• Journal of Microbiology
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• 제33권2호
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• pp.115-119
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• 1995

The alkaline protease of Xanthomonas sp. YL-37 has been purified, and the properties of the enzyme investigated. The alkaline protease of Xanthomonas sp. YL-37 was purified form crude enzyme by ammonium sulfate fractionation, CM-cellulose ion exchange chromatography, and Sephadex G-100 gel filtration. Through the series of chromatographies, the enzyme was purified to homogenecity with specific activity of 4.23 fold higher than that of the crude broth. The molecular weight of the purified protease has been estimated to be 62 KDa on SDS-polyacrylamide gel electrophoresis. The optimal pH and temperature for alkaline protease activity were 11.0 and 50.deg.C, respectively. The enzyme was stable between pH 5.0 and 10.0 and up to 50.deg.C. Enzyme activity was lost up to 50% on heating at 70.deg.C for 30 minutes. The activity of alkaline protease was inhibited by Cu$\^$2+/, Zn$\^$2+/, Hg$\^$2+/, PMSF, and activated by Mn$\^$2+/ and Ca$\^$2+/. The $K_{m}$ value for casein as a substrate was 4.0 mg/ml.

• Journal of Microbiology and Biotechnology
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• 제24권2호
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• pp.197-208
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• 2014

A novel protease gene from Bacillus gibsonii, aprBG, was cloned, expressed in B. subtilis, and characterized. High-level expression of aprBG was achieved in the recombinant strain when a junction was present between the promoter and the target gene. The purified recombinant enzyme exhibited similar N-terminal sequences and catalytic properties to the native enzyme, including high affinity and hydrolytic efficiency toward various substrates and a superior performance when exposed to various metal ions, surfactants, oxidants, and commercial detergents. AprBG was remarkably stable in 50% organic solvents and retained 100% activity and stability in 0-4 M NaCl, which is better than the characteristics of previously reported proteases. AprBG was most closely related to the high-alkaline proteases of the subtilisin family with a 57-68% identity. The secretion and maturation mechanism of AprBG was dependent on the enzyme activity, as analyzed by site-directed mutagenesis. Thus, when taken together, the results revealed that the halo-solvent-tolerant protease AprBG displays significant activity and stability under various extreme conditions, indicating its potential for use in many biotechnology applications.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권3호
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• pp.186-191
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• 2005

In this study, a microorganism-produced protease was used to improve the quality of fabrics. First, the protease-producing bacteria were isolated from soils, and one of them was selected and identified as Bacillus sp. SJ-121. The optimal medium composition for its growth and protease production was determined to be as follows: glucose 1g/L, soybean meal 0.5g/L, soy peptone 0.5, $K_2HPO_4\;0.2,\;MgSO_4\cdot7H_2O\; 0.002,\;NaCl\;0.002,\;and\;Na_2CO_3g/L$. Also, the optimal temperature for the production of the protease by Bacillus sp. SJ-121 was about $40^{\circ}C$ at pH 7. The wool and silk were treated with the protease from Bacillus sp. SJ-121. Following the protease treatment, changes in the surface of a single yarn of the fabrics were observed by both an optical microscope and a scanning electron microscope (SEM). Changes in the K/S value of the wool and silk were measured by spectrophotometric analysis, in order to determine the amount of dye uptake in the fabrics. We also performed a tensile strength examination in order to determine the degree and nature of mechanical changes in single yarns of the wool and silk fabrics. By increasing the protease treatment time to 48 h, the dyeing characteristics of the fabrics were enhanced, and the surfaces of the single yarns of the fabrics became smoother, due to the removal of soil and scale in them. However, no mechanical changes were detected in the fabrics. Therefore, we suggest that proper treatment of the protease produced by Bacillus sp. can improve the quality of silk and wool.

• 한국의류산업학회지
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• 제11권3호
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• pp.496-501
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• 2009

In this study, a kiwifruit-produced protease was used to improve the quality of the wool and silk fabrics. The wool and silk were treated with the actinidin from kiwifruit. Following this protease treatment, changes in the surface of a single yarn of the fabrics were observed via both an optical microscope and a scanning electron microscope (SEM). In order to determine the amount of dye uptake in the fabric, changes in the K/S value of the wool and silk were measured by spectrophotometric analysis. Also, we performed a tensile strength examination to determine variation in their mechanical properties. By increasing the protease treatment time to 48h, the dyeing properties of fabrics were enhanced, and the surfaces of the single yarns of the fabrics became smoother, because of the removal of soil and scale in them. However, no mechanical changes were detected in the fabrics. Thereby, we suggest that the kiwifruit-produced actinidin treatment can improve the quality of the fabrics.

