Pub Date : 2002-05-01DOI: 10.1002/1521-3846(200205)22:1/2<107::AID-ABIO107>3.0.CO;2-#
H. Moormann, P. Kuschk, U. Stottmeister
The effect of rhizodeposition from helophytes (aquatic plants) on the bacterial degradation of toxic compounds such as phenolic substances was tested. Investigations were carried out as batch experiments with rhizodeposition products obtained from helophytes. DOC concentrations, which were used as points of reference for rhizodeposition, were between 2.5 and 12 mg per litre. Rhizodeposition was found to advance the biodegradation of 4-chlorophenol when using a mixed bacterial culture and pure cultures of bacteria previously isolated from Phalaris arundinacea roots. This stimulation is a result of rhizodeposition products serving as growth substrates for the bacteria. Investigations with Ralstonia eutropha (DSMZ Braunschweig, strain 5536) confirmed the function of rhizodeposition products as growth substrates. Degradation by Acinetobacter baumannii and Ralstonia sp. obtained from Phalaris arundinacea was'accompanied by the dechlorination of 4-chlorophenol. There was no enhancing impact on the degradation of the substances phenol and 2,6-dimethylphenol by rhizodeposition products.
{"title":"The effect of rhizodeposition from helophytes on bacterial degradation of phenolic compounds","authors":"H. Moormann, P. Kuschk, U. Stottmeister","doi":"10.1002/1521-3846(200205)22:1/2<107::AID-ABIO107>3.0.CO;2-#","DOIUrl":"https://doi.org/10.1002/1521-3846(200205)22:1/2<107::AID-ABIO107>3.0.CO;2-#","url":null,"abstract":"The effect of rhizodeposition from helophytes (aquatic plants) on the bacterial degradation of toxic compounds such as phenolic substances was tested. Investigations were carried out as batch experiments with rhizodeposition products obtained from helophytes. DOC concentrations, which were used as points of reference for rhizodeposition, were between 2.5 and 12 mg per litre. Rhizodeposition was found to advance the biodegradation of 4-chlorophenol when using a mixed bacterial culture and pure cultures of bacteria previously isolated from Phalaris arundinacea roots. This stimulation is a result of rhizodeposition products serving as growth substrates for the bacteria. Investigations with Ralstonia eutropha (DSMZ Braunschweig, strain 5536) confirmed the function of rhizodeposition products as growth substrates. Degradation by Acinetobacter baumannii and Ralstonia sp. obtained from Phalaris arundinacea was'accompanied by the dechlorination of 4-chlorophenol. There was no enhancing impact on the degradation of the substances phenol and 2,6-dimethylphenol by rhizodeposition products.","PeriodicalId":7037,"journal":{"name":"Acta Biotechnologica","volume":"71 1","pages":"107-112"},"PeriodicalIF":0.0,"publicationDate":"2002-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75656058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-05-01DOI: 10.1002/1521-3846(200205)22:1/2<161::AID-ABIO161>3.0.CO;2-#
U. Soltmann, H. Wand, A. Müller, P. Kuschk, U. Stottmeister
Upon exposure to the aromatic xenobiotics 2,6-dimethylphenol and 4-nitrophenol, distinct changes occurred in the microbial structure of the rhizosphere of the helophytes Carex graclis, Phalaris arundinacea and Juncus effusus (total number, diversity, abundance). Generally speaking, exposure to xenobiotics resulted in an increase in the total numbers of xenobiotic-degrading bacteria on roots and sand particles. The number of bacteria per cm 2 was significantly higher on the root surface than on the surface of sand particles in the rhizosphere. PCR fingerprinting methods such as RAPD (Randomly Amplified Polymorphic DNA) and 16S-23S rDNA intergenic spacer amplification or alternatively rRNA-targeted gene probes for the α-, β-, γ-subclasses of Proteobacteria, the Xanthomonas branch of Proteobacteria and Actinobacteria, were used to determine the diversity of arbitrary samples of bacterial isolates. The diversity of bacteria isolated from the rhizosphere decreased depending on the exposure time. The degrading bacteria were dominated by GRAM-positives. In the case of exposure to 2,6-dimethylphenol of Carex gracilis, GRAM-positive isolates became more dominant as the exposure time increased. Thus it was that after more than six months exposure to 2,6-dimethylphenol, only the GRAM-positives were isolated from a sand-bed reactor planted with Carex gracilis. Some of these isolates show interesting properties in addition to a high 2,6-dimethylphenol degradation rate. The 2,6-dimethylphenol degrading Mycobacterium sp. DMP 20 represents the first fluorescing GRAM-positive bacterium so far described. The introduction of allochthonous, high-performance degraders resulted in Mycobacterium sp. DMP 20 being permanently established in the rhizosphere, whereas the naphthalene degrader Pseudomonas putida PpG7 did not remain in the system.
