Biofilm Research Group

Principal Investigator
Prof. Luyan Ma

Tel: 86-10-64807437
Fax: 86-10-64806101

Research Area

Molecular mechanisms for biofilm formation and persistence.

Research Interests
The surface-associated communities of microorganisms, biofilms, are prevalent in environmental and clinical settings. Biofilm bacteria are encased in an extracellular matrix and possess unique characteristics that are not seen in conventional test tube-grown bacteria. Therefore there is a growing appreciation for the need to study biofilm bacteria. Our primary research interests are to explore and define molecular mechanisms for biofilm persistence and eventually to design therapies for control of biofilm-related complications in medical, industrial, and environmental settings. The current research focuses are: 1. how does a biofilm matrix form? 2. the role of extracellular proteins in biofilm formation and persistence; 3. programmed cell death and autolysis in biofilms; 4. the biofilms of nitrogen-fixing bacteria and its applications.

Our current ongoing projects include:
By using Pseudomonas aeruginosa as a model organism for biofilm research, we have got the following discoveries about the Psl polysaccharide (encoded by psl, polysaccharide synthesis locus) during the past five years:

  1. The roles and contributions of Psl polysaccharide and alginate in P. aeruginosa biofilms;
  2. How a Psl matrix assembles and develops during a biofilm developmental cycle;
  3. How P. aeruginosa controls the synthesis of multiple exopolysaccharides;
  4. How P. aeruginosa builds a fiber-like Psl polysaccharide matrix to enmesh bacteria together in biofilms by type IV pili-mediated bacterial migration with a strategy similar to the spider web formation.

Lab Members

Principal Investigator

Luyan Ma Ph.D.

Professor of Molecular Microbiology,
Institute of Microbiology, Chinese Academy of Sciences,
No.1 West Beichen Road, Chaoyang District,
Beijing 100101, P. R. China
Tel: 86-10-64807437
Fax: 86-10-64806101


Education and Positions
1987-1991:  B.Sc. in Biology, Beijing Agricultural University, China
1991-1996:  Ph.D. in Microbiology, China Agricultural University, Beijing, China

Professional Experience

1996-2000: Assistant and Associate Professor,Dept. of Microbiology, China Agricultural University
1998-1999: Postdoctoral Fellow, Institut Pasteur, Paris, France
2000-2004: Visiting Scholar, University of Connecticut Health Center, Farmington, CT, USA
2005-2008: Research Associate, Wake Forest University Medical School, Winston-Salem, NC 
2008-2009: Research Assistant Professor, the Ohio State University Medical School, Columbus, OH
2010-current: Professor, Institute of Microbiology, Chinese Academy of Science

Editorial Board

Frontiers in Microbial Physiology and Metabolism (2012-present, Editor)

Permanent staff

Shiwei Wang
Assistant Professor
Research interests:
Biofilm matrix formation in Pseudomonas aeruginosa

Di Wang
Assistant Professor
Research interests:
Biofilm formation of Nitrogen fixing bacteria

Qing Wei
Assistant Professor
Research interests:
Gene regulation in biofilm formation

Graduate Students

Shan Yu    (2012 Ph. D student)
Bin Zhu     (2012 Ph. D student)
Tianhu Zhao(2013 Ph.D student)
HuiJun Wu  (2013 M. Sc student)
Anming Xu (2014 M. Sc student)
Pramod C. BHASME (2014 CAS-TWAS Ph. D student)

Former Graduate Students

Zhenyin Zhang(2012, M.Sc)
Jizhou Yang (2012. M.Sc. )

Representative pictures

Figure 1. How the P. aeruginosa Psl biofilm matrix forms and develops. A schematic showing five stages of biofilm development.  Red: Psl.  Green: GFP-labeled P. aeruginosa cells. (Ma et. al. 2009  PLoS Path)

Figure. 2. Spider-web-like Psl-fibre matrixes in the biofilms of P. aeruginosa PAO1-derived strains.
Green, Psl matrix. Red, bacteria membrane. Scale bar: 2 mm. (Wang et. al., 2013 Environ Microbiol)

Figure. 3. A model for how a radial patternPsl-fibre matrix may form. Starvation within a multiple-cell aggregate triggers Psl
polysaccharide release from the bacteria surface and T4P-mediated bacterial migration, resulting in a radial web-like Psl-fibre matrix. Psl and Psl-fibres may function as a structure/surface for T4P to recruit bacteria to join a matrix or biofilm. Green, bacteria; red, Psl; blue, T4P. (Wang et. al., 2013 Environ Microbiol)



