Source Of Energy For Growth Research Articles

A Defined, Glucose-Limited Mineral Medium for the Cultivation of Listeria spp

Members of the genus Listeria are fastidious bacteria with respect to their nutritional requirements, and several minimal media described in the literature fail to support growth of all Listeria spp. Furthermore, strict limitation by a single nutrient, e.g., the carbon source, has not been demonstrated for any of the published minimal media. This is an important prerequisite for defined studies of growth and physiology, including "omics." Based on a theoretical analysis of previously published mineral media for Listeria, an improved, well-balanced growth medium was designed. It supports the growth, not only of all tested Listeria monocytogenes strains, but of all other Listeria species, with the exception of L. ivanovii. The growth performance of L. monocytogenes strain Scott A was tested in the newly designed medium; glucose served as the only carbon and energy source for growth, whereas neither the supplied amino acids nor the buffering and complexing components (MOPS [morpholinepropanesulfonic acid] and EDTA) supported growth. Omission of amino acids, trace elements, or vitamins, alone or in combination, resulted in considerably reduced biomass yields. Furthermore, we monitored the specific growth rates of various Listeria strains cultivated in the designed mineral medium and compared them to growth in complex medium (brain heart infusion broth [BHI]). The novel mineral medium was optimized for the commonly used strain L. monocytogenes Scott A to achieve optimum cell yields and maximum specific growth rates. This mineral medium is the first published synthetic medium for Listeria that has been shown to be strictly carbon (glucose) limited.

Transports of acetate and haloacetate in Burkholderiaspecies MBA4 are operated by distinct systems

BackgroundAcetate is a commonly used substrate for biosynthesis while monochloroacetate is a structurally similar compound but toxic and inhibits cell metabolism by blocking the citric acid cycle. In Burkholderia species MBA4 haloacetate was utilized as a carbon and energy source for growth. The degradation of haloacid was mediated by the production of an inducible dehalogenase. Recent studies have identified the presence of a concomitantly induced haloacetate-uptake activity in MBA4. This uptake activity has also been found to transport acetate. Since acetate transporters are commonly found in bacteria it is likely that haloacetate was transported by such a system in MBA4.ResultsThe haloacetate-uptake activity of MBA4 was found to be induced by monochloroacetate (MCA) and monobromoacetate (MBA). While the acetate-uptake activity was also induced by MCA and MBA, other alkanoates: acetate, propionate and 2-monochloropropionate (2MCPA) were also inducers. Competing solute analysis showed that acetate and propionate interrupted the acetate- and MCA- induced acetate-uptake activities. While MCA, MBA, 2MCPA, and butyrate have no effect on acetate uptake they could significantly quenched the MCA-induced MCA-uptake activity. Transmembrane electrochemical potential was shown to be a driving force for both acetate- and MCA- transport systems.ConclusionsHere we showed that acetate- and MCA- uptake in Burkholderia species MBA4 are two transport systems that have different induction patterns and substrate specificities. It is envisaged that the shapes and the three dimensional structures of the solutes determine their recognition or exclusion by the two transport systems.

Biodegradation of tetrabromobisphenol A by a novel Comamonas sp. strain, JXS-2-02, isolated from anaerobic sludge

A bacterial strain able to rapidly degrade tetrabromobisphenol A (TBBPA), JXS-2-02, was isolated from anaerobic sludge that had been successfully enrichment by adding TBBPA for 240days. JXS-2-02 can use TBBPA as the sole carbon and energy source for growth in mineral salt medium. Based on morphology, biochemical characteristics and 16S rDNA sequence analysis, JXS-2-02 was identified as Comamonas sp.. Under the optimal conditions (pH 7.0, a temperature of 30°C and an inoculum of 1% OD600=0.6), more than 86% of the initial TBBPA (0.5mgL−1) was degraded after 10d. A TBBPA biodegradation pathway was proposed on the basis of the metabolite production patterns and the identification of the metabolites by GC–MS analysis. This study is the first report to isolate a single TBBPA-degrading bacterial strain under anaerobic conditions for TBBPA debromination and detoxification.

