• Microbiology and Biotechnology Letters
• /
• 제47권4호
• /
• pp.546-554
• /
• 2019

This study, for the first time, reports the functional expression of lipase B derived from the yeast Candida antarctica (CALB) in Corynebacterium strain using the Escherichia coli plasmid PK18. The CALB gene fragment encoding a 317-amino-acid protein was successfully obtained from the total RNA of C. antarctica. CALB was readily produced in the Corynebacterium strain without the use of induction methods described in previous studies. This demonstrated the extracellular production of CALB in the Corynebacterium strain. CALB produced in the Corynebacterium MB001 strain transformed with pEC-CALB recombinant plasmid exhibited maximum extracellular enzymatic activity and high substrate affinity. The optimal pH and temperature for the hydrolysis of 4-nitrophenyl laurate by CALB were 9.0 and 40℃, respectively. The enzyme was stable at pH 10.7 in the glycine-KOH buffer and functioned as an alkaline lipase. The CALB activity was inhibited in the presence of high concentration of Mg²⁺, which indicated that CALB is not a metalloenzyme. These properties are key for the industrial application of the enzyme.

• Microbiology and Biotechnology Letters
• /
• 제24권6호
• /
• pp.699-704
• /
• 1996

About 600 microorganisms isolated from soil, marsh, compost, etc. were examined for their flocculating ability in the kaolin suspension and swine wastewater. Among them, K-199 was the best producer of flocculant and was identified to be a species belong to the genus Corynebacterium. The maximum production of the flocculant from Corynebacterium sp. K-199 was observed in culture medium containing 2% glycerol, 0.4% peptone, 0.3% K$_{2}$HPO$_{4}$, 0.1% CaCO$_{3}$, 0.05% NaCl, 0.1% yeast extract, 0.1% MgSO$_{4}$,7H$_{2}$O and initial pH 7.5 when cultured with rotary shaker controlled at 25$\circ$C and 150 rpm. Under the optimal culture condition with jar fermentor, the maximum production was reached to flocculating activity of 780 units/ml after 4 days. From the results of the activity be fully maintained by periodate oxidization, it suggests that the activity is due to the protein.

• Journal of Microbiology and Biotechnology
• /
• 제11권5호
• /
• pp.819-824
• /
• 2001

The principal DNA modification systems of the amino-acid-producing bacteria Corynebacterium glutamicum AS019, Brevibacterium flavum BF4, and B. lactofermentum BL1 was investigated using two approaches; digestion of plasmid DNA isolated from these species TseI and Fnu4HI, and sequence analysis of the putative methyltransferase target sites following the derivatization of DNA using metabisulfite treatment. The C. glutamicum and B. flavum strains showed similar digestion patterns to the two enzymes, indicating that the target for cytidine methyltransferase recognizes 5'-GCSGC-3'(where S is either G or C). Mapping the methylated cytidine sites by bisulfite derivatization, followed by PCR amplification and sequencing, was only possible when the protocol included an additional step eliminating any underivatized DNA after PCR amplification, thereby indicating that the derivatization was not $100\%$ efficient. This may have been due to the high G0C content of this genus. It was confirmed that C. glutamicum AS019 and B. flavum BF4 methylated the cytidine in the $Gm^5CCGC$ sequences, yet there were no similar patterns of methylation in B. lactofermentum, which was consistent with the distinctive degradation pattern seen for the above enzymes. These findings demonstrate the successful application of a modified bisulfite derivatization method with the Corynebacterium species for determining methylation patterns, and showed that different species in the geneus contain distinctive restriction and modification systems.