• Journal of Animal Science and Technology
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• 제59권10호
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• pp.23.1-23.11
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• 2017

Background: Although soybean meal (SBM) is excellent source of protein in diets for poultry, it is sometimes inaccessible, costly and fluctuates in supply. The SBM can partially be replaced by full-fat SBM, but the meals prepared from raw full-fat soybean contain antinutritional factors. To avoid the risk of antinutritional factors, heat treatment is always advisable, but either excessive or under heating the soybean could negatively affect the quality. However, the potential for further improvement of SBM by supplementing with microbial enzymes has been suggested by many researchers. The objective of this study was to evaluate the performance and ileal nutrient digestibility of birds fed on diets containing raw soybeans and supplemented with microbial protease. Methods: A $3{\times}2$ factorial, involving 3 levels of raw full-fat soybean (RFFS; 0, 45 or 75 g/kg of diet) and 2 levels of protease (0 or 15,000 PROT/kg) was used. The birds were raised in a climate-controlled room. A nitrogen-free diet was also offered to a reference group from day 19 to 24 to determine protein and amino acid flow at the terminal ileum and calculate the standardized ileal digestibility of nutrients. On days 10, 24 and 35, body weight and feed leftover were recorded to calculate the body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR). On day 24, samples of ileal digesta were collected at least from two birds per replicate. Results: When RFFS was increased from 0 to 75 g/kg of diet, the content of trypsin inhibitors was increased from 1747 to 10,193 trypsin inhibitors unit (TIU)/g of diets, and feed consumption of birds was also reduced (P < 0.05). Increasing RFFS level reduced the BWG from hatch 0 to 10 d (P < 0.01) and hatch to 24 d (P < 0.05). The BWG of birds from hatch to 35 was not significantly (P = 0.07) affected. Feed intake was also reduced (P < 0.05) during 0 to 35 d. However, protease supplementation improved (P < 0.05) the BWG and FCR during 0 to 24 d. Rising levels of RFFS increased the weight of pancreas (P < 0.001) and small intestine (P < 0.001) at day 24. Except for methionine, apparent and the corresponding standardized ileal digestibility of CP and AA were reduced (P < 0.01) by increasing levels of RFFS in diets. Conclusion: This study showed that some commercial SBM could be replaced by RFFS in broiler diets, without markedly compromising productivity. The AID and SID of CP and lysine were slightly improved by dietary supplementation of microbial protease.

• Asian-Australasian Journal of Animal Sciences
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• 제14권12호
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• pp.1769-1774
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• 2001

Bacillus licheniformis strains L-25 and PWD-1 are two thermophilic feather-degrading bacteria. Despite isolated from different environmental conditions, they were both capable of breaking down chicken feathers and growing in a medium in which feather was the only source of carbon and nitrogen. A 1.46-kb keratinase gene (ker B) was isolated from strain L-25 by a polymerase chain reaction (PCR) using L-25 genomic DNA as templates. Sequencing results reveal that ker B shares great sequence identity with a previously published keratinase gene of B. licheniformis PWD-1 (ker A). Only two amino acids differences were found in the deduced amino acid sequence between the keratinases from L-25 and PWD-1. However several nucleotide changes were found upstream of the putative promoter region. Protease inhibition studies indicated that neutral protease activity accounted for approximate 25 to 30% of total extracellular proteolytic activity produced by strain L-25 in the feather medium. In contrast, no measurable neutral protease activity was produced by strain PWD-1 in the feather medium. When glucose (1%), a common catabolic repressor, was added into the feather medium, L-25 was still able to grow and produce keratinase. Strain PWD-1 produced no neutral protease activity and its growth was severely inhibited in the feather medium containing glucose. L-25 produced an enhanced level of keratinase in the feather medium in comparison with PWD-1.