Existence of a robust haloacid transport system in a Burkholderia species bacterium

Bacterium Burkholderia sp. MBA4 can utilize haloacids as the sole carbon and energy source for growth. We have previously reported that a haloacid operon, encoding for a dehalogenase (Deh4a) and an associated permease (Deh4p), was responsible for the transformation and uptake of haloacids in MBA4. A disruption of deh4p in MBA4 caused a decrease in monochloroacetate (MCA) uptake, confirming its role as a haloacid transporter. However, this disruptant retained 68% of its MCA-uptake activity indicating the possibility of an alternative system. In this study, we report the identification of a second MCA-inducible haloacid transporter (Dehp2) in MBA4. Its function was confirmed by gene disruption and heterologous expression in Escherichia coli. A dehp2− mutant has 30% less, and an E. coli expressing Dehp2 has 40% more, of wildtype MCA-uptake activity. Quantitative RT-PCR illustrated that the minor loss of MCA-uptake activity in single disruptants of deh4p and dehp2 was partly due to a compensatory expression of the alternative gene. Competition assay and kinetics study revealed that Deh4p has a higher affinity for MCA while Dehp2 prefers chloropropionate. A deh4p−dehp2− double mutant retained 36% of MCA-uptake activity, indicating a robustness of the haloacid uptake systems. The MCA uptake activities mediated by Deh4p, Dehp2 and the uncharacterized system were completely abolished by protonophore carbonyl cyanide 3-chlorophenylhydrazone, suggesting that transmembrane electrochemical gradient is the driving force for MCA uptake.

Novel dehalogenase mechanism for 2,3-dichloro-1-propanol utilization in Pseudomonas putida strain MC4.

A Pseudomonas putida strain (MC4) that can utilize 2,3-dichloro-1-propanol (DCP) and several aliphatic haloacids and haloalcohols as sole carbon and energy source for growth was isolated from contaminated soil. Degradation of DCP was found to start with oxidation and concomitant dehalogenation catalyzed by a 72-kDa monomeric protein (DppA) that was isolated from cell lysate. The dppA gene was cloned from a cosmid library and appeared to encode a protein equipped with a signal peptide and that possessed high similarity to quinohemoprotein alcohol dehydrogenases (ADHs), particularly ADH IIB and ADH IIG from Pseudomonas putida HK. This novel dehalogenating dehydrogenase has a broad substrate range, encompassing a number of nonhalogenated alcohols and haloalcohols. With DCP, DppA exhibited a k(cat) of 17 s(-1). (1)H nuclear magnetic resonance experiments indicated that DCP oxidation by DppA in the presence of 2,6-dichlorophenolindophenol (DCPIP) and potassium ferricyanide [K(3)Fe(CN)(6)] yielded 2-chloroacrolein, which was oxidized to 2-chloroacrylic acid.

Isolation and characterization of a benzoic acid degrading Pseudomonas putida from a pharmaceutical wastewater treatment plant

A Gram-negative benzoic acid degrading bacterial strain Bz was isolated from the wastewater treatment plant of Shandong Xinhua Pharmaceutical Co., Ltd in Zibo city, China. It could utilize benzoic acid as the sole carbon and energy source for growth. Under the optimum temperature of 30°C and pH value of 7.5, the benzoic acid degradation rate reached 94% in the basal medium in 96 h. Besides, it could utilize salicylic acid or phenylacetic acid as the sole carbon and energy source. Physiological and biochemical experiments revealed that the bacterium shared common characters with Pseudomoasputida not only in cytochrome oxidase positive, but also in the substrates assimilation profile tested. These properties supported the bacterium to be a member of P. putida. Furthermore, the 16S rRNA gene of the bacterium was obtained and sequenced (JN542509). The resulting phylogenetic analysis, based on the sequence and the relatives indicated that the bacterium shared 98 to 99% homologies with the members of P. putida. Therefore, strain Bz was identified to be a member of P. putida. This study presented valuable resources for the biodegradation and biotreatment of aromatic waste. Key words: Benzoic acid, degrading properties, physiology, 16S rRNA phylogeny,Pseudomoas putida.

