium and process. FOOD BIOSCI 2022. [DOI: 10.1016/j.fbio.2022.101608] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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2
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Vaishnav A, Upadhayay K, Tipre D, Dave S. Utilization of mixed fruit waste for exopolysaccharide production by Bacillus species SRA4: medium formulation and its optimization. 3 Biotech 2020; 10:550. [PMID: 33269184 DOI: 10.1007/s13205-020-02545-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 11/06/2020] [Indexed: 11/24/2022] Open
Abstract
The main focus of this research work was to carry out the fermentative production of EPS with mixed fruit waste as substrate. The medium formulation studied by sequential addition of medium components and replacement of sugar with mixed fruit waste. Amongst the six species of Bacillus studied, Bacillus species SRA4 produced EPS in range of 3.0-17.9 g/L, which was highest amongst all the species selected for the study. Thus for further optimization, the response surface methodology was used making use of Bacillus species SRA4. EPS production enhanced to 23.75 g/L. In 10 L shake flask and fermenter scale-up study was carried out. In the study, 10 L flask showed the highest EPS production of 17.95 g/L in 120 h, whereas in 10 L fermenter, it was as high as 25.1 g/L that too in 72 h only. The optimization study resulted in 1.76-fold increase in EPS production with nearly 48 h reduction in EPS production time as compared to initial production procedure. Replacement of sucrose with fruit waste extract made the process environmentally friendly; omission of l-cystine and use of 50% reduced amount of sodium acetate in the medium lowered the production cost of EPS. This method also solved the fruit waste disposal problem.
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Affiliation(s)
- Avni Vaishnav
- Department of Biochemistry and Biotechnology, Saint Xavier's Collage, Ahmedabad, India
| | - Kinjal Upadhayay
- Department of Biochemistry and Biotechnology, Saint Xavier's Collage, Ahmedabad, India
| | - Devayani Tipre
- Department of Microbiology, School of Science, Gujarat University, Ahmedabad, India
| | - Shailesh Dave
- Loyola Centre for Research and Development, Xavier's Research Foundation, Saint Xavier's Collage Campus, Ahmedabad, India
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Lu H, Dong S, Zhang G, Han T, Zhang Y, Li B. Enhancing the auto-flocculation of photosynthetic bacteria to realize biomass recovery in brewery wastewater treatment. ENVIRONMENTAL TECHNOLOGY 2019; 40:2147-2156. [PMID: 29421961 DOI: 10.1080/09593330.2018.1439107] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 02/06/2018] [Indexed: 06/08/2023]
Abstract
Photosynthetic bacteria (PSB) wastewater treatment technology can simultaneously realize wastewater purification and biomass production. The produced biomass contains high value-added products, which can be used in medical and agricultural industry. However, because of the small size and high electronegativity, PSB are hard to be collected from wastewater, which hampers the commercialization of PSB-based industrial processes. Auto-flocculation is a low cost, energy saving, non-toxic biomass collection method for microbiology. In this work, the influence factors with their optimal levels and mechanism for enhancing the auto-flocculation of PSB were investigated in pure cultivation medium. Then PSB auto-flocculation performance in real brewery wastewater was probed. Results showed that Na+ concentration, pH and light intensity were three crucial factors except the initial inoculum sizes and temperature. In the pure medium cultivation system, the optimal condition for PSB auto-flocculation was as follows: pH was 9.5, inoculum size was 420 mg l-1, Na+ concentration was 0.067 mol l-1, light intensity was 5000 lux, temperature was 30°C. Under the optimal condition, the auto-flocculation ratio and biomass recovery reached 85.0% and 1488 mg l-1, which improved by 1.67-fold and 2.14-fold compared with the PSB enrichment cultivation conditions, respectively. Mechanism analysis showed that the protein/polysaccharides ratio and absolute Zeta potential value had a liner relationship. For the brewery wastewater treatment, under the above optimal condition, the chemical oxygen demand removal reached 94.3% with the auto-flocculation ratio and biomass recovery of 89.6% and 1510 mg l-1, which increased 2.75-fold and 2.77-fold, respectively.