• Korean Journal of Microbiology
• /
• 제12권1호
• /
• pp.37-51
• /
• 1974

Three strains which accumulated large quantities of L-hlutamic acid as the chief product of metabolism in the presence of glucose and inorhanic ammonium salt under the aerobic condition sere newly isolated. These strains have the general characters as follows: Gram-positive, short fod-shaped, non-sporulating, non-motile, and facultative anaerobe. A change of cell shates was not almost observed in their life cycles and neither a phenomenon of cell-elongation nor a pleomorphism was recognized in any cases. Together with rigid stability in Gram-stain, these characters as above indicated evidences that newly isolates would belong to genus Brevibacterium clearly differentiated from genus Corynebacterium. At the same time the newly isolates, in addition to nutritional requirement of biotin and thiamine, showed the distinctive character of requirement of special amino acid such as histidine or cysteine for their considerable growth. These physiological characters including nitrates reduction, reaction on milk, and slow formation of acid from sugar also were useful in confirming that these bacteria would be Brevibacterium ammoniagenes.

• Korean Journal of Microbiology
• /
• 제38권2호
• /
• pp.57-61
• /
• 2002

To investigate the characteristics of carbon sources utilization by the intestinal microflora of starfish, starfishes (Asterias amurensis) were collected from the South Sea near Jangheung-gun sumun-ri of Jeollanam-do on July 14,2000. The population densities of heterotrophic bacteria were in the range of $8.65{\pm}0.65{\times}10^3\cfu{\cdot}g^{-1}$ in the interval organs of starfish. Total 24 strains (Gram-negative bacteria. 11 strains, Gram-positive bacteria: 13 strains) from the internal organs of starfish were isolated. Dominant bacteria were Genus nbrio, Staphylococcus, and Corynebacterium. A high percentage of isolates was Gram positive rods. The catalase and oxidase positive were shown 54.2% and 20.8% of isolated bacteria, respectively. Isolated Gram negative and positive bacteria utilized various carbon sources. Among them, glucose could be utilized by all the isolated Gram negative bacteria, and sucrose, mannose, and maltose were utilized by a relatively high percentage of isolates. On the other hands, adipate and phenyl acetate were shown no utilization. In case of Gram positive bacteria, glucose was shown the highest utilization and the next highest utilization was fructose, trehalose, and maltose.

• Journal of Species Research
• /
• 제11권1호
• /
• pp.1-9
• /
• 2022

The phylum Actinobacteria includes many groups of aerobic, Gram-stain-positive, rod, or filamentous shaped bacteria. Actinobacteria are known for multicellular differentiation in some groups, and also for production of various secondary metabolites such as antibiotics. During a series of extensive surveys of indigenous prokaryotic species diversity in Korea, bacterial strains belonging to Actinobacteria were isolated from various sources of terrestrial environments. A total of 21 bacterial strains, belonging to 10 genera in 8 families, were isolated as unrecorded species in Korea. Among them, 11 were assigned to the family Streptomycetaceae, two species assigned to each of the families Microbacteriaceae, Mycobacteriaceae and Nocardioidaceae, and one species assigned to each of the families Euzebyaceae, Corynebacteriaceae, Micrococcaceae and Intrasporangiaceae. At the genus level, Streptomyces (10 species) was the most abundant, followed by Microbacterium and Mycolicibacterium(2 species each), and one species in each of the genera Corynebacterium, Euzebya, Arthrobacter, Terracoccus, Kribbella, Nocardioides and Yinghuangia. The detailed descriptions of each unrecorded species are provided.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• 제25권4호
• /
• pp.314-321
• /
• 1992

To study the seasonal variation of heterotrophic bacteria on the blades of Porphyra species, samples were collected In the intertidal zone near Mokp'o of the Yellow Sea from February to December, 1990 Annual distribution of heterotrophic bacteria on the blades of Porphyra species ranged from $6.9\times10^2\;to\;1.04\times10^5\;cfu/cm^2$ at site 1, and from $9.4\times10^3\;to\;2.93\times10^5\;cfu/cm^2$ at site 2. Average sixty-five percent of isolates from the blades of Porphyra species were rods and $52.1-82.7\%$ of isolates were Gram-negative. Most isolates showed starch hydrolysis$(68\%)$ on March, but showed Poor utilization of carbon sources and no $H_2S$ production. Dominant genus isolated from the baldes of Porphyra species were Alcaligenes spp., Moraxella spp., on March and Micrococcus spp., Moraxella spp., Corynebacterium spp., on November.

