Influence of SRT on enriching halophilic MMC with capacity of PHA storage

doi:10.11949/j.issn.0438-1157.20151644

Abstract

Abstract:

Enriching mixed microbial culture (MMC) with capacity of PHA storage via controlling the enrichment process parameters is the first and the most important step for the fermentation production of PHA. This paper elucidated the role of sludge retention time (SRT) in the enrichment process under batch culture conditions. The results showed that SRT influenced the specific substrate degradation rate (q_S), specific PHA accumulation rate (q_P) and the PHA storage capacity of enriched MMC. The long SRT (SRT 4 d) led to the decreased q_S, q_P and PHA accumulation ability. The short SRT reduced the PHA conversion rate (Y_PHA/S) and PHA accumulation ability of MMC. The optimal SRT was determined as 2 d for enriched MMC in this study, which presented 56% cell dry weight PHA content. The study proved that the SRT played the important role in enriching halophilic MMC, which laid the foundation on enriching PHA-storage MMC rapidly.

Key words: SRT, PHA storage bacteria, polymers, fermentation, biological engineering

摘要：

调控菌群富集过程的工艺参数,富集具有高PHA积累能力的混合菌(MMC)是发酵生产PHA的第一步也是最重要的一步。采用批式培养条件,集中研究了污泥停留时间(SRT)对PHA积累菌群的富集作用。研究结果表明SRT影响富集MMC的底物降解速率(q_S),微生物积累PHA的速率(q_P)和PHA积累能力。长SRT(SRT4d)导致了较低的q_S,q_P和PHA细胞含量;过短的SRT(SRT1d)则降低了MMC的PHA转化率(Y_PHA/S)和PHA积累能力,刺激了非PHA积累菌群的快速增殖。研究确定的最佳SRT为2d,在此条件下富集的MMC最大PHA积累量可达细胞干重的56%。研究证明了SRT在选择嗜盐MMC中的重要作用,为快速富集PHA积累能力MMC奠定基础。

关键词: SRT, PHA积累菌, 聚合物, 发酵, 生物工程

CLC Number:

X703

CUI Youwei, LIN Xiaoyuan, JI Siyuan, SHI Yunpeng. Influence of SRT on enriching halophilic MMC with capacity of PHA storage[J]. CIESC Journal, 2016, 67(6): 2575-2582.

崔有为, 林小媛, 冀思远, 施云鹏. SRT对富集高聚PHA能力嗜盐MMC的影响[J]. 化工学报, 2016, 67(6): 2575-2582.

