• Applied Biological Chemistry
• /
• v.28 no.3
• /
• pp.209-217
• /
• 1985

Seventeen extracellular protein producing bacteria were isolated from soil samples, among which T219 strain having a strong capability of producing the protein was selected and identified for investigation of biological characteristics. The factors which affect the protein production were investigated and the results are summarized as follows. T219 strain which produces the most extracellular protein was identified as Bacillus sp. Optimum temperature and pH for production of the extracellular protein by T219 strain were $25^{\circ}C$ and 7.5 respectively. Almost no activities of protease and amylase were observed in the protein produced by the protein producing bacteria. In the medium containing yeast extract, the cell growth was moderately high, but almost no accumulation of protein was observed. However, polypeptone had significant effects on both the cell growth and the protein accumulation. The addition of glycine and L-isoleucine to the medium containing polypeptone, yeast extract and meat extract had a great effect on the protein production; 4mg/ml of protein accumulation was observed.

• Journal of Pharmacopuncture
• /
• v.26 no.4
• /
• pp.307-318
• /
• 2023

Objectives: Bacterial biofilm is regarded as a significant threat to the production of safe food and the arise of antibiotic-resistant bacteria. The objective of this investigation is to evaluate the quorum sensing inhibitory effect of Nepeta curviflora methanolic extract. Methods: The effectiveness of the leaves at sub-inhibitory concentrations of 2.5, 1.25, and 0.6 mg/mL on the virulence factors and biofilm formation of P. aeruginosa was evaluated. The effect of N. curviflora methanolic extract on the virulence factors of P. aeruginosa, including pyocyanin, rhamnolipid, protease, and chitinase, was evaluated. Other tests including the crystal violet assay, scanning electron microscopy (SEM), swarming motility, aggregation ability, hydrophobicity and exopolysaccharide production were conducted to assess the effect of the extract on the formation of biofilm. Insight into the mode of antiquorum sensing action was evaluated by examining the effect of the extract on the activity of N-Acyl homoserine lactone (AHL) and the expression of pslA and pelA genes. Results: The results showed a significant attenuation in the production of pyocyanin and rhamnolipid and in the activities of protease and chitinase enzymes at 2.5 and 1.25 mg/mL. In addition, N. curviflora methanolic extract significantly inhibited the formation of P. aeruginosa biofilm by decreasing aggregation, hydrophobicity, and swarming motility as well as the production of exopolysaccharide (EPS). A significant reduction in AHL secretion and pslA gene expression was observed, indicating that the extract inhibited quorum sensing by disrupting the quorum-sensing systems. The quorum-sensing inhibitory effect of N. curviflora extract appears to be attributed to the presence of kaempferol, quercetin, salicylic acid, rutin, and rosmarinic acid, as indicated by LCMS analysis. Conclusion: The results of the present study provide insight into the potential of developing anti-quorum sensing agents using the extract and the identified compounds to treat infections resulting from quorum sensing-mediated bacterial pathogenesis.

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

• Mycobiology
• /
• v.42 no.3
• /
• pp.291-295
• /
• 2014

Mycoflora was assessed in the commercial meju from four well-separated geographic origins. A total of 112 fungal isolates were identified by phenotypic characteristics and molecular taxonomy using sequencing the internal transcribed spacer of the rDNA and revealed 19 species from 13 genera. Enzymatic characteristics of protease and amylase, and mycotoxin production were analyzed.

• 한국생물공학회:학술대회논문집
• /
• 2002.04a
• /
• pp.427-430
• /
• 2002

Pilot scale(2.5 ton) three-stage methane fermentation process was developed for the rapid production of methane from food wastes in our laboratory. Eleven strains responsible for the primary semianaerobic hydrolysis/acidogenic fermentation system were isolated and characterized. Among them, the number of gram positive bacteria was eight and that of gram negative bacteria was three. They were rod and showed positive reaction to catalase. The strain K5 was found to have the highest enzyme activities of amylase and protease.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1998.11a
• /
• pp.161-161
• /
• 1998

To achieve the aim of this investigation, the extracellular protease was isolated from bacteria BAC-4, a strain was cultivated in the medium for the production of penicillin acilase in a period of 32 hours. The enzyme was first purified by aceton precipitation method, followed by ion exchange chromatography on DEAE-sephacel column. The highest specific activity of the aceton fraction was found to be 2.19 unit per mg, with degree of purification of 13 times. Further purification of the enzyme on DEAE -sephacel had a specific activity of 58.6 unit per mg and degree of purification of 344 times compared to its crude extract. The optimum pH of the enzyme was 8.4, and the potimum temparature was 37$^{\circ}C$. The K$\_$M/ and $V_{max}$ calculated at experiment conditions were found to be 0.66%(W/V) and 3.61 unit per mL respectively.

