Photo-fermentative bacteria aggregation triggered by L-cysteine during hydrogen production

Biotechnology for Biofuels

Guo-Jun Xie¹  Bing-Feng Liu¹  De-Feng Xing¹  Jun Nan¹  Jie Ding¹  Nan-Qi Ren¹ 

[1] State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 73 Huanghe Road, P.O. Box 2614, Harbin, 150090, China

关键词: DLVO;    Disulfide bonds;    Extracellular polymeric substances;    L-Cysteine;    Photo-hydrogen production;    Bioflocculation;   

Others  :  798071
DOI  :  10.1186/1754-6834-6-64

 received in 2012-11-26, accepted in 2013-04-29,  发布年份 2013

【 摘 要 】

Background

Hydrogen recovered from organic wastes and solar energy by photo-fermentative bacteria (PFB) has been suggested as a promising bioenergy strategy. However, the use of PFB for hydrogen production generally suffers from a serious biomass washout from photobioreactor, due to poor flocculation of PFB. In the continuous operation, PFB cells cannot be efficiently separated from supernatant and rush out with effluent from reactor continuously, which increased the effluent turbidity, meanwhile led to increases in pollutants. Moreover, to replenish the biomass washout, substrate was continuously utilized for cell growth rather than hydrogen production. Consequently, the poor flocculability not only deteriorated the effluent quality, but also decreased the potential yield of hydrogen from substrate. Therefore, enhancing the flocculability of PFB is urgent necessary to further develop photo-fermentative process.

Results

Here, we demonstrated that L-cysteine could improve hydrogen production of Rhodopseudomonas faecalis RLD-53, and more importantly, simultaneously trigger remarkable aggregation of PFB. Experiments showed that L-cysteine greatly promoted the production of extracellular polymeric substances, especially secretion of protein containing more disulfide bonds, and help for enhancement stability of floc of PFB. Through formation of disulfide bonds, L-cysteine not only promoted production of EPS, in particular the secretion of protein, but also stabilized the final confirmation of protein in EPS. In addition, the cell surface elements and functional groups, especially surface charged groups, have also been changed by L-cysteine. Consequently, absolute zeta potential reached a minimum value at 1.0 g/l of L-cysteine, which obviously decreased electrostatic repulsion interaction energy based on DLVO theory. Total interaction energy barrier decreased from 389.77 KT at 0.0 g/l of L-cysteine to 127.21 kT at 1.0 g/l.

Conclusions

Thus, the strain RLD-53 overcame the total energy barrier and flocculated effectively. After a short settlement, the biomass rush out will be significantly reduced and the effluent quality will be greatly improved in the continuous operation. Furthermore, aggregation of PFB could enable high biomass hold-up of photobioreactor, which allows the photobioreactor to operate at low hydraulic retention time and high organic loading rate. Therefore, the described flocculation behaviour during photo-hydrogen production is potentially suitable for practicable application.

【 授权许可】

   
2013 Xie et al.; licensee BioMed Central Ltd.

【 图 表 】

Figure 1.

Figure 2.

Figure 3.

Figure 4.

Figure 5.

Figure 6.

Figure 7.

Figure 8.

Figure 9.

Figure 10.

Figure 11.

