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Liu S, Qin Y, Wang Q, Zhang J, Zhou J, He B, Liang X, Xian L, Wu J. A novel pectate lyase with high specific activity from Bacillus sp. B58-2: Gene cloning, heterologous expression and use in ramie degumming. Enzyme Microb Technol 2024; 175:110395. [PMID: 38237242 DOI: 10.1016/j.enzmictec.2024.110395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 12/31/2023] [Accepted: 01/12/2024] [Indexed: 02/25/2024]
Abstract
Pectinase plays a crucial role in ramie degumming. A gene encoding a putative pectate lyase from Bacillus sp. strain B58-2 was cloned and heterologously expressed in Escherichia coli. The amplified gene BvelPL1 encoded a mature protein of 400 amino acids. BvelPL1 shared the highest amino acid sequence identity (78.75%) with the enzymatically characterized pectate lyase Pel from Bacillus subtilis strain RCK (GenBank: AFH66771.1). The purified recombinant enzyme rBvelPL1-Ec exhibited a maximum specific activity of 2433.26 U/mg at pH 8.5 and 50 °C towards polygalacturonic acid. This specific activity was higher than that of most reported pectate lyases. Remarkably, the enzymatic activity of rBvelPL1-Ec increased by 23.28 times in the presence of 0.4 mM calcium ion. The effect of calcium ion on promoting the enzymatic activity of rBvelPL1-Ec was greater than that for all reported pectate lyases. After degumming with rBvelPL1-Ec, a weight loss of 21.27 ± 1.17% of circled ramie fibers was obtained, and the surfaces of the ramie fibers became smoother. Moreover, a weight loss of 30.47 ± 0.46% was obtained through enzymatic treated and subsequent NaOH treated circled ramie fibers. The excellent performance in degumming suggests that rBvelPL1-Ec may serve as a promising biocatalyst in the textile industry.
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Affiliation(s)
- Sijia Liu
- School of Light Industry and Food Engineering, Guangxi University, Nanning 530000, Guangxi, PR China
| | - Yan Qin
- National Key Laboratory of Non-food Biomass Energy Technology, Guangxi Academy of Sciences, Nanning 530007, PR China
| | - Qingyan Wang
- National Key Laboratory of Non-food Biomass Energy Technology, Guangxi Academy of Sciences, Nanning 530007, PR China
| | - Jing Zhang
- School of Light Industry and Food Engineering, Guangxi University, Nanning 530000, Guangxi, PR China
| | - Jin Zhou
- School of Light Industry and Food Engineering, Guangxi University, Nanning 530000, Guangxi, PR China
| | - Baoxiang He
- School of Light Industry and Food Engineering, Guangxi University, Nanning 530000, Guangxi, PR China
| | - Xinquan Liang
- School of Light Industry and Food Engineering, Guangxi University, Nanning 530000, Guangxi, PR China.
| | - Liang Xian
- National Key Laboratory of Non-food Biomass Energy Technology, Guangxi Academy of Sciences, Nanning 530007, PR China.
| | - Junhua Wu
- National Key Laboratory of Non-food Biomass Energy Technology, Guangxi Academy of Sciences, Nanning 530007, PR China.
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Lin J, Xiang S, Lv H, Wang T, Rao Y, Liu L, Yuan D, Wang X, Chu Y, Luo D, Song T. Antimicrobial high molecular weight pectin polysaccharides production from diverse citrus peels using a novel PL10 family pectate lyase. Int J Biol Macromol 2023; 234:123457. [PMID: 36716843 DOI: 10.1016/j.ijbiomac.2023.123457] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 01/19/2023] [Accepted: 01/24/2023] [Indexed: 01/30/2023]
Abstract
The discovery of environmentally friendly enzymes that can convert inexpensive and abundant citrus peel pectin into high value-added product is a potential avenue for the citrus peel application. In this study, a novel PL10-family pectate lyase (pelA) was characterized from marine bacterium Echinicola pacifica. PelA was a Ca2+ dependent pectate lyase whose activity was highest at pH 8 and 40 °C. It was capable of degrading polygalacturonic acid (PGA) and citrus peel pectin (CPP), but not apple peel pectin. Notably, PelA hydrolyzed PGA to high molecular weight polysaccharide (average molecular weight 111.4 kDa). Moreover, PelA was also able to degrade CPP from nine distinct citrus species into polysaccharides (average molecular weight ranging from 84.7 to 539.2 kDa) that showed antimicrobial activity against Staphylococcus epidermidis (88.8 %), Bacillus subtilis (99.8 %), Staphylococcus aureus (92.1 %), Escherichia coli (100.0 %) and Klebsiella pneumoniae (86.4 %). Considering the high market value of pectin in the food industry, PelA's capacity to convert citrus pectin into high molecular weight polysaccharides lays a foundation for its applications.
