• Food Science and Preservation
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• v.24 no.2
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• pp.187-195
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• 2017

This study evaluated quality characteristics of soybean fermented by selected lactic acid bacteria, which were the enzyme strains with high antimicrobial activities isolated from traditionally prepared soybean paste. We determined total aerobic and lactic acid bacteria counts, protease and amylase activities, reducing sugar and amino-type nitrogen contents, and the amounts of amino acids, organic acids, and aroma-compounds. The total aerobic bacteria counts in soybean fermented with strain I13 ($7.75{\times}10^9CFU/mL$) were the highest among all the strains analyzed. Lactic acid bacteria numbers were $2.85{\times}10^9$ to $4.35{\times}10^9CFU/mL$ in soybean fermented with isolates. Amylase and protease activities of the JSB22 sample were the highest among all sample. Reducing sugar and amino-type nitrogen contents of soybean fermented with JSB22 (1.23%, 94.52 mg%) were highest. Total amino acid content of the samples was 15.88-17.62%, and glutamic acid, aspartic acid, leucine, lysine, and arginine were the major amino acids. Lactic acid (0.82-3.65 g/100 g), oxalic acid (22.74-63.57 mg/100 g), and fumaric acid (2.88-6.33 mg/100 g) were predominant organic acids. A total of 39 volatile aroma-compounds were identified, including 2 esters, 5 ketones, 7 alcohols, 14 hydrocarbons, 2 heterocyclic compounds, 4 acids, and 5 miscellaneous compounds. These results represent useful information for the development of a starter (single or complex) and will be used for production of functional fermented soybean foods.

• Microbiology and Biotechnology Letters
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• v.7 no.3
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• pp.157-164
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• 1979

These experiments were performed to investigate the culture condition, characteristic of crude enzyme and the heat resistance of the acid protease by Aspergillus awamori U-3. The results obtained were as follows: 1. The optimum culture temperature and time on wheat bran medium and defatted rice bran medium were 3$0^{\circ}C$ and 72 hrs, respectively. The optimum amount of added water was 100~120 ％ on wheat bran medium and 100~130 ％ on de-fatted rice bran medium. 2. Of the these various ingredients, addition of KN $O_3$, glutamic acid and glucose on wheat bran medium and addition Of KN $O_3$, (N $H_4$)$_2$S $O_4$, glucose, lactose, K $H_2$P $O_4$ and MgC $l_2$ on defatted rice bran medium were very effective. On wheat bran medium, concentration of addition of glucose, KN $O_3$ and glutamic acid were 3.0~4.0％, 0.2~0.4 ％ and 1.0％, respectively. 3. The optimum pH for the enzyme action was 2.4 ％, the optimum temperature about 45$^{\circ}C$ and the stable pH range 2.0~5.0, The enzyme was stable below 5$0^{\circ}C$ and was inactivated rapidly above 5$0^{\circ}C$. 4. The addition of CaC $l_2$ and CaS $O_4$ as the heat resistance agents showed the slight resistance. 5. When the enzyme solution added with the heat resistance agents (CaC1$_{2}$ and CaS $O_2$) was heated for 10-30 minutes at 6$0^{\circ}C$, their remaining activities were decreased largely above 20 minutes and The heat resistance effects of CaC $l_2$ and CaS $O_4$ were not observed almost at 8$0^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.5
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• pp.756-762
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• 2014

This study evaluated the quality characteristics of soybean fermented with several Bacillus sp., which were selected based on their high enzymatic and antimicrobial activities. Total aerobic bacterial counts of fermented soybeans with HJ5-2 ($3.00{\times}10^9CFU/mL$) were the highest among all strains. Lactic acid bacteria numbered $2.50{\times}10^2{\sim}7.30{\times}10^4CFU/mL$ in soybeans fermented with isolates. Amylase and protease activities of the RD7-7 sample were the highest among all strains. Reducing sugar and amino-type nitrogen contents of fermented soybeans with HJ18-4 (2.35%) and RD7-7 (227.96 mg%) were the highest. Total amino acid contents of the samples were 16.62~18.38%, and glutamic acid, aspartic acid, leucine, lysine, arginine were major amino acids. Oxalic acid (36.51~63.57 mg/100 g) and succinic acid (429.49~600.15 mg/100 g) were the predominant organic acid. These results provide useful information for development starter (single and complex) as well as for the production of high quality fermented soybean foods.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.127-133
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• 2010