{"title":"Exposure to xenobiotics deeply affects the bacteriocenosis in the rhizosphere of helophytes","authors":"U. Soltmann, H. Wand, A. Müller, P. Kuschk, U. Stottmeister","doi":"10.1002/1521-3846(200205)22:1/2<161::AID-ABIO161>3.0.CO;2-#","DOIUrl":"https://doi.org/10.1002/1521-3846(200205)22:1/2<161::AID-ABIO161>3.0.CO;2-#","url":null,"abstract":"Upon exposure to the aromatic xenobiotics 2,6-dimethylphenol and 4-nitrophenol, distinct changes occurred in the microbial structure of the rhizosphere of the helophytes Carex graclis, Phalaris arundinacea and Juncus effusus (total number, diversity, abundance). Generally speaking, exposure to xenobiotics resulted in an increase in the total numbers of xenobiotic-degrading bacteria on roots and sand particles. The number of bacteria per cm 2 was significantly higher on the root surface than on the surface of sand particles in the rhizosphere. PCR fingerprinting methods such as RAPD (Randomly Amplified Polymorphic DNA) and 16S-23S rDNA intergenic spacer amplification or alternatively rRNA-targeted gene probes for the α-, β-, γ-subclasses of Proteobacteria, the Xanthomonas branch of Proteobacteria and Actinobacteria, were used to determine the diversity of arbitrary samples of bacterial isolates. The diversity of bacteria isolated from the rhizosphere decreased depending on the exposure time. The degrading bacteria were dominated by GRAM-positives. In the case of exposure to 2,6-dimethylphenol of Carex gracilis, GRAM-positive isolates became more dominant as the exposure time increased. Thus it was that after more than six months exposure to 2,6-dimethylphenol, only the GRAM-positives were isolated from a sand-bed reactor planted with Carex gracilis. Some of these isolates show interesting properties in addition to a high 2,6-dimethylphenol degradation rate. The 2,6-dimethylphenol degrading Mycobacterium sp. DMP 20 represents the first fluorescing GRAM-positive bacterium so far described. The introduction of allochthonous, high-performance degraders resulted in Mycobacterium sp. DMP 20 being permanently established in the rhizosphere, whereas the naphthalene degrader Pseudomonas putida PpG7 did not remain in the system.","PeriodicalId":7037,"journal":{"name":"Acta Biotechnologica","volume":"7 1","pages":"161-166"},"PeriodicalIF":0.0,"publicationDate":"2002-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79475414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-02-01DOI: 10.1002/1521-3846(200102)21:1<65::AID-ABIO65>3.0.CO;2-#
P. S. Basu, A. C. Ghosh
The study of the rhizobial root nodules of the monocotyledonous tree Roystonea regia revealed that the Rhizobium sp. isolated from the root nodules produced high amounts (45.6 μg/ml) of indole acetic acid (IAA) from L-tryptophan supplemented basal medium. The IAA production reached its optimum using 3 mg/ml of L-tryptophan. The preferred carbon and nitrogen sources were glucose and KNO 3 and the optimum concentrations 1% and 0.02%, respectively. FeSO 4 x 7 H 2 O was found to be the only metal ion that increased IAA production. An optimum IAA production was also achieved when the basal medium was supplemented with glucose (1%), FeSO 4 x 7 H 2 O (10 μg/ml), KNO 3 (0.02%) as well as EDTA (5 μg/ml) and L-tryptophan (3 mg/ml). The possible role of IAA production in the monocotyledonous tree-Rhizobium symbiosis is discussed. Hormone production is shown to be the beneficial aspect of this symbiosis as shown earlier in dicotyledonous plants.
