Development and Future Challenges of Bio-Syncretic Robots

[1]  Takehiko Kitamori,et al.  Demonstration of a bio-microactuator powered by vascular smooth muscle cells coupled to polymer micropillars. , 2008, Lab on a chip.

[2]  Keisuke Morishima,et al.  Optogenetic induction of contractile ability in immature C2C12 myotubes , 2015, Scientific Reports.

[3]  H. Fujita,et al.  Magnetic force-based tissue engineering of skeletal muscle , 2010 .

[4]  Ritu Raman,et al.  Optogenetic skeletal muscle-powered adaptive biological machines , 2016, Proceedings of the National Academy of Sciences.

[5]  G. Dogangil,et al.  A review of medical robotics for minimally invasive soft tissue surgery , 2010, Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine.

[6]  Metin Sitti,et al.  Bio-hybrid cell-based actuators for microsystems. , 2014, Small.

[7]  J. Nerbonne,et al.  Molecular physiology of cardiac repolarization. , 2005, Physiological reviews.

[8]  Y. Chevalier,et al.  Monitoring of E. coli immobilization on modified gold electrode: A new bacteria-based glucose sensor , 2010 .

[9]  Keisuke Morishima,et al.  Optically controllable muscle for cell-based microdevice , 2014, 2014 International Symposium on Micro-NanoMechatronics and Human Science (MHS).

[10]  Kazunori Shimizu,et al.  Evaluation systems of generated forces of skeletal muscle cell-based bio-actuators. , 2013, Journal of bioscience and bioengineering.

[11]  Kazunori Shimizu,et al.  Fabrication of scaffold‐free contractile skeletal muscle tissue using magnetite‐incorporated myogenic C2C12 cells , 2010, Journal of tissue engineering and regenerative medicine.

[12]  Rashid Bashir,et al.  Multi-material bio-fabrication of hydrogel cantilevers and actuators with stereolithography. , 2012, Lab on a chip.

[13]  Ali Khademhosseini,et al.  Electrical stimulation as a biomimicry tool for regulating muscle cell behavior , 2013, Organogenesis.

[14]  Sung-Jin Park,et al.  Instrumented cardiac microphysiological devices via multi-material 3D printing , 2016, Nature materials.

[15]  S Sánchez,et al.  Applications of three-dimensional (3D) printing for microswimmers and bio-hybrid robotics. , 2015, Lab on a chip.

[16]  M. Su,et al.  A microarray-based resonance light scattering assay for detecting thrombin generation in human plasma by gold nanoparticle probes , 2013 .

[17]  Li Zhang,et al.  Fabrication and Characterization of Magnetic Microrobots for Three-Dimensional Cell Culture and Targeted Transportation , 2013, Advanced materials.

[18]  Nicholas L Abbott,et al.  Bacterial transport of colloids in liquid crystalline environments. , 2015, Soft matter.

[19]  Metin Sitti,et al.  Miniature devices: Voyage of the microrobots , 2009, Nature.

[20]  M. J. Kim,et al.  Artificial magnetotactic motion control of Tetrahymena pyriformis using ferromagnetic nanoparticles: A tool for fabrication of microbiorobots , 2010 .

[21]  Jaewon Yoon,et al.  Cardiomyocyte‐Driven Actuation in Biohybrid Microcylinders , 2015, Advanced materials.

[22]  Johan U. Lind,et al.  Instrumented cardiac microphysiological devices via multimaterial three-dimensional printing , 2016 .

[23]  R. Bashir,et al.  Development of Miniaturized Walking Biological Machines , 2012, Scientific Reports.

[24]  Hyoungshin Park,et al.  Pre-treatment of synthetic elastomeric scaffolds by cardiac fibroblasts improves engineered heart tissue. , 2008, Journal of biomedical materials research. Part A.

[25]  I. Aranson,et al.  Swimming bacteria power microscopic gears , 2009, Proceedings of the National Academy of Sciences.

[26]  Takayuki Hoshino,et al.  Atmospheric-operable bioactuator powered by insect muscle packaged with medium. , 2013, Lab on a chip.

[27]  K. Esser,et al.  Phosphorylation of p70S6kcorrelates with increased skeletal muscle mass following resistance exercise. , 1999, American journal of physiology. Cell physiology.