【 参考文献 】

• [1]Masset J, Calusinska M, Hamilton C, Hiligsmann S, Joris B, Wilmotte A, Thonart P: Fermentative hydrogen production from glucose and starch using pure strains and artificial co-cultures of Clostridium spp. Biotechnology for Biofuels 2012, 5:35. BioMed Central Full Text
• [2]Abreu AA, Karakashev D, Angelidaki I, Sousa DZ, Madalena Alves M: Biohydrogen production from arabinose and glucose using extreme thermophilic anaerobic mixed cultures. Biotechnology for Biofuels 2012, 5:36. BioMed Central Full Text
• [3]McKinlay JB, Harwood CS: Photobiological production of hydrogen gas as a biofuel. Curr Opin Biotechnol 2010, 21:244-251.
• [4]Gilbert JJ, Ray S, Das D: Hydrogen production using Rhodobacter sphaeroides (OU 001) in a flat panel rocking photobioreactor. Int J Hydrogen Energy 2011, 36:3434-3441.
• [5]Boran E, Özgür E, Yücel M, Gündüz U, Eroglu I: Biohydrogen production by Rhodobacter capsulatus Hup− mutant in pilot solar tubular photobioreactor. Int J Hydrogen Energy 2012, 37:16437-16445.
• [6]Adessi A, Torzillo G, Baccetti E, De Philippis R: Sustained outdoor H2 production with Rhodopseudomonas palustris cultures in a 50 L tubular photobioreactor. Int J Hydrogen Energy 2012, 37:8840-8849.
• [7]Xie GJ, Liu BF, Guo WQ, Ding J, Xing DF, Nan J, Ren HY, Ren NQ: Feasibility studies on continuous hydrogen production using photo-fermentative sequencing batch reactor. Int J Hydrogen Energy 2012, 37:13689-13695.
• [8]Tsygankov AA, Fedorov AS, Laurinavichene TV, Gogotov IN, Rao KK, Hall DO: Actual and potential rates of hydrogen photoproduction by continuous culture of the purple non-sulphur bacterium Rhodobacter capsulatus. Appl Microbiol Biotechnol 1998, 49:102-107.
• [9]Boran E, Ozgur E, van der Burg J, Yucel M, Gunduz U, Eroglu I: Biological hydrogen production by Rhodobacter capsulatus in solar tubular photo bioreactor. Journal of Cleaner Production 2010, 18:S29-S35.
• [10]Watanabe M, Sasaki K, Nakashimada Y, Kakizono T, Noparatnaraporn N, Nishio N: Growth and flocculation of a marine photosynthetic bacterium Rhodovulum sp. Appl Microbiol Biotechnol 1998, 50:682-691.
• [11]Watanabe M, Sasaki K, Nakashimada Y, Nishio N: High density cell culture of a marine photosynthetic bacterium Rhodovulum sp. with self-flocculated cells. Biotechnol Lett 1998, 20:1113-1117.
• [12]Liu XM, Sheng GP, Yu HQ: DLVO approach to the flocculability of a photosynthetic H2-producing bacterium, Rhodopseudomonas acidophila. Environ Sci Technol 2007, 41:4620-4625.
• [13]Sheng GP, Yu HQ, Li XY: Extracellular polymeric substances (EPS) of microbial aggregates in biological wastewater treatment systems: A review. Biotechnol Adv 2010, 28:882-894.
• [14]Liao BQ, Allen DG, Droppo IG, Leppard GG, Liss SN: Surface properties of sludge and their role in bioflocculation and settleability. Water Res 2001, 35:339-350.
• [15]Sobeck DC, Higgins MJ: Examination of three theories for mechanisms of cation-induced bioflocculation. Water Res 2002, 36:527-538.
• [16]Bardwell JCA, McGovern K, Beckwith J: Identification of a protein required for disulfide bond formation in vivo. Cell 1991, 67:581-589.
• [17]Doig AJ, Williams DH: Is the hydrophobic effect stabilizing or destabilizing in proteins?: The contribution of disulphide bonds to protein stability. J Mol Biol 1991, 217:389-398.
