• Microbiology and Biotechnology Letters
• /
• v.48 no.1
• /
• pp.64-71
• /
• 2020

A total of 262 bacterial strains were isolated from clay minerals, bentonite and zeolite, in Gyeongsangbukdo, Republic of Korea, and their hydrolytic enzyme activities were analyzed. Most of the isolated strains belonged to Micrococcales and Bacillales order. Of strains, 96 strains produced α-amylase activity, 42 strains showed cellulase activity, 111 strains had pectinase activity, and 70 strains showed protease activity. Among them, 177 isolates exhibited one or more of the hydrolytic enzyme activities and in particular Bacillus cereus MBLB1321, B. albus MBLB1326 and KIGAM017, B. mobilis MBLB1328, MBLB1329 and MBLB1330 showed all of the enzyme activities. These results demonstrate the diversity of functional Bacillus species in clay minerals as vital sources for the discovery of industrially valuable hydrolytic enzymes, which have a great commercial prospect in various bio-industrial applications.

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.10
• /
• pp.1450-1454
• /
• 2000

This study was conducted to examine the effects of dietary crude fiber levels on the growth and intestinal carbohydrases of goslings. Thirty-two, 2 week old female White Roman goslings were divided into four groups of 4 goslings with 2 replicates. Diets were isocaloric and isonitrogenous, containing 40, 80, 120 or 160 g/kg crude fiber. At the end of the 4 weeks of the experimental period, all goslings were sacrificed and the carbohydrases activities were measured. Feed intake was significantly higher in the 120 and 160 g/kg crude fiber groups over that in the 40 and 80 g/kg groups (p<0.05). The average daily gosling weight gain significantly increased with increasing crude fiber levels from 40 to 120 g/kg. However, both the daily gain and feed conversion of the 160 g/kg crude fiber diet group decreased significantly. Amylase, maltase and ${\alpha}-glucosidase$ activities in the duodenum significantly decreased as the dietary crude fiber level increased. The maltase and ${\alpha}-glucosidase$ activities in the jejunum-ileum showed a similar trend with those in the duodenum. By increasing the levels of crude fiber, cellulase activity in the caecum content significantly increased. There was, however, an adverse effect on the amylase activity.

• Microbiology and Biotechnology Letters
• /
• v.47 no.1
• /
• pp.69-77
• /
• 2019

Screening microorganisms that can produce glucan hydrolases for industrial, environmental, and biomedical applications is important. Herein, we describe a novel approach to perform glucan hydrolase screening-based on analysis of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) spectra-which involves degradation of the oligo- and polysaccharides. As a proof-of-concept study, glucan hydrolases that could break down glucans made of several glucose units were used to demonstrate the MALDI-MS-based enzyme assay. First, the enzyme activities of ${\alpha}$-amylase and cellulase on a mixture of glucan oligosaccharides were successfully discriminated, where changes of the MALDI-MS profiles directly reflected the glucan hydrolase activities. Next, we validated that this MALDI-MS-based enzyme assay could be applied to glucan polysaccharides (i.e., pullulan, lichenan, and schizophyllan). Finally, the bacterial glucan hydrolase activities were screened on 96-well plate-based platforms, using cell lysates or samples of secreted enzyme. Our results demonstrated that the MALDI-MS-based enzyme assay system would be useful for investigating bacterial glucoside hydrolases in a high-throughput manner.

• Journal of the Korean Society of Food Culture
• /
• v.8 no.3
• /
• pp.267-274
• /
• 1993

This study was aimed to investigate the changes in textural properties of Korean radish and relevant chemical, enzymatic activities during salting. During salting, pH was decreased and total acidity was increased. The maximum compression and puncture forces of Korean radish were decreased significantly whereas cutting force was increased. From the force-distance curves, the break point and maximum force point disappeared in salted Korean radish whereas these appeared apparently in fresh one. Also, the number of peak obtained by three types of test from salted Korean radish was decreased. Hot water soluble pectin and 0.4% Na-hexametaphosphate soluble pectin were increased whereas 0.05 N-HCl soluble pectin were decreased significantly. Polygalacturonase activity were increased in Korean radish solid(RS) and Korean radish juice(RJ) until 4 days of salting. Pectin esterase activity were decreased in RS and RJ. Cx-cellulase activity did not appear initially, however, they began to show their activities after 2 days of salting and were increased in RJ although it was low.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.1
• /
• pp.66-73
• /
• 2012