[28]  Arianna Menciassi,et al.  Bio-hybrid muscle cell-based actuators , 2012, Biomedical Microdevices.

[29]  B. Williams,et al.  A self-propelled biohybrid swimmer at low Reynolds number , 2014, Nature Communications.

[30]  Chiel Hillel,et al.  Skeletal muscle powered living machines utilizing electrocompacted and aligned collagen scaffolds , 2016 .

[31]  Taijiao Jiang,et al.  A magnetic protein biocompass. , 2016, Nature materials.

[32]  Daniel Barolet,et al.  Light-emitting diodes (LEDs) in dermatology. , 2008, Seminars in cutaneous medicine and surgery.

[33]  UesugiKaoru,et al.  Contractile Performance and Controllability of Insect Muscle-Powered Bioactuator with Different Stimulation Strategies for Soft Robotics , 2016 .

[34]  H. Berg,et al.  Moving fluid with bacterial carpets. , 2004, Biophysical journal.

[35]  G. Whitesides,et al.  Muscular Thin Films for Building Actuators and Powering Devices , 2007, Science.

[36]  H. Körber,et al.  Design and validation of a bioreactor for simulating the cardiac niche: a system incorporating cyclic stretch, electrical stimulation, and constant perfusion. , 2013, Tissue engineering. Part A.

[37]  K. Kataoka,et al.  Differentiation of myoblasts is accelerated in culture in a magnetic field , 2000, In Vitro Cellular & Developmental Biology - Animal.

[38]  James E. Bobrow,et al.  Modeling, Identification, and Control of a Pneumatically Actuated, Force Controllable Robot , 1996 .

[39]  Sylvain Martel,et al.  Bacterial microsystems and microrobots , 2012, Biomedical Microdevices.

[40]  Jeong-Woo Choi,et al.  Phototactic guidance of a tissue-engineered soft-robotic ray , 2016, Science.

[41]  K. Morishima,et al.  Biological contractile regulation of micropillar actuator driven by insect dorsal vessel tissue , 2008, 2008 2nd IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics.

[42]  Claire M. Brown,et al.  Live-cell microscopy – tips and tools , 2009, Journal of Cell Science.

[43]  P. Tracqui,et al.  Optimization of poly-di-methyl-siloxane (PDMS) substrates for studying cellular adhesion and motility , 2008 .

[44]  Sean P Sheehy,et al.  Biohybrid thin films for measuring contractility in engineered cardiovascular muscle. , 2010, Biomaterials.

[45]  A. Landesberg,et al.  Adaptive control of cardiac contraction to changes in loading: from theory of sarcomere dynamics to whole-heart function , 2011, Pflügers Archiv - European Journal of Physiology.

[46]  D. Häder,et al.  UV-induced DNA damage and repair: a review , 2002, Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology.

[47]  Keisuke Morishima,et al.  Culture of insect cells contracting spontaneously; research moving toward an environmentally robust hybrid robotic system. , 2008, Journal of biotechnology.

[48]  Changyou Chen,et al.  Construction and operation of a microrobot based on magnetotactic bacteria in a microfluidic chip. , 2012, Biomicrofluidics.

[49]  B. Mesick.  Titanium and Titanium Alloys. John L. Everhart.Reinhold, New York, 1954. v + 184 pp. Illus. $3 , 1954 .

[50]  Alexandre Campos,et al.  Application of High Brightness LEDs in the Human Tissue and Its Therapeutic Response , 2011 .

[51]  Jinchao Xu,et al.  Measuring single cardiac myocyte contractile force via moving a magnetic bead. , 2005, Biophysical journal.

[52]  H. Harry Asada,et al.  Fabrication and characterization of optogenetic, multi-strip cardiac muscles. , 2015, Lab on a chip.

[53]  K. Mabuchi,et al.  Simple micropatterning method for enhancing fusion efficiency and responsiveness to electrical stimulation of C2C12 myotubes , 2015, Biotechnology progress.

[54]  Chintae Choi,et al.  Practical Nonsingular Terminal Sliding-Mode Control of Robot Manipulators for High-Accuracy Tracking Control , 2009, IEEE Transactions on Industrial Electronics.