References 20

[1]	崔有为, 彭永臻, 李晶, 等. 盐度抑制下的MUCT处理效能及其微生物种群变化 [J]. 环境科学, 2009, (2): 488-492. CUI Y W, PENG Y Z, LI J, et al. Salt effects on treatment performance and microbial community structure in MUCT [J]. Environmental Sciences, 2009, (2): 488-492.
[2]	LITCHFIELD C D. Potential for industrial products from the halophilic Archaea[J]. Journal of Industrial Microbiology & Biotechnology, 2011, 38 (10): 1635-1647.
[3]	GAO X, CHEN J, WU Q, et al. Polyhydroxyalkanoates as a source of chemicals, polymers, and biofuels [J]. Current Opinion in Biotechnology, 2011, 22 (6): 768-774.
[4]	QUILLAGUAMAN J, GUZMAN H, VAN-THUOC D, et al. Synthesis and production of polyhydroxyalkanoates by halophiles: current potential and future prospects [J]. Applied Microbiology and Biotechnology, 2010, 85 (6): 1687-1696.
[5]	TAN G, CHEN C L, LI L, et al. Start a research on biopolymer polyhydroxyalkanoate (PHA): a review [J]. Polymers, 2014, 6 (3): 706-754.
[6]	GOBI K, VADIVELU V M. Aerobic dynamic feeding as a strategy for in situ accumulation of polyhydroxyalkanoate in aerobic granules [J]. Bioresource Technology, 2014, 161: 441-445.
[7]	JOHNSON K, JIANG Y, KLEEREBEZEM R, et al. Enrichment of a mixed bacterial culture with a high polyhydroxyalkanoate storage capacity [J].Biomacromolecules, 2009, 10 (4): 670-676.
[8]	MOROLEJO-GARATE H, PALMEIRO-SANCHEZ T, KLEEREBEZEM R, et al. Influence of the cycle length on the production of PHA and polyglucose from glycerol by bacterial enrichments in sequencing batch reactors [J]. Biotechnology and Bioengineering, 2013, 110 (12): 3148-3155.
[9]	ALBUQUERQUE M, EIROA M, TORRES C, et al. Strategies for the development of a side stream process for polyhydroxyalkanoate (PHA) production from sugar cane molasses [J]. Journal of Biotechnology, 2007, 130 (4): 411-421.
[10]	JOHNSON K, KLEEREBEZEM R, VAN LOOSDRECHT M. Influence of the C/N ratio on the performance of polyhydroxybutyrate (PHB) producing sequencing batch reactors at short SRTs [J]. Water Research, 2010, 44 (7): 2141-2152.
[11]	SERAFIM L S, LEMOS P C, OLIVEIRA R. Optimization of polyhydroxybutyrate production by mixed cultures submitted to aerobic dynamic feeding conditions [J]. Biotechnology and Bioengineering, 2004, 87 (2): 145-160.
[12]	MARANG L, JIANG Y, VAN LOOSDRECHT M C M, et al. Butyrate as preferred substrate for polyhydroxybutyrate production [J]. Bioresource Technology, 2013, 142: 232-239.
[13]	BARROCAL V M, TERESA GARCIA-CUBERO M, GONZALEZ-BENITO G, et al. Production of biomass by Spirulina maxima using sugar beet vinasse in growth media [J]. New Biotechnology, 2010, 27 (6): 851-856.
[14]	CUI Y W, DING J R, JI S Y, et al. Start-up of halophilic nitrogen removal via nitrite from hypersaline wastewater by estuarine sediments in sequencing batch reactor [J]. International Journal of Environmental Science and Technology, 2014, 11 (2): 281-292.
[15]	OEHMEN A, KELLER-LEHMANN B, ZENG R J, et al. Optimisation of poly-beta-hydroxyalkanoate analysis using gas chromatography for enhanced biological phosphorus removal systems [J]. Journal of Chromatography A, 2005, 1070 (1/2): 131-136.
[16]	APHA. Standard Methods for the Examination of Water and Wastewater [M]. New York: American Public Health Association, 1995.
[17]	崔有为, 张宏宇, 冀思远, 等. 容积负荷变化模式对嗜盐混合菌发酵乙酸合成PHB的影响 [J]. 化工学报, 2015, 66 (10): 4177-4184. DOI: 10.11949/j.issn.0438-1157.20150287. CUI Y W, ZHANG H Y, JI S Y, et al. Influence of organic loading rate change modes on PHB production by halophilic sludge fermenting acetate acid [J].CIESC Journal, 2015, 66 (10): 4177-4184. DOI: 10.11949/j.issn.0438-1157.20150287.
[18]	ALBUQUERQUE M G E, TORRES C A V, REIS M A M. Polyhydroxyalkanoate (PHA) production by a mixed microbial culture using sugar molasses: effect of the influent substrate concentration on culture selection [J]. Water Research, 2010, 44 (11): 3419-3433.
[19]	DIONISI D, BECCARI M, DI GREGORIO S, et al. Storage of biodegradable polymers by an enriched microbial community in a sequencing batch reactor operated at high organic load rate [J]. Journal of Chemical Technology and Biotechnology, 2005, 80 (11): 1306-1318.
[20]	MORALEJO-GARATE H, KLEEREBEZEM R, MOSQUERA-CORRAL A, et al. Impact of oxygen limitation on glycerol-based biopolymer production by bacterial enrichments [J]. Water Research, 2013, 47 (3): 1209-1217.