Plant growth promoting traits like production of indoleacetic acid (IAA), ammonia, hydrogen cyanide (HCN), siderophore, and like the enzyme activities of catalase, ACC deaminase, cellulase, chitinase and protease were assayed in vitro for twenty one phosphorus solubilizing bacteria isolated from soil isolates. Except SPP-5 and SPP-15 strains, all the other isolated strains produced IAA in various amounts of 10 to $23{\mu}g\;ml^{-1}$. All strains showed positive response for ammonia production and ACC deaminase activity implying that they are capable of growing in a N-free basal medium. Catalase activity was found to be superior in SPP-2, SPP-7, SPP-12 and SPP-17 compared to the other strains tested. HCN production was detected by 15 strains and among them SPP-9, SPP-15, SAph-11, and SAph-24 were found to be strong HCN producers. Except the isolates SPP-10, SPP-12, SPP-13 and SPP-14, all the other isolates produced more than 80% siderophore units. None of the strains showed cellulose and chitinase activity. SAph-8, SAPh-11, SAPh-24 and SPP-15 strains showed 35.84, 50.33, 56.64 and 34.78 U/ml protease activities, respectively. SPP-1, SPP-2, SPP-3, SPP-11, SPP-17, SPP-18, SAph-11 and SAph-24 strains showed positive response for all the tested plant growth promotion traits except cell wall degrading enzyme activities. According to the results, all the tested phosphorus solubilizing isolates could exhibit more than three or four plant growth promoting traits, which may promote plant growth directly or indirectly or synergistically. Therefore, these phosphorus solubilizing strains could be employed as bio-inoculants for agriculture soils.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.4
• /
• pp.666-674
• /
• 2016

The bacterial strains were screened as potential starters for fermenting low-salt doenjang (a Korean traditional fermented soybean paste) using Korean doenjang based on proteolytic and antipathogenic activities under 6.5-7.5% NaCl conditions. Phylogenetic analysis based on 16S rRNA gene sequences showed that they all belonged to the genus Bacillus. Proteolytic and antipathogenic activities against Escherichia coli, Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, and Aspergillus flavus, as well as fibrinolytic, amylase, and cellulase activities of the 10 strains were quantitatively evaluated. Of these, strains D2-2, JJ-D34, and D12-5 were selected, based on their activities. The functional, phenotypic, and safety-related characteristics of these three strains were additionally investigated and strains D2-2 and D12-5, which lacked antibiotic resistance, were finally selected. Strains D2-2 and D12-5 produced poly-γ-glutamic acid and showed various enzyme activities, including α-glucosidase and β-glucosidase. Growth properties of strains D2-2 and D12-5 included wide temperature and pH ranges, growth in up to 16% NaCl, and weak anaerobic growth, suggesting that they facilitate low-salt doenjang fermentation. Strains D2-2 and D12-5 were not hemolytic, carried no toxin genes, and did not produce biogenic amines. These results suggest that strains D2-2 and D12-5 can serve as appropriate starter cultures for fermenting low-salt doenjang with high quality and safety.

• The Korean Journal of Ecology
• /
• v.18 no.3
• /
• pp.409-418
• /
• 1995

As a part of studying the function and structure of the mudflat environment of the Yellow Sea, seawater samples in the overlying waters of sediment near Daesan were collected every hour on March 29 (spring tides) and on April 5 (neap tides), 1995 to study the diurnal distribution of aerobic saprophytic bacteria and their extracellular enzyme activities. The diurnal distribution of aerobic saprophytic bacteria ranged from 1.0 X $10^{2}$ to 7.07 X $10^{3}$ cfu /ml at spring tides and from 1.0 X $10^{2}$ to 8.3 X $10^{3}$ cfu /ml at neap tides. The diurnal variations of aerobic saprophytes at the suface waters were greater than those of middle and bottom waters. However, th diurnal fluctuation of saprophyte numbers at spring tides showed no significant difference compared with that at neap tides. The numbers of three physiological groups of aerobic hacteria (proteolytic, lipolytic and amylolytic bacteria) at the surface waters during spring and neap tides were lower than those at the middles and bottom waters. The diurnal variations of five extracellular enzyme activities at the surface waters during the survey period showed lower values than those at the middle and botton waters. Among the measured extracellular enzyme activities, phosphatase showed the highest. However, the activities of amylase, chitinase and cellulase showed a similar tendency.

