scholarly journals Phylogenetic, Microbiological, and Glycoside Hydrolase Diversities within the Extremely Thermophilic, Plant Biomass-Degrading Genus Caldicellulosiruptor

2010 ◽  
Vol 76 (24) ◽  
pp. 8084-8092 ◽  
Author(s):  
Sara E. Blumer-Schuette ◽  
Derrick L. Lewis ◽  
Robert M. Kelly
Keyword(s):  
Glycoside Hydrolase ◽  
Plant Biomass ◽  
Thermophilic Bacteria ◽  
Draft Genome ◽  
Comparative Genomic ◽  
Rrna Gene ◽  
Carbohydrate Binding ◽  
Sequence Information ◽  
Two Dimensional Gel Electrophoresis ◽  
Growth Physiology

ABSTRACT Phylogenetic, microbiological, and comparative genomic analyses were used to examine the diversity among members of the genus Caldicellulosiruptor, with an eye toward the capacity of these extremely thermophilic bacteria to degrade the complex carbohydrate content of plant biomass. Seven species from this genus (C. saccharolyticus, C. bescii, C. hydrothermalis, C. owensensis, C. kronotskyensis, C. lactoaceticus, and C. kristjanssonii) were compared on the basis of 16S rRNA gene phylogeny and cross-species DNA-DNA hybridization to a whole-genome C. saccharolyticus oligonucleotide microarray, revealing that C. saccharolyticus was the most divergent within this group. Growth physiology of the seven Caldicellulosiruptor species on a range of carbohydrates showed that, while all could be cultivated on acid-pretreated switchgrass, only C. saccharolyticus, C. bescii, C. kronotskyensis, and C. lactoaceticus were capable of hydrolyzing Whatman no. 1 filter paper. Two-dimensional gel electrophoresis of the secretomes from cells grown on microcrystalline cellulose revealed that the cellulolytic species also had diverse secretome fingerprints. The C. saccharolyticus secretome contained a prominent S-layer protein that appears in the cellulolytic Caldicellulosiruptor species, suggesting a possible role in cell-substrate interactions. Growth physiology also correlated with glycoside hydrolase (GH) and carbohydrate-binding module (CBM) inventories for the seven bacteria, as deduced from draft genome sequence information. These inventories indicated that the absence of a single GH and CBM family was responsible for diminished cellulolytic capacity. Overall, the genus Caldicellulosiruptor appears to contain more genomic and physiological diversity than previously reported, and this argues for continued efforts to isolate new members from high-temperature terrestrial biotopes.

scholarly journals Synergism of Glycoside Hydrolase Secretomes from Two Thermophilic Bacteria Cocultivated on Lignocellulose

2014 ◽  
Vol 80 (8) ◽  
pp. 2592-2601 ◽  
Author(s):  
Kundi Zhang ◽  
Xiaohua Chen ◽  
Wolfgang H. Schwarz ◽  
Fuli Li
Keyword(s):  
Glycoside Hydrolase ◽  
Thermophilic Bacteria ◽  
Xylanase Activity ◽  
Mass Spectrometry Analysis ◽  
Lignocellulose Degradation ◽  
Rrna Gene ◽  
Carbohydrate Binding ◽  
Bacterial Strains ◽  
Content Type ◽  
Carbohydrate Binding Modules

ABSTRACTTwo cellulolytic thermophilic bacterial strains, CS-3-2 and CS-4-4, were isolated from decayed cornstalk by the addition of growth-supporting factors to the medium. According to 16S rRNA gene-sequencing results, these strains belonged to the genusClostridiumand showed 98.87% and 98.86% identity withClostridiumstercorariumsubsp.leptospartumATCC 35414TandClostridiumcellulosiAS 1.1777T, respectively. The endoglucanase and exoglucanase activities of strain CS-4-4 were approximately 3 to 5 times those of strain CS-3-2, whereas the β-glucosidase activity of strain CS-3-2 was 18 times higher than that of strain CS-4-4. The xylanase activity of strain CS-3-2 was 9 times that of strain CS-4-4, whereas the β-xylosidase activity of strain CS-4-4 was 27 times that of strain CS-3-2. The enzyme activities in spent cultures following cocultivation of the two strains with cornstalk as the substrate were much greater than those in pure cultures or an artificial mixture of samples, indicating synergism of glycoside hydrolase secretomes between the two strains. Quantitative measurement of the two strains in the cocultivation system indicated that strain CS-3-2 grew robustly during the initial stages, whereas strain CS-4-4 dominated the system in the late-exponential phase. Liquid chromatography-tandem mass spectrometry analysis of protein bands appearing in the native zymograms showed that ORF3880 and ORF3883 from strain CS-4-4 played key roles in the lignocellulose degradation process. Both these open reading frames (ORFs) exhibited endoglucanase and xylanase activities, but ORF3880 showed tighter adhesion to insoluble substrates at 4, 25, and 60°C owing to its five carbohydrate-binding modules (CBMs).