The purpose of this work was to investigate the antibacterial activity derived from a lactic acid bacterium, Lactococcus lactis HK-9, isolated from the feces of a 2-day newborn infant. We characterized the physiological and biochemical properties of this strain. Both the BIOLOG system and phylogenetic analysis using 16S rRNA sequencing were utilized for identification, and the strain was assigned to the Lactococcus lactis species, designated as L. lactis HK-9, and registered in GenBank as [GU936712]. We monitored growth rate, production of lactic acid and acetic acid as metabolites, and pH during growth. The maximum concentrations of lactic acid and acetic acid reached 495.6 mM and 104.3 mM, respectively, and the initial pH of the cultures decreased from 7.0 to 4.1 after incubating for 60 h. HPLC was used to confirm the production of lactic acid and acetic acid. Significant antibacterial activity of the concentrated supernatant was demonstrated against Gram-positive (e.g., Staphylococcus aureus, Enterococcus faecalis, Listeria monocytogenes, MRSA) and Gram-negative (e.g., Escherichia coli, Salmonella enteritidis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Shigella sonnei) bacteria by the plate diffusion method. The antibacterial activity was sensitive to protease, and the molecular weight of the presumed bacteriocin molecule was estimated to be about 4 kDa by tricine-SDS-PAGE.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.527-530
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• 2000

A kiwi fruit ,called as the Chinese gooseberry, is originated from the Yangtze River Valley of Northern China and Zhejiang Province on the cost of Eastern China. Around 1950, a large mass production began at New Zealand with an Improved breeding. Plant origin actinidin from kiwi fruit belongs to the papain family of cysteine proteinase, which in plants includes papain from papaya, bromelain from pineapple, Cl4 protease from tomato and aleurain from barley. Actinidin is involved in the ripening-related gene family. In this study, protease gene of chinese wild kiwi fruit was isolated and characterized. 1.2kb PCR-amplified fragment was obtained from the total RNA using RT-PCR. pWACT-1 was obtained by subcloning of amplified fragment into pGEM-T Easy cloning vector and analyzed nucleotide sequence by DNA sequencing and amino acid sequence. In Result, high levels of homology between wild kiwi and New Zealand cultured-kiwi was obtained.

• The Korean Journal of Food And Nutrition
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• v.6 no.2
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• pp.89-95
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• 1993

A Nuluk, a Korean traditional Koji for brewing, was made with wheat flour and Aspergillus oryzae L2 which had a good aroma and strong abilities In producing saccharogenic and dextrogenic enzymes. The cultural conditions for the production of saccharogenic and proteolytic enzymes were tested. The productivity of dextrogenic enzyme was improved when Nuluk was made with unsteamed wheat flour as compared with steamed one, but that of proteolytic enzyme was reduced. The addition of water containing 0.5% hydrochloric acid was unfavorable for the production of those two enzymes. The optimum ratio of water added to wheat flour for the production of those two enzymes was 28$^{\circ}C$ on the basis of wheat flour, The productivity of saccharogenic enzyme was enhanced when the Nuluk was molded after 20 hours of precultivation, but that of proteolytic enzyme was reduced as compared with no molding. The optimum temperatures for the production of saccharogenic enzyme and proteolytic enzyme were 36$^{\circ}C$ and 28$^{\circ}C$, respectively.