{"title":"Production of Indole Acetic Acid in Culture by a Rhizobium Species from the Root Nodules of a Monocotyledonous Tree, Roystonea regia","authors":"P. S. Basu, A. C. Ghosh","doi":"10.1002/1521-3846(200102)21:1<65::AID-ABIO65>3.0.CO;2-#","DOIUrl":"https://doi.org/10.1002/1521-3846(200102)21:1<65::AID-ABIO65>3.0.CO;2-#","url":null,"abstract":"The study of the rhizobial root nodules of the monocotyledonous tree Roystonea regia revealed that the Rhizobium sp. isolated from the root nodules produced high amounts (45.6 μg/ml) of indole acetic acid (IAA) from L-tryptophan supplemented basal medium. The IAA production reached its optimum using 3 mg/ml of L-tryptophan. The preferred carbon and nitrogen sources were glucose and KNO 3 and the optimum concentrations 1% and 0.02%, respectively. FeSO 4 x 7 H 2 O was found to be the only metal ion that increased IAA production. An optimum IAA production was also achieved when the basal medium was supplemented with glucose (1%), FeSO 4 x 7 H 2 O (10 μg/ml), KNO 3 (0.02%) as well as EDTA (5 μg/ml) and L-tryptophan (3 mg/ml). The possible role of IAA production in the monocotyledonous tree-Rhizobium symbiosis is discussed. Hormone production is shown to be the beneficial aspect of this symbiosis as shown earlier in dicotyledonous plants.","PeriodicalId":7037,"journal":{"name":"Acta Biotechnologica","volume":"24 1","pages":"65-72"},"PeriodicalIF":0.0,"publicationDate":"2001-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85682660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Chemical sensors and biosensors for medical and biological applications. Chichester, New York, Weinheim, Brisbane, Singapore, Toronto: John Wiley & Sons XII + 413 pages, 82 figures, 41 tables; DM 198.00, ISBN 3-527-28855-4","authors":"H. Schmauder","doi":"10.1002/abio.370200307","DOIUrl":"https://doi.org/10.1002/abio.370200307","url":null,"abstract":"","PeriodicalId":7037,"journal":{"name":"Acta Biotechnologica","volume":"2 1","pages":"234-234"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73813004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The recent upsurge in information technology has provided the international community with an easy access to professional journals (e.g. Electronic Journal of Biotechnology at http://www.ejb.org; etc.), discussion groups (e.g. bioenergy@crest.org; digestion@crest.org; etc.) and recently to electronic international conferences (e.g. ICIBS; http://www.cid.harvard.edu/cidbiotech, etc.) as well as a series of biotechnological information material (e.g. http://www.psrast.org, etc.) to stay in contact and receive up-to-date information in biotechnology. There is no doubt that this new technology will be more cost effective in future and reach more people in communities around the globe. This review reports on one such an electronic conference aiming at bridging the communication gap between developed and developing countries. This conference dealt with integrated biosystems and has provided an excellent forum for more than 100 active participants from all regions of the world. As has been demonstrated in this review, the conference was able to show the very different approaches towards the use of biotechnology in developed and developing countries, cold and tropical climate regions owing to their different ecological, economical and societal problems. It also demonstrated very clearly that the field of molecular genetics and/or genetic engineering is not a priority issue in developing countries, but rather the need for clean technologies, multiproduct formation through socio-economic integrated biosystems, e.g. incorporating microbial waste management into agro-industries, in human activities and their roles in creating better health conditions, a better environment and sustain development. It is hoped that this review will lead to a greater use of the electronic facilities available to inform and educate both the northern and the southern communities more readily of their needs and requirements to improve understanding and efforts for a sustainable future.