scholarly journals S-Layer Homology Domain Proteins Csac_0678 and Csac_2722 Are Implicated in Plant Polysaccharide Deconstruction by the Extremely Thermophilic Bacterium Caldicellulosiruptor saccharolyticus

2011 ◽  
Vol 78 (3) ◽  
pp. 768-777 ◽  
Author(s):  
Inci Ozdemir ◽  
Sara E. Blumer-Schuette ◽  
Robert M. Kelly
Keyword(s):  
Cellular Localization ◽  
Catalytic Domain ◽  
Plant Biomass ◽  
Thermophilic Bacteria ◽  
Biochemical Properties ◽  
Crystalline Cellulose ◽  
Glycoside Hydrolase Family ◽  
Carbohydrate Binding ◽  
Caldicellulosiruptor Saccharolyticus ◽  
Content Type

ABSTRACTThe genusCaldicellulosiruptorcontains extremely thermophilic bacteria that grow on plant polysaccharides. The genomes ofCaldicellulosiruptorspecies reveal certain surface layer homology (SLH) domain proteins that have distinguishing features, pointing to a role in lignocellulose deconstruction. Two of these proteins inCaldicellulosiruptor saccharolyticus(Csac_0678 and Csac_2722) were examined from this perspective. In addition to three contiguous SLH domains, the Csac_0678 gene encodes a glycoside hydrolase family 5 (GH5) catalytic domain and a family 28 carbohydrate-binding module (CBM); orthologs to Csac_0678 could be identified in all genome-sequencedCaldicellulosiruptorspecies. Recombinant Csac_0678 was optimally active at 75°C and pH 5.0, exhibiting both endoglucanase and xylanase activities. SLH domain removal did not impact Csac_0678 GH activity, but deletion of the CBM28 domain eliminated binding to crystalline cellulose and rendered the enzyme inactive on this substrate. Csac_2722 is the largest open reading frame (ORF) in theC. saccharolyticusgenome (predicted molecular mass of 286,516 kDa) and contains two putative sugar-binding domains, two Big4 domains (bacterial domains with an immunoglobulin [Ig]-like fold), and a cadherin-like (Cd) domain. Recombinant Csac_2722, lacking the SLH and Cd domains, bound to cellulose and had detectable carboxymethylcellulose (CMC) hydrolytic activity. Antibodies directed against Csac_0678 and Csac_2722 confirmed that these proteins bound to theC. saccharolyticusS-layer. Their cellular localization and functional biochemical properties indicate roles for Csac_0678 and Csac_2722 in recruitment and hydrolysis of complex polysaccharides and the deconstruction of lignocellulosic biomass. Furthermore, these results suggest that related SLH domain proteins in otherCaldicellulosiruptorgenomes may also be important contributors to plant biomass utilization.

Classification of ‘Anaerocellum thermophilum’ strain DSM 6725 as Caldicellulosiruptor bescii sp. nov.

2010 ◽  
Vol 60 (9) ◽  
pp. 2011-2015 ◽  
Author(s):  
Sung-Jae Yang ◽  
Irina Kataeva ◽  
Juergen Wiegel ◽  
Yanbin Yin ◽  
Phuongan Dam ◽  
...  
Keyword(s):  
New Genus ◽  
Plant Biomass ◽  
Hot Spring ◽  
Crystalline Cellulose ◽  
Rrna Gene ◽  
Growth Physiology ◽  
Caldicellulosiruptor Bescii ◽  
Untreated Plant ◽  
The 16S Rrna Gene