  1. Das, P., Yang, X.-P., and Ma, L. Z. * (2014) Analysis of biosurfactants from industrially-viable Pseudomonas strain isolated from crude oil suggests how rhamnolipids congeners affect on emulsification property and antimicrobial activity. Front. Microbiol. doi: 10.3389/fmicb.2014.00696.
  2. Wang, S., Yu, S., Zhang, Z., Wei, Q., Yan, L., Ai, G., Liu, H. Ma, L.Z.* (2014) Coordination of swarming motility, biosurfactant synthesis, and biofilm matrix exopolysaccharides production in Pseudomonas aeruginosa. Appl. Environ. Microbiol. 80: 6724-6732.
  3. Wang, S., Parsek, M.R., Wozniak, D.J. and Ma, L-Y.* (2013) A spider web strategy of type IV pili-mediated migration to build a fibre-like Psl polysaccharide matrix in Pseudomonas aeruginosa biofilms. Environ. Microbiol. 15(8): 2238-2253
  4. Wei Q., Ma, L. Z. * (2013) Biofilm matrix and its regulation in Pseudomonas aeruginosa. Int J Mol Sci. 14, 20983-21005
  5. Ma, L-Y.*,Wang, J., Wang, S., Anderson E.M., Lam J.S., Parsek, M.R. and Wozniak, D.J. (2012) Synthesis of multiple Pseudomonas aeruginosa biofilm matrix exopolysaccharides is post-transcriptionally regulated.Environ. Microbiol.14 (8):1995-2005. 
  6. Ma, L-Y.*, Wang, S., Wang, D., Parsek, M.R., and Wozniak, D.J. (2012) The roles of biofilm matrix polysaccharide Psl in mucoid Pseudomonas aeruginosabiofilms. FEMS Immunol. & Med. Microbiol. 65:377-380. 
  7. Ma L.,Liu X-Y., Liang H-H., Che Y-Z., Chen C-X., Dai H-Q., Yu K, Liu M., Ma, L-Y., Yang C-H., Song F-H., Wang Y-Q., and Zhang L-X.(2012)Effects of 14-Alpha-Lipoyl Andrographolide on Quorum Sensing in Pseudomonas aeruginosa. Antimicrob.Agents and Chemother. 56:6088-6094. 
  8.  Ma, L-Y., Wang, S., Yang, J-Z., Zhang, Z-Y.(2012)Mechanism of biofilm formation. < Microbial Biofilm and Infection> People's Health Publisher. p1-34. 
  9.  Ma, L-Y.,Conover, M., Lu, H., Parsek, M. R.,Bayles, K. and Wozniak, D.J. (2009) Assembly and development of the Pseudomonas aeruginosa biofilm matrix.Plos Pathog. 5: e1000354. 
  10. Byrd, M.S., Sadovskaya, I., Vinogradov, E., Lu, H., Sprinkle, A., Richardson, S.,Ma, L-Y.,Ralston, B., Parsek, M.R., Lam, J. and Wozniak, D.J. (2009) Genetic and Biochemical Analyses of the Pseudomonas aeruginosa Psl Exopolysaccharide Reveals Overlapping Roles for Polysaccharide Synthesis Enzymes in Psl and LPS Production. Mol. Microbiol.73(4) 622-638. 
  11. Starkey, M., Hickman, J.H.,Ma, L-Y., Zhang, N., Long, S.D., Hinz, A., Palacios, S., Maoil, C., Kirisits, M., Starner, T., Wozniak, D.J., Hardwood, C.S. and Parsek, M.R. (2009) Pseudomonas aeruginosa rugose small colony variants have adtaptions that likely promote persistence in the cystic fibrosis lung. J. Bacteriol. 191:3492-3503.
  12. Huigens, R. W., Ma, L-Y.,Gambino, C. D., Moeller, P.D., Basso, A., Cavanagh, J. D., Wozniak, J., and Melander, C. (2008) Control of bacterial Biofilms with marine alkaloid derivatives. Mol Biosyst. 4(6):614-621.IF=3.534 
  13.  Ma, L-Y.,Parsek, M. R.and Wozniak, D.J. (2007) Pseudomonas aeruginosa Psl is a galactose- and mannose-rich exopolysaccharide.J. Bacteriol. 189:8353-8356. 
  14. Ma, L-Y.,Jackson,K.,Parsek, M. R.and Wozniak, D.J. (2006) Analysis ofPseudomonas aeruginosa conditional Psl variants reveals roles for the Psl as an adhesin and in maintaining biofilm structure post-attachment. J. Bacteriol.188:8213-8221. 