{"title":"Socio‐ecological strategies for future sustainability a review of an internet conference","authors":"H. Doelle, E. Foo","doi":"10.1002/ABIO.370200305","DOIUrl":"https://doi.org/10.1002/ABIO.370200305","url":null,"abstract":"The recent upsurge in information technology has provided the international community with an easy access to professional journals (e.g. Electronic Journal of Biotechnology at http://www.ejb.org; etc.), discussion groups (e.g. bioenergy@crest.org; digestion@crest.org; etc.) and recently to electronic international conferences (e.g. ICIBS; http://www.cid.harvard.edu/cidbiotech, etc.) as well as a series of biotechnological information material (e.g. http://www.psrast.org, etc.) to stay in contact and receive up-to-date information in biotechnology. There is no doubt that this new technology will be more cost effective in future and reach more people in communities around the globe. This review reports on one such an electronic conference aiming at bridging the communication gap between developed and developing countries. This conference dealt with integrated biosystems and has provided an excellent forum for more than 100 active participants from all regions of the world. As has been demonstrated in this review, the conference was able to show the very different approaches towards the use of biotechnology in developed and developing countries, cold and tropical climate regions owing to their different ecological, economical and societal problems. It also demonstrated very clearly that the field of molecular genetics and/or genetic engineering is not a priority issue in developing countries, but rather the need for clean technologies, multiproduct formation through socio-economic integrated biosystems, e.g. incorporating microbial waste management into agro-industries, in human activities and their roles in creating better health conditions, a better environment and sustain development. It is hoped that this review will lead to a greater use of the electronic facilities available to inform and educate both the northern and the southern communities more readily of their needs and requirements to improve understanding and efforts for a sustainable future.","PeriodicalId":7037,"journal":{"name":"Acta Biotechnologica","volume":"359 1","pages":"203-218"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84892926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Desulfovibrio vulgaris strain PY1 was isolated from a 3-chlorobenzoic acid (3CBA) degrading anaerobic enrichment culture, using anaerobic Percoll density centrifugation. When grown on pyruvate (20 mM), in the absence of sulphate and under strict anaerobic conditions, this organism converted not only the co-substrates benzoate (BA), 3-amino-BA and 3CBA to the corresponding alcohols but also ten other different halogenated benzoic acids, viz., 4-Cl-, 3-Br-, 4-Br-, 3-I-, 3-F-, 4-F-, 2,4-di-Cl-, 2,5-di-CI-, 3,4-di-Cl- and 3,5-di-Cl-BA. This was verified with HPLC and GC/MS spectrometric analyses. The yields of the co-substrate converted after 30 days of growth were between 20% and 88%, depending on the compounds which had been added at initial concentrations of 500 μM. Sulphate, sulphite, thiosulphate and disulphite inhibited the formation of 3-Cl-benzyl alcohol (3CBOH), i.e. a 97 to 99% inhibition, and nitrate and sulphur had no effect (a 7-10% inhibition). In cell-free extracts, the reduction of 3CBA to 3CBOH required strict anaerobic conditions, pyruvate or H 2 as electron donors and the addition of methylviologen (MV), FAD, FMN or ferre-doxin as electron carriers. The specific activity of the reduction of 3CBA to 3CBOH in crude extract was 5.3 nmol/(mg protein min). The reaction was not inhibited by additions of sulphate or sulphite (5 mM), but was completely inhibited at concentrations of 10 mM 3CBA or 50 mM BA. A carboxylic acid reductase (aldehyde dehydrogenase), which acted on non-activated 3CBA and was responsible for the reduction of 3CBA to 3-Cl-benzaldehyde, was found in the soluble fraction (94% of the total activity). These results demonstrate that strain PY1 was able to effectively reduce a wide range of halogenated benzoic acids to the corresponding alcohols.