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Affiliation(s)
- Haifeng Lu
- a College of Water Resource and Civil Engineering, China Agriculture University , Beijing , China
- b Ministry of Agriculture, Key Laboratory of Agricultural Engineering in Structure and Environment , Beijing , China
- c Beijing Engineering Research Center on Animal Healthy Environment , Beijing , China
| | - Shan Dong
- d State Key Laboratory of Urban Water Resource & Environment, Harbin Institute of Technology , Harbin , China
| | - Guangming Zhang
- e School of Environment and Natural Resources, Renmin University of China , Beijing , China
| | - Ting Han
- a College of Water Resource and Civil Engineering, China Agriculture University , Beijing , China
- b Ministry of Agriculture, Key Laboratory of Agricultural Engineering in Structure and Environment , Beijing , China
- c Beijing Engineering Research Center on Animal Healthy Environment , Beijing , China
| | - Yuanhui Zhang
- a College of Water Resource and Civil Engineering, China Agriculture University , Beijing , China
- b Ministry of Agriculture, Key Laboratory of Agricultural Engineering in Structure and Environment , Beijing , China
- c Beijing Engineering Research Center on Animal Healthy Environment , Beijing , China
- f Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign , Urbana , IL , USA
| | - Baoming Li
- a College of Water Resource and Civil Engineering, China Agriculture University , Beijing , China
- b Ministry of Agriculture, Key Laboratory of Agricultural Engineering in Structure and Environment , Beijing , China
- c Beijing Engineering Research Center on Animal Healthy Environment , Beijing , China
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Iritani E, Katagiri N, Minato J, Nishikawa M, Kawasaki K. Improvement in Settling Performance of Disrupted Sludge by Stepwise Addition of Inorganic Salts. KAGAKU KOGAKU RONBUN 2018. [DOI: 10.1252/kakoronbunshu.44.253] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Eiji Iritani
- Department of Chemical Systems Engineering, Nagoya University
| | | | - Jumpei Minato
- Department of Chemical Systems Engineering, Nagoya University
| | | | - Kenji Kawasaki
- Department of Materials Science and Biotechnology, Ehime University
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Sharafat I, Saeed DK, Yasmin S, Imran A, Zafar Z, Hameed A, Ali N. Interactive effect of trivalent iron on activated sludge digestion and biofilm structure in attached growth reactor of waste tire rubber. ENVIRONMENTAL TECHNOLOGY 2018; 39:130-143. [PMID: 28278106 DOI: 10.1080/09593330.2017.1296894] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 02/14/2017] [Indexed: 06/06/2023]
Abstract
Waste tire rubber (WTR) has been introduced as an alternative, novel media for biofilm development in several experimental systems including attached growth bioreactors. In this context, four laboratory-scale static batch bioreactors containing WTR as a support material for biofilm development were run under anoxic condition for 90 days using waste activated sludge as an inoculum under the influence of different concentrations (2.5, 6.5, 8.5 mg/l) of trivalent ferric iron (Fe3+). The data revealed that activated sludge with a Fe3+ concentration of 8.5 mg/l supported the maximum bacterial biomass [4.73E + 10 CFU/ml cm2]; besides, it removed 38% more Chemical oxygen demand compared to Fe3+ free condition from the reactor. Biochemical testing and 16S rDNA phylogenetic analysis of WTR-derived biofilm communities further suggested the role of varying concentrations of Fe3+ on the density and diversity of members of Enterobacteria(ceae), ammonium (AOB) and nitrite oxidizing bacteria. Furthermore, Fluorescent in situ hybridization with phylogenetic oligonucleotide probes and confocal laser scanning microscopy of WTR biofilms indicated a significant increase in density of eubacteria (3.00E + 01 to.05E + 02 cells/cm2) and beta proteobacteria (8.10E + 01 to 1.42E + 02 cells/cm2), respectively, with an increase in Fe3+ concentration in the reactors, whereas, the cell density of gamma proteobacteria in biofilms decreased.