• The Korean Journal of Mycology
• /
• v.51 no.3
• /
• pp.219-227
• /
• 2023

This study was conducted to analyze the distribution and characteristics of fungal species in meju using the traditional method. Fungal distribution in meju was investigated using metagenomic and morphological analyses, based on which Aspergillus flavus/oryzae strains were identified as the dominant fungi in all meju samples, followed by Pichia, Rhizopus and Lichtheimia spp. As A. flavus/oryzae was dominant, we further evaluated the aflatoxin production ability and enzymatic activity of the isolates. Thin-layer chromatography and polymerase chain reaction revealed that the A. flavus/oryzae strains isolated from meju are non-aflatoxigenic fungi. Based on the analyses of amylase and protease activities, strains with high activities of amylase or protease were identified, which are proposed to be used as starters for meju fermentation.

• Korean Journal of Microbiology
• /
• v.37 no.3
• /
• pp.214-220
• /
• 2001

To develop the effective composting system, we isolated bacteria that have the abilities to degrade organic matters such as cellulose, carbohydrate, protein and lipid during the compositing of livestock manureAmong 24 strains, 6 bacteria have all the enzymatic activities of protease, amylase, cellulase and lipase.These microorganisms were identified as Corynebacterium varibilis, Bacillus spp., Pseudomonas spinosa,Acetobacter calcoaceticus and Athrobacter cumminsii All the enzymes produced by the bacteria showedactivities at the broad pH range and the maximal activities were obtained at $60^{\circ}C$. It seemed that after theincrease of temperature caused by fermentation of livestock manure, the enzymes started to degrade the rawmaterials, which are added for the control of humidity. However cellulase activity was maximum at $37^{\circ}C$,suggesting that the cellulase-producing bacteria work at an early stage of livestock manure fermentation toprovide the organic material for the growth of other bacteria. The production of the enzymes were growth-associated and maximal activities appeared at the early stationary phase of growth.

• Applied Biological Chemistry
• /
• v.41 no.1
• /
• pp.73-77
• /
• 1998

The effects of soymilk residues solubilization by cellulase, protease, koji and yeast were investigated on dry matter and protein yields, amino acid and organic acid contents. Co-treatment of soymilk residues by cellulase and protease gave high dry matter yield and protein yield. Koji treatment followed by yeast fermentation was effective for increasing organic acid content and producing soy sauce-like taste and odor. Organic acid content of fermented hydrolysates was improved by cellulase treatment. Protease treatment rather than koji treatment gave high amino acid content, and cellulase treatment seemed to have little effect on increasing free amino acid content. In sensory evaluation, koji-treated hydrolysate showed higher overall acceptance than other hydrolysates, however it showed lower overall acceptance than commercial fermented soy sauce.

• KSBB Journal
• /
• v.31 no.4
• /
• pp.284-290
• /
• 2016

In this research, recombinant human cytotoxic T-lymphocyte antigen 4-immunoglobulin (hCTLA4Ig) was produced by transgenic rice cells. RAmy3D promoter was used for overcome the limitation of low expression level in transgenic plant cells, and the secretion of target protein was accomplished by signal peptide. However, the RAmy3D promoter system which can be induced only by sugar starvation causes the decrease of cell viability. As a result, cell death promotes the release of protease which degrades the target proteins. The protein stability and productivity can be significantly influenced by proteolysis activity. Therefore, development of new strategies are necessary for the in situ recovery of target proteins from cell culture media. In this study, in situ recovery was performed by various strategies. Direct addition of Protein A resin with nylon bag leads to cell death by increased shear stress and decrease in production of hCTLA4Ig by protease. Medium exchange through modified flask could recover hCTLA4Ig with high cell viability and low protease activity, on the other hand, the productivity was lower than that of control. When in situ recovery was conducted at day 7 after induction in air-lift bioreactor, 1.94-fold of hCTLA4Ig could be recovered compared to control culture without in situ recovery. Consequently, in situ recovery of hCTLA4Ig from transgenic rice cell culture could enhance productivity significantly and prevent degradation of target proteins effectively.