• [18]Zhang L, Feng X, Zhu N, Chen J: Role of extracellular protein in the formation and stability of aerobic granules. Enzyme Microb Technol 2007, 41:551-557.
• [19]Higgins MJ, Novak JT: Characterization of exocellular protein and its role in bioflocculation. J Environ Eng-Asce 1997, 123:479-485.
• [20]Rubio LM, Ludden PW: Maturation of nitrogenase: a biochemical puzzle. J Bacteriol 2005, 187:405-414.
• [21]Hausinger R, Howard J: Thiol reactivity of the nitrogenase Fe-protein from Azotobacter vinelandii. J Biol Chem 1983, 258:13486-13492.
• [22]Schrauzer GN, Schlesinger G: Chemical evolution of a nitrogenase model. I. Reduction of acetylene and other substrates by a molybdenum-thiol catalyst system. J Am Chem Soc 1970, 92:1808-1809.
• [23]Adiga P, Sivarama Sastry K, Sarma P: Amino acid interrelationships in cysteine toxicity in Neurospora crassa. J Gen Microbiol 1962, 29:149-155.
• [24]Liu Y, Fang HHP: Influences of extracellular polymeric substances (EPS) on flocculation, settling, and dewatering of activated sludge. Crit Rev Environ Sci Technol 2003, 33:237-273.
• [25]Cheng WP, Chi FH: A study of coagulation mechanisms of polyferric sulfate reacting with humic acid using a fluorescence-quenching method. Water Res 2002, 36:4583-4591.
• [26]Kowalski JM, Parekh RN, Wittrup KD: Secretion efficiency in Saccharomyces cerevisiae of bovine pancreatic trypsin inhibitor mutants lacking disulfide bonds is correlated with thermodynamic stability. Biochemistry 1998, 37:1264-1273.
• [27]Inan M, Aryasomayajula D, Sinha J, Meagher MM: Enhancement of protein secretion in Pichia pastoris by overexpression of protein disulfide isomerase. Biotechnol Bioeng 2006, 93:771-778.
• [28]Darby N, Creighton TE: Disulfide bonds in protein folding and stability. Methods Mol Biol 1995, 40:219-252.
• [29]Goldberg ME, Guillou Y: Native disulfide bonds greatly accelerate secondary structure formation in the folding of lysozyme. Protein Sci 1994, 3:883-887.
• [30]Byler DM, Susi H: Examination of the secondary structure of proteins by deconvolved FTIR spectra. Biopolymers 1986, 25:469-487.
• [31]Moulin AM, O’Shea SJ, Badley RA, Doyle P, Welland ME: Measuring Surface-Induced Conformational Changes in Proteins. Langmuir 1999, 15:8776-8779.
• [32]Roach P, Farrar D, Perry CC: Interpretation of protein adsorption: surface-induced conformational changes. J Am Chem Soc 2005, 127:8168-8173.
• [33]Lundqvist M, Sethson I, Jonsson BH: Protein adsorption onto silica nanoparticles: Conformational changes depend on the particles’ curvature and the protein stability. Langmuir 2004, 20:10639-10647.
• [34]Hermansson M: The DLVO theory in microbial adhesion. Colloids Surf B Biointerfaces 1999, 14:105-119.
• [35]Mill PJ: The Nature of the Interactions between Flocculent Cells in the Flocculation of Saccharomyces cerevisiae. J Gen Microbiol 1964, 35:61-68.
• [36]Nishihara H, Toraya T, Fukui S: Effect of chemical modification of cell surface components of a brewer’s yeast on the floc-forming ability. Arch Microbiol 1977, 115:19-23.
• [37]Cieśla J, Bieganowski A, Janczarek M, Urbanik Sypniewska T: Determination of the electrokinetic potential of Rhizobium leguminosarum bv trifolii Rt24.2 using Laser Doppler Velocimetry — A methodological study. J Microbiol Methods 2011, 85:199-205.