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Affiliation(s)
- Iqra Sharafat
- a Department of Microbiology , Quaid-i-Azam University Islamabad , Pakistan
| | - Dania Khalid Saeed
- a Department of Microbiology , Quaid-i-Azam University Islamabad , Pakistan
| | - Sumera Yasmin
- b National Institute for Biotechnology and Genetic Engineering (NIBGE) , Faisalabad , Pakistan
| | - Asma Imran
- b National Institute for Biotechnology and Genetic Engineering (NIBGE) , Faisalabad , Pakistan
| | - Zargona Zafar
- a Department of Microbiology , Quaid-i-Azam University Islamabad , Pakistan
| | - Abdul Hameed
- a Department of Microbiology , Quaid-i-Azam University Islamabad , Pakistan
| | - Naeem Ali
- a Department of Microbiology , Quaid-i-Azam University Islamabad , Pakistan
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Bas S, Kramer M, Stopar D. Biofilm Surface Density Determines Biocide Effectiveness. Front Microbiol 2017; 8:2443. [PMID: 29276508 PMCID: PMC5727120 DOI: 10.3389/fmicb.2017.02443] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 11/24/2017] [Indexed: 12/28/2022] Open
Abstract
High resistance of biofilms for chemical challenges is a serious industrial and medical problem. In this work a gradient of surface covered with biofilm has been produced and correlated to the effectiveness of different commercially available oxidative biocides. The results for thin Escherichia coli biofilms grown in rich media supplemented with glucose or lactose on glass or poly methyl methacrylate surfaces indicate that the effectiveness of hydrogen peroxide or chlorine dioxide and quaternary ammonium compounds is inversely proportional to the fraction of the surface covered with the biofilm. In areas where biofilm covered more than 90% of the available surface the biocide treatment was inefficient after 60 min of incubation. The combined effect of oxidant and surfactant increased the effectiveness of the biocide. On the other hand, the increased biofilm viscoelasticity reduced biocide effectiveness. The results emphasize differential biocide effectiveness depending on the fraction of the attached bacterial cells. The results suggest that biofilm biocide resistance is an acquired property that increases with biofilm maturation. The more dense sessile structures present lower log reductions compared to less dense ones.
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Affiliation(s)
- Sara Bas
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | | | - David Stopar
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
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Iritani E, Katagiri N, Minato J, Nishikawa M. Improvement in Settling Performance of Disrupted Sludge by Salt Addition. KAGAKU KOGAKU RONBUN 2017. [DOI: 10.1252/kakoronbunshu.43.327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Eiji Iritani
- Department of Chemical Systems Engineering, Nagoya University
| | | | - Jumpei Minato
- Department of Chemical Systems Engineering, Nagoya University
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8
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Gambuti A, Rinaldi A, Romano R, Manzo N, Moio L. Performance of a protein extracted from potatoes for fining of white musts. Food Chem 2016. [DOI: 10.1016/j.foodchem.2015.05.067] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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9
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Zhang P, Chen YP, Guo JS, Shen Y, Yang JX, Fang F, Li C, Gao X, Wang GX. Adsorption behavior of tightly bound extracellular polymeric substances on model organic surfaces under different pH and cations with surface plasmon resonance. WATER RESEARCH 2014; 57:31-39. [PMID: 24704902 DOI: 10.1016/j.watres.2014.03.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 03/07/2014] [Accepted: 03/09/2014] [Indexed: 06/03/2023]
Abstract
Tightly bound extracellular polymeric substances (TB-EPS) play a substantial role on microbial aggregates, which can promote microbial cells to aggregate and adhere onto the carrier in bioreactor. However, the attachment and adsorption of TB-EPS on different surfaces were awaited to be elucidated. In this study, four self-assembled monolayers (SAMs) carrying methyl (CH3-SAM), amino (NH2-SAM), hydroxyl (OH-SAM), and carboxyl (COOH-SAM) terminal groups were prepared to model different surfaces. TB-EPS adsorption on these surfaces under different pH conditions and additional cations were investigated using surface plasmon resonance. The adsorption of TB-EPS dramatically decreased with the decreasing pH values. CH3-SAM surface achieved the maximum adsorption at the same condition. Na(+) promoted the TB-EPS adsorbed on COOH-SAM surface. The Ca(2+)-mediated complexes were attracted by COOH-SAM and repelled by NH2-SAM, respectively. The adsorptions of TB-EPS on the four SAM surfaces were significantly increased by adding Fe(3+). These results demonstrated that the TB-EPS adsorption on the organic surfaces were dependent on the pH and cation of solution.