The thermophilic, cellulolytic, anaerobic bacterium ‘Anaerocellum thermophilum’ strain Z-1320 was isolated from a hot spring almost two decades ago and deposited in the German Collection of Microorganisms and Cell Cultures (DSMZ) as DSM 6725. The organism was classified as representing a new genus, ‘Anaerocellum’, primarily on its growth physiology, cell-wall type and morphology. The results of recent physiological studies and of phylogenetic and genome sequence analyses of strain DSM 6725 of ‘A. thermophilum’ obtained from the DSMZ showed that its properties differed from those originally described for strain Z-1320. In particular, when compared with strain Z-1320, strain DSM 6725 grew at higher temperatures and had an expanded range of growth substrates. Moreover, the 16S rRNA gene sequence of strain DSM 6725 fell within the Caldicellulosiruptor clade. It is therefore suggested that ‘Anaerocellum thermophilum’ should be classified as a member of the genus Caldicellulosiruptor, for which the name Caldicellulosiruptor bescii sp. nov. is proposed (type strain DSM 6725T=ATCC BAA-1888T). C. bescii sp. nov. DSM 6725T is the most thermophilic cellulose-degrading organism known. The strain was able to grow up to 90 °C (pH 7.2) and degraded crystalline cellulose and xylan as well as untreated plant biomass, including potential bioenergy plants such as poplar and switchgrass.

scholarly journals Draft Genome Sequence of Ralstonia solanacearum Strain Rs-T02, Which Represents the Most Prevalent Phylotype in Guangxi, China

2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Chengwu Zou ◽  
Kaihao Wang ◽  
Jiaorong Meng ◽  
Gaoqing Yuan ◽  
Wei Lin ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Ralstonia Solanacearum ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
Comparative Genomic ◽  
Sequence Information ◽  
Guangxi Province ◽  
Solanacearum Strain ◽  
Genomic Studies ◽  
Genome Sequence Information

Ralstonia solanacearum strain Rs-T02 was originally isolated from a bacterial wilt of tomato plant in Nanning City of Guangxi Province, China. It represents the most prevalent phylotype in Guangxi. Here, we present the draft genome sequence of this strain, which comprises 5,225 genes and 5,976,011 nucleotides with an average G+C content of 66.79%. There are 968 different genes between this isolate and the previously reported genome sequence of Ralstonia solanacearum GMl l000 (race l, biovar 3, phylotype I), and the genome sequence information of this isolate may be useful for comparative genomic studies to determine the genetic diversity in this species.

scholarly journals Genus-Wide Assessment of Lignocellulose Utilization in the Extremely Thermophilic GenusCaldicellulosiruptorby Genomic, Pangenomic, and Metagenomic Analyses

2018 ◽  
Vol 84 (9) ◽  
Author(s):  
Laura L. Lee ◽  
Sara E. Blumer-Schuette ◽  
Javier A. Izquierdo ◽  
Jeffrey V. Zurawski ◽  
Andrew J. Loder ◽  
...  
Keyword(s):  
Microcrystalline Cellulose ◽  
Plant Biomass ◽  
Thermophilic Bacteria ◽  
Cellulose Degradation ◽  
Glycoside Hydrolases ◽  
Metagenomic Data ◽  
Lignocellulose Degradation ◽  
Sequence Information ◽  
Metagenomic Sequence ◽  
Content Type