采用厌氧Percoll密度离心，从3-氯苯甲酸(3CBA)降解厌氧富集培养基中分离出寻常型脱硫弧菌PY1。当在丙酮酸盐(20 mM)上生长时，在没有硫酸盐和严格的厌氧条件下，该生物不仅将共底物苯甲酸(BA)， 3-氨基BA和3CBA转化为相应的醇，而且还将其他十种不同的卤代苯甲酸转化为4-Cl-， 3- br -， 4-Br-， 3- i-， 3- f -， 4-F-， 2,4-二- cl -， 2,5-二- ci -， 3,4-二- cl -和3,5-二- cl -BA。通过HPLC和GC/MS谱分析证实了这一点。生长30天后，共底物的转化率在20%到88%之间，这取决于初始浓度为500 μM时添加的化合物。硫酸盐、亚硫酸盐、硫代硫酸盐和二亚硫酸盐对3- cl -苄基醇(3CBOH)的形成有97% ~ 99%的抑制作用，而硝酸盐和硫对3- cl -苄基醇(3CBOH)的形成没有影响(7 ~ 10%的抑制作用)。在无细胞提取物中，3CBA还原为3CBOH需要严格的厌氧条件，丙酮酸或h2作为电子给体，甲基紫素(MV)、FAD、FMN或铁氧还蛋白作为电子载体。粗提物还原3CBA为3CBOH的比活性为5.3 nmol/(mg protein min)。硫酸盐或亚硫酸盐(5 mM)的加入对反应没有抑制作用，但在10 mM 3CBA或50 mM BA浓度下，反应完全被抑制。羧酸还原酶(醛脱氢酶)作用于未活化的3CBA，并在可溶性部分(占总活性的94%)将3CBA还原为3- cl -苯甲醛。这些结果表明，菌株PY1能够有效地将各种卤代苯甲酸还原为相应的醇类。
{"title":"Reduction of halogenated derivatives of benzoic acid to the corresponding alcohols by Desulfovibrio vulgaris PY1","authors":"M. Bock, H. Kneifel, S. Schoberth, H. Sahm","doi":"10.1002/ABIO.370200303","DOIUrl":"https://doi.org/10.1002/ABIO.370200303","url":null,"abstract":"Desulfovibrio vulgaris strain PY1 was isolated from a 3-chlorobenzoic acid (3CBA) degrading anaerobic enrichment culture, using anaerobic Percoll density centrifugation. When grown on pyruvate (20 mM), in the absence of sulphate and under strict anaerobic conditions, this organism converted not only the co-substrates benzoate (BA), 3-amino-BA and 3CBA to the corresponding alcohols but also ten other different halogenated benzoic acids, viz., 4-Cl-, 3-Br-, 4-Br-, 3-I-, 3-F-, 4-F-, 2,4-di-Cl-, 2,5-di-CI-, 3,4-di-Cl- and 3,5-di-Cl-BA. This was verified with HPLC and GC/MS spectrometric analyses. The yields of the co-substrate converted after 30 days of growth were between 20% and 88%, depending on the compounds which had been added at initial concentrations of 500 μM. Sulphate, sulphite, thiosulphate and disulphite inhibited the formation of 3-Cl-benzyl alcohol (3CBOH), i.e. a 97 to 99% inhibition, and nitrate and sulphur had no effect (a 7-10% inhibition). In cell-free extracts, the reduction of 3CBA to 3CBOH required strict anaerobic conditions, pyruvate or H 2 as electron donors and the addition of methylviologen (MV), FAD, FMN or ferre-doxin as electron carriers. The specific activity of the reduction of 3CBA to 3CBOH in crude extract was 5.3 nmol/(mg protein min). The reaction was not inhibited by additions of sulphate or sulphite (5 mM), but was completely inhibited at concentrations of 10 mM 3CBA or 50 mM BA. A carboxylic acid reductase (aldehyde dehydrogenase), which acted on non-activated 3CBA and was responsible for the reduction of 3CBA to 3-Cl-benzaldehyde, was found in the soluble fraction (94% of the total activity). These results demonstrate that strain PY1 was able to effectively reduce a wide range of halogenated benzoic acids to the corresponding alcohols.","PeriodicalId":7037,"journal":{"name":"Acta Biotechnologica","volume":"160 1","pages":"189-201"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75682857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Müler, A. Lösche, H. Mertingk, W. Beisker, W. Babel
The GRAM-positive bacterium Rhodococcus erythropolis K2-3 and the GRAM-negative Ochrobactrum anthropi K2-14 are capable of synergistically degrading 4-(2,4-dichlorophenoxy)butyric acid (2,4-DB). The two strains execute this task in a symbiotic manner, but the nature of the interactions involved in the degradation is only partially understood as yet. An essential first step in elucidating the interaction is to be able to monitor the two strains separately, at the cellular level, within mixed populations. Therefore a method exploiting fluorescently labelled lectin probes was developed. Since Concanavalin A (Con A) binds specifically to R. erythropolis K2-3, it was selected and linked to the fluorescent dye Bodipy 630/650, which has an excitation maximum in the red part of the visible light spectrum. Forward light scatter (FSC) and DNA fluorescence from both strains were also measured to obtain simultaneous information about their physiological states. The three parameters were conveniently monitored by dual and triple excitation flow cytometry in conjunction with double fluorescent staining techniques. In addition, the strains were identified using an epifluorescence microscope. These techniques were found powerful tools for the population analysis of this mixed bacterial system.