[55]  K. Shoji,et al.  Insect biofuel cells using trehalose included in insect hemolymph leading to an insect-mountable biofuel cell , 2012, Biomedical microdevices.

[56]  D. Kaplan,et al.  Self-assembled insect muscle bioactuators with long term function under a range of environmental conditions. , 2014, RSC advances.

[57]  Sylvain Martel,et al.  A Feasibility Study for Microwave Breast Cancer Detection Using Contrast-Agent-Loaded Bacterial Microbots , 2013 .

[58]  K. Baar,et al.  Regulating fibrinolysis to engineer skeletal muscle from the C2C12 cell line. , 2009, Tissue engineering. Part C, Methods.

[59]  K. Esser,et al.  Phosphorylation of p70(S6k) correlates with increased skeletal muscle mass following resistance exercise. , 1999, The American journal of physiology.

[60]  Ali Khademhosseini,et al.  Interdigitated array of Pt electrodes for electrical stimulation and engineering of aligned muscle tissue. , 2012, Lab on a chip.

[61]  D. Kaplan,et al.  Isolation and Maintenance-Free Culture of Contractile Myotubes from Manduca sexta Embryos , 2012, PloS one.

[62]  Takehiko Kitamori,et al.  Biological cells on microchips: new technologies and applications. , 2007, Biosensors & bioelectronics.

[63]  K. Hosoda,et al.  Muscle Tissue Actuator Driven with Light-gated Ion Channels Channelrhodopsin☆ , 2013 .

[64]  Marko Virta,et al.  Luminescent bacteria-based sensing method for methylmercury specific determination , 2011, Analytical and bioanalytical chemistry.

[65]  Ali Khademhosseini,et al.  Engineered contractile skeletal muscle tissue on a microgrooved methacrylated gelatin substrate. , 2012, Tissue engineering. Part A.

[66]  Thomas Eschenhagen,et al.  Three‐dimensional reconstitution of embryonic cardiomyocytes in a collagen matrix: a new heart muscle model system , 1997, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[67]  Adam W Feinberg,et al.  Engineered skeletal muscle tissue for soft robotics: fabrication strategies, current applications, and future challenges. , 2014, Wiley interdisciplinary reviews. Nanomedicine and nanobiotechnology.

[68]  Sylvain Martel,et al.  Flagellated Magnetotactic Bacteria as Controlled MRI-trackable Propulsion and Steering Systems for Medical Nanorobots Operating in the Human Microvasculature , 2009, Int. J. Robotics Res..

[69]  Nikhil Koratkar,et al.  Viscoelasticity in carbon nanotube composites , 2005, Nature materials.

[70]  Toshiaki Hisada,et al.  Single cell mechanics of rat cardiomyocytes under isometric, unloaded, and physiologically loaded conditions. , 2004, American journal of physiology. Heart and circulatory physiology.

[71]  Jeong-Sik Park,et al.  Feature vector classification based speech emotion recognition for service robots , 2009, IEEE Transactions on Consumer Electronics.

[72]  Yuji Furukawa,et al.  FABRICATION AND EVALUATION OF TEMPERATURE-TOLERANT BIOACTUATOR DRIVEN BY INSECT HEART CELLS , 2008 .

[73]  Debby Gawlitta,et al.  Scaffold porosity and oxygenation of printed hydrogel constructs affect functionality of embedded osteogenic progenitors. , 2011, Tissue engineering. Part A.

[74]  M. J. Kim,et al.  Control of microfabricated structures powered by flagellated bacteria using phototaxis , 2007 .

[75]  Milica Radisic,et al.  Functional assembly of engineered myocardium by electrical stimulation of cardiac myocytes cultured on scaffolds , 2004, Proceedings of the National Academy of Sciences of the United States of America.

[76]  Megan L. McCain,et al.  A tissue-engineered jellyfish with biomimetic propulsion , 2012, Nature Biotechnology.

[77]  Keith Baar,et al.  Rapid formation of functional muscle in vitro using fibrin gels. , 2005, Journal of applied physiology.

[78]  M. Nishizawa,et al.  Spatiotemporally controlled contraction of micropatterned skeletal muscle cells on a hydrogel sheet. , 2011, Lab on a chip.