• [38]Wilson WW, Wade MM, Holman SC, Champlin FR: Status of methods for assessing bacterial cell surface charge properties based on zeta potential measurements. J Microbiol Methods 2001, 43:153-164.
• [39]Jucker BA, Zehnder AJB, Harms H: Quantification of polymer interactions in bacterial adhesion. Environ Sci Technol 1998, 32:2909-2915.
• [40]Liu XM, Sheng GP, Luo HW, Zhang F, Yuan SJ, Xu J, Zeng RJ, Wu JG, Yu HQ: Contribution of extracellular polymeric substances (EPS) to the sludge aggregation. Environ Sci Technol 2010, 44:4355-4360.
• [41]Chrysikopoulos CV, Syngouna VI: Attachment of bacteriophages MS2 and ΦX174 onto kaolinite and montmorillonite: Extended-DLVO interactions. Colloids Surf B Biointerfaces 2012, 92:74-83.
• [42]Ren NQ, Liu BF, Ding J, Xie GJ: Hydrogen production with R. faecalis RLD-53 isolated from freshwater pond sludge. Bioresour Technol 2009, 100:484-487.
• [43]Xie GJ, Liu BF, Ding J, Xing DF, Ren HY, Guo WQ, Ren NQ: Enhanced photo-H2 production by Rhodopseudomonas faecalis RLD-53 immobilization on activated carbon fibers. Biomass Bioenergy 2012, 44:122-129.
• [44]Xie GJ, Liu B-F, Ding J, Ren H-Y, Xing DF, Ren NQ: Hydrogen production by photo-fermentative bacteria immobilized on fluidized bio-carrier. Int J Hydrogen Energy 2011, 36:13991-13996.
• [45]Xie GJ, Liu BF, Xing DF, Nan J, Ding J, Ren HY, Guo WQ, Ren NQ: Photo-hydrogen production by Rhodopseudomonas faecalis RLD-53 immobilized on the surface of modified activated carbon fibers. Rsc Advances 2012, 2:2225-2228.
• [46]Liao BQ, Lin HJ, Langevin SP, Gao WJ, Leppard GG: Effects of temperature and dissolved oxygen on sludge properties and their role in bioflocculation and settling. Water Res 2011, 45:509-520.
• [47]Chan KY, Xu LC, Fang HHP: Anaerobic Electrochemical Corrosion of Mild Steel in the Presence of Extracellular Polymeric Substances Produced by a Culture Enriched in Sulfate-Reducing Bacteria. Environ Sci Technol 2002, 36:1720-1727.
• [48]Bayoudh S, Othmane A, Mora L, Ben Ouada H: Assessing bacterial adhesion using DLVO and XDLVO theories and the jet impingement technique. Colloids Surf B Biointerfaces 2009, 73:1-9.
• [49]Omoike A, Chorover J: Spectroscopic Study of Extracellular Polymeric Substances from Bacillus subtilis: Aqueous Chemistry and Adsorption Effects. Biomacromolecules 2004, 5:1219-1230.
• [50]Kataoka Y, Kondo T: FT-IR Microscopic Analysis of Changing Cellulose Crystalline Structure during Wood Cell Wall Formation. Macromolecules 1998, 31:760-764.
• [51]Xie GJ, Liu BF, Xing DF, Ding J, Nan J, Ren HY, Guo WQ, Ren NQ: The kinetic characterization of photofermentative bacterium Rhodopseudomonas faecalis RLD-53 and its application for enhancing continuous hydrogen production. Int J Hydrogen Energy 2012, 37:13718-13724.
• [52]Garidel P: Mid-FTIR-Microspectroscopy of stratum corneum single cells and stratum corneum tissue. PCCP 2002, 4:5671-5677.
• [53]Frølund B, Griebe T, Nielsen PH: Enzymatic-Activity in the Activated-Sludge Floc Matrix. Appl Microbiol Biotechnol 1995, 43:755-761.
• [54]Beech I, Hanjagsit L, Kalaji M, Neal AL, Zinkevich V: Chemical and structural characterization of exopolymers produced by Pseudomonas sp NCIMB 2021 in continuous culture. Microbiology 1999, 145:1491-1497.
• [55]Kalapathy U, Hettiarachchy N, Rhee K: Effect of drying methods on molecular properties and functionalities of disulfide bond-cleaved soy proteins. J Am Oil Chem Soc 1997, 74:195-199.