• Journal of Microbiology and Biotechnology
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• v.16 no.5
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• pp.786-790
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• 2006

Cellular components of Lactococcus lactis ssp. lactis (heat-killed whole cells, cytoplasm, and cell walls) were tested for their in vivo immunopotentiating activity. Peritoneal macrophages from mice orally administered with heat-killed whole cells exhibited significantly greater phagocytic activity than the groups administered with cell-wall fraction or cytoplasm fraction. The cytotoxicity of natural-killer cells was the highest in the group administered with whole cells, and the production of cytokines ($IFN-\gamma$, IL-2, and IL-12) in spleen cells was significantly higher, when cellular components were injected, and it tended to be higher in the cell-wall and cytoplasm groups than in the whole-cell group. Interestingly, the cytokine production of Peyer's patch cells was high, when cytoplasm fractions were administered. These results demonstrate that whole cells and cytoplasm and cell-wall fractions of L. lactis ssp. lactis have immunopotentiating activities, which are related to the stimulation of Peyer's patches.

• Journal of Microbiology and Biotechnology
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• v.24 no.5
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• pp.619-628
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• 2014

To identify lipase LipA (PFL_0617) from Pseudomonas protegens Pf-5, a lipA deletion mutant (Pf0617) and a complementary strain (Pf0617lipA) were constructed, and their effects on the lipase production were examined. Pf0617 remarkably decreased its whole-cell lipase activity, whereas Pf0617lipA made its whole-cell lipase activity not only restore to wild-type level but also get a further increment. However, the deletion and overexpression of lipA did not affect the extracellular lipase activity. In addition, the unbroken whole cells of these strains were able to catalyze the hydrolysis of membrane-permeable p-nitrophenyl esters, but could not hydrolyze the membrane-impermeable olive oil. These results confirmed that LipA was an intracellular lipase and Pf-5 could also be used as a natural whole-cell biocatalyst. To evaluate the potential of Pf-5 as a whole-cell biocatalyst and separately characterize the whole-cell LipA, the properties of the whole-cell lipases from Pf-5 and Top10lipA were characterized. The results demonstrated that both Pf-5 and Top10lipA exhibited high tolerance to alkaline condition, high temperature, heavy metal ions, surfactants, and organic solvents. Taken together, lipA can realize functional expression in E. coli Top10, and Pf-5 and Top10lipA as whole-cell biocatalysts may have enormous potential in applications.

• KSBB Journal
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• v.14 no.3
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• pp.264-272
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• 1999

Benzoylformate was converted to benzaldehyde by whole cell enzyme from Pseudomonas putida KCTC 1751. We investigated the effect of the composition of the growth medium on th accumulation of benzoylformate decarboxylase in the microbial cell. We prepared a calcium alginate capsule containing Pseudomonas putida cells to develop a reusable whole cell enzyme. Pseudomonas putida cells were inoculated in the capsule and cultured in M1 medium for 1 day followed by cultivation in M3 medium for 3 days. The dry cell density reached 77.75 g/L on the basis of the inner volume of the capsule. The specific activity of encapsulated whole cell benzoylformate decarboxylase was half as high as that of free whole cell enzyme. The activity of encapsulated whole cell benzoylformate decarboxylase was half as high as that of free whole cell enzyme. The activity of encapsulated whole cell benzoylformate decarboxylase decreased 20 % after use for 20 batches and 40% after use for 30 batches. The dry cell density reduced about 10 % after 30 trials.

• Korean Journal of Microbiology
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• v.24 no.3
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• pp.276-287
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• 1986

Chlorella ellipsoidea were cultured in the media containing rifampicin for 7 days. Aliquot cells were taken out after the inoculation and at intervals during cultivation and growth rate of Chlorella cells was measured. In order to investigate the effect of rifampicin on the nucleic acid synthesis, nucleic acid and RNA polymerase were extracted from chloroplast isolated from these cells, and the contents of nucleic acid and activity of enzyme were measured to compared with those of the control. The inhibitory concentration of rifampicin on growth was 80 ppm. The DNA contents in chloroplasts isolated were decreased 60% to compared with control, whole cells were markedly decreased 70% by rifampicin. The contents of base in the RNA were decreased 46% by rifampicin in shole cell, and 77% of base contents were decreased in chloroplast. Rifampicin also inhibited the activity of RNA polymerase, therefore whole cell was decreased 10% of activity and chloroplasts were decreased 42% of activity.

• Food Science and Biotechnology
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• v.14 no.3
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• pp.405-409
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• 2005

Cellular components of Lactococcus lactis ssp. lactis (heat-killed whole cells, cytoplasm, and cell walls) were tested for their in vivo immunopotentiating activities. Peritoneal macrophages from mice injected intraperitoneally with cell-wall fractions exhibited significantly greater phagocytic activity than groups injected with whole cells or cytoplasm fraction. Cytotoxicity of natural-killer cells was highest in cytoplasm fractions. Production of cytokines (IFN-${\gamma}$, IL-2, IL-6, and IL-12) in spleen cells was significantly higher when cellular components were injected intraperitoneally, and tended to be higher in whole-cell and cytoplasm groups than in cell-wall group. These results demonstrate lactic acid bacteria whole cells and their cytoplasm and cell-wall tractions have immunopotentiating activities.