[79]  N Xi,et al.  Bio-syncretic tweezers actuated by microorganisms: modeling and analysis. , 2016, Soft matter.

[80]  Rashid Bashir,et al.  Patterning the differentiation of C2C12 skeletal myoblasts. , 2011, Integrative biology : quantitative biosciences from nano to macro.

[81]  C. Sicard,et al.  Micro-algal biosensors , 2011, Analytical and bioanalytical chemistry.

[82]  Hiromu Yawo,et al.  Optically controlled contraction of photosensitive skeletal muscle cells , 2012, Biotechnology and bioengineering.

[83]  G. Forte,et al.  IL-12 involvement in myogenic differentiation of C2C12 in vitro. , 2015, Biomaterials science.

[84]  Yuechao Wang,et al.  A bio-syncretic micro-swimmer assisted by magnetism , 2015, 2015 International Conference on Manipulation, Manufacturing and Measurement on the Nanoscale (3M-NANO).

[85]  E. Olson,et al.  Muscle : fundamental biology and mechanisms of disease , 2012 .

[86]  R. Bashir,et al.  Directed cell growth and alignment on protein-patterned 3D hydrogels with stereolithography , 2012 .

[87]  Matsuhiko Nishizawa,et al.  Micropatterning contractile C2C12 myotubes embedded in a fibrin gel , 2010, Biotechnology and bioengineering.

[88]  L. Guttmann,et al.  EFFECT OF ELECTROTHERAPY ON DENERVATED MUSCLES IN RABBITS , 1942 .

[89]  Marcus L. Roper,et al.  Microscopic artificial swimmers , 2005, Nature.

[90]  Milica Radisic,et al.  Influence of substrate stiffness on the phenotype of heart cells , 2010, Biotechnology and bioengineering.

[91]  Taher A. Saif,et al.  Emergent dynamics of cardiomyocyte clusters on deformable polymeric substrates , 2016 .

[92]  Ravi Birla,et al.  Self‐organization of rat cardiac cells into contractile 3‐D cardiac tissue , 2005, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[93]  H. Vandenburgh,et al.  Automated drug screening with contractile muscle tissue engineered from dystrophic myoblasts , 2009, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[94]  Roger D. Quinn,et al.  3D-Printed Biohybrid Robots Powered by Neuromuscular Tissue Circuits from Aplysia californica , 2017, Living Machines.

[95]  T. Hoshino,et al.  Fabrication and Evaluation of Reconstructed Cardiac Tissue and Its Application to Bio-actuated Microdevices , 2009, IEEE Transactions on NanoBioscience.

[96]  Keisuke Morishima,et al.  Long-term and room temperature operable bioactuator powered by insect dorsal vessel tissue. , 2009, Lab on a chip.

[97]  Susumu Sugiyama,et al.  Designing of a Si-MEMS device with an integrated skeletal muscle cell-based bio-actuator , 2011, Biomedical microdevices.

[98]  Megan L. McCain,et al.  Ensembles of engineered cardiac tissues for physiological and pharmacological study: heart on a chip. , 2011, Lab on a chip.

[99]  A. Terzic,et al.  Mechanical unloading versus neurohumoral stimulation on myocardial structure and endocrine function In vivo. , 2000, Circulation.

[100]  Donald E Ingber,et al.  Engineered in vitro disease models. , 2015, Annual review of pathology.

[101]  Xiaoyang Long,et al.  Magnetogenetics: remote non-invasive magnetic activation of neuronal activity with a magnetoreceptor , 2015, Science bulletin.

[102]  Louise Deldicque,et al.  A novel bioreactor for stimulating skeletal muscle in vitro. , 2010, Tissue engineering. Part C, Methods.

[103]  Takayuki Hoshino,et al.  Micro-encapsulation of bio-actuator using insect dorsal vessel , 2009, 2009 International Symposium on Micro-NanoMechatronics and Human Science.

[104]  Wei Wang,et al.  Small power: Autonomous nano- and micromotors propelled by self-generated gradients , 2013 .

[105]  M. Medina‐Sánchez,et al.  Spermatozoa as Functional Components of Robotic Microswimmers , 2017, Advanced materials.