Biodegradation of di-n-butyl phthalate by an isolated Gordonia sp. strain QH-11: Genetic identification and degradation kinetics

Di-n-butyl phthalate (DBP) is one of the most widely used phthalic acid esters (PAEs), which have shown increasing environmental concerns worldwide. A bacterial strain designated as QH-11, was isolated from activated sludge and found to be capable of utilizing DBP as carbon and energy sources for growth. 16S rRNA and gyrb gene sequence analysis revealed that strain QH-11 was most closely related to Gordonia sp. Kinetics studies of DBP degradation by the strain QH-11 revealed that DBP depletion curves fit with the modified Gompertz model (R2>0.98). Meanwhile, substrate utilization tests showed that strain QH-11 could utilize other common PAEs and also the main intermediate product phthalic acid (PA). A gene encoding the large subunit of the phthalate dioxygenase, which is responsible for PA degradation, was successfully detected in strain QH-11. Furthermore, the results of reverse transcription quantitative PCR demonstrate that mRNA expression level of phthalate dioxygenase increased significantly after strain QH-11 was induced by DBP and PA.

Metabolic engineering of β-oxidation in Penicillium chrysogenum for improved semi-synthetic cephalosporin biosynthesis

Industrial production of semi-synthetic cephalosporins by Penicillium chrysogenum requires supplementation of the growth media with the side-chain precursor adipic acid. In glucose-limited chemostat cultures of P. chrysogenum, up to 88% of the consumed adipic acid was not recovered in cephalosporin-related products, but used as an additional carbon and energy source for growth. This low efficiency of side-chain precursor incorporation provides an economic incentive for studying and engineering the metabolism of adipic acid in P. chrysogenum. Chemostat-based transcriptome analysis in the presence and absence of adipic acid confirmed that adipic acid metabolism in this fungus occurs via β-oxidation. A set of 52 adipate-responsive genes included six putative genes for acyl-CoA oxidases and dehydrogenases, enzymes responsible for the first step of β-oxidation. Subcellular localization of the differentially expressed acyl-CoA oxidases and dehydrogenases revealed that the oxidases were exclusively targeted to peroxisomes, while the dehydrogenases were found either in peroxisomes or in mitochondria. Deletion of the genes encoding the peroxisomal acyl-CoA oxidase Pc20g01800 and the mitochondrial acyl-CoA dehydrogenase Pc20g07920 resulted in a 1.6- and 3.7-fold increase in the production of the semi-synthetic cephalosporin intermediate adipoyl-6-APA, respectively. The deletion strains also showed reduced adipate consumption compared to the reference strain, indicating that engineering of the first step of β-oxidation successfully redirected a larger fraction of adipic acid towards cephalosporin biosynthesis.

Biodegradation of bensulphuron-methyl by a novel Penicillium pinophilum strain, BP-H-02

A fungal strain able to rapidly degrade bensulphuron-methyl (BSM), called BP-H-02, was isolated for the first time from soil that had been contaminated with BSM for several years. BP-H-02 can use BSM as the sole carbon and energy source for growth in a mineral salt medium. Based on morphological and internal transcribed spacer (ITS) analysis, BP-H-02 was identified as Penicillium pinophilum. Under optimal conditions (pH 6.5, temperature 30°C and 200mg/L VSSinoculum), more than 87% of the initially added BSM (50mg/L) was degraded after 60h. Metabolites were identified as 2-amino-4,6-dimethoxypyrimidine and 1-(4,6-dimethoxypyrimidin-2-yl) urea by liquid chromatography–mass spectrometry (LC–MS), and a possible degradation pathway was deduced. In a soil bioremediation experiment, inoculation of soil with BP-H-02 promoted the degradation of BSM more effectively than did the control. These results revealed that BP-H-02 can biodegrade bensulphuron-methyl efficiently and could potentially be used to bioremediate sulphonylurea herbicides contamination.