{"title":"Flow cytometric monitoring of Rhodococcus erythropolis and Ochrobactrum anthropi in a mixed culture","authors":"S. Müler, A. Lösche, H. Mertingk, W. Beisker, W. Babel","doi":"10.1002/ABIO.370200306","DOIUrl":"https://doi.org/10.1002/ABIO.370200306","url":null,"abstract":"The GRAM-positive bacterium Rhodococcus erythropolis K2-3 and the GRAM-negative Ochrobactrum anthropi K2-14 are capable of synergistically degrading 4-(2,4-dichlorophenoxy)butyric acid (2,4-DB). The two strains execute this task in a symbiotic manner, but the nature of the interactions involved in the degradation is only partially understood as yet. An essential first step in elucidating the interaction is to be able to monitor the two strains separately, at the cellular level, within mixed populations. Therefore a method exploiting fluorescently labelled lectin probes was developed. Since Concanavalin A (Con A) binds specifically to R. erythropolis K2-3, it was selected and linked to the fluorescent dye Bodipy 630/650, which has an excitation maximum in the red part of the visible light spectrum. Forward light scatter (FSC) and DNA fluorescence from both strains were also measured to obtain simultaneous information about their physiological states. The three parameters were conveniently monitored by dual and triple excitation flow cytometry in conjunction with double fluorescent staining techniques. In addition, the strains were identified using an epifluorescence microscope. These techniques were found powerful tools for the population analysis of this mixed bacterial system.","PeriodicalId":7037,"journal":{"name":"Acta Biotechnologica","volume":"22 1","pages":"219-233"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75095167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Kamm, M. Kamm, K. Richter, W. Reimann, A. Siebert
A fermentation process for manufacturing 1,4-piperazinium-(L,L)-dilactate from renewable raw materials and a method for processing this product into L,L-dilactide are described. Lactic acid fermentation with Lactobacillus paracasei was modified in such a way that pH control occurred by using an aqueous solution of piperazine as a correcting agent instead of sodium hydroxide solution. The production of a stoichiometrically composed piperazinium lactate was possible when the pH was 5.0. From 5.0 kg of glucose and 2.15 kg of piperazine, 6.65 kg of 1,4-piperazinium-(L,L)-dilactate were formed in the fermentation process. Separation from fermentation broth, purification and concentration of the product in aqueous solutions were carried out by means of ultrafiltration, nanofiltration and electrodialysis. Total product retention by the membranes used was about 33%. The crystalline salt was obtained by vacuum evaporation. Processing of the 1,4- piperazinium-(L,L)-dilactate into L,L-dilactide was performed in a special glass reactor. A product yield of 70% was achieved. The purified product was characterized by elementary analysis, as well as solubility behaviour, polarity and spectroscopic data. An overall process consisting of the stages fermentation, purification and concentration of piperazinium dilactate as well as cyclization of the latter to dilactide is described.