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Affiliation(s)
- Jiafu Lin
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, 610106 Chengdu, China
| | - Shengwei Xiang
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, 610106 Chengdu, China
| | - Hua Lv
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, 610106 Chengdu, China
| | - Tiantian Wang
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, 610106 Chengdu, China
| | - Yulu Rao
- Department of Immunology, School of Basic Medical Sciences, Chengdu Medical College, Chengdu, China
| | - Ling Liu
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, 610106 Chengdu, China
| | - Dezhi Yuan
- Moutai Institute, Renhuai 564500, Guizhou Province, China
| | - Xinrong Wang
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, 610106 Chengdu, China
| | - Yiwen Chu
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, 610106 Chengdu, China
| | - Dan Luo
- Department of Immunology, School of Basic Medical Sciences, Chengdu Medical College, Chengdu, China.
| | - Tao Song
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, 610106 Chengdu, China; Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Chengdu University, Chengdu 610106, China.
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3
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Zheng L, Xu Y, Li Q, Zhu B. Pectinolytic lyases: a comprehensive review of sources, category, property, structure, and catalytic mechanism of pectate lyases and pectin lyases. BIORESOUR BIOPROCESS 2021; 8:79. [PMID: 38650254 PMCID: PMC10992409 DOI: 10.1186/s40643-021-00432-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 08/16/2021] [Indexed: 12/22/2022] Open
Abstract
Pectate lyases and pectin lyases have essential roles in various biotechnological applications, such as textile industry, paper making, pectic wastewater pretreatment, juice clarification and oil extraction. They can effectively cleave the α-1,4-glycosidic bond of pectin molecules back bone by β-elimination reaction to produce pectin oligosaccharides. In this way, it will not generate highly toxic methanol and has the advantages of good enzymatic selectivity, less by-products, mild reaction conditions and high efficiency. However, numerous researches have been done for several decades; there are still no comprehensive reviews to summarize the recent advances of pectate lyases and pectin lyases. This review tries to fill this gap by providing all relevant information, including the substrate, origin, biochemical properties, sequence analysis, mode of action, the three-dimensional structure and catalytic mechanism.
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Affiliation(s)
- Ling Zheng
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, 211816, P. R. China
| | - Yinxiao Xu
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, 211816, P. R. China
| | - Qian Li
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, 211816, P. R. China
| | - Benwei Zhu
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, 211816, P. R. China.
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Screening of a Novel Polysaccharide Lyase Family 10 Pectate Lyase from Paenibacillus polymyxa KF-1: Cloning, Expression and Characterization. Molecules 2018; 23:molecules23112774. [PMID: 30373112 PMCID: PMC6278402 DOI: 10.3390/molecules23112774] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 10/16/2018] [Accepted: 10/25/2018] [Indexed: 01/23/2023] Open
Abstract
Pectate lyase (EC 4.2.2.2) catalyzes the cleavage of α-1,4-glycosidic bonds of pectin polymers, and it has potential uses in the textile industry. In this study, a novel pectate lyase belonging to polysaccharide lyase family 10 was screened from the secreted enzyme extract of Paenibacillus polymyxa KF-1 and identified by liquid chromatography-MS/MS. The gene was cloned from P. polymyxa KF-1 genomic DNA and expressed in Escherichia coli. The recombinant enzyme PpPel10a had a predicted Mr of 45.2 kDa and pI of 9.41. Using polygalacturonic acid (PGA) as substrate, the optimal conditions for PpPel10a reaction were determined to be 50 °C and pH 9.0, respectively. The Km, vmax and kcat values of PpPel10a with PGA as substrate were 0.12 g/L, 289 μmol/min/mg, and 202.3 s−1, respectively. Recombinant PpPel10a degraded citrus pectin, producing unsaturated mono- and oligogalacturonic acids. PpPel10a reduced the viscosity of PGA, and weight loss of ramie (Boehmeria nivea) fibers was observed after treatment with the enzyme alone (22.5%) or the enzyme in combination with alkali (26.3%). This enzyme has potential for use in plant fiber processing.