Research on 17β-Estradiol Degradation Bacteria Isolated from Activated Sludge and its Degrade Characteristics

17β-estradiol(E2) has estrogenic activity at very low concentrations and are emerging as a major concern for water quality. Great endeavors have been done on the removal of E2 in wastewater. This article was mainly researched the isolated of E2 degradation bacteria from activated sludge and its degradation characteristics of the bacteria were also researched. According to its physiological biochemical results analysis, this strain was identified as K.pnem. pneumoniae .This strain can use E2 as sole carbon and energy source for growth. The optimal temperature, pH for the bacterial growth and degradation of E2 was 30°C,7.0, respectively, meanwhile degradation rate reached to 86% and 87%; degradation rate and bacterial growth increased along with E2 concentration increasing, 81% E2 was degraded when E2 concentration is 30mg/L, degradation rate decreased when E2>50mg/L; metal ions such as Fe2+ and Zn2+ almost have no effect on E2 degradation and bacterial growth; Mn 2+ can promote growth of strain and degradation, while, metal ions such as Hg2+ ,Ag+ ,Cu 2+ have negative effect on bacterial growth and degradation. The degradation process for E2 with initial concentration of 1mg/L indicated that the degradation rate of E2 by strain within 7days was 98%.

Biodegradation of methyl parathion and p-nitrophenol by a newly isolated Agrobacterium sp. strain Yw12

Strain Yw12, isolated from activated sludge, could completely degrade and utilize methyl parathion as the sole carbon, phosphorus and energy sources for growth in the basic salt media. It could also completely degrade and utilize p-nitrophenol as the sole carbon and energy sources for growth in the minimal salt media. Phenotypic features, physiological and biochemical characteristics, and phylogenetic analysis of 16S rRNA sequence showed that this strain belongs to the genus of Agrobacterium sp. Response surface methodology was used to optimize degradation conditions. Under its optimal degradation conditions, 50mgl(-1) MP was completely degraded within 2h by strain Yw12 and the degradation product PNP was also completely degraded within 6h. Furthermore, strain Yw12 could also degrade phoxim, methamidophos, chlorpyrifos, carbofuran, deltamethrin and atrazine when provided as the sole carbon and energy sources. Enzymatic analysis revealed that the MP degrading enzyme of strain Yw12 is an intracellular enzyme and is expressed constitutively. These results indicated that strain Yw12 might be used as a potential and effective organophosphate pesticides degrader for bioremediation of contaminated sites.

Acidipila rosea gen. nov., sp. nov., an acidophilic chemoorganotrophic bacterium belonging to the phylum Acidobacteria

Two strains of aerobic acidophilic chemoorganotrophic bacteria designed strains AP8(T) and AP9 were isolated from acid mine drainage and acidic soil, respectively. These isolates were gram-negative, nonmotile cocci and coccobacilli measuring 0.5-0.8 μm in diameter. Cells were capsulated. Colonies on solid media were pink colored. The pH range for growth was 3.0-6.0 (optimum pH 4.5). Sugars, gluconate, and some amino acids were good carbon and energy sources for growth. The main components of cellular fatty acids were C(15:0) iso and C(16:1) ω7c. Menaquinone-8 was the major quinone. The G+C content of genomic DNA was 59.5%. Both strains had identical sequences of 16S rRNA genes that were most closely related to that of the type strain of Acidobacterium capsulatum (96% similarity). There were major differences between the isolates and A. capsulatum in cell morphology, carbon nutrition, and fatty acid profiles. Based on these phylogenetic and phenotypic data, we propose the name Acidipila rosea gen. nov., sp. nov. to accommodate the novel isolates. The type strain is AP8(T) (NBRC 107607(T), KCTC 23427(T)).