• Korean Journal of Food Science and Technology
• /
• 제28권2호
• /
• pp.260-266
• /
• 1996

This study was carried out to investigate the bacterial microflora of commercial and traditional Kochujang. Computer aided idetification systems were used to identify the bacteria in Kochujang. Seven genera such as Bacillus, Corynebacterium, Enterococcus, pasteurella, Pseudomonas, Staphylococcus and Streptococcus in commercial process and 10 genera such as Bacillus, Corynebacterium, Enterococcus, Flavimonas, Flavobacterium, Gemella, Pasteurella, Pseudomonas, Staphylococcus and Streptococcus in traditional process were identified. Distribution of genus Bacillus was $56{\sim}70%$ during fermentation in the commercial process and $38{\sim}50%$ in the traditional process. B. lichenoformis strains identified in this study were classified into three types by their physiological characteristics.

• Journal of Korean society of Dental Hygiene
• /
• 제18권5호
• /
• pp.843-852
• /
• 2018

Objectives: The study aimed to isolate the abundant bacteria in dental caries in children and to investigate the bacterial species involved in addition to those that have been previously reported. Methods: The specimens were collected from the supragingival plaques of each dental caries area, pit and fissure caries, deep dentinal caries, smooth surface caries, and dental caries, and from healthy subjects in the control group. Bacteria were cultured from these specimens, DNA was extracted from the isolated bacteria, and the 16S rRNA gene sequences were analyzed and identified. Results: Based on the results of the 16S rRNA gene sequence analysis for the 90 strains of dominant bacteria from the 45 specimens, 5, 7, 8, 7, and 13 species were identified from the supragingival plaques from healthy teeth, pit and fissure caries, deep dentinal caries, smooth surface caries, and dental caries, respectively. In healthy teeth, Actinomyces naeslundii dominated. Corynebacterium durum, Ralstonia pickettii, and Streptococcus intermedius showed equal distribution. The dominant bacterial species in dental caries, S. sanguinis, showed the greatest difference in prevalence in pit and fissure caries. In deep dentinal caries, S. mutans and Lactobacillus rhamnosus were dominant; in smooth surface caries, S. mutans and S. sanguinis were dominant; and in the supragingival plaques of dental caries, S. sanguinis and S. mutans were dominant. Conclusions: The bacterial species isolated from dental caries encompassed four phyla, eight genera, and 22 species. In addition, the SS1-2 strain, belonging to the genus Neisseria, was identified as a new species from among the isolated strains.

• Korean Journal of Environmental Biology
• /
• 제38권3호
• /
• pp.433-449
• /
• 2020

Nine fish and one clam species were collected from freshwater environments in Korea, including four lakes, two streams, and the Nakdong River, to investigate the host-associated bacteria. Hundreds of bacterial strains were isolated from the samples using a cell sorter and a dilution plating method. After identification of the bacterial strains using 16S rRNA gene sequences, 42 strains with greater than 98.7% sequence similarity with validly published species were determined to be unrecorded bacterial species in Korea. These strains were phylogenetically diverse and assigned to four phyla, six classes, 17 orders, 27 families, and 32 genera. At the genus level, the unrecorded species were classified as Corynebacterium, Mycobacterium, Mycolicibacterium, Gordonia, Williamsia, Modestobacter, Brachybacterium, Sanquibacter, Arthrobacter, and Mycolicibacterium of the class Actinobacteria; Empedobacter, and Flavobacterium of the class Flavobacteriia; Fictibacillus, Psychrobacillus, Cohnella, Paenibacillus, Rummeliibacillus, Enterococcus, and Vagococcus of the class Bacilli; Aquamicrobium, Paracoccus, and Sphingomonas of the class Alphaproteobacteria; Achromobacter, Delftia, and Deefgea of the class Betaproteobacteria; and Aeromonas, Providencia, Yersinia, Marinomonas, Acinetobacter, and Pseudomonas of the class Gammaproteobacteria. The 42 unrecorded species were subjected to further taxonomic characterization using gram staining, cellular and colony morphological determination, biochemical analyses, and phylogenetic analyses. This paper provides detailed descriptions of the 42 previously unrecorded bacterial species.