• Journal of Microbiology and Biotechnology
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• v.26 no.7
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• pp.1206-1215
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• 2016

Ginsenosides are the major active ingredients in ginseng used for human therapeutic plant medicines. One of the most well-known probiotic bacteria among the various strains on the functional food market is Lactobacillus rhamnosus GG. Biocatalytic methods using probiotic enzymes for producing deglycosylated ginsenosides such as Rd have a growing significance in the functional food industry. The addition of 2% cellobiose (w/v) to glucose-free de Man-Rogosa-Sharpe broths notably induced β-glucosidase production from L. rhamnosus GG. Enzyme production and activity were optimized at a pH, temperature, and cellobiose concentration of 6.0, 40℃, and 2% (w/v), respectively. Under these controlled conditions, β-glucosidase production in L. rhamnosus GG was enhanced by 25-fold. Additionally, whole-cell homogenates showed the highest β-glucosidase activity when compared with disrupted cell suspensions; the cell disruption step significantly decreased the β-glucosidase activity. Based on the optimized enzyme conditions, whole-cell L. rhamnosus GG was successfully used to convert ginsenoside Rb1 into Rd.

• Archives of Pharmacal Research
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• v.3 no.1
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• pp.7-12
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• 1980

Ampliciline was synthesized from 6-amino-pencillanic acid (6-APA) and D-.alpha. phenylglycine methyl ester by using amplicilin synthesizing enzyme from Peudomonas melanogenum (IAM 1655). The whole cell enzyme was immobilized by entrapping it in the polyacrylamide gel lattices. The polymer used in the enzyme entrapment was made from 150 mg per ml of acrylamide monomer and 8 mg per ml of N, N'-methylenebisacrylamide. About 200 mg/whole cell enzyme was mixed in the polymer for entrapment. The maximal activity retention after immobilization was 56%. The optimal pH values for the whole cell enzyme and the immobilized whole cell enzyme were 6.0 and 5.9, respectively. The optimal temperature for the enzyme activity were the same for both type of preparations. The enzyme stabilities against pH and heat increased for immobilized whole cell enzyme. Immobilized cell was more stable especially in the acidic condition while both type were found to be very suceptible to thermal inactivation at a temperature above 4.deg.C. The kinetic constants obtained from Lineweaver-Burk plot based on two substate reaction mechanism showed somewhat higher value for immobilized whole cell enzyme as compared to the whole cell enzyme : the Km value for 6-APA were 7.0 mM and 12.5 mM while Km values for phenylglycine methyl ester were 4.5 mM and 8.2 mM, respectively. Using the immobilized whole cell enzyme packed in a column reactor, the productivity of ampiciline was studied by varying the flow rate of substrate solution. At the space velocity, SV, 0.14 hr$^{-1}$ the conversion was 45%. Operational stability found in terms of half life was 30 hr at SV = 0.2 hr.

• KSBB Journal
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• v.11 no.4
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• pp.398-404
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• 1996

Escherichia coli was inoculated in calcium alginate capsules and cultivated to prepare encapsulated whole cell ${\beta}$-galactosidase. The dry cell weight in the capsule reached 100 g/L based on the inner space of the capsule. The activity of the encapsulated whole cell ${\beta}$-galactosidase increased with the dry cell weight increase during cultivation in the production medium. The activity of the encapsulated whole cell ${\beta}$-galactosidase was increased 25% by adding $2{\times}10^{-4}M Zn^{+2}$ ion in the production medium and 10% by coencapsulating with 2% (v/v) sunflower seed oil. The activity of encapsulated whole cell ${\beta}$-galactosidase produced in the concentric air lift reactor in which kLa was 82/hr was 86% higher than that in the shaking flask incubator where kLa was 2.55/hr.

• KSBB Journal
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• v.26 no.3
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• pp.199-205
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• 2011

Using tetrameric ${\beta}$-galactosidase as a model protein, anchoring motives were screened in Bacillus subtilis spore display system. Eleven spore coat proteins were selected considering their expression levels and the location in the spore coat layer. After chromosomal single-copy homologous integration in the amyE site of Bacillus subtilis chromosome, cotE and cotG were chosen as possible spore surface anchoring motives with their higher whole cell ${\beta}$-galactosidase activity. PAGE and Wester blot of extracted fraction of outer layer of purified spore, which express CotE-LacZ or CotG-LacZ fusion verified the existence of exact size of fusion protein and its location in outer coat layer of purified spore. ${\beta}$-galactosidase activity of spore with CotE-LacZ or CotG-LacZ fusion reached its highest value around 16~20 h of culture time in terms of whole cell and purified spore. After intensive spore purification with lysozyme treatment and renografin treatment, spore of BJH135, which expresses CotE-LacZ, retained only 1~2% of its whole cell ${\beta}$-galactosidase activity. Whereas spore of BJH136, which has cotG-lacZ cassette in the chromosome, retained 10~15% of its whole cell ${\beta}$-galactosidase activity, proving minor perturbation of CotG-LacZ, when incorporated in the spore coat layer of Bacillus subtilis compared to CotE-LacZ. Usage of Bacillus subtilis WB700, of which 7 proteases are knocked-out and thereby resulting in 99.7% decrease in protease activity of the host, did not prevent the proteolytic degradation of spore surface expressed CotG-LacZ fusion protein.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.1
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• pp.67-71
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• 2001

Most of the Cyclodextrin glucanotransferase (Gtases) which have been produced from B. subtilis were found to be excreted from the cells during cultivation. Immobilized whole cell CGTase from B. subtilis was prepared by encapsulating the broth solution which had been concentrated ten times with a rotary vacuum evaporator. Cyclization activity of CGTase was reduced by about 10% during the concentrating process, however, its transglycosylation activity, to convert xylitol to glucosyl-xylitol, using dextrin as glucosyl donor, increased by a factor of 3 or 5.