Development of a mutant strain of Bacillus subtilis showing enhanced production of acetoin

This paper described the screening process of a mutant strain of Bacillus subtilis TH-49 showing specific characteristic and enhanced production of acetoin. The mutant was obtained by treating B. subtilis N-12 with ultraviolet ray (ultraviolet ray (UV)) or nitrosoguanidine (NTG) or compound mutation and subjecting it to a shake flask fermentation selection procedure. The acetoin production rate reached the highest value of 43.8 and 46.9 g/l in flask and 10-l fermenter fermentations, respectively. It was almost 4 times higher than that of the starting strain B. subtilis N-12. Through fermentation experiments, it was confirmed that the mutant strain, TH-49, was not capable of using acetoin accumulated in broth as its energy sources for growth after glucose was consumed. This phenomenon was inconsistent with that the majorities of bacteria accumulate acetoin as stored energy sources and could continue to use acetoin as energy sources after the exhaustion of glucose. By gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analysis, it was proved that the main metabolite produced by mutant strain TH-49 was acetoin and there were no other metabolites commonly found as byproducts of acetoin fermentation, such as 2,3-butanediol and 2,3butanedione. The above characteristic of the mutant strain, TH-49, may be related to its specific composition of acetoin metabolism-related enzymes system. These results indicated that, the mutant strain TH-49 is conspicuously different from other acetoin producing strains reported previously in metabolic mechanism of acetoin.

Biodegradation of beta-cypermethrin and 3-phenoxybenzoic acid by a novel Ochrobactrum lupini DG-S-01

A newly isolated bacterium DG-S-01 from activated sludge utilized beta-cypermethrin (beta-CP) and its major metabolite 3-phenoxybenzoic acid (3-PBA) as sole carbon and energy source for growth in mineral salt medium (MSM). Based on the morphology, physio-biochemical characteristics, and 16S rDNA sequence analysis, DG-S-01 was identified as Ochrobactrum lupini. DG-S-01 effectively degraded beta-CP with total inocula biomass A590nm=0.1–0.8, at 20–40°C, pH 5–9, initial beta-CP 50–400mgL−1 and metabolized to yield 3-PBA leading to complete degradation. Andrews equation was used to describe the special degradation rate at different initial concentrations. Degradation rate parameters qmax, Ks and Ki were determined to be 1.14d−1, 52.06mgL−1 and 142.80mgL−1, respectively. Maximum degradation was observed at 30°C and pH 7.0. Degradation of beta-CP was accelerated when MSM was supplemented with glucose, beef extract and yeast extract. Studies on biodegradation in liquid medium showed that over 90% of the initial dose of beta-CP (50mgL−1) was degraded under the optimal conditions within 5d. Moreover, the strain also degraded beta-cyfluthrin, fenpropathrin, cyhalothrin and deltamethrin. These results reveal that DG-S-01 may possess potential to be used in bioremediation of pyrethroid-contaminated environment.

Screening and degrading characteristics and community structure of a high molecular weight polycyclic aromatic hydrocarbon-degrading bacterial consortium from contaminated soil