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Affiliation(s)
- Peng Zhang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China
| | - You-Peng Chen
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China; Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China.
| | - Jin-Song Guo
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China; Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
| | - Yu Shen
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
| | - Ji-Xiang Yang
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
| | - Fang Fang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China
| | - Chun Li
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China
| | - Xu Gao
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China
| | - Gui-Xue Wang
- College of Bioengineering, Chongqing University, Chongqing 400045, China
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Nwodo U, Okoh A. Characterization and flocculation properties of biopolymeric flocculant (glycosaminoglycan) produced by Cellulomonas
sp. Okoh. J Appl Microbiol 2013; 114:1325-37. [DOI: 10.1111/jam.12095] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 11/27/2012] [Accepted: 11/28/2012] [Indexed: 11/26/2022]
Affiliation(s)
- U.U. Nwodo
- Department of Biochemistry and Microbiology; Applied and Environmental Microbiology Research Group (AEMREG), University of Fort Hare; Alice South Africa
| | - A.I. Okoh
- Department of Biochemistry and Microbiology; Applied and Environmental Microbiology Research Group (AEMREG), University of Fort Hare; Alice South Africa
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11
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Gong AS, Lanzl CA, Cwiertny DM, Walker SL. Lack of influence of extracellular polymeric substances (EPS) level on hydroxyl radical mediated disinfection of Escherichia coli. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:241-249. [PMID: 22082030 DOI: 10.1021/es202541r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Photolysis of nitrate, a prevalent constituent in agriculturally impacted waters, may influence pathogen attenuation in such systems through production of hydroxyl radical ((•)OH). This study focuses on the efficacy of (•)OH generated during nitrate photolysis in promoting E. coli die-off as a function of extracellular polymeric substances (EPS) coverage. EPS levels of four E. coli isolates were systematically altered through a sonication extraction method and photochemical batch experiments with a solar simulator examined isolate viability loss as a function of time in nitrate solutions. E. coli viability loss over time exhibited two regimes: an initial induction time, t(s), with little decay was followed by rapid exponential decay characterized by a first-order disinfection rate constant, k. Increasing steady-state (•)OH concentrations enhanced E. coli viability loss, increasing values of k and decreasing t(s) values, both of which were quantified with a multitarget bacterial disinfection model. Notably, at a given steady-state (•)OH concentration, values of t(s) and k were independent of EPS levels, nor did they vary among the different E. coli strains considered. Results herein show that while (•)OH generated via nitrate photolysis enhances rates of disinfection in surface water, the mechanism by which (•)OH kills E. coli is relatively insensitive to common bacterial variables.
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Affiliation(s)
- Amy S Gong
- Department of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
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12
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Wang L, Ma F, Qu Y, Sun D, Li A, Guo J, Yu B. Characterization of a compound bioflocculant produced by mixed culture of Rhizobium radiobacter F2 and Bacillus sphaeicus F6. World J Microbiol Biotechnol 2011. [DOI: 10.1007/s11274-011-0726-2] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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13
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Heijstra BD, Pichler FB, Liang Q, Blaza RG, Turner SJ. Extracellular DNA and Type IV pili mediate surface attachment by Acidovorax temperans. Antonie van Leeuwenhoek 2009; 95:343-9. [PMID: 19263234 DOI: 10.1007/s10482-009-9320-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2008] [Accepted: 02/18/2009] [Indexed: 11/26/2022]
Abstract
Extracellular DNA can play a structural role in the microbial environment. Here evidence is presented that an environmental isolate of Acidovorax temperans utilises extracellular DNA for intercellular and cell-surface attachment and that Type IV pili and electrostatic interactions play a role in this interaction. Preliminary attempts to isolate and purify extracellular polysaccharides from A. temperans strain CB2 yielded significant amounts of DNA raising the question of whether this molecule was present as a structural component in the extracellular matrix. The role of DNA in attachment was indicated by experiments in which the addition of DNase to liquid medium inhibited the attachment of Acidovorax to glass wool. A Tn5 insertional mutant, lacking Type IV pili, was unable to initiate attachment. Addition of DNase caused rapid detachment of bound cells, but no detachment occurred when proteinase, RNase or inactivated DNase were used. Addition of MgCl(2) also caused significant detachment, supporting the possible mechanistic role of electrostatic interactions in the attachment process. Although attachment was apparent in early to mid-log phase growth, surprisingly DNA was not detected in the culture supernatant until late stationary phase and coincided with an appreciable loss of cell viability. This suggests that during log-phase growth attachment is mediated by eDNA that is released in low quantities and/or is highly localised within the extracellular matrix and also that stationary phase DNA release through widespread cell lysis may be a separate and unrelated event.