[106]  Corinne Dejous,et al.  Escherichia coli-functionalized magnetic nanobeads as an ultrasensitive biosensor for heavy metals , 2009 .

[107]  W. Zimmermann,et al.  Three-dimensional engineered heart tissue from neonatal rat cardiac myocytes. , 2000, Biotechnology and bioengineering.

[108]  Yuechao Wang,et al.  Modeling and analysis of bio-syncretic micro-swimmers for cardiomyocyte-based actuation , 2016, Bioinspiration & biomimetics.

[109]  Bernd K. Fleischmann,et al.  Optogenetic control of contractile function in skeletal muscle , 2015, Nature Communications.

[110]  J. Kristjánsson,et al.  Ecology and habitats of extremophiles , 1995, World journal of microbiology & biotechnology.

[111]  弓削 類.  Differentiation of myoblasts is accelerated in culture in a magnetic field , 2000 .

[112]  G. Whitesides,et al.  Microoxen: microorganisms to move microscale loads. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[113]  P. Zorlutuna,et al.  Development and characterization of muscle-based actuators for self-stabilizing swimming biorobots. , 2016, Lab on a chip.

[114]  Howard C. Berg,et al.  Visualization of Flagella during Bacterial Swarming , 2010, Journal of bacteriology.

[115]  J. Xi,et al.  Self-assembled microdevices driven by muscle , 2005, Nature materials.

[116]  S. Ko,et al.  Motility analysis of bacteria‐based microrobot (bacteriobot) using chemical gradient microchamber , 2014, Biotechnology and bioengineering.

[117]  S. Shroff,et al.  Engineered early embryonic cardiac tissue retains proliferative and contractile properties of developing embryonic myocardium. , 2006, American journal of physiology. Heart and circulatory physiology.

[118]  E. Nagamori,et al.  Enhanced contractile force generation by artificial skeletal muscle tissues using IGF-I gene-engineered myoblast cells. , 2011, Journal of bioscience and bioengineering.

[119]  Y. Akiyama,et al.  Rapidly-moving insect muscle-powered microrobot and its chemical acceleration , 2012, Biomedical microdevices.

[120]  Ritu Raman,et al.  Three-dimensionally printed biological machines powered by skeletal muscle , 2014, Proceedings of the National Academy of Sciences.

[121]  M. Taher A. Saif,et al.  Fabrication of Freestanding 1-D PDMS Microstructures Using Capillary Micromolding , 2013, Journal of Microelectromechanical Systems.

[122]  Xiaohong Wang,et al.  Cardiomyocytes driven piezoelectric nanofiber generator with anisotropic enhancement , 2016, 2016 IEEE 29th International Conference on Micro Electro Mechanical Systems (MEMS).

[123]  Seong Young Ko,et al.  Development of bacteria-based microrobot using biocompatible poly(ethylene glycol) , 2012, Biomedical microdevices.

[124]  Keisuke Morishima,et al.  Electrical stimulation of cultured lepidopteran dorsal vessel tissue: an experiment for development of bioactuators , 2010, In Vitro Cellular & Developmental Biology - Animal.

[125]  Keisuke Morishima,et al.  Multi-scale reconstruction and performance of insect muscle powered bioactuator from tissue to cell sheet , 2010, 2010 3rd IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics.

[126]  Toshio Fukuda,et al.  Rotation of bacteria sheet driven micro gear in open micro channel , 2012, 2012 IEEE International Conference on Robotics and Automation.

[127]  Byung Kyu Kim,et al.  Fabrication of patterned micromuscles with high activity for powering biohybrid microdevices , 2006 .

[128]  Ritu Raman,et al.  Damage, Healing, and Remodeling in Optogenetic Skeletal Muscle Bioactuators , 2017, Advanced healthcare materials.

[129]  Wonhye Lee,et al.  Bio-printing of collagen and VEGF-releasing fibrin gel scaffolds for neural stem cell culture , 2010, Experimental Neurology.

[130]  M. Sitti,et al.  Biohybrid Microtube Swimmers Driven by Single Captured Bacteria. , 2017, Small.

[131]  Takayuki Hoshino,et al.  Voluntary movement controlled by the surface EMG signal for tissue-engineered skeletal muscle on a gripping tool. , 2013, Tissue engineering. Part A.