Inoculation with efficient microbes had been proved to be the most important way for the bioremediation of polluted environments. For the treatment of abandoned site of Beijing Coking Chemical Plant contaminated with high level of high-molecular-weight polycyclic aromatic hydrocarbons (HMW-PAHs), a bacterial consortium capable of degrading HMW-PAHs, designated 1-18-1, was enriched and screened from HMW-PAHs contaminated soil. Its degrading ability was analyzed by high performance liquid chromatography (HPLC), and the community structure was investigated by construction and analyses of the 16S rRNA gene clone libraries (A, B and F) at different transfers. The results indicated that 1-18-1 was able to utilize pyrene, fluoranthene and benzo[a]pyrene as sole carbon and energy source for growth. The degradation rate of pyrene and fluoranthene reached 82.8% and 96.2% after incubation for 8 days at 30°C, respectively; while the degradation rate of benzo[a]pyrene was only 65.1% after incubation for 28 days at 30C. Totally, 108, 100 and 100 valid clones were randomly selected and sequenced from the libraries A, B, and F. Phylogenetic analyses showed that all the clones could be divided into 5 groups, Bacteroidetes, α-Proteobacteria, Actinobacteria, βProteobacteria and γ-Proteobacteria. Sequence similarity analyses showed total 39 operational taxonomic units (OTUs) in the libraries. The predominant bacterial groups were α-Proteobacteria (19 OTUs, 48.7%), γ-Proteobacteria (9 OTUs, 23.1%) and β-Proteobacteria (8 OTUs, 20.5%). During the transfer process, the proportions of α-Proteobacteria and β-Proteobacteria increased greatly (from 47% to 93%), while γ-Proteobacteria decreased from 32% (library A) to 6% (library F); and Bacteroidetes group disappeared in libraries B and F.

Complete genome sequence of Sulfurospirillum deleyianum type strain (5175T)

Sulfurospirillum deleyianum Schumacher et al. 1993 is the type species of the genus Sulfurospirillum. S. deleyianum is a model organism for studying sulfur reduction and dissimilatory nitrate reduction as an energy source for growth. Also, it is a prominent model organism for studying the structural and functional characteristics of cytochrome c nitrite reductase. Here, we describe the features of this organism, together with the complete genome sequence and annotation. This is the first completed genome sequence of the genus Sulfurospirillum. The 2,306,351 bp long genome with its 2,291 protein-coding and 52 RNA genes is part of the Genomic Encyclopedia of Bacteria and Archaea project.

Kinetic analysis on the production of polyhydroxyalkanoates from volatile fatty acids by Cupriavidus necator with a consideration of substrate inhibition, cell growth, maintenance, and product formation

Volatile fatty acids (VFAs) could be utilized by Cupriavidus necator (previously named as Ralstonia eutropha) as its sole carbon and energy source for growth and polyhydroxyalkanoates (PHAs) synthesis. In such a biosynthesis, VFAs at a high concentration had an inhibition on cell growth and deteriorate metabolite production. In this work the kinetics of PHAs production and consumption of VFAs by C. necator with simultaneous considerations of substrate inhibition, cell growth, maintenance and product formation were explored. The growth of C. necator and production of PHAs were significantly affected by the initial VFAs concentration. The cell growth was inhibited under initial substrate-sufficient conditions, and the cell activities could be resumed with the consumption of VFAs in batch cultures. Experimental results verify that the model established in this work was able to appropriately describe the PHA production from VFAs by C. necator.

Biodegradation of beta-cypermethrin by two Serratia spp. with different cell surface hydrophobicity

Serratia spp. strain JC1 and JCN13, isolated from activated sludge, could degrade and utilize beta-cypermethrin (beta-CP) as the sole carbon and energy sources for growth in the minimal salt media (MSM). The two strains could effectively degrade beta-CP with total inocula biomass 0.1–0.3 g dry wt L −1, at 20–38 °C, pH 6–9, initial beta-CP 25–1000 mg L −1 and metabolize it by cleavage of ester and diphenyl ether to yield 3-phenoxybenzoic acid (3-PBA) and phenol, then completely mineralize it. Response surface methodology (RSM) was used to optimize degradation conditions. Under their own optimal degradation conditions, strain JC1 could degrade 92% beta-CP within 10 days and the degradation rate of strain JCN13 reached 89% within 4 days. Cell surface hydrophobicity (CSH) and biodegradation assays indicated that JCN13 has higher hydrophobicity and degradation ability than JC1, and it means the high hydrophobicity of strains could enhance the degradation of beta-CP.