ABSTRACTMetagenomic data from Obsidian Pool (Yellowstone National Park, USA) and 13 genome sequences were used to reassess genus-wide biodiversity for the extremely thermophilicCaldicellulosiruptor. The updated core genome contains 1,401 ortholog groups (average genome size for 13 species = 2,516 genes). The pangenome, which remains open with a revised total of 3,493 ortholog groups, encodes a variety of multidomain glycoside hydrolases (GHs). These include three cellulases with GH48 domains that are colocated in the glucan degradation locus (GDL) and are specific determinants for microcrystalline cellulose utilization. Three recently sequenced species,Caldicellulosiruptorsp. strain Rt8.B8 (renamed hereCaldicellulosiruptor morganii),Thermoanaerobacter cellulolyticusstrain NA10 (renamed hereCaldicellulosiruptor naganoensis), andCaldicellulosiruptorsp. strain Wai35.B1 (renamed hereCaldicellulosiruptor danielii), degraded Avicel and lignocellulose (switchgrass).C. morganiiwas more efficient thanCaldicellulosiruptor besciiin this regard and differed from the other 12 species examined, both based on genome content and organization and in the specific domain features of conserved GHs. Metagenomic analysis of lignocellulose-enriched samples from Obsidian Pool revealed limited new information on genus biodiversity. Enrichments yielded genomic signatures closely related to that ofCaldicellulosiruptor obsidiansis, but there was also evidence for other thermophilic fermentative anaerobes (Caldanaerobacter,Fervidobacterium,Caloramator, andClostridium). One enrichment, containing 89.8%Caldicellulosiruptorand 9.7%Caloramator, had a capacity for switchgrass solubilization comparable to that ofC. bescii. These results refine the known biodiversity ofCaldicellulosiruptorand indicate that microcrystalline cellulose degradation at temperatures above 70°C, based on current information, is limited to certain members of this genus that produce GH48 domain-containing enzymes.IMPORTANCEThe genusCaldicellulosiruptorcontains the most thermophilic bacteria capable of lignocellulose deconstruction, which are promising candidates for consolidated bioprocessing for the production of biofuels and bio-based chemicals. The focus here is on the extant capability of this genus for plant biomass degradation and the extent to which this can be inferred from the core and pangenomes, based on analysis of 13 species and metagenomic sequence information from environmental samples. Key to microcrystalline hydrolysis is the content of the glucan degradation locus (GDL), a set of genes encoding glycoside hydrolases (GHs), several of which have GH48 and family 3 carbohydrate binding module domains, that function as primary cellulases. Resolving the relationship between the GDL and lignocellulose degradation will inform efforts to identify more prolific members of the genus and to develop metabolic engineering strategies to improve this characteristic.

scholarly journals Draft Genome Sequences of Elsinoë fawcettii and Elsinoë australis Causing Scab Diseases on Citrus

2020 ◽  
Vol 33 (2) ◽  
pp. 135-137 ◽  
Author(s):  
Gnanendra Shanmugam ◽  
Junhyun Jeon ◽  
Jae-Wook Hyun
Keyword(s):  
Ab Initio ◽  
Host Range ◽  
Draft Genome ◽  
Phytopathogenic Fungi ◽  
Comparative Genomic ◽  
Sequence Information ◽  
Genome Sequences ◽  
High Quality ◽  
Genomic Analyses ◽  
Genome Sequence Information

Elsinoë fawcettii and E. australis (phylum Ascomycota) are phytopathogenic fungi causing scab diseases on citrus plants. We report here the high-quality draft genome sequences and ab initio gene predictions of two E. fawcettii strains and one E. australis strain, which differ in their host range. This genome sequence information will provide valuable resources to underpin genomic attributes for determining host range through comparative genomic analyses of citrus scab fungi.

scholarly journals Comparative genomics reveals a novel genetic organization of the sad cluster in the sulfonamide-degrader ‘Candidatus Leucobacter sulfamidivorax’ strain GP

BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Ana C. Reis ◽  
Boris A. Kolvenbach ◽  
Mohamed Chami ◽  
Luís Gales ◽  
Conceição Egas ◽  
...  
Keyword(s):  
Comparative Genomics ◽  
Draft Genome ◽  
Genomic Analysis ◽  
Amino Acid Identity ◽  
Culture Conditions ◽  
Comparative Genomic ◽  
Rrna Gene ◽  
Functional Studies ◽  
Conserved Genes ◽  
Gene Similarity

Abstract Background Microbial communities recurrently establish metabolic associations resulting in increased fitness and ability to perform complex tasks, such as xenobiotic degradation. In a previous study, we have described a sulfonamide-degrading consortium consisting of a novel low-abundant actinobacterium, named strain GP, and Achromobacter denitrificans PR1. However, we found that strain GP was unable to grow independently and could not be further purified. Results Previous studies suggested that strain GP might represent a new putative species within the Leucobacter genus (16S rRNA gene similarity < 97%). In this study, we found that average nucleotide identity (ANI) with other Leucobacter spp. ranged between 76.8 and 82.1%, further corroborating the affiliation of strain GP to a new provisional species. The average amino acid identity (AAI) and percentage of conserved genes (POCP) values were near the lower edge of the genus delimitation thresholds (65 and 55%, respectively). Phylogenetic analysis of core genes between strain GP and Leucobacter spp. corroborated these findings. Comparative genomic analysis indicates that strain GP may have lost genes related to tetrapyrrole biosynthesis and thiol transporters, both crucial for the correct assembly of cytochromes and aerobic growth. However, supplying exogenous heme and catalase was insufficient to abolish the dependent phenotype. The actinobacterium harbors at least two copies of a novel genetic element containing a sulfonamide monooxygenase (sadA) flanked by a single IS1380 family transposase. Additionally, two homologs of sadB (4-aminophenol monooxygenase) were identified in the metagenome-assembled draft genome of strain GP, but these were not located in the vicinity of sadA nor of mobile or integrative elements. Conclusions Comparative genomics of the genus Leucobacter suggested the absence of some genes encoding for important metabolic traits in strain GP. Nevertheless, although media and culture conditions were tailored to supply its potential metabolic needs, these conditions were insufficient to isolate the PR1-dependent actinobacterium further. This study gives important insights regarding strain GP metabolism; however, gene expression and functional studies are necessary to characterize and further isolate strain GP. Based on our data, we propose to classify strain GP in a provisional new species within the genus Leucobacter, ‘Candidatus Leucobacter sulfamidivorax‘.