[132]  Xiaobo Tan,et al.  Modeling of biomimetic robotic fish propelled by an ionic polymer-metal composite actuator , 2008, 2008 IEEE International Conference on Robotics and Automation.

[133]  Metin Sitti,et al.  Magnetic steering control of multi-cellular bio-hybrid microswimmers. , 2014, Lab on a chip.

[134]  Thomas Eschenhagen,et al.  Engineered heart tissue for regeneration of diseased hearts. , 2004, Biomaterials.

[135]  L. Greensmith,et al.  Neuromuscular Junction Formation in Tissue-Engineered Skeletal Muscle Augments Contractile Function and Improves Cytoskeletal Organization , 2015, Tissue engineering. Part A.

[136]  A. Khademhosseini,et al.  Carbon-nanotube-embedded hydrogel sheets for engineering cardiac constructs and bioactuators. , 2013, ACS nano.

[137]  T. Takenaka,et al.  The development of Honda humanoid robot , 1998, Proceedings. 1998 IEEE International Conference on Robotics and Automation (Cat. No.98CH36146).

[138]  S Sugiura,et al.  A novel method to study contraction characteristics of a single cardiac myocyte using carbon fibers. , 2001, American journal of physiology. Heart and circulatory physiology.

[139]  Yeonkyung Lee,et al.  New paradigm for tumor theranostic methodology using bacteria-based microrobot , 2013, Scientific Reports.

[140]  Peptidergic control of the heart of the stick insect, Baculum extradentatum , 2008, Peptides.

[141]  Joe Rigelsford.  Industrial Robotics Technology, Programming and Application , 1999 .

[142]  Mitsuru Akashi,et al.  Fabrication of three-dimensional cell constructs using temperature-responsive hydrogel. , 2010, Tissue engineering. Part A.

[143]  D. Wilkie,et al.  Muscle Physiology , 1959, Nature.

[144]  Keith Baar,et al.  Defined electrical stimulation emphasizing excitability for the development and testing of engineered skeletal muscle. , 2012, Tissue engineering. Part C, Methods.

[145]  Ron Weiss,et al.  Formation and optogenetic control of engineered 3D skeletal muscle bioactuators. , 2012, Lab on a chip.

[146]  Zhenhai Zhang,et al.  Development of a Biomedical Micro/Nano Robot for Drug Delivery. , 2015, Journal of nanoscience and nanotechnology.

[147]  S. Salmons,et al.  Significance of impulse activity in the transformation of skeletal muscle type , 1976, Nature.

[148]  H. Asada,et al.  Utilization and control of bioactuators across multiple length scales. , 2014, Lab on a chip.

[149]  Roger D. Quinn,et al.  Aplysia Californica as a Novel Source of Material for Biohybrid Robots and Organic Machines , 2016, Living Machines.

[150]  Chang Liu,et al.  Re-configurable fluid circuits by PDMS elastomer micromachining , 1999, Technical Digest. IEEE International MEMS 99 Conference. Twelfth IEEE International Conference on Micro Electro Mechanical Systems (Cat. No.99CH36291).

[151]  Y. Akiyama,et al.  Room Temperature Operable Autonomously Moving Bio-Microrobot Powered by Insect Dorsal Vessel Tissue , 2012, PloS one.

[152]  Y. C. Shin,et al.  Stimulated myogenic differentiation of C2C12 murine myoblasts by using graphene oxide , 2015 .

[153]  Uwe Marx,et al.  Biological cardio-micro-pumps for microbioreactors and analytical micro-systems , 2011 .

[154]  John P Wikswo,et al.  Measurement Techniques for Cellular Biomechanics In Vitro , 2008, Experimental biology and medicine.

[155]  Milica Radisic,et al.  Electrical stimulation systems for cardiac tissue engineering , 2009, Nature Protocols.

[156]  Jian-Fu Chen,et al.  Muscling Through the microRNA World , 2008, Experimental biology and medicine.

[157]  George J. Pappas,et al.  Electrokinetic and optical control of bacterial microrobots , 2011 .

[158]  S. Martel,et al.  Controlled manipulation and actuation of micro-objects with magnetotactic bacteria , 2006 .