介绍了一种利用可再生原料发酵生产1,4-哌嗪-(L,L)-dilactate的工艺及将该产品加工成L,L- dilactate的方法。对副干酪乳杆菌的乳酸发酵进行了改进，通过使用哌嗪水溶液代替氢氧化钠溶液来控制pH值。当pH为5.0时，可以生产化学计量组成的乳酸哌嗪。在发酵过程中，由5.0 kg葡萄糖和2.15 kg哌嗪生成6.65 kg 1,4-哌嗪-(L,L)-dilactate。通过超滤、纳滤和电渗析对发酵液进行分离、纯化和水溶液浓缩。所使用的膜的总产物保留率约为33%。采用真空蒸发法制备结晶盐。在专用玻璃反应器中将1,4-哌嗪-(L,L)-dilactate加工成L,L- dilactate。产品收率达70%。通过元素分析、溶解度、极性和光谱数据对纯化产物进行了表征。整个过程包括发酵阶段，纯化和浓缩的戊二酸哌嗪，以及后者的环化到戊二酸。
{"title":"Formation of aminium lactates in lactic acid fermentation. Fermentative production of 1,4‐piperazinium‐(L,L)‐dilactate and its use as a starting material for the synthesis of dilactide (Part 2)","authors":"B. Kamm, M. Kamm, K. Richter, W. Reimann, A. Siebert","doi":"10.1002/ABIO.370200310","DOIUrl":"https://doi.org/10.1002/ABIO.370200310","url":null,"abstract":"A fermentation process for manufacturing 1,4-piperazinium-(L,L)-dilactate from renewable raw materials and a method for processing this product into L,L-dilactide are described. Lactic acid fermentation with Lactobacillus paracasei was modified in such a way that pH control occurred by using an aqueous solution of piperazine as a correcting agent instead of sodium hydroxide solution. The production of a stoichiometrically composed piperazinium lactate was possible when the pH was 5.0. From 5.0 kg of glucose and 2.15 kg of piperazine, 6.65 kg of 1,4-piperazinium-(L,L)-dilactate were formed in the fermentation process. Separation from fermentation broth, purification and concentration of the product in aqueous solutions were carried out by means of ultrafiltration, nanofiltration and electrodialysis. Total product retention by the membranes used was about 33%. The crystalline salt was obtained by vacuum evaporation. Processing of the 1,4- piperazinium-(L,L)-dilactate into L,L-dilactide was performed in a special glass reactor. A product yield of 70% was achieved. The purified product was characterized by elementary analysis, as well as solubility behaviour, polarity and spectroscopic data. An overall process consisting of the stages fermentation, purification and concentration of piperazinium dilactate as well as cyclization of the latter to dilactide is described.","PeriodicalId":7037,"journal":{"name":"Acta Biotechnologica","volume":"1 1","pages":"289-304"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79923849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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