• Biomedical Science Letters
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• v.12 no.3
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• pp.225-231
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• 2006

Fibrinolytic enzyme was purified from the fruiting bodies of Lepista nuda, using DEAE-Cellulose chromatography, Phenyl Sepharose chromatography, and Mono-S column chromatography. The substance has a molecular weight of 30006.62 Da as measured by MALD-TOF mass spectrometry. The N-terminal amino acid sequence of the enzyme was Tyr-Pro-Ser-Pro-Ser-His-Gln-Thr-Ala-Val-Asn-Ala-Ile-Ile-X. The activity of the enzyme was inhibited by PMSF, indicating that the enzyme is a serine protease. No inhibition was found with E-64, pepstatin, and EDTA. It has broad substrate specificity for synthetic peptides. The enzyme was stable up to $30^{\circ}C$. The enzyme hydrolyzes both Aa and y chains of human fibrinogen but did not show any reactivity for $B{\beta}$ chain of human fibrinogen.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.1
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• pp.103-108
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• 2002

We describe here the cDNA sequence and mRNA expression of a novel serine pretense from the firefly, Pyrocoelia rufa. The 771 bp cDNA encodes for 257 amino acid residues. The deduced protein of P. rufa serine pretense gene contains the catalytic triad and six-conserved cysteine residues. Alignment of the deduced protein of P. rufa serine pretense gene showed 47.4% protein sequence identity to known coleopteran insect Rhyzopertha dominica midgut trpsin-like enzyme. Northern blot analysis revealed that the P. rufa serine pretense is specifically expressed in the midgut of P. rufa larvae.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.466-472
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• 1997

Peptides separated from fish paste washing liquid of an Alaska pollak (Theragria chalcogramma) were purified and characterized. The fish paste washing liquid (supernatant) was separated by centrifugation of fish paste homogenate. The fish paste washing liquid of $0.5\%$ concentration was hydrolyzed for 24 hour at $50^{\circ}C$ by immobilized protease in bioreactor and decomposing liquid of protein having $50\%$ decomposing rate (OPA method) was obtained. The crude peptide fractions were obtained from this liquid by Dowex 50w $(H^+)$ column chromatograpy. Purified peptides (SP-fraction peptides) were fractionated by using SP-Sepadex C-25 $(H^+)$ column chromatography. Molecular weights and amino acid compositions of these peptides were estimated by Sephadex G-50 column chromatography and HPLC, respectively. when the washed peptides was eluated with $0.6\~0.9\%\;and\;1.2\~2.0\%$ of NaCl, peptides composed of weakly basic amino acids and strongly basic amino acid were respectively eluted. Molecular weights of each peptide fractions showed the broad distribution from 1,000 Da to 3,000 Da in the order of SP-4>SP-3>SP-2>SP-1. Peptides contained a large quantity of glycine, arginine, glutamic acid, and alanine in the washed peptide and its SP-tractions, respectively.

• Korean Journal of Microbiology
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• v.42 no.2
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• pp.160-163
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• 2006

Brown rice contains rice bran and germ with higher nutritional value and dietary fiber content compared with the polished rice. However, brown rice has a limitation of poor digestion. fermented brown rice could be better nutritional source and improve digestibility. Therefore, we tried to select good fermentative microorganisms which have nutritional values with high amylase and protease activities, and probiotic effects. Nineteen micro-organisms, including eight Bacillus strains isolated from Chongkukjang and 11 lactic acid bacteria, were screened for the fermentation ability and enzyme production. The liquid broths containing 2.5%(w/v) of raw brown rice powder as a sole nutritional source were used for culture media. Among the strains tested, all of the Bacillus strains and two lactic acid bacteria (Leuconostoc gelidum and Pediococcus pentosaceus) showed increase in cell population and enzyme activities. The viable cell counts of all the Bacillus strains and two lactic acid bacteria exceeded $10^7 CFU/mL$. The maximal enzyme activities produced by Bacillus sp. Bl, Bacillus sp. B2, Bacillus sp. B11, L. gelidum and P. pentosaceus were 17.85, 17.50, 17.10, 17.10 and 3.24 U/mL for amylase and 22.48, 22.04, 23.76, 12.13, and 3.4 U/mL for pretense, respectively. Therefore, the results of this study demonstrated that the above strains could be potential starters for the fermentation of raw brown rice.