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Purification and characterisation of thermo-alkaline pectinase enzyme from Hylocereus polyrhizus. Eur Food Res Technol 2014. [DOI: 10.1007/s00217-014-2188-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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6
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Characterization and high-level expression of a metagenome-derived alkaline pectate lyase in recombinant Escherichia coli. Process Biochem 2014. [DOI: 10.1016/j.procbio.2013.10.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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7
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Yuan P, Meng K, Shi P, Luo H, Huang H, Tu T, Yang P, Yao B. An alkaline-active and alkali-stable pectate lyase from Streptomyces sp. S27 with potential in textile industry. ACTA ACUST UNITED AC 2012; 39:909-15. [DOI: 10.1007/s10295-012-1085-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 01/04/2012] [Indexed: 10/14/2022]
Abstract
Abstract
A pectate lyase gene (pl-str) was cloned from Streptomyces sp. S27 and expressed in Escherichia coli Rosetta. The full-length pl-str consists of 972 bp and encodes for a protein of 323 amino acids without signal peptide that belongs to family PF00544. The recombinant enzyme (r-PL-STR) was purified to electrophoretic homogeneity using Ni2+–NTA chromatography and showed apparent molecular mass of ~35 kDa. The pH optimum of r-PL-STR was found to be 10.0, and it exhibited >70% of the maximal activity at pH 12.0. After incubation at 37°C for 1 h without substrate, the enzyme retained more than 55% activity at pH 7.0–12.0. Compared with the commercial complex enzyme Scourzyme@301L from Novozymes, purified r-PL-STR showed similar efficacy in reducing the intrinsic viscosity of polygalacturonic acid (49.0 vs. 49.7%). When combined with cellulase and α-amylase, r-PL-STR had comparable performance in bioscouring of jute fabric (22.39 vs. 22.99%). Thus, r-PL-STR might represent a good candidate for use in alkaline industries such as textile.
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Affiliation(s)
- Peng Yuan
- grid.410727.7 0000000105261937 Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute Chinese Academy of Agricultural Sciences No. 12 Zhongguancun South Street 100081 Beijing People’s Republic of China
| | - Kun Meng
- grid.410727.7 0000000105261937 Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute Chinese Academy of Agricultural Sciences No. 12 Zhongguancun South Street 100081 Beijing People’s Republic of China
| | - Pengjun Shi
- grid.410727.7 0000000105261937 Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute Chinese Academy of Agricultural Sciences No. 12 Zhongguancun South Street 100081 Beijing People’s Republic of China
| | - Huiying Luo
- grid.410727.7 0000000105261937 Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute Chinese Academy of Agricultural Sciences No. 12 Zhongguancun South Street 100081 Beijing People’s Republic of China
| | - Huoqing Huang
- grid.410727.7 0000000105261937 Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute Chinese Academy of Agricultural Sciences No. 12 Zhongguancun South Street 100081 Beijing People’s Republic of China
| | - Tao Tu
- grid.410727.7 0000000105261937 Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute Chinese Academy of Agricultural Sciences No. 12 Zhongguancun South Street 100081 Beijing People’s Republic of China
| | - Peilong Yang
- grid.410727.7 0000000105261937 Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute Chinese Academy of Agricultural Sciences No. 12 Zhongguancun South Street 100081 Beijing People’s Republic of China
| | - Bin Yao
- grid.410727.7 0000000105261937 Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute Chinese Academy of Agricultural Sciences No. 12 Zhongguancun South Street 100081 Beijing People’s Republic of China
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Kumar L, Awasthi G, Singh B. Extremophiles: A Novel Source of Industrially Important Enzymes. ACTA ACUST UNITED AC 2011. [DOI: 10.3923/biotech.2011.121.135] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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9