• Asian-Australasian Journal of Animal Sciences
• /
• v.24 no.3
• /
• pp.364-368
• /
• 2011

An experiment was conducted to examine the effects of Cordyceps militaris mycelia on microbial populations and fibrolytic enzyme activities in vitro. C. militaris mycelia was added to buffered rumen fluid with final concentrations of 0.00, 0.10, 0.15, 0.20, 0.25 and 0.30 g/L and incubation times were for 3, 6, 9, 12, 24, 36, 48 and 72 h. At all incubation times, the supplementation of C. militaris mycelia linearly increased the number of total viable and celluloytic bacteria; maximum responses were seen with 0.25 g/L supplementation of C. militaris mycelia. The addition of C. militaris mycelia above the level of 0.20 g/L significantly (p<0.01) increased the number of total and cellulolytic bacteria compared with the control. On the other hand, the response of fungal counts to the supplementation of C. militaris mycelia showed a linear decrease; the lowest response was seen with 0.30 g/L supplementation of C. militaris mycelia. It would seem that C. militaris mycelia possess a strong negative effect on rumen fungi since the lowest level of C. militaris mycelia supplementation markedly decreased fungal counts. Carboxylmethyl cellulase activities were linearly increased by the addition of C. militaris mycelia except at 3 and 9 h incubation times. At all incubation times, the supplementation of C. militaris mycelia linearly increased the activities of xylanase and avicelase. In conclusion, the supplementation of C. militaris mycelia to the culture of mixed rumen microorganisms showed a positive effect on cellulolytic bacteria and cellulolytic enzyme activities but a negative effect on fungi.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.90.2-91
• /
• 2003

In commercial greenhouses, senescent flower petals or flowers of vegetables such as tomato, strawberry, hot pepper and zucchini squash were blighted to be removed from fruits within five days after spraying of Trichoderma harzianum YC459 (TORY), a biocontrol agent for the gray mold rot of vegetables caused by B. cinerea The mechanism for selective colonization of senescent floral tissues by T. harzianum YC459 was elucidated using fresh and senescent (Hays and 14days after flowering, respectively) floral tissues of zucchini squash (Cucurbita moschata Duchesne). The spores of T. hrzianum YC459 were produced more on agar and liquid culture media supplemented with 5％ dry powder of senescent floral tissues than fresh tissues during 15days. Mycelial growth was also much better in the media with senescent tissues than with fresh tissues. Enzyme activities of amylase, polygalacturonase and cellulase in the liquid media which might be involved in the colonization of tissues by T. harzianum YC459 were compared. The activities of three enzymes were much higher in the media with senescent floral tissues than with fresh floral tissues reaching to the maximum during 9 to 12days of incubation. Based on the results, the removal of senescent floral tissues, a possible inoculum source of the pathogen, may be another mechanism for biocontrol of gray mold rot of vegetables by T. harzianum YC459.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.37 no.1 s.109
• /
• pp.38-46
• /
• 2005

This study was focused on the optimum culture condition in CMCase, FPase and xylanase activities of two fungal strains that secret extracellular enzymes for using enzymatic deinking agent to old newsprint. The results of this study were as follows. When Fusarium pallidoroseum was grown on the medium, containing of rice bran+xylan $2.0\%,\;peptone\;0.6\%,\;KH_2PO_4\;0.075\%\;and\;MnSO_4\;0.06\%\;with\;pH\;9.0,\;at\;29^{\circ}C$ for 6 days, the quantitative degree of extracellular enzyme production was the highest. Optimum culture condition for Aspergillus niger was pH 5.0, $27^{\circ}C$ incubating temperature and 7 days incubation period on liquid medium, containing of CMC+xylan $2.5\%,\;yeast\;extract\;0.4\%,\;K_3PO_4\;0.05\%\;and\;CaCl_2+FeSO_4\;0.08\%$. Aspergillus niger was fairly higher FPase and xylanase activities than Trichoderma reesei ATCC 28217.