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Affiliation(s)
- Björn D Heijstra
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
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Pal A, Paul AK. Microbial extracellular polymeric substances: central elements in heavy metal bioremediation. Indian J Microbiol 2008; 48:49-64. [PMID: 23100700 PMCID: PMC3450203 DOI: 10.1007/s12088-008-0006-5] [Citation(s) in RCA: 205] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Revised: 11/26/2007] [Accepted: 01/08/2008] [Indexed: 11/30/2022] Open
Abstract
Extracellular polymeric substances (EPS) of microbial origin are a complex mixture of biopolymers comprising polysaccharides, proteins, nucleic acids, uronic acids, humic substances, lipids, etc. Bacterial secretions, shedding of cell surface materials, cell lysates and adsorption of organic constituents from the environment result in EPS formation in a wide variety of free-living bacteria as well as microbial aggregates like biofilms, bioflocs and biogranules. Irrespective of origin, EPS may be loosely attached to the cell surface or bacteria may be embedded in EPS. Compositional variation exists amongst EPS extracted from pure bacterial cultures and heterogeneous microbial communities which are regulated by the organic and inorganic constituents of the microenvironment. Functionally, EPS aid in cell-to-cell aggregation, adhesion to substratum, formation of flocs, protection from dessication and resistance to harmful exogenous materials. In addition, exopolymers serve as biosorbing agents by accumulating nutrients from the surrounding environment and also play a crucial role in biosorption of heavy metals. Being polyanionic in nature, EPS forms complexes with metal cations resulting in metal immobilization within the exopolymeric matrix. These complexes generally result from electrostatic interactions between the metal ligands and negatively charged components of biopolymers. Moreover, enzymatic activities in EPS also assist detoxification of heavy metals by transformation and subsequent precipitation in the polymeric mass. Although the core mechanism for metal binding and / or transformation using microbial exopolymer remains identical, the existence and complexity of EPS from pure bacterial cultures, biofilms, biogranules and activated sludge systems differ significantly, which in turn affects the EPS-metal interactions. This paper presents the features of EPS from various sources with a view to establish their role as central elements in bioremediation of heavy metals.
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Affiliation(s)
- Arundhati Pal
- Microbiology Laboratory, Department of Botany, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700 019 India
| | - A. K. Paul
- Microbiology Laboratory, Department of Botany, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700 019 India
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Lee YH, Son MK, Jung YM, Kim TK, Park DC, Lee HS, Kim PS, Ku SK. Mouse Single Oral Dose Toxicity Studies of PGB-1, a Novel Polyglucosamine Polymer Produce from Enterobacter sp. BL-2. Toxicol Res 2007. [DOI: 10.5487/tr.2007.23.4.373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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16
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Characterization and flocculating properties of an extracellular biopolymer produced from a Bacillus subtilis DYU1 isolate. Process Biochem 2007. [DOI: 10.1016/j.procbio.2007.05.006] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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17
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Lee YH, Son MK, Jung YM, Kim TK, Park DC, Kim PS, Ku SK. Single Oral Dose Toxicity Studies of PGB-2, a Novel Polyglucosamine Polymer Produced from Citrobacter sp. BL-4 in Mice. Toxicol Res 2007. [DOI: 10.5487/tr.2007.23.1.065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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18
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Watanabe M, Kawahara K, Sasaki K, Noparatnaraporn N. Biosorption of cadmium ions using a photosynthetic bacterium, Rhodobacter sphaeroides S and a marine photosynthetic bacterium, Rhodovulum sp. and their biosorption kinetics. J Biosci Bioeng 2005; 95:374-8. [PMID: 16233422 DOI: 10.1016/s1389-1723(03)80070-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2002] [Accepted: 12/16/2002] [Indexed: 11/30/2022]
Abstract
We examined the biosorption characteristics of cadmium ions onto a photosynthetic bacterium, Rhodobacter sphaeroides S and a marine photosynthetic bacterium Rhodovulum sp. PS88 in a batch culture system. Both photosynthetic bacteria are capable of cadmium removal with 30 g/l sodium chloride and divalent cations (Mg2+ and Ca2+) in the culture medium. In particular, the strain PS88 shows a high removal ratio and high specific removal rate of cadmium ions from the culture medium under aerobic-dark (heterotrophic) and anaerobic-light (photoheterotrophic) conditions. The adsorption of cadmium onto strains PS88 and S is dependent on the cadmium concentration, and follows the Freundlich adsorption isotherm. In addition, biosorption isotherms for cadmium show that the strain PS88 exhibits higher values of the empirical constant for the cadmium adsorption capacity, Kr, than that of the strain S under both aerobic-dark (K(f)=17.44) and anaerobic-light (K(f)=1.270) conditions.