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Dubey AK, Yadav S, Kumar M, Singh VK, Sarangi BK, Yadav D. In silico characterization of pectate lyase protein sequences from different source organisms. Enzyme Res 2010; 2010:950230. [PMID: 21048874 PMCID: PMC2962914 DOI: 10.4061/2010/950230] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Accepted: 08/15/2010] [Indexed: 11/24/2022] Open
Abstract
A total of 121 protein sequences of pectate lyases were subjected to homology search, multiple sequence alignment, phylogenetic tree construction, and motif analysis. The phylogenetic tree constructed revealed different clusters based on different source organisms representing bacterial, fungal, plant, and nematode pectate lyases. The multiple accessions of bacterial, fungal, nematode, and plant pectate lyase protein sequences were placed closely revealing a sequence level similarity. The multiple sequence alignment of these pectate lyase protein sequences from different source organisms showed conserved regions at different stretches with maximum homology from amino acid residues 439–467, 715–816, and 829–910 which could be used for designing degenerate primers or probes specific for pectate lyases. The motif analysis revealed a conserved Pec_Lyase_C domain uniformly observed in all pectate lyases irrespective of variable sources suggesting its possible role in structural and enzymatic functions.
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Affiliation(s)
- Amit Kumar Dubey
- Department of Biotechnology, D.D.U Gorakhpur University, Gorakhpur 273 009, India
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10
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Basu S, Roy A, Ghosh A, Bera A, Chattopadhyay D, Chakrabarti K. Arg235 is an essential catalytic residue of Bacillus pumilus DKS1 pectate lyase to degum ramie fibre. Biodegradation 2010; 22:153-61. [DOI: 10.1007/s10532-010-9384-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Accepted: 06/23/2010] [Indexed: 10/19/2022]
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Characterisation of a new thermoalkaliphilic bacterium for the production of high-quality hemp fibres, Geobacillus thermoglucosidasius strain PB94A. Appl Microbiol Biotechnol 2009; 83:521-7. [DOI: 10.1007/s00253-009-1969-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Revised: 03/16/2009] [Accepted: 03/16/2009] [Indexed: 11/26/2022]
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12
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13
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Zhao Q, Ding R, Kang Y, Chen J. Expression of pectate lyase A from Aspergillus nidulans in Bacillus subtilis. World J Microbiol Biotechnol 2008. [DOI: 10.1007/s11274-008-9784-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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14
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Xiao Z, Boyd J, Grosse S, Beauchemin M, Coupe E, Lau PCK. Mining Xanthomonas and Streptomyces genomes for new pectinase-encoding sequences and their heterologous expression in Escherichia coli. Appl Microbiol Biotechnol 2008; 78:973-81. [DOI: 10.1007/s00253-008-1389-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Revised: 01/25/2008] [Accepted: 01/29/2008] [Indexed: 11/29/2022]
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Zhao Q, Yuan S, Zhang Y, Zhu H, Dai C, Yang F, Han F. Expression, purification and characterization of pectate lyase A from Aspergillus nidulans in Escherichia coli. World J Microbiol Biotechnol 2006. [DOI: 10.1007/s11274-006-9331-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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16
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Celestino SMC, Maria de Freitas S, Javier Medrano F, Valle de Sousa M, Filho EXF. Purification and characterization of a novel pectinase from Acrophialophora nainiana with emphasis on its physicochemical properties. J Biotechnol 2006; 123:33-42. [PMID: 16337707 DOI: 10.1016/j.jbiotec.2005.10.024] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2005] [Revised: 09/28/2005] [Accepted: 10/24/2005] [Indexed: 11/19/2022]
Abstract