scholarly journals A genomic perspective on the potential of termite-associated Cellulosimicrobium cellulans MP1 as producer of plant biomass-acting enzymes and exopolysaccharides

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11839
Author(s):  
Nguyen Thi-Hanh Vu ◽  
Tung Ngoc Quach ◽  
Xuan Thi-Thanh Dao ◽  
Ha Thanh Le ◽  
Chi Phuong Le ◽  
...  
Keyword(s):  
Plant Biomass ◽  
Draft Genome ◽  
Gc Content ◽  
Rrna Genes ◽  
Trna Genes ◽  
Rrna Gene ◽  
Whole Genome ◽  
Potential Candidate ◽  
Circular Chromosome ◽  
Cellulosimicrobium Cellulans

Background Lignocellulose is a renewable and enormous biomass resource, which can be degraded efficiently by a range of cocktails of carbohydrate-active enzymes secreted by termite gut symbiotic bacteria. There is an urgent need to find enzymes with novel characteristics for improving the conversion processes in the production of lignocellulosic-based products. Although various studies dedicated to the genus Cellulosimicrobium as gut symbiont, genetic potential related to plant biomass-acting enzymes and exopolysaccharides production has been fully untapped to date. Methods The cellulolytic bacterial strain MP1 was isolated from termite guts and identified to the species level by phenotypic, phylogenetic, and genomic analysis. To further explore genes related to cellulose and hemicellulose degradation, the draft genome of strain MP1 was obtained by using whole-genome sequencing, assembly, and annotation through the Illumina platform. Lignocellulose degrading enzymes and levan production in the liquid medium were also examined to shed light on bacterial activities. Results Among 65 isolates obtained, the strain MP1 was the most efficient cellulase producer with cellulase activity of 0.65 ± 0.02 IU/ml. The whole genome analysis depicted that strain MP1 consists of a circular chromosome that contained 4,580,223 bp with an average GC content of 73.9%. The genome comprises 23 contigs including 67 rRNA genes, three tRNA genes, a single tmRNA gene, and 4,046 protein-coding sequences. In support of the phenotypic identification, the 16S rRNA gene sequence, average nucleotide identity, and whole-genome-based taxonomic analysis demonstrated that the strain MP1 belongs to the species Cellulosimicrobium cellulans. A total of 30 genes related to the degradation of cellulases and hemicellulases were identified in the C. cellulans MP1 genome. Of note, the presence of sacC1-levB-sacC2-ls operon responsible for levan and levan-type fructooligosaccharides biosynthesis was detected in strain MP1 genome, but not with closely related C. cellulans strains, proving this strain to be a potential candidate for further studies. Endoglucanases, exoglucanases, and xylanase were achieved by using cheaply available agro-residues such as rice bran and sugar cane bagasse. The maximum levan production by C. cellulans MP1 was 14.8 ± 1.2 g/l after 20 h of cultivation in media containing 200 g/l sucrose. To the best of our knowledge, the present study is the first genome-based analysis of a Cellulosimicrobium species which focuses on lignocellulosic enzymes and levan biosynthesis, illustrating that the C. cellulans MP1 has a great potential to be an efficient platform for basic research and industrial exploitation.

scholarly journals Evolution of a major virion protein of the giant pandoraviruses from an inactivated bacterial glycoside hydrolase