• Asian-Australasian Journal of Animal Sciences
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• 제30권9호
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• pp.1303-1313
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• 2017

Objective: This study evaluated the change and function of the pancreas, and small intestine in relation to growth performance of broilers on diets supplemented with raw soybean meal (RSBM) and protease. Samples of test ingredients and diets, after mixing and prior to being used were also assessed on contents of anti-nutritional factors. Methods: A $3{\times}3$ factorial study was used, with three levels of RSBM (commercial soybean meal [SBM] was replaced by RSBM at 0, 10%, or 20%) and protease (0.1, 0.2, or 0.3 g/kg). Each treatment was replicated six times with nine birds per replicate. Birds were housed in cages, in climate-controlled room and fed starter, grower and finisher diets. Results: Levels of trypsin inhibitors in the diets, containing varying levels of RSBM ranged between 1,730.5 and 9,913.2 trypsin inhibitor units/g DM. Neither RSBM nor protease supplementation in diets significantly affected (p>0.05) the body weight of broilers in the entire periods (0 to 35-d). Increasing the level of RSBM in diets increased the weight of the pancreas at d 10 (p<0.000), d 24 (p<0.001), and d 35 (p<0.05). Increasing levels of RSBM in the diets reduced the apparent ileal digestibility of crude protein (CP), and amino acid (AA) at d 24. Increasing level of RSBM in the diets decreased (p<0.01) pancreatic protein content, but this was increased (p<0.05) when protease was added to the diets (0 to 10-d). Increasing the level of protease improved the pancreatic digestive enzymes, including trypsin (p<0.05), chymotrypsin (p<0.01), and general proteolytic enzymes (p<0.05). Conclusion: The commercial SBM could be replaced at up to 20% by RSBM for broilers. Although protease supplementation slightly improved the digestive enzymes, and the ileal digestibilities of CP and AA, the CP and AA were negatively affected by increasing RSBM.

• 한국미생물·생명공학회지
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• 제48권4호
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• pp.515-524
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• 2020

With the increasing demand for enzymes in industrial applications there is a growing need to easily produce industrially important microbial enzymes. This study was carried out to screen the indigenous refinery bacterial isolates for their production of two industrially important enzymes i.e. lipase and protease. A total of 15 bacterial strains were isolated using Soil Extract Agar media from the oil-contaminated environment and one was shown to produce high quality lipase and protease enzymes. The culture conditions (culture duration, temperature, source of nitrogen, carbon, and pH) were optimized to produce the optimum amount of both the lipase (37.6 ± 0.2 Uml-1) and the protease (41 ± 0.4 Uml-1) from this isolate. Productivity of both enzymes was shown to be maximized at pH 7.5 in a medium containing yeast extract and peptone as nitrogen sources and sucrose and galactose as carbon sources when incubated at 35 ± 1℃ for 48 h. Bacterial strain SAB06 was identified as Bacillus licheniformis (MT250345) based on biochemical, morphological, and molecular characteristics. Further studies are required to evaluate and optimize the purification and characterization of these enzymes before they can be recommended for industrial or environmental applications.

• 한국해양생명과학회지
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• 제8권1호
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• pp.56-67
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• 2023

Marine macroalgae are important in coastal ecosystems and interact with marine microorganisms. In this study, we isolated fungi from seven types of marine macroalgae including Cladophora sp., Gloiopeltis furcate, Gracilariopsis chorda, Hydroclathrus clathratus, Prionitis crispata, Sargassum micracanthum, and Ulva lactuca collected in Korea. Morphological and phylogenetic analyses identified the isolates as four Aspergillus spp. (A. fumigatus, A. sydowii, A. tamarii, and A. terreus), three Penicillium spp. (P. crustosum, P. jejuense, and P. rubens), and Cladosporium tenuissimum. Among them, A. fumigatus TOP-U2, A. tamarii SH-Sw5, and A. terreus GJ-Gf2 strains showed the activities of all enzymes examined (amylase, chitinase, lipase, and protease). Based on the enzymatic index (EI) values in solid media, A. terreus GJ-Gf2 and C. tenuissimum UL-Pr1 exhibited the highest amylase and lipase activities, respectively. Chitinolytic activity was only observed in A. terreus GJ-Gf2, A. tamarii SH-Sw5, and A. fumigatus TOP-U2. Penicillium crustosum UL-Cl2 and C. tenuissimum UL-Pr1 showed the highest protease activities. To the best of our knowledge, this is the first report of lipolytic and proteolytic activities in a marine-derived C. tenuissimum strain. Overall, the fungal strains isolated from the marine macroalgae in this study actively produced industrially important enzymes.

• 미생물학회지
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• 제18권1호
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• pp.15-19
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• 1980

In order to study on the pigment and protease of Serratia marcescens, the correlation between protease activity and pigment formation was investigated. The results are as follows ; (1) The protease activity exhibitied two pH optima 6.0 and 7.5, respectively. (2) The optimal temeprature of proteolytic activity was $45^{\circ}C$. With these-results, it is suggested that the proteolytic enzymes of Serratia masrecescens is stable at neutral pH range and more active at the high temeprature than lthat of otehr proteolytic enzymes.