An extracellular pectinase (PECI) was purified to apparent homogeneity from liquid state cultures of the thermophilic fungus Acrophialophora nainiana by ultrafiltration and a combination of gel filtration and ion-exchange chromatographic procedures. The molecular masses of PECI were 35,500 and 30,749 Da, as determined by SDS-PAGE and mass spectrometry, respectively. It was more active at 60 degrees C and pH 8.0 and showed high stability at 50 degrees C with half-life of 7 days. However at 60 and 70 degrees C, PECI was much less stable with half lives of approximately 20 and 3 min, respectively. The thermostability of purified PECI was also investigated by fluorescence and circular dichroism spectroscopy. Fluorescence revealed that the unfolding transition region was observed between 45 and 70 degrees C. A major decrease in the stability was found at 70 degrees C. Circular dichroism measurements at pH between 5.0 and 9.0 showed a transition temperature (T(m)) range of 50-55 degrees . The thermodynamic analysis of these results showed that EPGI is thermal stable protein exhibiting maximum stability (DeltaG(25)) of 22.65 and 19.19 kcal/mol at pH 8.0 and 9.0, respectively. The apparent K(m) value on pectin from citrus fruits was 4.22 mgml(-1). PECI exhibited no detectable activity of pectin methylesterase, endo-polygalacturonase, mannanase, xylanase and cellulase. However, it showed exo-polygalacturonase and pectin lyase activities. The presence of carbohydrate was detected in the pure PECI. It was activated by l-tryptophan, DEPC, DTT, DTNB, DTP, l-cystein and beta-mercaptoethanol and inhibited by NBS, Fe(2+), Cu(2+), Zn(2+), Mn(2+), Al(3+) and Ca(2+). The enzyme showed homology with a pectin lyases from Xanthomonas campestris and Bacillus licheniformis.
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Affiliation(s)
- S Maria C Celestino
- Laboratório de Enzimologia, Departamento de Biologia Celular, Universidade de Brasília, Brasília, DF, CEP 70910-900, Brazil
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Klug-Santner BG, Schnitzhofer W, Vrsanská M, Weber J, Agrawal PB, Nierstrasz VA, Guebitz GM. Purification and characterization of a new bioscouring pectate lyase from Bacillus pumilus BK2. J Biotechnol 2006; 121:390-401. [PMID: 16168510 DOI: 10.1016/j.jbiotec.2005.07.019] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2004] [Revised: 07/08/2005] [Accepted: 07/14/2005] [Indexed: 10/25/2022]
Abstract
An alkalophilic bacterium was isolated based on the potential of extra-cellular enzymes for bioscouring. The bacterium was identified as a new strain of Bacillus pumilus BK2 producing an extra-cellular endo-pectate lyase PL (EC 4.2.2.2). PL was purified to homogeneity in three steps and has a molecular mass of 37.3+/-4.8 kDa as determined by SDS-PAGE and an isoelectric point of pH 8.5. Peptide mass mapping by nano-LC-MS of PL revealed 15% homology with a pectate lyase from Bacillus sp. The pectate lyase exhibited optimum activity at pH 8.5 and around 70 degrees C in Tris/HCl buffer. It showed a half-life at 30 degrees C of more than 75 h. Stability decreased with increasing temperature, extremely over 60 degrees C. The enzyme did not require Ca2+ ions for activity, and was strongly inhibited by EDTA and Co2+. PL was active on polygalacturonic acid and esterified pectin, but the affinity showed a maximum for intermediate esterified pectins and decreased over a value of 50% of esterification. The best substrate was 29.5% methylated pectin. PL cleaved polygalacturonic acid via a beta-elimination mechanism as shown by NMR analysis. PL released unsaturated tetragalacturonic acid from citrus pectin and polygalacturonic acid, but did not show any side activities on other hemicelluloses. On polygalacturonic acid PL showed a Km of 0.24 gl(-1) and a vmax of 0.72 gl(-1)min(-1). The applicability of pectate lyase for the bioscouring process was tested on a cotton fabric. Removal of up to 80% of pectin was proven by means of ruthenium red dyeing and HPAEC (65%). Structural contact angle measurements clearly indicated the increased hydrophilicity of enzyme treated fabrics.
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Affiliation(s)
- Barbara G Klug-Santner
- Department of Environmental Biotechnology, Graz University of Technology, Petersgasse 12, A-8010 Graz, Austria
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