• KSBB Journal
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• v.13 no.3
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• pp.308-311
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• 1998

A novel process was developed to simultaneously produce invertase and yeast extract from baker's yeast using ultrafiltration (UF) and microfiltration (MF) membrane processing. After the extraction of invertase under the optimal condition obtained in this study, invertase was separated from yeast cells using a hollow fiber membrane with a pore size of 0.1 $\mu\textrm{m}$. The resulting permeate containing invertase was concentrated using a hollow fiber membrane with a nominal molecular weight cut-off of 30 kDa. The yeast cell and permeate solutions, which were obtained after MF and UF membrane processing, respectively, were mixed together, and the autolysis was performed at 50$^{\circ}C$ in the presence of 5% (w/v) ethanol and 1% (w/v) NaCl. As a result, the yeast extract and invertase could be simultaneously produced from baker's yeast by this novel process.

• Proceedings of the Botanical Society of Korea Conference
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• 1999.07a
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• pp.69-73
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• 1999

In plants as well as in other multicellular organisms, programmed cell death plays essential roles in the abortion or formation of specific cells and tissues during development to organize the plant [11, 15, 18]. A typical example of developmentally programmed cell death in plants is the death during differentiation of tracheary elements which are components of vessels and tracheids, a water-conducting system. The programming of cell death during tracheary element differentiation has been revealed to be unique to plant cells by using the in vitro Zinnia mesophyll cell culture system. In particular, new biosynthesis of autolysis-related enzymes such as cysteine proteases and nucleases, their accumulation of the vacuole and the programmed collapse of the vacuole are essential to the death of tracheary elements and differ greatly from the process of the apoptotic cell death in animals.

• The Journal of the Korean Society for Microbiology
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• v.5 no.1
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• pp.9-18
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• 1970

The present study is of ultra-fine structures of Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum canis and Epidermophyton floccosum by means of electron microscopy and reveals the following. 1. In contrast to the bacteria, the normal fungus contains nuclear membrane, mitochondria, endoplasmic reticulun, distinct cell wall and cell membrane and secretory granules as observed in the higher plants and animals. 2. Thickening of the cell wall, inapparent cell wall, inapparent cell membrane with the appearance of electron thin area(ETA) and increase of inclusions were observed in the L-1 treated groups. 3. Thickening of cell wall and increase of ETA were more apparent in the Epidermophyton floccosum than the other groups. 4. Increase of electron thin area was thought to be associated with autolysis.

• Korean Journal of Food Science and Technology
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• v.35 no.2
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• pp.201-205
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• 2003

The optimum autolysis conditions were investigated to prepare yeast autolyzate (extract) using yeast slurry collected from brewery plants. Brewers yeast slurry was washed with caustic soda to eliminate bitter hof substances attached to yeast cell walks. The pH of brewers yeast slurry was adjusted to 9.8 with caustic soda, and centrifuged at 3,000 rpm for 5 min. The supernatant was discarded, and the bottom cake was rehydrated and collected. Bitterness unit (BU) of washed yeast slurry was 24.1 BU, below the threshold value of 25.0. Yeast extract could be obtained from washed brewers yeast slurry at maximum yield up to 38% by autolyzing at pH 6.8 and $53^{\circ}C$ for 20 h.

• Microbiology and Biotechnology Letters
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• v.21 no.3
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• pp.276-280
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• 1993

Cell lytic enzyme, 5'-phosphodiesterase, and AMP-deaminase were used to produce yeast extract as a natural seasoning from beer yeast cells. Prior to the addition of cell lytic enzyme, heat treatment was performed to increase the cell wall degradation` the optimum condition of the cell lytic enzyme was 50C at pH 7.0. The production yields by the enzymatic method and conventional autolysis method were 42% and 35%, respectively. The total quantity of 5'-nucleotides, GMP and IMP, produced by enzymatic method was increased by 45% than that by the conventional method. Futhermore, the operation time of enzymatic method was only 6.5 hrs, significantly reduced from 24 hrs of the conventional method.

• Journal of Life Science
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• v.24 no.12
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• pp.1316-1324
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• 2014

Most beta-glucans obtained from various fruit bodies of mushrooms and mushroom mycelial cultures have high-molecular weight glycoproteins, conjugated with beta-glucans. We report that isoflavone-conjugated glycolproteins (designated as gluvone) were isolated and exhibited stronger anticarcinogenic activities. Agaricus blazei mycelia (ABM) was cultured in a liquid medium containing soybean flakes for 14 days. The liquid culture was autolyzed by incubating at $53^{\circ}C$ (pH 5.5) for 3 h. A crude glycoprotein (CGP) fraction with a cytotoxic effect on a mouse ascite cancer cell line (S-180) and a human breast cancer cell line (MCF-7) was isolated from the autolyzed ABM cultures by 80% ethanol treatment. Gluvone was isolated from the CGP with Sephadex G-75 column chromatography. It exhibited a stronger anticancer effect than CGP against the S-180 cell-induced female ICR mouse ascites carcinogenesis. Gluvone with 9,400 daltons was identified as a glycoprotein conjugated with isoflavone. According to HPLC and GC analysis, in conjunction with $^1H$-NMR spectral analysis, it contained 60% carbohydrates (glucose, fructose, and ribose), 31% protein, and 2% isoflavone (daidzein and genistein), which is a novel material. These results indicate that a strong anticarcinogenic gluvone was isolated from the autolyzed product of a submerged liquid culture of ABM, suggesting that autolysis could be a useful tool to produce antitumor agents.