A novel degradation pathway of chloroaniline in Diaphorobacter sp. PCA039 entails initial hydroxylation

A novel degradation pathway of chloroaniline in Diaphorobacter sp. PCA039 entails initial hydroxylation. A novel gene cluster (pca), involved in the degradation of p-chloroaniline, was identified from Diaphorobacter sp. PCA039 capable of utilizing p-chloroaniline as sole carbon, nitrogen and energy source for growth. There were 29 ORFs in the pca cluster, in the order of pcaTRKLMNOPR1D1CIU1R2D2C2U2EFGXJHYWZI1I2QS. Based on sequence analysis, they were putatively identified as encoding a multicomponent phenol-hydroxylating oxygenase (pcaKLMNOP), two extradiol ring-cleavage dioxygenases, transcriptional regulatory proteins, enzymes mediating chlorocatechol degradation, and transportation functions. The genes pcaKLMNOP exhibited significant sequence identity (94%) to those of phenol hydroxylases (PH) from other bacteria, inferring that they might encode a multicomponent PH. This PH activity was also functionally characterized with the recombinant strain E. coli TOP10-S201 showing only PH activity, indicating that the degradation of p-chloroaniline by strain PCA039 was initiated by hydroxylation instead of normal dioxygenation. The other nineteen genes, pcaR1D1CIU1R2D2C2U2EFGXJHYWZI1I2, encode for further degradation of p-chloroaniline to intermediates of the TCA-cycle and transposases. RT-PCR revealed that the hydrolytic (pcaF) and dehydrogenetic pathways (pcaE, pcaH), the two degrading branches, are both necessary for complete degradation of aniline, p-chloroaniline, phenol and also 4-aminophenol; and of the two C23O sets, PcaR1D1C1U1 and PcaR2D2C2U2, PcaC1 is produced in the degradation of above four substrates, while PcaC2 is only expressed in p-chloroaniline degradation, suggesting that both C23O sets are needed for complete degradation of p-chloroaniline.

Racemase activity effected by two dehydrogenases in sulfolactate degradation by Chromohalobacter salexigens: purification of (S)-sulfolactate dehydrogenase

Chromohalobacter salexigens DSM 3043, whose genome has been sequenced, is known to degrade (R,S)-sulfolactate as a sole carbon and energy source for growth. Utilization of the compound(s) was shown to be quantitative, and an eight-gene cluster (Csal_1764-Csal_1771) was hypothesized to encode the enzymes in the degradative pathway. It comprised a transcriptional regulator (SuyR), a Tripartite Tricarboxylate Transporter-family uptake system for sulfolactate (SlcHFG), two sulfolactate dehydrogenases of opposite sulfonate stereochemistry, namely novel SlcC and ComC [(R)-sulfolactate dehydrogenase] [EC 1.1.1.272] and desulfonative sulfolactate sulfo-lyase (SuyAB) [EC 4.4.1.24]. Inducible reduction of 3-sulfopyruvate, inducible SuyAB activity and induction of an unknown protein were detected. Separation of the soluble proteins from induced cells on an anion-exchange column yielded four relevant fractions. Two different fractions reduced sulfopyruvate with NAD(P)H, a third yielded SuyAB activity, and the fourth contained the unknown protein. The latter was identified by peptide-mass fingerprinting as SlcH, the candidate periplasmic binding protein of the transport system. Separated SuyB was also identified by peptide-mass fingerprinting. ComC was partially purified and identified by peptide-mass fingerprinting. The (R)-sulfolactate that ComC produced from sulfopyruvate was a substrate for SuyAB, which showed that SuyAB is (R)-sulfolactate sulfo-lyase. SlcC was purified to homogeneity. This enzyme also formed sulfolactate from sulfopyruvate, but the latter enantiomer was not a substrate for SuyAB. SlcC was obviously ( S)-sulfolactate dehydrogenase.