  15. Taghbalout,A.,Ma, L-Y.andRothfield, L. (2006)Role of MinD-membrane association in Min protein interaction.J. Bacteriol. 188:2993-3001. 
  16. Cui, Y., Tu, R., Guan, Y.,Ma, L-Y.and Chen, S.(2006) Cloning, sequencing, and characrization of the Azospirillum brasilense fluE Gene.Curr. Microbiol.52(3):169-177. 
  17. Ma, L-Y.,King, G. And Rothfield, L. (2004) Positioning of MinE and MinC binding sites on the MinD surface provides a plausible mechanism for activation of the E. coli MinD ATPase during division site selection.Mol. Microbiol.54(1):99-108. 
  18. Schimanski, B.,Ma, L-Y.andGunzl, A.(2004) Failure to detect binding ofTrypanosoma brucei SNAPc to U2 and U6 snRNA genes byin vitrotranscription competition and pull-down assays. Mol & Biochem. Parasitol.137:293-296.
  19. Ma, L-Y.,King, G. and Rothfield, L. (2003) Mapping the MinE Site involved in interaction with the MinD division site selection protein of Escherichia coliJ. Bacteriol.185:4948-4955. 
  20. Desnoues, N., Li, M., Guo, X.,Ma, L-Y., Carreno-Lopez, R. and Elmerich, C.(2003) Nitrogen fixation genetics and regulation in Pseudomonas stutzeri strain associated with rice.Microbiol.149:2251-2262. 
  21. Wang, J , Chen, S-F., Ma, L-Y., , Li, J-L.(2001)  Cloning , sequencing and expression pattern, functional analysis of nifA in Azospirillum brasilense Yu62.Acta Microbiologia Sinica. 41:655-661(in Chinese ). 
  22. Ma, L-Y., Wu, Y. Wang, J., Zhao, Y-S., Li, J-L.(1999)  Site-directed mutagenesis analysis of draTG genes and their downstream region from Azospirillum brasilense Yu62. Chinese J. of Biotechnology 15:281-287 (in Chinese ). 
  23. Ma, L-Y. and Li, J-L.(1998)  Advance in genetics researches of nitrogen fixation(a review). In Engineering of Agriculural Biology. Man, K-Q., Chen, S-Y., Li, J-L., Zhu, Y-D.(eds.). Chemical Industry Publisher. p15-48. (in Chinese ) 
  24.  Ma, L-Y. and Li, J-L.(1997)  Advance in genetics of Azospirillum and plant-root interactions (a review).  High Technology letters 11:56-59. (in Chinese )
  25. Ma, L-Y. and Li, J-L.(1997)  Sequencing and analysis of function of the upstream region of draTG genes from Azospirillum brasilense Yu62.  Chinese J. of Biotechnology 13(4):343-349 (in Chinese and English).
  26. Ma, L-Y. and Li, J-L.(1997)  Cloning and sequencing of draTG genes and downstream region from Azospirillum brasilense Yu62. Chinese J. of Biotechnology 13(3):227-235 (in Chinese and English). 
  27. Yan, D-L., He, L-H., Ma, L-Y., Li, J-L.(1995)  Effect of Klebsiella pneumoniae nifA on the regulation of nif gene expression by ammonia in Azospirillum brasilenseChinese J. of Biotechnology 11(4):385-388. (in Chinese ) 
  28. Yan, D-L., He, L-H., Ma, L-Y., Li, J-L.(1995)  Transcriptional activation ofAzospirillum brasilense nifH promoter by NifA of Klebsiella pneumoniaeChinese J. of Biotechnology 11(3):205-210. (in Chinese) 
  29. Ma, L-Y., Yan, D-L., He, L-H., Li, J-L.(1994)  Insertion mutagensis used in nitrogen-fixing bacteria (a review). Microbiology 21:101-105 . (in Chinese )
  30.  Nan, Q-X., Ren, F-ZH., Yang, Z-B., Zhang, X-J., Ma, L-Y.(1992)  Studies on the forming process of milk fan in Yun nan province. Chinese J. of Animal Science 28(2):25-27.