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Mart Krupovic ◽  
Natalya Yutin ◽  
Eugene Koonin
Keyword(s):  
Glycoside Hydrolase ◽  
Carbohydrate Binding ◽  
Virion Protein ◽  
Gene Encoding ◽  
Dna Viruses ◽  
Virus Particles ◽  
Major Increase ◽  
A Minor ◽  
Particle Shapes ◽  
Icosahedral Capsid

Abstract The diverse viruses in the phylum Nucleocytoviricota (also known as NLCDVs, Nucleo-cytoplasmic Large DNA Viruses) typically possess large icosahedral virions. However, in several families of Nucleocytoviricota, the icosahedral capsid was replaced by irregular particle shapes, most notably, the amphora-like virions of pandoraviruses and pithoviruses, the largest known virus particles in the entire virosphere. Pandoraviruses appear to be the most highly derived viruses in this phylum because their evolution involved not only the change in the virion shape, but also, the actual loss of the gene encoding double-jelly roll major capsid protein (DJR MCP), the main building block of icosahedral capsids in this virus assemblage. Instead, pandoravirus virions are built of unrelated abundant proteins. Here we show that the second most abundant virion protein of pandoraviruses, major virion protein 2 (MVP2), evolved from an inactivated derivative of a bacterial glycoside hydrolase of the GH16 family. The ancestral form of MVP2 was apparently acquired early in the evolution of the Nucleocytoviricota, to become a minor virion protein. After a duplication in the common ancestor of pandoraviruses and molliviruses, one of the paralogs displaces DJR MCP in pandoraviruses, conceivably, opening the way for a major increase in the size of the virion and the genome. Exaptation of a carbohydrate-binding protein for the function of the MVP is a general trend in virus evolution and might underlie the transformation of the virion shape in other groups of the Nucleocytoviricota as well.

scholarly journals Identification of Poly(cis-1,4-Isoprene) Degradation Intermediates during Growth of Moderately Thermophilic Actinomycetes on Rubber and Cloning of a Functional lcp Homologue from Nocardia farcinica Strain E1

2006 ◽  
Vol 72 (5) ◽  
pp. 3375-3382 ◽  
Author(s):  
Ebaid M. A. Ibrahim ◽  
Matthias Arensk�tter ◽  
Heinrich Luftmann ◽  
Alexander Steinb�chel
Keyword(s):  
Thermophilic Bacteria ◽  
Natural Rubber Latex ◽  
Gel Permeation Chromatography ◽  
Mycolic Acid ◽  
Rrna Gene ◽  
Ionization Mass ◽  
Thermophilic Actinomycetes ◽  
Moderately Thermophilic ◽  
Nocardia Farcinica ◽  
Different Strains

ABSTRACT The enrichment and isolation of thermophilic bacteria capable of rubber [poly(cis-1,4-isoprene)] degradation revealed eight different strains exhibiting both currently known strategies used by rubber-degrading mesophilic bacteria. Taxonomic characterization of these isolates by 16S rRNA gene sequence analysis demonstrated closest relationships to Actinomadura nitritigenes, Nocardia farcinica, and Thermomonospora curvata. While strains related to N. farcinica exhibited adhesive growth as described for mycolic acid-containing actinomycetes belonging to the genus Gordonia, strains related to A. nitritigenes and T. curvata formed translucent halos on natural rubber latex agar as described for several mycelium-forming actinomycetes. For all strains, optimum growth rates were observed at 50�C. The capability of rubber degradation was confirmed by mineralization experiments and by gel permeation chromatography (GPC). Intermediates resulting from early degradation steps were purified by preparative GPC, and their analysis by infrared spectroscopy revealed the occurrence of carbonyl carbon atoms. Staining with Schiff's reagent also revealed the presence of aldehyde groups in the intermediates. Bifunctional isoprenoid species terminated with a keto and aldehyde function were found by matrix-assisted laser desorption ionization-time-of-flight and electrospray ionization mass spectrometry analyses. Evidence was obtained that biodegradation of poly(cis-1,4-isoprene) is initiated by endocleavage, rather than by exocleavage. A gene (lcp) coding for a protein with high homology to Lcp (latex-clearing protein) from Streptomyces sp. strain K30 was identified in Nocardia farcinica E1. Streptomyces lividans TK23 expressing this Lcp homologue was able to cleave synthetic poly(cis-1,4-isoprene), confirming its involvement in initial polymer cleavage.

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