• Journal of Microbiology and Biotechnology
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• v.28 no.5
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• pp.739-747
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• 2018

The low solubility and high-cost recovery of Propionibacterium acnes polyunsaturated fatty acid isomerase (PAI) are key problems in the bioproduction of high value-added conjugated linoleic acid (CLA). To improve the solubility of recombinant PAI, six chaperone proteins were coexpressed with PAI. Introduction of GroELS proteins dramatically improved the PAI solubility from 29% to 97%, with increased activity by 57.8%. Combined expression of DnaKJ-GrpE and GroELS proteins increased the activity by 11.9%. In contrast, coexpression of DnaKJ-GrpE proteins significantly reduced the activity by 57.4%. Plasmids pTf16 harboring the tig gene and pG-Tf2 containing the tig and groEL-groES genes had no visible impact on PAI expression. The lytic protein E was then introduced into the recombinant Escherichia coli to develop a cell autolysis system. A 35% activity of total intracellular PAI was released from the cytoplasm by suspending the lysed cells in distilled water. The PAI recovery was further improved to 81% by optimizing the release conditions. The lipase from Rhizopus oryzae was also expressed in E. coli, with an extracellular activity of 110.9 U/ml. By using the free PAI and lipase as catalysts, a joint system was established for producing CLA from sunflower oil. Under the optimized conditions, the maximum titer of t-10,c-12-CLA reached 9.4 g/l. This work provides an effective and low-cost strategy to improve the solubility and recovery of the recombinant intracellular PAI for further large-scale production of CLA.

• Animal Bioscience
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• v.35 no.9
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• pp.1400-1407
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• 2022

Objective: This research determined the chemical composition and the apparent and standardized ileal digestibility (AID and SID) of crude protein (CP) and amino acids (AA) in whole yeast and autolyzed yeast derived from sugarcane ethanol production fed to growing pigs. Methods: Six growing pigs were randomly allocated in a replicated 3×3 Latin square design with 3 diets and 3 periods of 7 days each, resulting in a total of 6 experimental replications. Three assay diets were formulated using whole yeast, autolyzed yeast, or soybean meal as the sole sources of dietary CP and AA. Pigs were allowed to adapt to the assay diets for 5 days. Thereafter, ileal digesta samples were collected continuously for 8 hours on days 6 and 7. Results: There was no difference in the chemical composition between whole yeast and autolyzed yeast, but whole yeast had low digestibility of CP and AA due to the presence of a rigid cell wall. As conducting autolysis can induce cell wall damage, the AID and SID of CP and AA were greater in autolyzed yeast than in whole yeast. Conclusion: The information obtained on the SID of CP and AA in both yeast products can be used for the accurate estimation of the bioavailability of CP and AA in feed formulations. The yeast products derived from sugarcane ethanol production are an alternative protein source in pig diets.

• Applied Microscopy
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• v.14 no.2
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• pp.15-28
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• 1984

The endosperm cells and the umbiliform layer of ginseng (Panax ginseng C.A. Meyer) seed are studied with light and electron microscope. Differentiated mitochondria, ER cisternae, proplastids and ribosomes are characteristically observed in the endosperm cells of matured seed. The cell inclusions contain the protein bodies and the spherosomes. Protein body contains, in proteinaceous matrix, globoids and crystalloids. Particularly the crystalloids have the lattice structure, and the formation of globoids is closely related with ER. Umbiliform layer has the positive reaction on alcian blue (pH 2.5) and the metachromasis on the toluidine blue. The umbiliform layer is formed by autolysis of endosperm cells, and composed of the deformated cell wall and the lipoprotein bodies. Particularly a part of the lipoprotein body and the fibrilar network structure have the positive reaction on acid phosphatase.

• Molecules and Cells
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• v.45 no.11
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• pp.771-780
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• 2022

The field of extracellular vesicles (EVs) has expanded tremendously over the last decade. The role of cell-to-cell communication in neighboring or distant cells has been increasingly ascribed to EVs generated by various cells. Initially, EVs were thought to a means of cellular debris or disposal system of unwanted cellular materials that provided an alternative to autolysis in lysosomes. Intercellular exchange of information has been considered to be achieved by well-known systems such as hormones, cytokines, and nervous networks. However, most research in this field has searched for and found evidence to support paracrine or endocrine roles of EV, which inevitably leads to a new concept that EVs are synthesized to achieve their paracrine or endocrine purposes. Here, we attempted to verify the endocrine role of EV production and their contents, such as RNAs and bioactive proteins, from the regulation of biogenesis, secretion, and action mechanisms while discussing the current technical limitations. It will also be important to discuss how blood EV concentrations are regulated as if EVs are humoral endocrine machinery.