Formation of a Tree having a Low Lignin Content

Received 30 September 2001/ Accepted in revised form 26 October 2001     

Determination of taxonomic resolution capacity of conventional one-dimensional SDS-polyacrylamide gel electrophoresis of whole-cell proteins using Enterobacteriaceae

The capacity of one-dimensional SDS-PAGE of whole bacterial cells to both separate and cluster taxonomic units is studied using members of Enterobacteriaceae as test material. The results show that intraspecies variation can be detected and on the other hand the degree of taxonomic divergence which still can be grouped together is determined. In addition the system has high tolerance to changes in cell culture conditions making the usage of SDS-PAGE suitable for applications where rapid and reliable bacterial identification is needed.     

Methanogenic bacteria as a key factor involved in changes of town gas stored in an underground reservoir

Growth of Phanerochaete chrysosporium in a nitrogen-limited medium buffered with sodium acetate, instead of the commonly used 2,2-dimethylsuccinate (DMS), resulted in quantitative and qualitative differences in the production of various extracellular lignin peroxidases (LIPs) and manganese-dependent peroxidases (MNPs) involved in lignin degradation. The results indicate that production of LIPs and MNPs can be selectively enhanced by manipulation of culture conditions. Partial N-terminal analyses of the major LIPs and MNPs have made it possible to assign a specific protein to the specific genes and cDNAs that have been reported recently. The LIPs and MNPs differed widely in their ability to decolorize various dyes that are known to be degraded by the lignin degrading enzyme system of P. chrysosporium.     

Degradation of diarylethane structures by Pseudomonas fluorescens biovar I

Pseudomonas fluorescens biovar I was isolated from a pulp mill effluent based on its ability to grow on synthetic media containing 1,2-diarylethane structures as the sole carbon and energy source. Analysis of samples taken from cultures of this strain in benzoin or 4,4-dimethoxybenzoin (anisoin), showed that cleavage between the two aliphatic carbons takes place prior to ring fission. Intermonomeric cleavage was also obtained with crude extracts. Substrates of this reaction were only those 1,2-diarylethane compounds that supported growth of the bacterium. The purification and partial characterization of an enzyme that catalyzes the NADH-dependent reduction of the carbonyl group of benzoin and anisoin is also reported.     

A berberine-aniline blue fluorescent staining procedure for suberin,lignin, and callose in plant tissue

Summary A fluorescent staining procedure to detect suberin, lignin and callose in plants has been developed. This procedure greatly improves on previous methods for visualizing Casparian bands in root exodermal and endodermal cells, and performs equally well on a variety of other plant tissues. Berberine was selected as the most suitable replacement forChelidonium majus root extract after comparing the staining properties of the extract with those of four of its constituent alkaloids. Aniline blue counterstaining efficiently quenched unwanted background fluorescence and nonspecific berberine staining, while providing a fluorochrome for callose. When used with multichambered holders which allow simultaneous processing of freehand sections, this efficient staining procedure facilitates morphological studies involving large numbers of samples.Abbreviations ISCC-NBS Inter-Society Color Council-National Bureau of Standards - UV ultraviolet light     

Novel extracellular enzymes (ligninases) of Phanerochaete chrysosporium

Abstract 3 New spectrophotometric enzyme assays were developed for the study of microbial lignin-degrading enzymes. The conversion of 2-methoxy-3-phenylbenzoic acid to 2-hydroxy-3-phenylbenzoic acid led to the discovery of an extracellular, aromatic methyl ether demethylase produced by the white-rot fungus Phanerochaete chrysosporium . The conversion of methyl 2-hydroxy-3-phenylbenzoate to 2-hydroxy-3-phenylbenzoic acid allowed the identification of an extracellular, aromatic methyl ester esterase produced by this fungus. The Phanerochaete sp. also excreted an enzyme complex that oxidized 4-(4-hydroxy-3-methoxyphenyl)-3-buten-2-one, probably to aliphatic products. All 3 novel enzyme activities were produced together with, and probably comprise a part of, the Phanerochaete ligninolytic enzyme complex. Unlike previously known ligninases, these enzymes did not oxidize 3,4-dimethoxybenzyl alcohol. All 3 were H₂O₂-dependent and were activated by Mn²⁺ ions.     

A new bacterial alcohol dehydrogenase active on degraded lignin and several low molecular weight aromatic compounds

A new intracellular bacterial dehydrogenase has been purified. It was active in the reversible reduction by NADH of conjugated carbonyl groups in partially degraded lignin. It was also active on various aromatic aldehydes such as vanillin, syringaldehyde and cinnamaldehyde, but had no effect on acetovanillone and lignin models carrying a conjugated ketone. It is proposed that this enzyme functions as a broadly specific lignin dehydrogenase at the level of aldehydic groups that are present in the lignin preparations.     

Immunocytochemical localization of phenylalanine ammonia-lyase in tissues of Populus kitakamiensis

The polypeptide encoded by the partial fragment of cDNA of phenylalanine ammonia-lyase (PAL; EC 4.3.1.5), PALcDNAl (Osakabe et al., 1995, Plant Sci. 105: 217–226), isolated from Populus kitakamiensis (P. sieboldii x P. grandidentata), was expressed in Escherichia coli cells. The polypeptide was purified and an antiserum raised against it. The antiserum recognized a protein of 77 kDa on nitrocellulose blots after sodium dodecyl sulfate-poly-acrylamide gel electrophoresis of total protein and the partially purified PAL protein from P. kitakamiensis. Moreover,the antiserum recognized a protein on the blot after non-denaturing polyacrylamide gel electrophoresis of P. kitakamiensis proteins and this protein had PAL activity. Furthermore, the antibody inhibited PAL activity of extracts from stem tissues. These results showed that the antiserum against the partial PAL peptide recognized only the PAL subunits in extracts of P. kitakamiensis. Immunolocalization studies of P. kitakamiensis tissues revealed that the PAL protein was specifically localized in the xylem and the phloem fibers and no immunogold signal was found in the epidermis, the cortex, the pith, or the cambium of either stems or leaves.Abbreviations IgG immunoglobulin G - IPTG isopropylthio--d-galactoside - PAL phenylalanine ammonia-lyase The authors thank Dr. Kunio Hata of Nippon Paper Industries Co., Ltd. (Japan) for supplying P. kitakamiensis. This work was supported in part by a grant-in-aid for Scientific Research from the Ministry of Education, Science and Culture of Japan (No. 07406008).     

A proposed role of oxalic acid in wood decay systems of wood-rotting basidiomycetes

Abstract: The possible roles of oxalic acid, veratryl alcohol, and manganese were investigated in relation to lignin biodegradation by white-rot basidiomycetes. Oxalate inhibited both lignin peroxidase (LiP) and manganese-peroxidase (MnP). and was decarboxylated by the mediation of veratryl alcohol and Mn. Oxalate was shown to regulate the mineralization of lignin in the in vivo system of Phanerochaete chrysosporium . In the brown-rot wood decay process, oxalic acid may serve as an acid catalyst as well as an electron donor for the Fenton reaction, to breakdown cellulose and hemicellulose. Oxaloacetase and glyoxylate oxidase may play a key role in production of oxalic acid by white-rot and brown-rot basidiomycetes such as Phanerochaete chrysosporium, Coriolus versicolor and Tyromyces palustris . A possible role of oxalate metabolism is discussed in relation to the physiology of wood-rotting fungi.