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Affiliation(s)
- Masanori Watanabe
- Materials Science and Engineering, Graduate School of Engineering, Hiroshima Kokusai Gakuin University, 6-20-1 Nakano, Akiku, Hiroshima 739-0321, Japan
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Dogsa I, Kriechbaum M, Stopar D, Laggner P. Structure of bacterial extracellular polymeric substances at different pH values as determined by SAXS. Biophys J 2005; 89:2711-20. [PMID: 16085763 PMCID: PMC1366772 DOI: 10.1529/biophysj.105.061648] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2005] [Accepted: 07/21/2005] [Indexed: 11/18/2022] Open
Abstract
Extracellular polymeric substances (EPS) play an important role in cell aggregation, cell adhesion, and biofilm formation, and protect cells from a hostile environment. The EPS was isolated by trichloroacetic acid/ethanol extraction from broth culture of a marine bacterium isolate. The EPS was composed of glucose and galactose as determined by HPLC and TLC; the protein content was on average 15 +/- 5% of EPS dry mass. The solution structure of EPS at different values of pH was revealed by small-angle x-ray scattering. Scattering curves of EPS solutions (0.4%, w/v) consistently showed two nearly linear log-log regions with slopes a and b in the q-ranges from 0.06 nm(-1) to 0.26 nm(-1), and from 0.27 nm(-1) to 0.88 nm(-1), respectively. Slope a was sensitive to pH changes whereas slope b was not. The observed sensitivity to pH was not a consequence of ionic strength variation with pH, as checked by salt addition. The pH variation causes major rearrangements of EPS structure mainly at length scales above 24 nm. To get a better understanding of the pH effect on EPS structure, the original model proposed by Geissler was refined into a mathematical model that enabled fitting of the experimental scattering curves in the pH range from 0.7 to 11.0. The model describes EPS structure as a network of randomly coiled polymeric chains with denser domains of polymeric chains. The results obtained from the model indicate that dense domains increase in average size from 19 nm at pH 11.0 to 52 nm at pH 0.7. The average distance between the polysaccharide chains at pH 0.7 was 2.3 nm, which indicates a compact EPS structure. Swelling was found to be at a maximum around pH = 8.8, where the average distance between the chains was 4.8 nm.
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Affiliation(s)
- Iztok Dogsa
- Laboratory for Biophysics, Jozef Stefan Institute, Ljubljana, Slovenia
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Lang S, Hüners M, Verena L. Bioprocess Engineering Data on the Cultivation of Marine Prokaryotes and Fungi. MARINE BIOTECHNOLOGY II 2005; 97:29-62. [PMID: 16261805 DOI: 10.1007/b135822] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The temperature/pressure dependency of marine prokaryotes and fungi, in terms of their growth behaviour as well as their potential to produce new metabolites or enzymes, is evaluated. Advanced shake-flask cultivations and controlled bioreactor cultivations following the batch-type, fed-batch-type and/or continuous-type procedures are summarized. After a summary of the fermentation data available so far, values on maximal biomass, specific growth rates, and (sub)optimal production yields are presented. The application of mesophilic microbes, especially bioactive metabolites, to intensify bioprocess engineering studies, is the goal. Cold-active enzymes and thermostable enzymes are the targets of experiments with psychrophilic and hyperthermophilic enzymes. A special challenge to bioengineers is also provided by barophilic strains originating from depths of, say, nearly 11000 m, or from hydrothermal vents.
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Affiliation(s)
- Siegmund Lang
- Technische Universität Braunschweig, Institut für Biochemie und Biotechnologie, Spielmannstr. 7, 38106 Braunschweig, Germany.
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